阅读说明：本技术 发光二极管和发光二极管显示器的有源控制 (Light emitting diode and active control of a light emitting diode display ) 是由 克勒斯托弗·P·胡赛尔 鲍里斯·久边科 科林·布莱克利 于 2020-03-17 设计创作，主要内容包括：公开了通过脉冲宽度调制(PWM)对LED、LED封装件和相关LED显示器的有源控制。通过分段工作周期提高LED的有效PWM频率,在工作周期中LED在单个PWM周期内被电激活。分段工作周期可以通过变换或重新排序向LED提供控制信号的序列来提供。因此,LED可以在每个PWM周期内被多次电激活和断开。并入LED显示器的一个或多个LED封装件中的有源电气元件能够分段每个LED封装件内的工作周期。有源电气元件还能够从数据流接收复位信号,以发起复位动作或将复位信号传递到显示器的其他有源电气元件。(Active control of LEDs, LED packages, and related LED displays by Pulse Width Modulation (PWM) is disclosed. By increasing the effective PWM frequency of the LED by segmenting the duty cycle in which the LED is electrically activated within a single PWM cycle. The segmented duty cycle may be provided by shifting or reordering the sequence of providing control signals to the LEDs. Thus, the LED may be electrically activated and turned off multiple times within each PWM cycle. Active electrical elements incorporated into one or more LED packages of an LED display can segment the duty cycle within each LED package. The active electrical elements are also capable of receiving a reset signal from the data stream to initiate a reset action or to pass the reset signal to other active electrical elements of the display.)

1. A Light Emitting Diode (LED) package, comprising:

at least one LED; and

an active electrical element electrically connected to the at least one LED, the active electrical element configured to:

receiving at least one data packet in a data stream, wherein the at least one data packet includes a command code that at least partially identifies at least one action to be taken; and

taking the at least one action in response to the command code.

2. The LED package of claim 1, wherein the at least one action comprises sending the at least one data packet to a port of the LED package.

3. The LED package of claim 1, wherein said at least one action comprises driving said at least one LED.

4. The LED package of claim 1, wherein said at least one action comprises driving said at least one LED without sending said at least one data packet.

5. The LED package of claim 1, wherein the at least one action comprises sending the at least one data packet without performing any other action inside the LED package.

6. The LED package of claim 5, wherein said sending said at least one data packet without performing any other action inside said LED package is based, at least in part, on contents of one or more other data packets previously received by said LED package.

7. The LED package of claim 1, wherein said at least one action comprises performing an internal action within said LED package and transmitting said at least one data packet.

8. The LED package of claim 1, wherein said at least one action comprises performing an internal action within said LED package without sending said at least one data packet.

9. The LED package of claim 1, wherein said at least one data packet comprises color selection data and brightness level data for said at least one LED.

10. The LED package of claim 1, wherein the at least one data packet comprises information configured to provide a data handshake with another device.

11. The LED package of claim 1, wherein said data stream comprises null transmission periods between successive data packets, said null transmission periods configured to control a communication speed of said LED package, signal a reset or restart condition, or signal a next frame condition.

12. The LED package of claim 1, wherein the plurality of data packets of the data stream have the same data length.

13. The LED package of claim 1, wherein the plurality of data packets of the data stream have varying data lengths.

14. The LED package of claim 1, wherein said active electrical element is arranged to receive said at least one data packet from a control element.

15. The LED package of claim 1, wherein the active electrical element is arranged to receive the at least one data packet after the at least one data packet is sent by another LED package along a communications bus.

16. The LED package of claim 1, wherein the at least one data packet comprises a first data packet and a consecutive data packet arranged in the data stream after the first data packet, wherein the first data packet and the consecutive data packet are configured to provide data to the active electrical element.

17. The LED package of claim 16, wherein said continuous data packets comprise at least one of color selection data, brightness level data, setup data, option selection data, and calibration data.

18. The LED package of claim 1, wherein the at least one action comprises replacing the at least one data packet with a talk-over data packet in the data stream exiting the LED package.

19. The LED package of claim 1, further comprising a substrate, wherein said at least one LED and said active electrical element are formed on said substrate.

20. The LED package of claim 1, further comprising at least one bi-directional communication port, wherein said active electrical element is configured to assign said at least one bi-directional communication port as one of an input port and an output port in response to a signal received by said LED package.

21. The LED package of claim 1, wherein the at least one LED forms a pixel in an LED display.

22. The LED package of claim 1, wherein the active electrical element comprises a finite state machine configured to switch between one or more start or reset states, a communication port set state, and one or more command states.

23. A Light Emitting Diode (LED) package, comprising:

at least one LED; and

An active electrical element electrically connected to the at least one LED, the active electrical element configured to receive data in a data stream and to introduce different data into the data stream.

24. The LED package of claim 23, wherein said data comprises at least one data packet and said different data comprises a talk-back data packet, and wherein said active electrical element is configured to replace said at least one data packet with said talk-back data packet in said data stream exiting said LED package.

25. The LED package of claim 24, wherein said intercom packet comprises at least one of an operating temperature, an operating current, and an operating status of said at least one LED.

26. The LED package of claim 24, wherein said intercom packet comprises data parity information configured to provide data verification of said data stream.

27. The LED package of claim 23, wherein said data comprises at least one data packet and said at least one data packet comprises a command code identifying at least one action to be taken by said active electrical element.

28. The LED package of claim 27, wherein said at least one action comprises providing said different data to said data stream.

29. The LED package of claim 27, wherein said at least one action comprises performing an internal action within said LED package and transmitting said data.

30. The LED package of claim 27, wherein said at least one action comprises performing an internal action within said LED package without sending said at least one data packet.

31. The LED package of claim 27, wherein said at least one action comprises sending said at least one data packet without performing any other action inside said LED package.

32. The LED package of claim 31, wherein said sending said at least one data packet without performing any other action inside said LED package is based, at least in part, on one or more other data packets previously received by said LED package.

33. The LED package of claim 24, wherein said at least one data packet comprises a first data packet and a consecutive data packet, said consecutive data packet being disposed in said data stream after said first data packet, and said first data packet and said consecutive data packet being configured to provide data to said active electrical element.

34. The LED package of claim 23, wherein said active electrical element is arranged to receive said data from a control element.

35. The LED package of claim 23, wherein said active electrical element is arranged to receive said data from another LED package.

36. The LED package of claim 23, wherein said at least one LED forms a pixel in an LED display.

37. A Light Emitting Diode (LED) package, comprising:

at least one LED; and

at least one bi-directional communication port.

38. The LED package of claim 37, further comprising an active electrical element configured to assign a status of said at least one bidirectional communication port as an input port or an output port.

39. The LED package of claim 38, further comprising at least two bi-directional communication ports, wherein said active electrical element is configured to distribute said input port and said output port from said at least two bi-directional communication ports in response to input signals received by said LED package.

40. The LED package of claim 39, wherein the active electrical element is configured to distribute the input port and the output port in response to the input signal received by at least one of the at least two bi-directional communication ports.

41. The LED package of claim 38, wherein said input port is configured to receive at least one data packet in a data stream, and said at least one data packet includes a command code that at least partially identifies at least one action to be taken by said active electrical element.

42. The LED package of claim 41, wherein said at least one action comprises performing an internal action within said LED package and transmitting said at least one data packet.

43. The LED package of claim 41, wherein said at least one action comprises performing an internal action within said LED package without sending said at least one data packet.

44. The LED package of claim 41, wherein said at least one action comprises sending said at least one data packet without performing any other action inside said LED package.

45. The LED package of claim 37, wherein said at least one LED forms a pixel in an LED display.

46. A Light Emitting Diode (LED) package, comprising:

at least one LED; and

an active electrical element comprising a volatile memory element, wherein the active electrical element is configured to change a driving condition of the at least one LED according to the temporarily stored operating state, and wherein an electrical connection for the active electrical element is arranged below the active electrical element with respect to a main emission face of the LED package.

47. The LED package of claim 46, wherein said at least one LED comprises a plurality of LEDs, and wherein said active electrical element is configured to independently vary a driving condition of each of said plurality of LEDs based on a plurality of operating states.

48. The LED package of claim 46, wherein said active electrical element further comprises a non-volatile memory element.

49. The LED package of claim 46, wherein said active electrical element further comprises a decoder element configured to receive and convert an input signal from an external source.

50. The LED package of claim 46, wherein said at least one LED comprises a plurality of LEDs, and wherein said active electrical element further comprises a driver element configured to drive said plurality of LEDs according to a plurality of operating states.

51. The LED package of claim 50, wherein said driver element comprises at least one of a source driver and a sink driver.

52. The LED package of claim 51, wherein said driver element further comprises an active cascode configuration.

53. The LED package of claim 51, wherein said driver element further comprises a Howland current pump.

54. The LED package of claim 53, wherein said Howland current pump further comprises a voltage follower connected to a voltage input of said driver element.

55. The LED package of claim 51, wherein said driver element is configured to drive said plurality of LEDs by pulse width modulation.

56. The LED package of claim 46, further comprising a thermal management element configured to monitor an operating temperature of the LED package.

57. The LED package of claim 46, wherein said active electrical element further comprises at least one of a decoder element, a driver element, and a signal conditioning element.

58. The LED package of claim 46, wherein said active electrical element further comprises a detector signal conditioning element configured to detect light impingement on said LED package.

59. The LED package of claim 58, wherein photodiode is configured to input a signal to said detector signal conditioning element based on said light impingement.

60. The LED package of claim 58, wherein said at least one LED is configured to input a signal to said detector signal conditioning element based on said light impact.

61. The LED package of claim 46, wherein said active electrical element further comprises a sample and hold circuit.

62. The LED package of claim 46, wherein said active electrical element further comprises a serial communication element.

63. The LED package of claim 62, wherein said active electrical element comprises a driver element comprising a pulse width modulation driver element configured to independently drive said at least one LED based on a digital input signal.

64. The LED package of claim 63, wherein the digital input signal comprises a self-clocking signal and the active electrical element further comprises a decoder element configured to decode the self-clocking signal.

65. The LED package of claim 46, wherein said active electrical element is configured to be addressed and an operating state of said at least one LED changes in a manner dependent on information stored in a local memory.

66. The LED package of claim 65, wherein said information stored in said local memory comprises an address.

67. The LED package of claim 46, wherein said active electrical element further comprises a programmable active electrical element.

68. The LED package of claim 46, wherein said active electrical element is configured to change said driving condition of said at least one LED according to a temporarily stored operating state and a non-temporary operating state.

69. A Light Emitting Diode (LED) package, comprising:

at least one LED chip; and

an active electrical element comprising a signal conditioning element, a memory element and a driver element, wherein electrical connections for the active electrical element are arranged below the active electrical element with respect to a main emission face of the LED package.

70. The LED package of claim 69, wherein said signal conditioning element is electrically connected between said memory element and said driver element.

71. The LED package of claim 69, wherein said signal conditioning element is electrically connected between an input signal line and said memory element.

72. The LED package of claim 69, wherein said signal conditioning element is configured to convert an analog signal.

73. The LED package of claim 69, wherein said signal conditioning element is configured to convert a digital signal.

74. The LED package of claim 69, wherein said signal conditioning element is configured to provide gamma correction or apply another non-linear transfer function.

75. The LED package of claim 69, wherein said active electrical element further comprises an electrostatic discharge element.

76. The LED package of claim 69, wherein said active electrical element further comprises a thermal management element.

77. The LED package of claim 69, wherein the driver element comprises at least one of a source driver and a sink driver.

78. The LED package of claim 69, wherein the at least one LED chip comprises a red LED chip, a blue LED chip, and a green LED chip, and the active electrical element further comprises a first contact pad configured to receive a first power input for the red LED chip and a second contact pad configured to receive a second power input for the blue LED chip and the green LED chip.

79. The LED package of claim 69, wherein said active electrical element is configured to receive a device selection signal from an external source.

80. The LED package of claim 79, wherein the device selection signal comprises at least one of a row selection signal and a column selection signal from the external source.

81. The LED package of claim 69, wherein said active electrical element further comprises a detector element.

82. The LED package of claim 69, wherein said at least one LED chip comprises a first LED chip, a second LED chip, and a third LED chip, and said active electrical element further comprises separate contact pads for each of a row select signal, a brightness level signal of said first LED chip, a brightness level signal of said second LED chip, and a brightness level signal of said third LED chip.

83. The LED package of claim 69, wherein said at least one LED chip comprises a first LED chip, a second LED chip, and a third LED chip, and said active electrical element is configured to control four LED selection conditions including selecting said first LED chip, selecting said second LED chip, selecting said third LED chip, and not selecting any of said first LED chip, said second LED chip, and said third LED chip.

84. The LED package of claim 83, wherein the active electrical element further comprises two contact pads configured to receive signals for the four LED selection conditions.

85. The LED package of claim 69, wherein said at least one LED chip comprises a first LED chip, a second LED chip, and a third LED chip, and said active electrical element further comprises separate contact pads for each of a row select signal for said first LED chip, a row select signal for said second LED chip, a row select signal for said third LED chip, and a brightness level signal.

86. The LED package of claim 69, wherein said active electrical element further comprises at least one contact pad configured to receive an encoded analog signal.

87. The LED package of claim 86, wherein said encoded analog signal comprises at least one of a multi-level logic signal, a variable frequency signal, a variable phase signal, and a variable amplitude signal.

88. The LED package of claim 87, wherein said active electrical element further comprises a decoder element configured to receive and convert said encoded analog signal.

89. The LED package of claim 69, wherein said active electrical element further comprises at least one contact pad configured to receive an encoded digital signal.

90. The LED package of claim 69, wherein said active electrical element further comprises a serial communication element configured to receive a digital input signal.

91. The LED package of claim 90, wherein said at least one LED chip comprises a first LED chip, a second LED chip, and a third LED chip, and said active electrical element further comprises at least one contact pad configured to receive a digital input signal corresponding to four LED selection conditions including selecting said first LED chip, selecting said second LED chip, selecting said third LED chip, and deselecting any of said first LED chip, said second LED chip, and said third LED chip.

92. The LED package of claim 90, wherein said driver element comprises a pulse width modulation driver element configured to independently drive said at least one LED chip based on said digital input signal.

93. The LED package of claim 69, wherein said memory element comprises a volatile memory element configured to update and store an operating state of said at least one LED chip.

94. The LED package of claim 69, wherein said memory element comprises a non-volatile memory element configured to store a predetermined location setting of said LED package.

95. A Light Emitting Diode (LED) package, comprising:

a plurality of LED chips forming a plurality of LED pixels; and

an active electrical element comprising no more than five input electrical connections, the active electrical element configured to independently vary a driving condition of each of the plurality of LED chips in accordance with an input signal.

96. The LED package of claim 95, wherein said active electrical element comprises no more than four input electrical connections.

97. The LED package of claim 95, wherein said input electrical connections comprise a power supply voltage, ground, a coded device selection signal, and a brightness level signal.

98. The LED package of claim 95, wherein said input electrical connections comprise a supply voltage, ground, a digital signal, and a clock signal.

99. The LED package of claim 95, wherein said input electrical connections comprise a first supply voltage, a second supply voltage, ground, and a digital signal.

100. The LED package of claim 99, wherein said first supply voltage is configured to drive one or more red LED chips of said plurality of LED chips and said second supply voltage is configured to drive one or more blue and green LED chips of said plurality of LED chips.

101. The LED package of claim 95, wherein the input signal comprises an asynchronous data signal.

102. The LED package of claim 95, wherein said input electrical connections comprise a first power supply voltage, a second power supply voltage, ground, a brightness level signal, and an encoded device selection signal.

103. The LED package of claim 95, wherein each of the plurality of LED pixels comprises at least one of a red LED chip, a green LED chip, and a blue LED chip.

104. A Light Emitting Diode (LED) package, comprising:

at least one LED chip; and

an active electrical element comprising a serial communication element configured for digital input or output signals and a driver element configured for independently changing driving conditions of the at least one LED chip, wherein electrical connections for the active electrical element are arranged below the active electrical element with respect to a main emitting surface of the LED package.

105. The LED package of claim 104, wherein said driver element comprises a pulse width modulation driver element configured to independently drive said at least one LED chip based on said digital input signal.

106. The LED package of claim 104, wherein at least one LED chip comprises a first LED chip, a second LED chip, and a third LED chip, and said active electrical element further comprises one or more digital-to-analog converters configured to provide independent drive signals to said first LED chip, said second LED chip, and said third LED chip.

107. The LED package of claim 104, wherein said digital input or output signal comprises a self-clocking signal and said active electrical element further comprises a decoder element configured to encode or decode said self-clocking signal.

108. The LED package of claim 107, wherein said self-clocking signal comprises at least one of an 8b/10b code, a manchester code, a phase code, a pulse count code, an isochronous signal and a non-isochronous signal.

109. The LED package of claim 104, wherein said active electrical element is configured to transmit or receive with I²At least a subset of the C protocol compatible signals.

110. The LED package of claim 104, wherein said active electrical element is configured to send or receive differential signaling.

111. The LED package of claim 110, wherein said active electrical element is further configured to send or receive low voltage differential signaling.

112. The LED package of claim 110, wherein said active electrical element is further configured to send or receive current mode logic.

113. A Light Emitting Diode (LED) package, comprising:

at least one LED; and

an active electrical element configured to change a driving condition of the at least one LED according to an input signal received from an external source, wherein the active electrical element is further configured to monitor, store, and output one or more operating conditions of the LED package to the external source.

114. The LED package of claim 113, wherein said active electrical element comprises a thermal management element configured to monitor and/or report an operating temperature of said LED package.

115. The LED package of claim 113, wherein said active electrical element comprises a detector element configured to perform monitoring and/or reporting of an operating voltage or current of said at least one LED.

116. A Light Emitting Diode (LED) package, comprising:

at least one LED; and

an active electrical element configured to change a driving condition of the at least one LED according to an input signal received from an external source, wherein the active electrical element includes a detector signal conditioning element configured to detect light impingement on the LED package.

117. The LED package of claim 116, wherein a photodiode is configured to input a signal to said detector signal conditioning element based on said light impingement.

118. The LED package of claim 116, wherein said at least one LED is configured to input a signal to said detector signal conditioning element based on said light impact.

119. The LED package of claim 116, wherein said at least one LED is configured to provide light emission from said LED package and input a signal to said detector signal conditioning element based on said light impingement.

120. The LED package of claim 116, wherein said at least one LED is configured to provide light emission from said LED package and said detector signal conditioning element is configured to receive a signal corresponding to said light impact during a setup process.

121. A Light Emitting Diode (LED) package, comprising:

at least one LED; and

an active electrical element electrically connected to the at least one LED, the active electrical element configured to receive a data value and transform the data value according to a transfer function.

122. The LED package of claim 121, wherein said transfer function is a linear function.

123. The LED package of claim 121, wherein said transfer function is a non-linear function.

124. The LED package of claim 121, wherein said transfer function comprises one or more subsets of transfer function coefficients for said active electrical element for interpolation.

125. The LED package of claim 121, wherein said transfer function comprises a piecewise transfer function.

126. The LED package of claim 121, wherein said data value comprises a compressed data code received by said active electrical element, and said active electrical element is configured to transform said compressed data code into a decompressed data code.

127. The LED package of claim 126, wherein said decompressed data codes comprise a brightness level of said at least one LED.

128. The LED package of claim 126, wherein said decompressed data codes comprise a higher dynamic range than said compressed data codes.

129. The LED package of claim 126, wherein said transformation of said compressed data codes to said decompressed data codes follows a power law expression for gamma correction.

130. The LED package of claim 121, wherein said at least one LED comprises two or more adjacent LED pixels, and said decompressed data code is determined based on an expected data redundancy between adjacent ones of said two or more adjacent LED pixels.

131. The LED package of claim 121, wherein said data values are received from a plurality of sources.

132. The LED package of claim 121, wherein said active electrical element is configured to receive at least one of parameters and options of said transfer function at any of a plurality of connection ports.

133. The LED package of claim 132, wherein said plurality of connection ports comprises a plurality of polarity agnostic connection ports.

134. The LED package of claim 121, wherein said transfer function is applied to direct a temperature measurement of said at least one LED.

135. The LED package of claim 121, wherein said transfer function is applied to direct the luminance output of said at least one LED.

136. The LED package of claim 121, wherein said active electrical element comprises an analog-to-digital converter and said transfer function is applied to an output of said analog-to-digital converter.

137. The LED package of claim 121, wherein said active electrical element comprises a pulse width modulation controller and said transfer function is applied to direct an output of said pulse width modulation controller.

138. The LED package of claim 121, wherein said active electrical element comprises a digital-to-analog converter and said transfer function is applied to direct an output of said digital-to-analog converter.

139. The LED package of claim 121, wherein said active electrical element is configured to drive and switch between a forward-biased state and a reverse-biased state of said at least one LED.

140. The LED package of claim 121, wherein said active electrical element is configured to receive selectable color depth data.

141. The LED package of claim 121, wherein said active electrical element comprises at least two bidirectional communication ports.

142. The LED package of claim 121, further comprising a light transmissive substrate comprising a first side and a second side opposite said first side, wherein said at least one LED and said active electrical component are mounted on said first side and said second side is a primary emission side of said LED package.

143. A Light Emitting Diode (LED) package, comprising:

at least one LED; and

an active electrical element electrically connected to the at least one LED, the active electrical element configured to receive selectable color depth data.

144. The LED package of claim 143, wherein said selectable color depth data is in a range comprising a 1-bit color depth to a 100-bit color depth.

145. The LED package of claim 143, wherein said selectable color depth data is selectable from any one of 24-bit, 30-bit, 36-bit and 48-bit color depths.

146. The LED package of claim 145, wherein a particular bit depth is achieved by selecting a next higher bit depth and zero padding a plurality of least significant bits associated with the difference.

147. The LED package of claim 143, wherein said active electrical element is configured to receive data values and transform said data values according to a transfer function.

148. The LED package of claim 143, wherein said active electrical element is configured to drive and switch between a forward-biased state and a reverse-biased state of said at least one LED.

149. The LED package of claim 143, wherein said active electrical element comprises at least two bidirectional communication ports.

150. The LED package of claim 143, further comprising a light transmissive substrate comprising a first side and a second side opposite said first side, wherein said at least one LED and said active electrical component are mounted on said first side, and said second side is a primary emission side of said LED package.

151. A Light Emitting Diode (LED) package, comprising:

at least one LED; and

An active electrical element electrically connected to the at least one LED, the active electrical element configured to drive and switch between a forward-biased state and a reverse-biased state of the at least one LED.

152. The LED package of claim 151, wherein said active electrical element further comprises a level sensor configured to provide an error signal when said at least one LED is in said reverse biased state.

153. The LED package of claim 151, wherein said active electrical element further comprises an analog-to-digital converter configured to provide a reverse leakage measurement when said at least one LED is in said reverse biased state.

154. The LED package of claim 153, wherein said analog-to-digital converter comprises at least one of an analog filter circuit and a digital filter circuit.

155. The LED package of claim 153, wherein said analog-to-digital converter is configured to detect a voltage related to an operating condition of said at least one LED when said at least one LED is in said reverse biased state.

156. The LED package of claim 153, wherein said analog-to-digital converter is configured to detect a voltage related to an operating condition of said at least one LED when said at least one LED is in said forward biased state.

157. The LED package of claim 156, wherein said active electrical element is configured to adjust a drive signal of said at least one LED based on said voltage detected when said at least one LED is in said forward biased state.

158. The LED package of claim 157, wherein said drive signal comprises a pulse width modulated signal and said active electrical element is configured to adjust a pulse width modulated duty cycle of said at least one LED.

159. The LED package of claim 151, wherein said active electrical element comprises a resistor network providing a predetermined current limit to said at least one LED.

160. The LED package of claim 151, wherein said active electrical element comprises a current source providing an adjustable current to said at least one LED.

161. The LED package of claim 151, wherein said active electrical element comprises an inverter configured to provide said reverse bias state.

162. The LED package of claim 151, wherein said active electrical element is configured to communicate with and respond to commands from another control element.

163. The LED package of claim 151, wherein said active electrical element is configured to receive data values and transform said data values according to a transfer function.

164. The LED package of claim 151, wherein said active electrical element is configured to receive selectable color depth data.

165. The LED package of claim 151, wherein said active electrical element comprises at least two bidirectional communication ports.

166. The LED package of claim 151, further comprising a light transmissive substrate comprising a first side and a second side opposite said first side, wherein said at least one LED and said active electrical component are mounted on said first side and said second side is a primary emission side of said LED package.

167. A Light Emitting Diode (LED) package, comprising:

at least one LED; and

an active electrical element electrically connected to the at least one LED, the active electrical element comprising at least one analog-to-digital converter.

168. The LED package of claim 167, wherein said at least one analog-to-digital converter is configured to detect a voltage related to a reverse leakage measurement of said at least one LED when said at least one LED is in a reverse biased state.

169. The LED package of claim 167, wherein said at least one analog-to-digital converter is configured to detect a voltage related to a forward voltage measurement of said at least one LED.

170. The LED package of claim 167, wherein said at least one analog-to-digital converter is configured to detect an electrical short condition of said at least one LED.

171. The LED package of claim 167, wherein said at least one analog-to-digital converter is configured to detect an electrically open condition of said at least one LED.

172. The LED package of claim 167, wherein said active electrical element is configured to adjust a pulse width modulation duty cycle of said at least one LED based on a voltage level detected by said at least one analog-to-digital converter.

173. The LED package of claim 167, wherein said at least one analog-to-digital converter is configured to send measurement data from said at least one LED to said active electrical element for serial output.

174. The LED package of claim 167, wherein said at least one ADC is configured to provide at least one of a reverse leakage measurement and a forward voltage measurement of a plurality of LEDs.

175. The LED package of claim 167, wherein said at least one ADC is configured to provide a temperature measurement by measuring a voltage provided by a thermal sensor.

176. The LED package of claim 167, wherein said active electrical element is configured to drive and switch between a forward-biased state and a reverse-biased state of said at least one LED.

177. The LED package of claim 167, wherein said active electrical element is configured to receive data values and transform said data values according to a transfer function.

178. The LED package of claim 167, wherein said active electrical element is configured to receive selectable color depth data.

179. The LED package of claim 167, wherein said active electrical element further comprises at least two bidirectional communication ports.

180. The LED package of claim 167, further comprising a light transmissive substrate comprising a first side and a second side opposite said first side, wherein said at least one LED and said active electrical component are mounted on said first side, and said second side is a primary emission side of said LED package.

181. A method of controlling a Light Emitting Diode (LED) device, the method comprising:

providing a Pulse Width Modulation (PWM) signal to one or more LED chips, the PWM signal including a PWM period and a PWM duty cycle, the PWM duty cycle corresponding to a portion of the PWM period in which the one or more LED chips are electrically activated; and

segmenting the PWM duty cycle such that the one or more LED chips are electrically activated and electrically disconnected a plurality of times within the PWM cycle.

182. The method of claim 181, further comprising selectively segmenting the PWM duty cycle such that the one or more LED chips can receive a segmented duty cycle or a continuous duty cycle.

183. The method of claim 181, further comprising transforming a counter signal into a non-digitally ordered sequence of counters for the PWM periods.

184. The method of claim 183, further comprising comparing command signals for the one or more LED chips to the sequence of non-digital sequencing counters and providing control signals to the one or more LED chips during the PWM period.

185. The method of claim 184, wherein the non-digitally ordered counter sequence counts a total number of values in the PWM period that correspond to a bit depth of the command signal.

186. The method of claim 184, wherein the non-digitally ordered counter sequence is formed by a bit inversion of the counter signal.

187. The method of claim 184, wherein the non-digitally ordered sequence of counters is formed by partial bit inversion of the counter signal.

188. The method of claim 184, wherein the non-digitally ordered counter sequence is formed by swapping bit segments corresponding to the counter signal.

189. The method of claim 184, wherein the sequence of non-digitally ordered counters comprises 8 segments within the PWM period.

190. The method of claim 184, wherein the sequence of non-digitally ordered counters comprises 16 segments within the PWM period.

191. The method of claim 184, wherein the sequence of non-digitally ordered counters comprises 32 segments within the PWM period.

192. The method of claim 184, wherein the sequence of non-digitally ordered counters comprises 64 segments within the PWM period.

193. The method of claim 181, wherein an active electrical element of the LED device is configured to initiate a reset command upon receipt of a reset signal.

194. A Light Emitting Diode (LED) package, comprising:

at least one LED chip; and

an active electrical element electrically connected to the at least one LED chip, the active electrical element configured to:

providing a Pulse Width Modulation (PWM) signal to the at least one LED chip, the PWM signal including a PWM period and a PWM duty cycle, the PWM duty cycle corresponding to a portion of the PWM period in which the at least one LED chip is electrically activated; and

segmenting the PWM duty cycle such that the at least one LED chip is electrically activated and electrically disconnected a plurality of times within the PWM cycle.

195. The LED package of claim 194, wherein said active electrical element is further configured to be selectable between a segmented PWM duty cycle and a continuous PWM duty cycle for said at least one LED chip.

196. The LED package of claim 194, wherein said active electrical element comprises a signal conditioning element configured to transform command signals received from a data stream.

197. The LED package of claim 194, wherein said active electrical element comprises a counter transformation device configured to transform a counter signal into a non-digitally ordered sequence of counters of said PWM periods.

198. The LED package of claim 197, wherein said non-digitally ordered counter sequence is formed by bit inversion of said counter signal.

199. The LED package of claim 197, wherein said non-digitally ordered counter sequence is formed by partial bit inversion of said counter signal.

200. The LED package of claim 197, wherein said non-digitally ordered counter sequence is formed by exchanging bit segments corresponding to said counter signal.

201. The LED package of claim 197, wherein said sequence of non-numeric sequencing counters comprises 8 segments within said PWM period.

202. The LED package of claim 197, wherein said sequence of non-numeric sequenced counters comprises 16 segments within said PWM period.

203. The LED package of claim 197, wherein said sequence of non-numeric sequencing counters comprises 32 segments within said PWM period.

204. The LED package of claim 197, wherein said sequence of non-numeric sequencing counters comprises 64 segments within said PWM period.

205. The LED package of claim 197, wherein said sequence of non-numeric ordered counters counts a total number of values in said PWM period corresponding to a bit depth of a command signal.

206. The LED package of claim 197, wherein said active electrical element comprises a comparator device configured to compare a command signal from a data stream with said non-digitally ordered counter sequence to provide a control signal for said at least one LED chip.

207. The LED package of claim 206, wherein said active electrical element comprises a driver configured to receive said control signal and drive said at least one LED chip.

208. The LED package of claim 194, wherein said active electrical element comprises a memory element configured to receive and store command signals from a data stream.

209. The LED package of claim 194, wherein said at least one LED chip comprises a plurality of LED chips forming at least one LED pixel.

210. A Light Emitting Diode (LED) package, comprising:

at least one LED; and

an active electrical element electrically connected to the at least one LED, the active electrical element configured to receive a reset signal, the reset signal comprising at least one pulse of a serial communication signal.

211. The LED package of claim 210, wherein said at least one pulse comprises a duration of time to maintain a line state of said serial communication signal in a high state or a low state for longer than other pulses of said serial communication signal.

212. The LED package of claim 210, wherein said at least one pulse comprises a plurality of pulses of said serial communication signal.

213. The LED package of claim 210, wherein said active electrical element is further configured to initiate a reset action upon receipt of said reset signal.

214. The LED package of claim 210, wherein said active electrical element is further configured to pass said reset signal without initiating a reset action.

215. The LED package of claim 210, wherein said active electrical element is further configured to:

providing a Pulse Width Modulated (PWM) signal to the at least one LED, the PWM signal including a PWM period and a PWM duty cycle, the PWM duty cycle corresponding to a portion of the PWM period in which the at least one LED is electrically activated; and

segmenting the PWM duty cycle such that the at least one LED is electrically activated and electrically disconnected a plurality of times within the PWM cycle.

Technical Field

The present disclosure relates to solid state lighting devices including light emitting diode devices and light emitting diode displays.

Background

Light Emitting Diodes (LEDs) are solid state devices that convert electrical energy into light and typically include one or more active layers (or active regions) of semiconductor material disposed between oppositely doped n-type and p-type layers. When a bias is applied across the doped layers, holes and electrons are injected into the active layer or layers and recombine in the active layer to produce an emission, for example, a visible or ultraviolet emission. LED chips typically include an active region, which may be made of epitaxial layers of materials such as silicon carbide, gallium nitride, aluminum gallium nitride, indium nitride, gallium phosphide, aluminum nitride, gallium arsenide based materials, and/or organic semiconductor materials.

LEDs are widely employed in various lighting environments for backlighting of Liquid Crystal Display (LCD) systems (e.g., as a replacement for cold cathode fluorescent lamps) and for direct view LED displays. Applications that utilize LED arrays include vehicle headlamps, roadway lighting, light fixtures, and various indoor, outdoor, and professional environments. Desirable characteristics of LED devices include high luminous efficiency, long lifetime, and wide color gamut.

Conventional LCD systems require polarizers and color filters (e.g., red, green, and blue), which inherently reduce the efficiency of light utilization. Direct view LED displays utilize self-emitting LEDs without the need for a backlight, polarizer, and color filters, improving the efficiency of light utilization.

Large-size, multi-color, direct-view LED displays (including full-color LED video screens) typically include many individual LED panels, packages, and/or assemblies that provide image resolution determined by the distance between adjacent pixels, or "pixel pitch". The direct-view LED display includes a three-color display that employs red, green, and blue (RGB) LED arrays and a two-color display that employs Red and Green (RG) LED arrays. Other colors and combinations of colors may be used. Large-size displays for long-distance viewing (e.g., electronic billboards and stadium displays) typically have a relatively large pixel pitch and typically include an array of discrete LEDs having multi-color (e.g., red, green, and blue) LEDs that can be independently operated to create what appears to a viewer to be a full-color pixel. Mesodisplays with relatively small viewing distances require shorter pixel pitches (e.g., 3 millimeters or less) and may include a panel with red, green, and blue arrayed LED assemblies mounted on a single electronic device attached to a driver printed circuit board that controls the LEDs. Driver printed circuit boards are often densely populated with electrical devices for driving the pixels of the display, including capacitors, Field Effect Transistors (FETs), decoders, microcontrollers, and the like. As pixel pitch continues to decrease for higher resolution displays, the density of such electronic devices becomes higher for a given panel area corresponding to an increasing number of pixels. This tends to increase the higher complexity and cost of LED panels for display applications, as well as increasing thermal crowding in areas where driver electronics are more closely spaced.

The art continues to seek improved LED array devices having small pixel pitches while overcoming limitations associated with conventional devices and production methods.

Disclosure of Invention

The present disclosure relates to light emitting diodes, LED packages, and related LED displays, and more particularly to active control of LEDs within LED displays. An LED display may comprise rows and columns of LED diodes forming an array of LED pixels. A particular LED pixel may include a cluster of LED chips of the same color or multiple colors, with exemplary LED pixels including red, green, and blue LED chips. In certain embodiments, an LED package includes a plurality of LED chips forming at least one LED pixel, and a plurality of such LED packages may be arranged to form an LED pixel array for an LED display. Each LED package may include an active electrical element configured to receive a control signal and actively maintain an operating state of an LED chip for the LED package, such as a brightness or grayscale or color selection signal, when addressing other LED packages. In some embodiments, the active electrical elements may include active circuitry including one or more of driver devices, signal conditioning or transformation devices, memory devices, decoder devices, electrostatic discharge (ESD) protection devices, thermal management devices, detection devices, and the like. In this regard, each LED pixel of the LED display may be configured to operate in an active matrix addressed manner. The active electrical element may be configured to receive one or more of an analog control signal, a coded analog control signal, a digital control signal, and a coded digital control signal. A display panel is disclosed that includes an array of such LED pixels on a first side of the panel and control circuitry on a back side of the panel configured to communicate with each active electrical element of the LED pixels.

In one aspect, an LED package includes: at least one LED; and an active electrical element electrically connected to the at least one LED, the active electrical element configured to: receiving at least one data packet from a data stream, wherein the at least one data packet includes a command code that at least partially identifies at least one action to be taken; and taking at least one action in response to the command code. In certain embodiments, the at least one action includes sending the at least one data packet to a port of the LED enclosure. In certain embodiments, the at least one action comprises driving at least one LED. In some embodiments, the at least one action includes driving the at least one LED without sending the at least one data packet. In certain embodiments, the at least one action includes sending the at least one data packet without performing any other action inside the LED package. In certain embodiments, sending the at least one data packet without performing any other action inside the LED package is based at least in part on the content of one or more other data packets previously received by the LED package. In certain embodiments, the at least one action includes performing an internal action within the LED package and sending at least one data packet. In certain embodiments, the at least one action includes performing an internal action within the LED package without sending the at least one data packet. In certain embodiments, the at least one data packet includes color selection data and brightness level data for the at least one LED. In some embodiments, the at least one data packet includes information configured to provide a data handshake with another apparatus. In certain embodiments, the data stream includes null transmission periods between successive data packets configured to control the communication speed of the LED package, signal a reset or restart condition, or signal a next frame condition. In some embodiments, the plurality of data packets of the data stream have the same data length. In some embodiments, the plurality of data packets of the data stream have varying data lengths. In certain embodiments, the active electrical element is arranged to receive at least one data packet from the control element. In certain embodiments, the active electrical element is arranged to receive the at least one data packet after the at least one data packet is retransmitted by another LED package along the communication bus. In certain embodiments, the at least one data packet comprises a first data packet and a consecutive data packet arranged after the first data packet in the data stream, wherein the first data packet and the consecutive data packet are configured to provide data to the active electrical element. In certain embodiments, the continuous data packet includes at least one of color selection data, brightness level data, setting data, option selection data, or calibration data. In certain embodiments, the at least one action includes replacing at least one data packet in the data stream with a talk-back packet (talk-back packet) that leaves the LED enclosure. In some embodiments, the LED package further comprises a substrate, wherein the at least one LED and the active electrical element are formed on the substrate. In certain embodiments, the LED package further comprises at least one bidirectional communication port, wherein the active electrical element is configured to assign the at least one bidirectional communication port as one of an input port or an output port in response to a signal received by the LED package. In certain embodiments, at least one LED forms a pixel in an LED display. In certain embodiments, the active electrical component includes a finite state machine configured to switch between one or more start or reset states, a communication port set state, or one or more command states.

In another aspect, an LED package includes: at least one LED; and an active electrical element electrically connected to the at least one LED, the active electrical element configured to receive data from the data stream and to introduce additional data into the data stream. In certain embodiments, the data comprises at least one data packet and the additional data comprises a talk-back data packet, and wherein the active electrical element is configured to replace the at least one data packet with the talk-back data packet in the data stream exiting the LED package. In certain embodiments, the talk-back data packet includes at least one of an operating temperature, an operating current, or an operating state of the at least one LED. In some embodiments, the talkback packet includes data parity information configured to provide data validation of the data stream. In certain embodiments, the data includes at least one data packet, and the at least one data packet includes a command code identifying at least one action to be taken by the active electrical component. In some embodiments, the at least one action includes providing additional data to the data stream. In certain embodiments, the at least one action includes performing an internal action within the LED package and sending data. In certain embodiments, the at least one action includes performing an internal action within the LED package without sending the at least one data packet. In certain embodiments, the at least one action includes sending the at least one data packet without performing any other action inside the LED package. In certain embodiments, sending the at least one data packet without performing any other action inside the LED package is based, at least in part, on one or more other data packets previously received by the LED package. In certain embodiments, the at least one data packet comprises a first data packet and a consecutive data packet, the consecutive data packet being arranged in the data stream after the first (first) start data packet, and the first data packet and the consecutive data packet being configured to provide data to the active electrical element. In certain embodiments, the active electrical element is arranged to receive input data from the control element. In certain embodiments, the active electrical element is arranged to receive data from another LED package. In certain embodiments, at least one LED forms a pixel in an LED display.

In another aspect, an LED package includes: at least one LED; and at least one bi-directional communication port. In certain embodiments, the LED package further comprises an active electrical element configured to assign a status of the at least one bi-directional communication port as an input port or an output port. In certain embodiments, the LED package further comprises at least two bidirectional communication ports, wherein the active electrical element is configured to distribute the input port and the output port from the at least two bidirectional communication ports in response to an input signal received by the LED package. In certain embodiments, the active electrical component is configured to distribute the input port and the output port in response to an input signal received by at least one of the at least two bidirectional communication ports. In certain embodiments, the input port is configured to receive at least one data packet from the data stream, and the at least one data packet includes a command code that at least partially identifies at least one action to be taken by the active electrical component. In certain embodiments, the at least one action includes performing an internal action within the LED package and sending at least one data packet. In certain embodiments, the at least one action includes performing an internal action within the LED package without sending the at least one data packet. In certain embodiments, the at least one action includes sending the at least one data packet without performing any other action inside the LED package. In certain embodiments, at least one LED forms a pixel in an LED display.

An LED package configured to receive a data stream including a plurality of data packets is disclosed. Each data packet may include an identifier that enables each LED package receiving the array of data packets to take one or more actions based on the identifier or series of identifiers. Various additional data packets are disclosed, including a talk-back data packet, a data packet for all LED packages receiving the data stream, and a continuous data packet. LED packages having selectively assignable communication ports are also disclosed.

In one aspect, an LED package includes: at least one LED; and an active electrical element including a volatile memory element, wherein the active electrical element is configured to change a driving condition of the at least one LED according to the temporarily stored operating state. In some embodiments, the at least one LED comprises a plurality of LEDs, and wherein the active electrical element is configured to independently vary a driving condition of each LED of the plurality of LEDs based on the plurality of operating states. The active electrical element may include a non-volatile memory element. The active electrical element may include a decoder element configured to receive and convert an input signal from an external source. In certain embodiments, the at least one LED comprises a plurality of LEDs, and wherein the active electrical element further comprises a driver element configured to drive the plurality of LEDs according to a plurality of operating states. The driver element may include at least one of a source driver or a sink driver. The driver element may comprise an active cascode (cascode) configuration. The driver element may comprise a Howland current pump. The Howland current pump may further comprise a voltage follower connected to the voltage input of the driver element. In certain embodiments, the driver element is configured to drive the at least one LED by pulse width modulation. In certain embodiments, the LED package may further comprise a thermal management element configured to monitor an operating temperature of the LED package. In certain embodiments, the active electrical elements further comprise at least one of decoder elements, driver elements, and signal conditioning elements. In certain embodiments, the active electrical component further comprises a detector signal conditioning element configured to detect light impingement on the LED package. In certain embodiments, the photodiode is configured to input a signal to the detector signal conditioning element based on the light impingement. In certain embodiments, the at least one LED is configured to input a signal to the detector signal conditioning element based on the light impingement. In certain embodiments, the active electrical component further comprises a sample and hold circuit. The active electrical component may further include a serial communication component. In certain embodiments, the active electrical element is configured to be addressed and the operating state of the at least one LED is changed in a manner dependent on information stored in the local memory. The information may include an address. In some embodiments, the active electrical element further comprises a programmable active electrical element. In some embodiments, the active electrical element is configured to change a driving condition of the at least one LED according to the temporarily stored operating state and the non-temporarily operating state.

In another aspect, an LED package includes: a light-transmitting substrate including a first face and a second face opposite to the first face; at least one LED mounted on the first face, wherein the second face is a primary emission face of the LED package; and an active electrical component mounted on the first face. In certain embodiments, the light emitting face of the at least one LED is mounted to a light transmissive substrate. In certain embodiments, the at least one LED comprises a plurality of LEDs, and the plurality of LEDs comprises a red LED chip, a blue LED chip, and a green LED chip. In some embodiments, the at least one LED comprises a plurality of LEDs, and the plurality of LEDs comprises an active LED structure separated into a plurality of active LED structure portions, wherein each active LED structure portion of the plurality of active LED structure portions is independently addressable. The LED package may further include an encapsulant layer surrounding a perimeter edge of the at least one LED. The encapsulant layer may surround a peripheral edge of the active electrical component. In certain embodiments, the sealant layer comprises a black material. In certain embodiments, the encapsulant layer covers at least a portion of a bottom surface of the at least one LED. The LED package may further include a plurality of conductive traces on the bottom surface of the encapsulant layer, wherein some of the plurality of conductive traces are electrically connected to the at least one LED. The LED package may further include: an additional encapsulant layer on bottom surfaces of the plurality of conductive traces; and a plurality of package bond pads on a bottom surface of the additional encapsulant layer, wherein the plurality of package bond pads are electrically connected to at least some of the plurality of conductive traces. In some embodiments, portions of some of the plurality of conductive traces form at least one package bond pad. The LED package may further include an insulating material on a bottom surface of the plurality of conductive traces, and a portion of the plurality of conductive traces not covered by the insulating material forms at least one package bond pad. In certain embodiments, the at least one LED and the active electrical component are mounted along the same horizontal plane of the LED package. In certain embodiments, the at least one LED is mounted along a first horizontal plane of the LED package and the active electrical component is mounted along a second horizontal plane of the LED package, the second horizontal plane being different from the first horizontal plane. The LED package may further include an encapsulant layer disposed between the first level and the second level. The LED package may further include a plurality of conductive traces disposed between the at least one LED and the active electrical element. In some embodiments, the active electrical component is embedded in an additional substrate. In some embodiments, the active electrical component is mounted to an additional substrate.

In another aspect, a method comprises: mounting at least one LED and an active electrical element on a substrate; forming electrical connectors on the at least one LED and the active electrical chip; applying an encapsulant layer over the at least one LED, the active electrical element and the electrical connector; and planarizing the encapsulant layer to form an exposed surface of the electrical connector. In some embodiments, the method further includes forming at least one conductive trace on the encapsulant layer, the conductive trace electrically connected to an exposed surface of the electrical connector. In some embodiments, the at least one conductive trace comprises a plurality of conductive traces, and the method further comprises forming an insulating material on portions of the plurality of conductive traces, and portions of the plurality of conductive traces not covered by the insulating material form a plurality of package bond pads. In some embodiments, the method further comprises forming an additional electrical connector on the at least one conductive trace or on the at least one electrical connector. In certain embodiments, the method further comprises applying an additional encapsulant layer over the at least one conductive trace and the additional electrical connector. In certain embodiments, the method further comprises planarizing the additional encapsulant layer to form an exposed surface of the additional electrical connector. In some embodiments, the method further includes forming a plurality of package bond pads on a bottom surface of the additional encapsulant layer, the package bond pads electrically connected to exposed surfaces of the additional electrical connectors. In some embodiments, the method further comprises forming an insulating material on portions of the plurality of package bond pads. In some embodiments, the method further comprises forming a plurality of additional encapsulant layers and at least one additional conductive trace prior to forming the plurality of package bond pads.

In another aspect, an LED package includes: at least one LED chip; and an active electrical element including a signal conditioning element, a memory element, and a driver element. In some embodiments, the signal conditioning element is electrically connected between the memory element and the driver element. In some embodiments, the signal conditioning element is electrically connected between the input signal line and the memory element. In certain embodiments, the signal conditioning element is configured to transform an analog signal. In certain embodiments, the signal conditioning element is configured to convert a digital signal. In certain embodiments, the signal conditioning element is configured to provide gamma correction or apply another non-linear transfer function. In some embodiments, the active electrical element further comprises an electrostatic discharge element. In certain embodiments, the active electrical component further comprises a thermal management element. The driver element may include at least one of a source driver and a sink driver. In some embodiments, the at least one LED chip comprises a red LED chip, a blue LED chip, and a green LED chip, and the active electrical element further comprises a first contact pad configured to receive a first power input for the red LED chip and a second contact pad configured to receive a second power input for the blue LED chip and the green LED chip. In certain embodiments, the active electrical element is configured to receive a device selection signal from an external source. In some embodiments, the device selection signal includes at least one of a row selection signal and a column selection signal from an external source. In certain embodiments, the active electrical element further comprises a detector element. In some embodiments, the at least one LED chip comprises a first LED chip, a second LED chip, and a third LED chip, and the active electrical element further comprises a separate contact pad for each of the row select signal, the brightness level signal of the first LED chip, the brightness level signal of the second LED chip, and the brightness level signal of the third LED chip. In some embodiments, the at least one LED chip includes a first LED chip, a second LED chip, and a third LED chip, and the active electrical element is configured to control four LED selection conditions including selecting the first LED chip, selecting the second LED chip, selecting the third LED chip, and not selecting any of the first LED chip, the second LED chip, and the third LED chip. In some embodiments, the active electrical element further comprises two contact pads configured to receive signals for four LED selection conditions. In some embodiments, the at least one LED chip comprises a first LED chip, a second LED chip, and a third LED chip, and the active electrical element further comprises a separate contact pad for each of the row select signal of the first LED chip, the row select signal of the second LED chip, the row select signal of the third LED chip, and the brightness level signal. In certain embodiments, the active electrical element further comprises at least one contact pad configured to receive the encoded analog signal. In some embodiments, the encoded analog signal includes at least one of a multi-level logic signal, a variable frequency signal, a variable phase signal, or a variable amplitude signal. In certain embodiments, the active electrical element further comprises a decoder element configured to receive and convert the encoded analog signal. In certain embodiments, the active electrical component further comprises at least one contact pad configured to receive the encoded digital signal. In certain embodiments, the active electrical element further comprises a serial communication element configured to receive a digital input signal. In some embodiments, the at least one LED chip includes a first LED chip, a second LED chip, and a third LED chip, and the active electrical element further includes at least one contact pad configured to receive a digital input signal corresponding to four LED selection conditions including selecting the first LED chip, selecting the second LED chip, selecting the third LED chip, and not selecting any of the first LED chip, the second LED chip, and the third LED chip. In some embodiments, the driver element comprises a pulse width modulation driver element configured to independently drive the at least one LED chip based on the digital input signal. In certain embodiments, the memory element comprises a volatile memory element configured to update and store an operating state of the at least one LED chip. In some embodiments, the memory element comprises a non-volatile memory element configured to store a predetermined location setting of the LED package.

In another aspect, an LED package includes: a plurality of LED chips forming a plurality of LED pixels; and an active electrical element including no more than five input electrical connections, the active electrical element configured to independently change a driving condition of each of the plurality of LED chips in accordance with an input signal. In certain embodiments, the active electrical component includes no more than four input electrical connections. In some embodiments, the input electrical connections include a supply voltage, ground, a coding device selection signal, and a brightness level signal. In some embodiments, the input electrical connections include a supply voltage, ground, a digital signal, and a clock signal. In some embodiments, the input electrical connections include a first power supply voltage, a second power supply voltage, ground, and a digital signal. In some embodiments, the first supply voltage is configured to drive one or more red LED chips of the plurality of LED chips, and the second supply voltage is configured to drive one or more blue and green LED chips of the plurality of LED chips. In some embodiments, the input signal comprises an asynchronous data signal. In some embodiments, the input electrical connection includes a first power supply voltage, a second power supply voltage, ground, a brightness level signal, and an encoded device selection signal. In certain embodiments, each LED pixel of the plurality of LED pixels includes at least one of a red LED chip, a green LED chip, and a blue LED chip.

In another aspect, an LED package includes: at least one LED chip; and an active electrical element including a serial communication element configured for digital input or output and a driver element configured for independently changing a driving condition of the at least one LED chip. In some embodiments, the driver element comprises a pulse width modulation driver element configured to independently drive the at least one LED chip based on the digital input signal. In some embodiments, the at least one LED chip comprises a first LED chip, a second LED chip, and a third LED chip, and the active electrical element further comprises one or more digital-to-analog converters configured to provide independent drive signals to the first LED chip, the second LED chip, and the third LED chip. In certain embodiments, the digital input or output signal comprises a self-clocking signal and the active electrical element further comprises a decoder element configured to encode or decode the self-clocking signal. In certain embodiments, the self-clocking signal comprises at least one of an 8b/10b code, a Manchester code, a phase code, a pulse count code, an isochronous signal or a non-isochronous signal. In certain embodiments, the active electrical element is configured to transmit or receive at least a subset of signals compatible with the I2C protocol. In some embodiments, the active electrical element is configured to send or receive differential signaling. In some embodiments, the active electrical element is further configured to send or receive low voltage differential signaling. In certain embodiments, the active electrical element is further configured to transmit or receive current mode logic.

In another aspect, an LED package includes: at least one LED; and an active electrical element configured to change a driving condition of the at least one LED according to an input signal received from an external source, wherein the active electrical element is further configured to monitor, store and output one or more operating conditions of the LED package to the external source. In certain embodiments, the active electrical element includes a thermal management element configured to at least one of monitor and report an operating temperature of the LED package. In certain embodiments, the active electrical element comprises a detector element configured to perform monitoring and reporting of at least one of an operating voltage or current of the at least one LED.

In another aspect, a display panel for video display includes: a plurality of LED packages forming an array on a front surface of the display panel, wherein each of the plurality of LED packages includes an LED pixel and an active electrical element; and an integrated circuit registered (integrated) on the display panel and configured to receive input signals of the plurality of LED packages, wherein the active electrical element of each LED package is configured to independently change a driving condition of the LED pixel within each LED package in response to the input signal from the integrated circuit. In some embodiments, the integrated circuit comprises an Application Specific Integrated Circuit (ASIC). In some embodiments, the integrated circuit comprises a Field Programmable Gate Array (FPGA). The display panel may further include an input signal connector registered with the display panel, the input signal connector including at least one of a Digital Visual Interface (DVI) connector, a high-definition multimedia interface (HDMI) connector, a display port connector, or a HUB75 interface. In some embodiments, the display panel is configured to receive a first power line having a voltage in a range of about 3 volts to about 3.3 volts. In some embodiments, the display panel is configured to receive a second power line having a voltage in a range of about 1.8 volts to about 2.4 volts. The display panel may further include a decoder element registered with the display panel, the decoder element configured to receive control signals from the integrated circuit and route the control signals to the plurality of control lines for the plurality of LED packages. The display panel may further include a digital-to-analog converter registered with the display panel, the digital-to-analog converter being configured to convert data into an analog signal. In some embodiments, the digital-to-analog converter is configured to send the control signal along a single control line of the plurality of control lines. In certain embodiments, a single control line is electrically connected to at least two columns of LED packages of the plurality of LED packages. In some embodiments, a particular LED package of the at least two columns of LED packages is configured to individually respond to a control signal from a single control line based on a position setting of the particular LED package. In certain embodiments, the location settings include predetermined location settings. In certain embodiments, the positional settings are determined after installation and stored in the active electrical components of the particular LED package. In certain embodiments, the active electrical elements of each LED package include a decoder element, a memory element, and a driver element. In some embodiments, the display system includes a plurality of display panels. In some embodiments, the integrated circuit is disposed on the back side of the display panel. The display panel may further include another plurality of LED packages forming another array on the rear surface of the display panel. In some embodiments, the integrated circuit includes a control element that includes at least one serial communication interface. In certain embodiments, the control element is configured to communicate directly with the plurality of LED packages. In some embodiments, the input electrical connections to the active electrical elements of each LED package are arranged along the same plane of the display panel.

The data signal sent to the active electrical element may include a compressed data code that is subsequently decompressed, and one or more of transfer function, gamma correction, and color depth data. Active electrical components are disclosed that are configured to provide forward and reverse bias conditions to an LED in order to detect undesirable operating conditions such as reverse leakage and deviation from a forward voltage level. Such poor operating conditions may be performed as part of a self-test routine of the LED package. An active electrical element as disclosed herein may include an analog-to-digital converter (ADC). LED packages that are self-configurable based on the manner in which various input or output lines are connected are also disclosed.

In one aspect, an LED package includes: at least one LED; and an active electrical element electrically connected to the at least one LED, the active electrical element configured to receive the data value and transform the data value according to a transfer function. In certain embodiments, the transfer function is a linear function. In certain embodiments, the transfer function is a non-linear function. In certain embodiments, the transfer function includes one or more subsets of transfer function coefficients for the active electrical element for interpolation. In certain embodiments, the transfer function comprises a piecewise transfer function. In certain embodiments, the data value comprises a compressed data code received by the active electrical element, and the active electrical element is configured to transform the compressed data code into a decompressed data code. In some embodiments, the decompressed data codes include a brightness level of the at least one LED. In some embodiments, the decompressed data code includes a higher dynamic range than the compressed data code. In certain embodiments, the transformation of compressed data codes to decompressed data codes follows a power law expression for gamma correction. In certain embodiments, the at least one LED comprises two or more adjacent LED pixels, and the decompressed data code is determined based on an expected data redundancy between adjacent LED pixels of the two or more adjacent LED pixels. In certain embodiments, data values are received from multiple sources. In certain embodiments, the active electrical component is configured to receive at least one of parameters and options of a transfer function at any of the plurality of connection ports. In some embodiments, the plurality of connection ports comprises a plurality of polarity agnostic connection ports. In certain embodiments, a transfer function is applied to direct a temperature measurement of at least one LED. In some embodiments, a transfer function is applied to direct the brightness output of the at least one LED. In certain embodiments, the active electrical element comprises an analog-to-digital converter, and the transfer function is applied to an output of the analog-to-digital converter. In certain embodiments, the active electrical component comprises a pulse width modulation controller, and the transfer function is applied to direct an output of the pulse width modulation controller. In certain embodiments, the active electrical element comprises a digital-to-analog converter, and the transfer function is applied to direct an output of the digital-to-analog converter. In certain embodiments, the active electrical element is configured to drive and switch between a forward-biased state and a reverse-biased state of the at least one LED. In some embodiments, the active electrical element is configured to receive selectable color depth data. In certain embodiments, the active electrical component includes at least two bidirectional communication ports. In some embodiments, the LED package further comprises a light transmissive substrate comprising a first side and a second side opposite the first side, wherein the at least one LED and the active electrical component are mounted on the first side, and the second side is a primary emission side of the LED package.

In another aspect, an LED package includes: at least one LED; and an active electrical element electrically connected to the at least one LED, the active electrical element configured to drive and switch between a forward-biased state and a reverse-biased state of the at least one LED. In certain embodiments, the active electrical element further comprises a level sensor configured to provide an error signal when the at least one LED is in a reverse biased state. In some embodiments, the active electrical element further comprises an analog-to-digital converter configured to provide a reverse leakage measurement when the at least one LED is in a reverse biased state. In certain embodiments, the analog-to-digital converter includes at least one of an analog filter circuit and a digital filter circuit. In some embodiments, the analog-to-digital converter is configured to detect a voltage associated with an operating condition of the at least one LED when the at least one LED is in a reverse biased state. In certain embodiments, the analog-to-digital converter is configured to detect a voltage associated with an operating condition of the at least one LED when the at least one LED is in a forward-biased state. In certain embodiments, the active electrical element is configured to adjust a drive signal of the at least one LED based on a voltage detected when the at least one LED is in a forward biased state. In certain embodiments, the drive signal comprises a pulse width modulated signal and the active electrical element is configured to adjust a pulse width modulated duty cycle of the at least one LED. In certain embodiments, the active electrical element comprises a resistor network that provides a predetermined current limit to the at least one LED. In some embodiments, the active electrical component includes a current source that provides an adjustable current to the at least one LED. In certain embodiments, the active electrical element comprises an inverter configured to provide a reverse bias state. In certain embodiments, the active electrical element is configured to communicate with and respond to commands from another control element. In certain embodiments, the active electrical element is configured to receive the data value and transform the data value according to a transfer function. In some embodiments, the active electrical element is configured to receive selectable color depth data. In certain embodiments, the active electrical component includes at least two bidirectional communication ports. In some embodiments, the LED package further comprises a light transmissive substrate comprising a first side and a second side opposite the first side, wherein the at least one LED and the active electrical component are mounted on the first side, and the second side is a primary emission side of the LED package.

In another aspect, an LED package includes: at least one LED; and an active electrical element electrically connected to the at least one LED, the active electrical element comprising at least one analog-to-digital converter. In some embodiments, the at least one analog-to-digital converter is configured to detect a voltage associated with a reverse leakage measurement of the at least one LED when the at least one LED is in a reverse biased state. In certain embodiments, the at least one analog-to-digital converter is configured to detect a voltage related to a forward voltage measurement of the at least one LED. In certain embodiments, the at least one analog-to-digital converter is configured to detect an electrical short condition of the at least one LED. In certain embodiments, the at least one analog-to-digital converter is configured to detect an electrically open condition of the at least one LED. In certain embodiments, the active electrical element is configured to adjust a pulse width modulation duty cycle of the at least one LED based on a voltage level detected by the at least one analog-to-digital converter. In certain embodiments, the at least one analog-to-digital converter is configured to send measurement data from the at least one LED to the active electrical element for serial output. In certain embodiments, the at least one ADC is configured to provide at least one of a reverse leakage measurement and a forward voltage measurement of the plurality of LEDs. In certain embodiments, the at least one ADC is configured to provide the temperature measurement by measuring a voltage provided by the thermal sensor. In certain embodiments, the active electrical element is configured to drive and switch between a forward-biased state and a reverse-biased state of the at least one LED. In certain embodiments, the active electrical element is configured to receive the data value and transform the data value according to a transfer function. In some embodiments, the active electrical element is configured to receive selectable color depth data. In certain embodiments, the active electrical component further comprises at least two bidirectional communication ports. In some embodiments, the LED package further comprises a light transmissive substrate comprising a first side and a second side opposite the first side, wherein the at least one LED and the active electrical component are mounted on the first side, and the second side is a primary emission side of the LED package.

In another aspect, an LED package includes: at least one LED; and an active electrical element electrically connected to the at least one LED, the active electrical element configured to receive selectable color depth data. In some embodiments, the selectable color depth data is in a range including a 1-bit color depth to a 100-bit color depth. In some embodiments, the selectable color depth data can be selected from any one of 24-bit, 30-bit, 36-bit, and 48-bit color depths. In some embodiments, the particular bit depth is achieved by selecting the next higher bit depth and zero padding the least significant bits associated with the difference. In certain embodiments, the active electrical element is configured to receive the data value and transform the data value according to a transfer function. In certain embodiments, the active electrical element is configured to drive and switch between a forward-biased state and a reverse-biased state of the at least one LED. In certain embodiments, the active electrical component includes at least two bidirectional communication ports. In some embodiments, the LED package further comprises a light transmissive substrate comprising a first side and a second side opposite the first side, wherein the at least one LED and the active electrical component are mounted on the first side, and the second side is a primary emission side of the LED package.

In another aspect, an LED package includes: at least one LED; and an active electrical element electrically connected to the at least one LED, the active electrical element configured to run a self-test routine that provides at least one output signal indicative of at least one of a pass or fail condition of the at least one LED. In certain embodiments, the at least one pass or fail condition comprises a forward voltage requirement of the at least one LED. In certain embodiments, the at least one pass or fail condition comprises a reverse leakage requirement of the at least one LED. In certain embodiments, the self-test routine provides a temperature estimate for the at least one LED. In certain embodiments, the active electrical element is configured to run a self-test routine upon power-up. In some embodiments, the active electrical element is configured to run a self-test routine when directly connected to the power source. In certain embodiments, at least one output signal is transmitted to an electrical port. In certain embodiments, the at least one output signal is transmitted as a light signal through the at least one LED. In certain embodiments, the light signal comprises flashing the at least one LED according to one or more of a predetermined color, duration, and count. In some embodiments, the optical signal is configured to provide high speed communication and then low speed communication, and only the low speed communication includes the human readable code. In some embodiments, the self-test routine is configured to provide a time delay before low-speed communications, such that the self-test routine may be aborted before sending the low-speed communications.

In another aspect, an LED package includes: at least one LED; an active electrical element electrically connected to the at least one LED; and a plurality of polarity agnostic connection ports connected to the active electrical components. In some embodiments, each of the plurality of polarity agnostic inputs is connectable with one of a supply voltage input, a ground input, a communication input, and a communication output. In certain embodiments, the active electrical component further comprises an active switching network connected to the plurality of polarity-agnostic connection ports. In certain embodiments, the active electrical component further comprises at least two bidirectional communication ports connected to the active switching network. In some embodiments, the plurality of polarity agnostic connection ports are package bond pads of the LED package.

The present disclosure relates to active control of LEDs, LED packages, and related LED displays by Pulse Width Modulation (PWM). In some embodiments, the effective PWM frequency of the LEDs is increased by segmenting the duty cycle, wherein the LEDs are electrically activated during individual PWM cycles. Segmenting the duty cycle within the PWM period may be accomplished by shifting or reordering a sequence in which the comparator outputs a control signal to a driver that operates the LED. In this manner, the duty cycle within each PWM cycle may be segmented over a series of pulses that electrically activate and turn off each LED multiple times within each PWM cycle, rather than continuously maintaining the LEDs in an electrically activated state for the duration of the duty cycle. In certain embodiments, an active electrical element incorporated into one or more LED packages of an LED display is capable of segmenting the duty cycle of one or more LEDs. In certain embodiments, active electrical elements are disclosed that are capable of receiving a reset signal from a data stream to initiate a reset action or to pass the reset signal to other active electrical elements of a display.

In one aspect, a method of controlling an LED device includes: providing a PWM signal to the one or more LED chips, the PWM signal comprising a PWM period and a PWM duty cycle, the PWM duty cycle corresponding to a portion of the PWM period in which the one or more LED chips are electrically activated; and segmenting the PWM duty cycle such that the one or more LED chips are electrically activated and electrically deactivated a plurality of times within the PWM cycle. In some embodiments, the method further includes selectively segmenting the PWM duty cycle such that one or more LED chips may receive a segmented duty cycle or a continuous duty cycle. In some embodiments, the method further comprises converting the counter signal to a non-digitally ordered sequence of counters for the PWM periods. In certain embodiments, the method further comprises comparing the command signal for the one or more LED chips to a non-digital sequencing counter sequence, and providing a control signal to the one or more LED chips during the PWM period. In some embodiments, the non-numeric ordered counter sequence counts the total number of values in the PWM cycle corresponding to the bit depth of the command signal. In certain embodiments, the non-digitally ordered counter sequence is formed by bit inversion of the counter signal. In some embodiments, the non-digitally ordered counter sequence is formed by partial bit inversion of the counter signal. In certain embodiments, the non-digitally ordered counter sequence is formed by swapping bit segments corresponding to the counter signals. In certain embodiments, the non-numeric sequencing counter sequence comprises 8 segments within a PWM period. In certain embodiments, the non-numeric sequencing counter sequence comprises 16 segments within a PWM period. In certain embodiments, the non-numeric sequencing counter sequence comprises 32 segments within a PWM period. In certain embodiments, the non-numeric sequencing counter sequence comprises 64 segments within a PWM period. In certain embodiments, the active electrical element of the LED device is configured to initiate a reset command upon receiving a reset signal.

In another aspect, an LED package includes: at least one LED chip; and an active electrical element electrically connected to the at least one LED chip, the active electrical element configured to: providing a PWM signal to the at least one LED chip, the PWM signal including a PWM period and a PWM duty cycle, the PWM duty cycle corresponding to a portion of the PWM period in which the at least one LED chip is electrically activated; and segmenting the PWM duty cycle such that the at least one LED chip is electrically activated and electrically deactivated a plurality of times within the PWM cycle. In certain embodiments, the active electrical element is further configured to be capable of selecting between a segmented PWM duty cycle and a continuous PWM duty cycle for the at least one LED chip. In certain embodiments, the active electrical component includes a signal conditioning component configured to transform a command signal received from the data stream. In certain embodiments, the active electrical component comprises a counter transformation device configured to transform the counter signal into a non-digitally ordered sequence of counters for the PWM periods. In certain embodiments, the non-digitally ordered counter sequence is formed by bit inversion of the counter signal. In some embodiments, the non-digitally ordered counter sequence is formed by partial bit inversion of the counter signal. In certain embodiments, the non-digitally ordered counter sequence is formed by swapping bit segments corresponding to the counter signals. In certain embodiments, the non-numeric sequencing counter sequence comprises 8 segments within a PWM period. In certain embodiments, the non-numeric sequencing counter sequence comprises 16 segments within a PWM period. In certain embodiments, the non-numeric sequencing counter sequence comprises 32 segments within a PWM period. In certain embodiments, the non-numeric sequencing counter sequence comprises 64 segments within a PWM period. In some embodiments, the non-numeric ordered counter sequence counts the total number of values in the PWM cycle corresponding to the bit depth of the command signal. In certain embodiments, the active electrical element comprises a comparator device configured to compare a command signal from the data stream with a non-digital sequencing counter sequence to provide a control signal for the at least one LED chip. In certain embodiments, the active electrical element comprises a driver configured to receive the control signal and drive the at least one LED chip. In certain embodiments, the active electrical element comprises a memory element configured to receive and store command signals from a data stream. In some embodiments, the at least one LED chip includes a plurality of LED chips forming at least one LED pixel.

In another aspect, an LED package includes: at least one LED; and an active electrical element electrically connected to the at least one LED, the active electrical element configured to receive a reset signal, the reset signal comprising at least one pulse of the serial communication signal. In some embodiments, at least one includes maintaining the line state of the serial communication signal in a high state or a low state for a time interval that is longer than other pulses of the serial communication signal. In certain embodiments, the at least one pulse comprises a plurality of pulses of the serial communication signal. In some embodiments, the active electrical element is further configured to initiate a reset command upon receiving a reset signal. In some embodiments, the active electrical element is further configured to pass a reset signal without initiating a reset command. In some embodiments, the active electrical element is further configured to: providing a PWM signal to the at least one LED, the PWM signal comprising a PWM period and a PWM duty cycle, the PWM duty cycle corresponding to a portion of the PWM period in which the at least one LED is electrically activated; and segmenting the PWM duty cycle such that at least one LED is electrically activated and electrically deactivated a plurality of times within the PWM cycle.

In another aspect, any of the foregoing aspects and/or various individual aspects and features as described herein may be combined to obtain additional advantages. Any of the various features and elements disclosed herein may be combined with one or more other disclosed features and elements, unless the context indicates otherwise.

Those skilled in the art will appreciate the scope of the present disclosure and realize additional aspects thereof after reading the following detailed description of the preferred embodiments in association with the accompanying drawing figures.

Drawings

The accompanying drawings incorporated in and forming a part of the specification illustrate several aspects of the present disclosure and, together with the description, serve to explain the principles of the disclosure.

Fig. 1A is a top view of the front side of a representative display panel for a Light Emitting Diode (LED) display including a plurality of active LED pixels.

Fig. 1B is a bottom view of the back side of the representative display panel of fig. 1A.

Fig. 2A is a bottom view of an LED package in a particular manufacturing state, wherein a plurality of LEDs and active electrical components are mounted on a substrate.

FIG. 2B is a cross-sectional view taken along section line A-A of FIG. 2A.

Fig. 2C is a bottom view of the LED package of fig. 2A in a subsequent state of manufacture, wherein an encapsulant layer and a plurality of conductive traces have been formed.

Fig. 2D is a cross-sectional view taken along section line B-B of fig. 2C.

Fig. 2E is a bottom view of the LED package of fig. 2C in a subsequent state of manufacture, wherein an additional encapsulant layer and a plurality of package bond pads have been formed.

FIG. 2F is a cross-sectional view taken along section line C-C of FIG. 2E.

FIG. 2G is a cross-sectional view taken along section line D-D of FIG. 2E.

Figure 2H is a simplified top view of the LED package of figure 2E.

Fig. 2I is a simplified bottom view of the LED package of fig. 2E.

Fig. 3A is a bottom view of a representative LED package that includes a plurality of conductive traces, with portions of some of the conductive traces forming package bond pads for the LED package.

FIG. 3B is a cross-sectional view taken along section line E-E of FIG. 3A.

Fig. 4 is a cross-sectional view of an LED package showing a configuration in which one or more LED chips and an active electrical element are mounted along the same horizontal plane.

Fig. 5 is a cross-sectional view of an LED package showing a configuration in which one or more LED chips are mounted along a first horizontal plane and an active electrical element is mounted along a second horizontal plane different from the first horizontal plane.

Fig. 6 is a cross-sectional view of an LED package showing a configuration in which one or more LED chips and an active electrical element are mounted on opposite sides of a substrate.

Fig. 7 is a bottom view of an LED package including a plurality of LED pixels according to embodiments disclosed herein.

Fig. 8 is a block diagram schematically illustrating components of an active electrical element according to embodiments disclosed herein.

Fig. 9 is a block diagram schematically illustrating components of an active electrical element according to embodiments disclosed herein.

Fig. 10 is a schematic diagram illustrating an example structure of a volatile memory element that may be included within an active electrical element according to embodiments disclosed herein.

Fig. 11A is a schematic diagram showing a driver element including a voltage-controlled current source circuit.

Fig. 11B is a schematic diagram illustrating a driver element including transconductance amplifiers arranged in an active cascode configuration.

Fig. 11C is a schematic diagram showing a driver element including an input amplifier added to the driver element of fig. 11B.

Fig. 11D is a schematic diagram showing a driver element similar to that of fig. 11C but with reversed polarity connections.

Fig. 11E is a schematic diagram showing an actuator element including a Howland current pump.

Fig. 11F is a schematic diagram showing a driver element similar to that of fig. 11E, with the addition of a voltage divider and an additional operational amplifier.

Fig. 12A is a block diagram schematically illustrating an embodiment of an active electrical element comprising a detector element.

Figure 12B is a bottom view of an LED package including a photodiode according to embodiments disclosed herein.

FIG. 13 is a block diagram that schematically illustrates various components that may be included in a system level control scheme for an LED display panel, in accordance with embodiments disclosed herein.

Fig. 14 is a schematic diagram showing a configuration in which an active electrical element corresponding to a particular LED pixel is configured to receive a row selection signal line and independent control signals for each of red, green, and blue LED chips included within the LED pixel.

Fig. 15 is a schematic diagram representing a configuration in which the active electrical element corresponding to a particular LED pixel is configured to receive a separate row select signal line for each LED chip of the LED pixel and a single color level signal line for all LED chips within the LED pixel.

Fig. 16 is a schematic diagram showing a configuration in which an active electrical element corresponding to a particular LED pixel is configured to receive an encoded row selection signal for each LED chip of the LED pixel and a single color level signal line for all LED chips within the LED pixel.

Fig. 17 is a schematic diagram showing a configuration in which active electrical elements of a particular LED package are configured to receive row select signals, color level signals, and one or more color select signals for red, green, and blue LED chips included in the LED package.

Fig. 18 is a schematic diagram showing an independent symbol configuration similar to that of fig. 16 and 17.

Fig. 19 is a schematic diagram showing a configuration in which an active electrical element corresponding to a particular LED pixel is configured to receive a single row select signal line and a single color level signal line for all LED chips of the LED pixel.

Fig. 20 is a schematic diagram showing a configuration in which an active electrical element corresponding to a particular LED pixel is configured to receive a single row select signal line and a single color level signal line for all LED chips of the LED pixel.

FIG. 21 is a block diagram schematically illustrating a system level control scheme for an LED display panel in which each active electrical element of the LED pixel array is configured to receive a signal line, according to the embodiment of FIG. 20.

Fig. 22 is a partial plan view showing a path configuration of the LED display panel configured to operate according to the configuration of fig. 20 and 21.

Fig. 23 is a schematic diagram representing a configuration in which the active electrical elements corresponding to a particular LED pixel are configured to receive all-digital communication of row, column and/or color selection signals.

FIG. 24 is a block diagram schematically illustrating a system level control scheme for an LED display panel in which each active electrical element of the LED pixel array is configured to receive a signal line, according to the embodiment of FIG. 23.

Fig. 25 is a partial plan view showing a path configuration of the LED display panel configured for operation according to the configuration of fig. 23.

Fig. 26A and 26B are schematic diagrams illustrating an arrangement of exemplary data packets according to embodiments disclosed herein.

Fig. 27 is a schematic diagram illustrating a cascading flow of data packets from a control element to a plurality of LED packages according to embodiments disclosed herein.

Fig. 28 is a schematic diagram illustrating a cascading flow of data packets from a control element to a plurality of LED packages and a flow of one or more talk-back data packets to the control element, according to embodiments disclosed herein.

Fig. 29 is a schematic diagram illustrating a cascading flow of data packets from a control element that additionally includes data packets configured to provide information to all LED packages, according to embodiments disclosed herein.

Fig. 30 is a schematic diagram illustrating a cascading flow of data packets from a control element additionally including one or more consecutive data packets configured to provide additional information to at least one LED package, according to embodiments disclosed herein.

Fig. 31 is a partial plan view illustrating a path configuration of an LED panel configured for operation according to embodiments disclosed herein.

Fig. 32 is a partial plan view illustrating a routing configuration for an LED panel including LED packages having selectively assignable communication ports according to embodiments disclosed herein.

Fig. 33 is a partial plan view illustrating another routing configuration for an LED panel including LED packages having selectively assignable communication ports according to embodiments disclosed herein.

Fig. 34 is a partial plan view illustrating a path configuration of the LED panel of fig. 33 with the addition of voltage and ground lines, according to embodiments disclosed herein.

Fig. 35 is a schematic diagram illustrating various inputs and corresponding actions for an active electrical element, according to embodiments disclosed herein.

Fig. 36 is a schematic diagram illustrating an active electrical component including a finite state machine, according to embodiments disclosed herein.

Fig. 37 is a schematic diagram illustrating an embodiment in which an active electrical element is configured to detect a normal or poor operating condition of at least one LED in accordance with embodiments disclosed herein.

Fig. 38 is a schematic diagram illustrating an embodiment in which an active electrical element is configured to provide forward and reverse bias conditions to at least one LED, according to embodiments disclosed herein.

Fig. 39 is a schematic diagram illustrating an embodiment in which the resistor network and corresponding select switches of fig. 38 are replaced with current sources according to embodiments disclosed herein.

Fig. 40 is a schematic diagram showing a multiple LED embodiment similar to the schematic diagram of fig. 39.

Fig. 41 is a schematic diagram illustrating the active electrical component of fig. 40 configured with a plurality of ports including a supply voltage, ground, and a bidirectional communication port in accordance with embodiments disclosed herein.

Fig. 42 is a schematic diagram illustrating the active electrical element of fig. 41 configured with polarity agnostic input capability according to embodiments disclosed herein.

Fig. 43 is a schematic diagram illustrating a four-input rectifier that may be used to provide initial power to the switching network of fig. 42.

Fig. 44A is a schematic diagram illustrating an embodiment in which the active electrical elements are configured to segment the duty cycle for Pulse Width Modulation (PWM) control of one or more LEDs.

FIG. 44B is a schematic diagram illustrating an embodiment in which the counter translation device is configured to share respective duty cycles between multiple LEDs to segment the LEDs.

FIG. 45 shows a tabular representation for providing a sequence sequencing counter for PWM control of one or more LEDs.

FIG. 46 shows a tabular diagram for providing a non-sequential ordering counter according to a bit inversion sequence for PWM control of one or more LEDs.

FIG. 47 shows a tabular diagram for providing a non-sequential ordering counter according to a partial bit reversal sequence for PWM control of one or more LEDs.

FIG. 48 shows a tabular representation for providing a non-sequential sequencing counter according to a two-segment sequencing for PWM control of one or more LEDs.

FIG. 49 shows a tabular representation for providing a non-sequential sequencing counter according to a four-segment sequencing for PWM control of one or more LEDs.

FIG. 50 shows a tabular representation for providing a non-sequential sequencing counter according to eight segment sequencing for PWM control of one or more LEDs.

Fig. 51A shows a data flow in return-to-zero (RZ) format that may be provided to active electrical components.

Fig. 51B shows a data flow in RZ format, which includes a reset signal that can be provided to the active electrical elements.

Detailed Description

The embodiments set forth below represent the necessary information to enable those skilled in the art to practice the embodiments and illustrate the best mode of practicing the embodiments. Upon reading the following description in light of the accompanying drawing figures, those skilled in the art will understand the concepts of the disclosure and will recognize applications of these concepts not particularly addressed herein. It should be understood that these concepts and applications fall within the scope of the disclosure and the accompanying claims.

It will be understood that, although the terms first, second, etc. may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another. For example, a first element could be termed a second element, and, similarly, a second element could be termed a first element, without departing from the scope of the present disclosure. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.

It will be understood that when an element such as a layer, region or substrate is referred to as being on or extending over another element, it can be directly on or extend directly onto the other element or intervening elements may also be present. In contrast, when an element is referred to as being "directly on" or "directly extending" onto another element, there are no intervening elements present. Also, it will be understood that when an element such as a layer, region or substrate is referred to as extending "on" or "over" another element, it can extend directly on or over the other element or intervening elements may also be present. In contrast, when an element is referred to as being "directly on" or extending "directly over" another element, there are no intervening elements present. It will also be understood that when an element is referred to as being "connected" or "coupled" to another element, it can be directly connected or coupled to the other element or intervening elements may be present. In contrast, when an element is referred to as being "directly connected" or "directly coupled" to another element, there are no intervening elements present.

Relative terms, such as "below" or "above" or "upper" or "lower" or "horizontal" or "vertical" or "top" or "bottom" or "row" or "column," may be used herein to describe one element, layer, surface or region's relationship to another element, layer, surface or region as illustrated in the figures. It will be understood that these terms and those discussed above are intended to encompass different orientations of the device in addition to the orientation depicted in the figures. For example, if the device in a particular figure were turned over, elements, layers, surfaces or regions described as "above" would now be oriented "below".

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the disclosure. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises," "comprising," "includes" and/or "including," when used herein, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.

Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. It will be further understood that terms used herein should be interpreted as having a meaning that is consistent with their meaning in the context of this specification and the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

The present disclosure relates to Light Emitting Diodes (LEDs), LED packages, and related LED displays, and more particularly to active control of LEDs within LED displays. An LED display may include rows and columns of LEDs forming an array of LED pixels. A particular LED pixel may include a cluster of LED chips of the same color or multiple colors, with exemplary LED pixels including red, green, and blue LED chips. In certain embodiments, an LED package includes a plurality of LED chips forming at least one LED pixel, and a plurality of such LED packages may be arranged to form an LED pixel array for an LED display. Each LED package may comprise an active electrical element configured to receive a control signal and to actively maintain an operational state of an LED chip of the LED package, such as a brightness or grey level or color selection signal, when addressing other LED packages. In some embodiments, the active electrical elements may include active circuitry including one or more of driver devices, signal conditioning or transformation devices, memory devices, decoder devices, electrostatic discharge (ESD) protection devices, thermal management devices, detection devices, and the like. In this regard, each LED pixel of the LED display may be configured to operate in an active matrix addressed manner. The active electrical element may be configured to receive one or more of an analog control signal, a coded analog control signal, a digital control signal, and a coded digital control signal. A display panel is disclosed that includes an array of such LED pixels on a first side of the panel and control circuitry on a back side of the panel configured to communicate with each active electrical element of the LED pixels.

An LED package configured to receive a data stream including a plurality of data packets is disclosed. Each data packet may include an identifier that enables each LED package receiving the array of data packets to take one or more actions based on the identifier or series of identifiers. Various additional data packets are disclosed, including a talk-back data packet, a data packet for all LED packages receiving the data stream, and a continuous data packet. LED packages having selectively assignable communication ports are also disclosed. The data signals and data packets sent to the active electrical elements may include compressed data codes that are subsequently decompressed, as well as one or more of transfer function, gamma correction, and color depth data. Active electrical components are disclosed that are configured to provide forward and reverse bias conditions to an LED in order to detect undesirable operating conditions, such as reverse leakage and deviations from forward voltage levels. Such poor operating conditions may be performed as part of a self-test routine of the LED package. An active electrical element as disclosed herein may include an analog-to-digital converter (ADC). LED packages that are self-configurable based on the manner in which various input or output lines are connected are also disclosed.

The present disclosure relates to active control of LEDs, LED packages, and related LED displays by Pulse Width Modulation (PWM). In some embodiments, the effective PWM frequency of the LEDs is increased by segmenting the duty cycle, wherein the LEDs are electrically activated during individual PWM cycles. Segmenting the duty cycle within the PWM period may be accomplished by shifting or reordering a sequence in which the comparator outputs a control signal to a driver that operates the LED. In this manner, the duty cycle within each PWM cycle may be segmented over a series of pulses that electrically activate and turn off each LED multiple times within each PWM cycle, rather than continuously maintaining the LEDs in an electrically activated state for the duration of the duty cycle. In certain embodiments, an active electrical element incorporated into one or more LED packages of an LED display is capable of segmenting the duty cycle of one or more LEDs. In certain embodiments, active electrical elements are disclosed that are capable of receiving a reset signal from a data stream to initiate a reset action or to pass the reset signal to other active electrical elements of a display.

LED chips typically include an active LED structure or region, which may have many different semiconductor layers arranged in different ways. The fabrication and operation of LEDs and their active structures is well known in the art and will only be briefly discussed herein. The layers of the active LED structure may be fabricated using known processes, a suitable process being fabrication using metal organic chemical vapor deposition. The layers of the active LED structure may include many different layers and typically include an active layer sandwiched between n-type and p-type oppositely doped epitaxial layers, all of which are successively formed on a growth substrate. It should be understood that additional layers and elements may also be included in the active LED structure, including but not limited to: buffer layers, nucleation layers, superlattice structures, undoped layers, cladding layers, contact layers, current spreading layers, and light extraction layers and elements. The active layer may include a single quantum well, a multiple quantum well, a double heterostructure, or a superlattice structure.

The active LED structure may be made of different material systems, some of which are group iii nitride based material systems. Group iii nitrides refer to these semiconductor compounds formed between nitrogen and group iii elements of the periodic table, and are typically aluminum (Al), gallium (Ga), and indium (In). Gallium nitride (GaN) is a common binary compound. Group iii nitrides also refer to ternary and quaternary compounds, such as aluminum gallium nitride (AlGaN), indium gallium nitride (InGaN), and aluminum indium gallium nitride (AlInGaN). For group iii nitrides, silicon (Si) is a common n-type dopant and magnesium (Mg) is a common p-type dopant. Thus, for group iii nitride based material systems, the active layer, the n-type layer, and the p-type layer may comprise one or more of GaN, AIGaN, InGaN, and AlInGaN that are undoped or doped with silicon or magnesium. Other material systems include silicon carbide (SiC), organic semiconductor materials, and other group III-V systems, such as gallium phosphide (GaP), gallium arsenide (GaAs), and related compounds.

The active LED structure may be grown on a growth substrate that may comprise many materials, for example, sapphire, SiC, aluminum nitride (AIN), GaN, a suitable substrate being 4H polytype SiC, but other SiC polytypes may also be used, including 3C, 6H and 15R polytypes. SiC has certain advantages, such as a tighter lattice match with group iii nitrides than other substrates, and results in high quality group iii nitride films. SiC also has very high thermal conductivity, so the total output power of group iii nitride devices on SiC is not limited by substrate heat dissipation. Sapphire is another common substrate for group iii nitrides and also has certain advantages, including lower cost, established manufacturing processes, and good light-transmissive optical properties.

Different embodiments of the active LED structure may emit light of different wavelengths depending on the composition of the active layer and the n-type and p-type layers. For example, the active LED structure of various LEDs may emit blue light having a peak wavelength range of about 430 nanometers (nm) to 480nm, green light having a peak wavelength range of 500nm to 570nm, or red light having a peak wavelength range of 600nm to 650 nm. The LED chip may also be covered with one or more luminescent phosphors or other conversion materials, e.g., phosphors, such that at least some of the light from the LED chip is absorbed by the one or more phosphors and converted into one or more different wavelength spectra according to the characteristic emission from the one or more phosphors. In some embodiments, the combination of the LED chip and the one or more phosphors emits a generally white combination of light. The one or more phosphors can include a yellow (e.g., YAG: Ce), green (e.g., LuAg: Ce) and red (e.g., Ca) emission_i-x-ySr_xEu_yAISiN₃) And combinations thereof. The luminescent material described herein may be or comprise one or more of a phosphor, a scintillator, a luminescent ink, a quantum dot material, a daylight lamp strip, or the like. The luminescent material may be provided by any suitable means, for example, coated directly on one or more surfaces of the LED, dispersed in an encapsulant material configured to cover the one or more LEDs, and/or coated on one or more optical or support elements (e.g., by powder coating, inkjet printing, etc.). In certain embodiments, the luminescent material may be down-converted or up-converted, and a combination of down-converting and up-converting materials may be provided. In some embodiments, are configured to produce different peak wavelengths May be arranged to receive emissions from one or more LED chips.

The light emitted by the active layer or region of the LED chip typically has a lambertian emission pattern. For directional applications, internal mirrors or external reflective surfaces may be used to redirect as much light as possible into the desired emission direction. The internal mirror may comprise a single layer or multiple layers. Some multilayer mirrors include a metallic reflective layer and a dielectric reflective layer, wherein the dielectric reflective layer is disposed between the metallic reflective layer and the plurality of semiconductor layers. The passivation layer may be disposed between the metal reflective layer and first and second electrical contacts, wherein the first electrical contact is disposed in conductive communication with the first semiconductor layer and the second electrical contact is disposed in conductive communication with the second semiconductor layer. In some embodiments, the first and second electrical contacts may themselves be configured as mirror layers. For single or multilayer mirrors comprising a surface with a reflectivity of less than 100%, some light may be absorbed by the mirror. Furthermore, light redirected by the active LED structure may be absorbed by other layers or elements within the LED chip.

As used herein, a layer or region of a light-emitting device can be considered "transparent" when at least 80% of the emitted radiation incident on the layer or region exits through the layer or region. Further, as used herein, a layer or region of an LED is considered "reflective" or embodied as a "mirror" or "reflector" when at least 80% of the emitted radiation incident on the layer or region is reflected. In some embodiments, the emitted radiation comprises visible light, e.g., blue and/or green LEDs with or without luminescent materials. In other embodiments, the emitted radiation may include invisible light. For example, in the case of GaN-based blue and/or green LEDs, silver (e.g., at least 80% reflective) may be considered a reflective material. In the case of Ultraviolet (UV) LEDs, suitable materials may be selected to provide the desired reflectivity, in some embodiments high reflectivity; and/or desired absorption, in some embodiments providing low absorption. In certain embodiments, the "optically transmissive" material may be configured to transmit at least 50% of the emitted radiation of the desired wavelength. In certain embodiments, the initial "light transmissive" material can be changed to a "light absorbing material" that transmits less than 50% of the emitted radiation at the desired wavelength by adding one or more light absorbing materials (e.g., opaque or non-reflective materials, including gray, dark, or black particles or materials).

The present disclosure can be used with LED chips having a variety of geometries, for example, a vertical geometry or a lateral geometry. A vertical geometry LED chip typically includes anode and cathode connections on opposite sides of the LED chip. The lateral geometry LED chip typically includes anode and cathode connections on the same side of the LED chip, which is opposite the substrate (e.g., growth substrate). Certain embodiments disclosed herein relate to the use of flip-chip LED devices, wherein the light transmissive substrate represents an exposed light emitting surface.

LED chips or LED packages comprising one or more LED chips can be arranged in many different applications to provide illumination of an object, surface or area. In some applications, clusters of different colored LED chips or LED packages may be arranged as pixels for LED display applications, including video displays. For example, individual clusters of red, green, and blue LED chips may form LED pixels of a larger LED display. In some applications, the red, green, and blue LED chips of each pixel may be packaged together as a multi-LED package, and when an array of such multi-LED packages are arranged together, an LED display is formed. In this regard, each pixel may include a single LED package including a red LED chip, a green LED chip, and a blue LED chip. In other embodiments, the red, green, and blue LED chips may be individually packaged or arranged in a chip-on-board configuration. In some LED display applications, an array of LED pixels is arranged on a panel, which may also be referred to as a tile or LED module, and the array of such panels are arranged together to form a larger LED display. Depending on the application, each panel of the LED display may include a different number of LED pixels. In some applications, each panel of an LED display may include an array of 64 rows by 64 columns of LED pixels or more. In some embodiments, each panel of the LED display may be configured to have a horizontal display resolution of approximately 4,000 LED pixels, or 4K resolution. For applications requiring LED displays with higher screen resolution, each panel may include more rows and columns of LED pixels spaced closer together. Depending on the desired screen resolution, the pixel pitch may be about 3 millimeters (mm), or about 2.5mm, or about 1.6mm, or in the range of about 1.5mm to about 3mm, or in the range of about 1.6mm to about 3mm, or in the range of about 1.5mm to about 2.5 mm. Further, for some embodiments, the pixel pitch may be configured to be less than 1mm, or less than 0.8mm, or in the range of about 0.5mm to about 1mm, or about 0.7mm for fine pitch LED displays with higher screen resolution.

In conventional video display applications, LED pixels are typically configured for passive matrix addressing. In this regard, the LED pixels may be arranged to be coupled to a passive interface element that provides an electrical connection to a separate driver or controller. For example, orthogonally arranged (e.g., vertical and horizontal) conductors form rows and columns in a grid pattern, whereby a separate LED chip for each LED pixel is defined by each intersection of a row and column. A multiplexed ordering may be used to allow individual control of each LED chip of the array while employing fewer conductors than the number of LED chips in the array, or by using a common row anode or common row cathode matrix arrangement, and brightness control may be provided by pulse width modulation. In this way, the conductors for a row or column are shared between many LED pixels, and time division multiplexing is employed to address each individual LED pixel. Due to their passive configuration, each LED pixel emits light only during its respective communication time. The individual drivers for controlling the display are typically arranged remotely from the pixels of the display, for example on separate boards or modules, or on a Printed Circuit Board (PCB) attached or otherwise mounted to the back of each panel, or on the back of a common PCB including an array of pixels on the front. As previously mentioned, PCBs are typically densely populated with electrical devices, including capacitors, Field Effect Transistors (FETs), decoders, microcontrollers, etc., for driving each pixel on a particular panel. For higher resolution displays, the density of such electrical devices becomes higher corresponding to an increased number of pixels per panel. As previously mentioned, this can increase the higher complexity and cost of LED panels for display applications, as well as increase thermal crowding in areas where driver electronics are more closely spaced. For passive matrix addressing, the LED pixels are typically driven by a sequence of pulsed signals. In this regard, the LED pixels may be rapidly pulsed at certain frequencies, such as 60 hertz (Hz) or 120Hz, depending on the display scan rate. While a video display may not appear to the human eye to be a fast pulse, it may be detected by an image capture device, and in some cases, there may be a disturbing jump between the video display and other pulsed displays or light sources adjacent to the video display.

According to embodiments disclosed herein, each LED pixel of the LED display may be configured to operate in an active matrix addressed manner. For active matrix addressing, each LED pixel is configured to actively maintain an operating or driving state, such as brightness or gray scale, or color selection, while other LED pixels are addressed, thereby allowing each LED pixel to maintain its driving state with reduced or no pulses, depending on the driving configuration. Thus, each LED pixel may be configured to maintain its respective operating state by a continuous drive signal rather than by a pulsed signal associated with passive matrix addressing. In this regard, each LED pixel may include an active electrical chip or element, which may include a memory device and the ability to change the drive conditions or driver conditions of the LED pixel based on the stored content from the memory device. In some embodiments, the continuous drive signal is a constant analog drive current, and in other embodiments where the brightness level may be controlled by a pulse method such as Pulse Width Modulation (PWM), the continuous drive signal may refer to a PWM signal that is not interrupted by the scanning of other LED pixels within the array or sub-array. In some embodiments, the active electrical chip may include active circuitry including one or more of driver devices, signal conditioning or transformation devices, memory devices, decoder devices, ESD protection devices, thermal management devices, detection devices, and the like. As used herein, the term "active electrical chip", "active electrical element" or "active electrical component" includes any chip or component that is capable of changing the driving conditions of the LED based on stored content (memory) or other information that may be stored within the chip or component. As used herein, the term "active LED pixel" includes one or more LED devices that form a pixel and an active electrical chip as described above. In some embodiments, each LED pixel may include a single LED package configured as an active LED package including a plurality of LED chips and an active electrical element as described above. In this way, the number of individual electrical devices required for the LED display, for example, on the back of the LED panel of the LED display, as previously described, can be reduced. Furthermore, the overall operating power required to operate the LED panel may be reduced.

Fig. 1A is a top view of the front side of a representative display panel 10 for an LED display comprising a plurality of active LED pixels 12. As shown, a plurality of active LED pixels 12 may be arranged in rows and columns to form an array of active LED pixels 12 across the front of the display panel 10. In certain embodiments, each active LED pixel 12 is configured with an active electrical element that includes the ability to receive an input signal, store memory content based on the input signal, change the driving conditions of the LEDs within each active LED pixel 12 based on the stored memory content, and update the driving conditions each time the memory content is updated by the input signal. In certain embodiments, each active LED pixel 12 comprises an LED package comprising a plurality of LED chips forming the LED pixel and an active electrical element. Fig. 1B is a bottom view of the back of the representative display panel 10 of fig. 1A. All shown, the display panel 10 may include additional passive or active elements configured to receive, process, and distribute signals to the active LED pixels (12 of fig. 1A). For example, the display panel 10 may include an input signal connector 14 and an output signal connector 16, each of which may be configured as a video source connector, including a Video Graphics Array (VGA) connector, a Digital Visual Interface (DVI) connector, a High Definition Multimedia Interface (HDMI) connector, or a display port connector, among others. The display panel 10 may include control elements 18 including control circuitry, such as semiconductor control elements. The control element 18 may be configured to receive an input signal via the input signal connector 14 and output a control signal for the active LED pixels. As will be described in more detail later, the active electrical element of each LED pixel is configured to independently change the driving condition of each LED chip within the LED pixel in response to a control signal output from the control element 18. In certain embodiments, the control element 18 comprises an integrated circuit, such as one or more of an Application Specific Integrated Circuit (ASIC), a microcontroller, a programmable control element, and a Field Programmable Gate Array (FPGA). In some embodiments, a plurality of control elements 18 may be configured on each display panel 10 or recorded to each display panel 10. Decoder element 20 may be configured to receive and route control signals from control element 18 to a plurality of signal lines for active LED pixels (12 of fig. 1A). In some embodiments, one or more digital-to-analog converters (DACs) 22 may be provided to convert the digital signals from control element 18 and decoder element 20 before reaching the active LED pixels (12 of fig. 1A). The display panel 10 may also include other passive or active elements 24, which may include additional decoders, resistors, capacitors, or other electrical elements or circuits for video display. In this way, the signal connectors 14 and 16, the control element 18, the decoder element 20, the DAC 22 and other passive or active elements 24 are registered with the display panel 10. In alternative embodiments, the back side of display panel 10 may include another plurality of LED packages forming another LED pixel array. In this regard, the display panel 10 may be configured for dual-sided display applications. In such embodiments, at least some of the signal connectors 14 and 16, control elements 18, decoder elements 20, DACs 22, and other passive or active elements 24 may be recorded in the configuration at locations other than the back of the display panel 10 to provide control signals from one or more edges of the display panel 10.

Fig. 2A-2I illustrate various states of manufacture of an LED package 26 including a plurality of LEDs 28-1 to 28-3 and an active electrical element 30 according to embodiments disclosed herein. In some embodiments, the individual LED packages 26 may be configured to form each active LED pixel (12 of fig. 1A) in the display panel (10 of fig. 1A). The active electrical component 30 may also be referred to as an active electrical chip or an active electrical component. Fig. 2A is a bottom view of the LED package 26 in a particular manufacturing state in which the plurality of LEDs 28-1 to 28-3 and the active electrical component 30 are mounted on the substrate 32. Specifically, the plurality of LEDs 28-1 to 28-3 and the active electrical component 30 may be mounted on a first side 32' of the substrate 32. A light transmissive die attach material may be disposed between the plurality of LEDs 28-1 to 28-3 and the substrate 32 to facilitate mounting. Each of the plurality of LEDs 28-1 to 28-3 may include a corresponding cathode contact 34-1 to 34-3 (e.g., an N-type contact pad) and a corresponding anode contact 36-1 to 36-3 (e.g., a P-type contact pad). In certain embodiments, the plurality of LEDs 28-1 to 28-3 comprise individual LED chips that generate different dominant wavelengths of light. For example, LED 28-1 may be configured to primarily generate green emissions, LED 28-2 may be configured to primarily generate blue emissions, and LED 28-3 may be configured to primarily generate red emissions. Accordingly, the plurality of LEDs 28-1 to 28-3 may include green LED chips, blue LED chips, and red LED chips. In other embodiments, different combinations of colors and numbers of LEDs are possible. In yet further embodiments, each of the plurality of LEDs 28-1 through 28-3 may be configured to generate light emissions that are predominantly the same as one another. In other embodiments, the plurality of LEDs 28-1 to 28-3 may comprise micro LED structures, wherein a common active LED structure is separated into a plurality of active LED structure portions to form a plurality of LEDs 28-1 to 28-3 that are addressable independently of each other.

In certain embodiments, the active electrical component 30 is configured to receive the signal or signals and to independently drive each of the plurality of LEDs 28-1 to 28-3. In certain embodiments, the active electrical component 30 includes a memory element, chip, or assembly configured to store one or more operating states received from an external source, such as a control element (18 of FIG. 1B), regarding the plurality of LEDs 28-1 to 28-3. The active electrical element 30 may be further configured to change one or more driving conditions of the plurality of LEDs 28-1 to 28-3 based on the stored one or more operating states. In certain embodiments, the active electrical element 30 is configured to independently vary the driving conditions of each of the plurality of LEDs 28-1 to 28-3 based on the plurality of operating states stored by the memory element. In this regard, the active electrical element 30 may be configured to receive and store one or more operating conditions and to independently drive each of the plurality of LEDs 28-1 to 28-3 according to the one or more operating conditions. The active electrical element 30 may continue to drive and maintain the operating state of each of the plurality of LEDs 28-1 to 28-3 until the active electrical element 30 receives a refresh or updated signal corresponding to the updated operating state. In this way, the active electrical element 30 may be configured to change the driving conditions of the plurality of LEDs 28-1 to 28-3 according to the temporarily stored operating state of the memory element. Thus, the plurality of LEDs 28-1 to 28-3 may be configured for active matrix addressing as previously described. To quickly receive one or more operating states of the plurality of LEDs 28-1 to 28-3, the active electrical element 30 may include a plurality of contact pads 38. In some embodiments, some of the plurality of contact pads 38 are configured to receive one or more signals and others of the plurality of contact pads 38 are configured to send signals to independently drive or address the plurality of LEDs 28-1 through 28-3. In certain embodiments, the active electrical components 30 comprise one or more of an integrated circuit chip, an ASIC, a microcontroller, or an FPGA. In certain embodiments, the active electrical element 30 may be configured to be programmable or reprogrammable after being manufactured by various memory elements and logic incorporated within the active electrical element 30. In this regard, for embodiments in which the active electrical elements 30 do not include a complete FPGA, the active electrical elements 30 may be considered programmable.

Substrate 32 may be formed of many different materials, with the preferred material being electrically insulating. Suitable materials include, but are not limited to, ceramic materials (e.g., alumina or bauxite), AIN, or organic insulators (e.g., Polyimide (PI) and polyphthalamide (PPA)). In other embodiments, substrate 32 may comprise PCB, sapphire, Si, or any other suitable material. For PCB embodiments, different PCB types may be used, such as standard FR-4PCB, bismaleimide-triazine (BT) or related materials, metal core PCB or any other type of PCB. In certain embodiments, the substrate 32 includes a light transmissive material such that light emission from the plurality of LEDs 28-1 to 28-3 may pass through the substrate 32. In this regard, the light emitting face of each of the plurality of LEDs 28-1 to 28-3 may be mounted to the substrate 32. Suitable light transmissive materials for substrate 32 include glass, sapphire, epoxy, and silicone. In certain embodiments where the substrate 32 is a light-transmissive substrate, the substrate 32 may be referred to as a superstrate. The term "superstrate" is used herein, in part, to avoid confusion with other substrates that may be part of the semiconductor light emitting device, such as a growth or carrier substrate for an LED chip or a different submount for the LED package 26. The term "sheathing" is not intended to limit the orientation, location and/or composition of the structure it describes. In some embodiments, the substrate 32 may comprise a light-transmissive superstrate and the LED packages 26 may lack another substrate. In other embodiments, the substrate 32 may comprise a light-transmissive superstrate and the LED package 26 comprises an additional substrate, wherein the plurality of LEDs 28-1 to 28-3 are disposed between the substrate 32 and the additional substrate.

FIG. 2B is a cross-sectional view taken along section line A-A of FIG. 2A. As shown, the LED28-1 is mounted to a first side 32' of the substrate 32. Thus, the emission from the LED28-1 may be configured to pass through the substrate 32 such that the second side 32 ″ of the substrate 32 is configured as the primary emission side of the LED package 26. Notably, the anode contact 36-1 and the cathode contact (34-1) of the LED28-1 are disposed on opposite sides of the LED28-1 relative to the substrate 32. In this regard, light emission from the LED28-1 may pass through the substrate and out the opposing face 32 "without interaction or absorption by the anode contact 36-1 and the cathode contact (34-1). The orientation of the cross-sectional view in FIG. 2B is intended to illustrate that the second face 32' of the substrate 32 will be configured as a primary light emitting face; however, during intermediate fabrication steps, the orientation of fig. 2B and subsequent cross-sectional fabrication views may be rotated 180 degrees such that LEDs 28-1 are assembled sequentially over substrate 32.

Fig. 2C is a bottom view of the LED package 26 of fig. 2A in a subsequent manufacturing state, in which the encapsulant layer 40 and the plurality of conductive traces 42-1 through 42-7 have been formed. Fig. 2D is a cross-sectional view taken along section line B-B of fig. 2C, in which the electrical connector 44 is visible. Before the encapsulant layer 40 and the plurality of conductive traces 42-1 to 42-7 are formed, a plurality of electrical connectors 44 may be formed on the cathode contacts 34-1 to 34-3 and the anode contacts 36-1 to 36-3 of each of the plurality of LEDs 28-1 to 28-3. A plurality of electrical connectors 44 may also be formed on the plurality of contact pads 38 of the active electrical component 30. In some embodiments, the plurality of electrical connectors 44 may include at least one of metal bump bonds, metal pads, metal wires, metal interconnects, and metal pedestals, among others. The plurality of electrical connectors 44 may be formed by a variety of methods including, but not limited to, wire bump bonding, solder bumping, electroplating, laser drilling of subsequently filled metal vias, or other metallization forming techniques. The electrical connectors 44 may be formed at the wafer level, prior to assembly of the assembly, after die attachment of the LEDs 28-1 to 28-3, or in other manufacturing steps, depending on various process configurations. After forming the plurality of electrical connectors 44, the encapsulant layer 40 may be blanket deposited to cover the plurality of LEDs 28-1 to 28-3 and the active electrical elements 30. In certain embodiments, the sealant layer 40 may further cover the plurality of electrical connectors 44. The encapsulant layer 40 may be configured to surround a perimeter or side edge of each of the plurality of LEDs 28-1-28-3. As shown in fig. 2D, the encapsulant layer 40 may cover at least a portion of a bottom surface of each of the plurality of LEDs 28-1 through 28-3. The encapsulant layer 40 may also be configured to surround the perimeter or side edges of the active electrical element 30. In such embodiments, a removal step may then be applied to the sealant layer 40, thereby removing a portion of the sealant layer 40 to form the exposed surfaces of the plurality of electrical connectors 44. The removing step may include a planarization process, such as grinding, lapping, or polishing the encapsulant layer 40 to expose the plurality of electrical connectors 44. For embodiments in which the plurality of electrical connectors 44 comprise laser drilled through holes or micro-vias, the removal step may not be required.

The sealant layer 40 may be applied or deposited by a coating or dispensing process. In certain embodiments, sealant layer 40 may comprise one or more of silicone, epoxy, and thermoplastic (e.g., polycarbonate, aliphatic urethane or polyester), among others. The encapsulant layer 40 may be configured to vary or control the light output from the plurality of LEDs 28-1 to 28-3. For example, the encapsulant layer 40 may include an opaque or non-reflective material, such as a gray, dark, or black material, that may absorb some of the light propagating between the plurality of LEDs 28-1 to 28-3, thereby improving the contrast between the emissions of the plurality of LEDs 28-1 to 28-3 through the substrate 32. In certain embodiments, the encapsulant layer 40 may include light absorbing particles suspended in an adhesive (e.g., silicone or epoxy). The light absorbing particles may comprise at least one of carbon, silicon or metal particles or nanoparticles. In certain embodiments, the light absorbing particles comprise a predominantly black color that, when suspended in an adhesive, provides the encapsulant layer 40 with a predominantly black or dark color. Depending on the desired application, the sealant layer 40 may be configured to be transparent or light transmissive, or the sealant layer 40 may include light reflecting or light redirecting materials, such as fused silica, fumed silica, or titanium dioxide (TiO2) particles, which form a predominantly white sealant layer 40. Other particles or fillers may be used to enhance the mechanical, thermal, optical, or electrical properties of the sealant layer 40. In certain embodiments, the encapsulant layer 40 may include multiple layers with varying mechanical, thermal, optical, or electrical properties.

After the surfaces of the electrical connectors 44 are exposed through the encapsulant layer 40, a plurality of conductive traces 42-1 through 42-7 are formed on the encapsulant layer 40 (e.g., on the bottom surface of the encapsulant layer 40 for the orientation shown in fig. 2D), and some of the conductive traces 42-4 through 42-7 are electrically connected to the plurality of LEDs 28-1 through 28-3 through the exposed surfaces of some of the electrical connectors 44. Some of the plurality of conductive traces 42-1 through 42-7 may be configured to provide an electrically conductive path between the plurality of contact pads 38 of the active electrical component 30 and the cathode contacts 34-1 through 34-3 and the anode contacts 36-1 through 36-3 of each LED 28-1-28-3. As shown in FIG. 2C, conductive traces 42-1, 42-2, and 42-3 are electrically connected to active electrical element 30, but are not electrically connected to any of the plurality of LEDs 28-1 through 28-3. In this regard, the conductive traces 42-1, 42-2, and 42-3 may be configured to provide signals to the active electrical element 30 from an external source (e.g., the control element 18 of FIG. 1B). Notably, the conductive trace 42-7 in FIG. 2C is configured to provide a conductive path between the active electrical component 30 and the anode contact 36-1 to 36-3 of each of the plurality of LEDs 28-1 to 28-3. In this regard, the plurality of LEDs 28-1 to 28-3 may be configured for common anode control. In other embodiments, the plurality of conductive traces 42-1 through 42-7 and the plurality of LEDs 28-1 through 28-3 may be configured for common cathode control.

Fig. 2E is a bottom view of the LED package 26 of fig. 2C in a subsequent manufacturing state in which an additional encapsulant layer 46 and a plurality of package bond pads 48-1 through 48-4 have been formed. FIG. 2F is a cross-sectional view taken along section line C-C of FIG. 2E. Fig. 2G is a cross-sectional view taken along section line D-D of fig. 2E, with the additional electrical connector 50 visible. A plurality of additional electrical connectors 50 may be formed on and electrically connected to conductive traces 42-1, 42-2, 42-3, and 42-7 prior to forming additional encapsulant layer 46 and the plurality of package bond pads 48-1 through 48-4. The additional electrical connector 50 may be configured and formed in a similar manner as the electrical connector 44 previously described. In some embodiments, the additional electrical connector 50 may be formed on the electrical connector 44 without intervening conductive traces. Alternatively, the additional encapsulant layer 46 may be applied first, and then vias or openings for the additional electrical connectors 50 may be formed by a selective removal step (e.g., laser drilling). In a similar manner, the selective removal step may also be used to form the openings for the electrical connectors 44 described above. Additional encapsulant layer 46 may then be blanket deposited to cover the bottom surfaces of the plurality of conductive traces 42-1 through 42-7 and additional electrical connectors 50. The additional sealant layer 46 may be configured and formed in a similar manner as the previously described sealant layer 40. Notably, the additional encapsulant layer 46 may also be formed on portions of the encapsulant layer 40 not covered by the plurality of conductive traces 42-1 through 42-7. In this regard, the sealant layer 40 and the additional sealant layer 46 may together form a continuous sealant layer 40, 46 such that at least some of the plurality of conductive traces 42-1 through 42-7 are partially embedded within the sealant layer 40, 46. After forming the additional encapsulant layer 46, a removal step (e.g., planarization) as previously described may be applied to form exposed surfaces of the plurality of additional electrical connectors 50. A plurality of package bond pads 48-1 through 48-4 may then be formed on the bottom surface of the additional encapsulant layer 46 and in electrical communication with the additional electrical connectors 50. In this regard, package bond pads 48-1 through 48-4 are configured to receive signals external to LED package 26. In some embodiments, package bond pads 48-1 to 48-4 are configured to mount and bond to another surface (e.g., a mounting surface of an LED panel that includes electrical traces or other types of signal lines) to receive external signals (e.g., from control element 18 of FIG. 1B). As shown, package bond pads 48-4 are electrically connected to active electrical component 30 through electrical paths that include some additional electrical connector 50 and conductive traces 42-1. In a similar manner, package bond pads 48-3 are electrically connected to active electrical component 30 by different electrical paths, including different additional electrical connectors 50 and conductive traces 42-2. Package bond pads 48-2 are electrically connected to active electrical component 30 by various electrical paths, including various additional electrical connectors 50 and conductive traces 42-3. Notably, package bond pad 48-1 is electrically connected to anode contacts 36-1 through 36-3 of each of LEDs 28-1 through 28-3 through various additional electrical connectors 50 and conductive traces 42-7 for configuration for common anode control. As previously described, the LED package 26 may be configured for common cathode control for rearranging the path of the plurality of conductive traces 42-1 through 42-7. Additional layers, such as solder masks or other insulating layers or materials, may be applied over selected areas of additional encapsulant layer 46 and package bond pads 48-1 through 48-4 to further delineate the footprint of package bond pads 48-1 through 48-4 and prevent shorting of the solder material when assembled or mounted on a PCB. In some embodiments, a plurality of additional encapsulant layers 46 and at least one additional electrical trace may be formed in a similar manner prior to forming package bond pads 48-1 through 48-4. In this manner, additional layers of traces may be laminated or alternated with additional encapsulant layers 46 to provide more conductive paths and connections for the LED package 26.

Figure 2H is a simplified top view of the LED package 26 of figure 2E. In operation, the view shown in FIG. 2H represents the primary emission surface 52 of the LED package 26. Accordingly, the plurality of LEDs 28-1 to 28-3 are arranged below the substrate 32 to provide light emission through the substrate 32 (e.g., a light transmissive substrate or a light transmissive superstrate). The active electrical component 30 is also arranged below the substrate 32 and all electrical and conductive paths as previously described are arranged below the active electrical component 30 and below the plurality of LEDs 28-1 to 28-3, respectively, with respect to the main emission surface 52. Accordingly, light generated from the plurality of LEDs 28-1 through 28-3 may pass through the substrate 32 and exit the primary emission surface 52 while reducing loss or absorption of electrical connections, conductive paths, or other elements within the LED package 26. In certain embodiments, the plurality of LEDs 28-1 through 28-3 form LED pixels for the LED package 26, which LED package 26 may be combined with other LED packages to form an array of LED pixels for video display applications.

Fig. 2I is a simplified bottom view of the LED package 26 of fig. 2E. In operation, the bottom view shown in FIG. 2I represents the major mounting surface 54 of the LED package 26. In this regard, the LED packages 26 are configured to be mounted to an external surface (e.g., a panel or PCB of a video display) such that the package bond pads 48-1 through 48-4 are bonded or soldered to electrical wires disposed on the external surface. In some embodiments, at least one package bond pad 48-1 may include an identifier 56, such as a notch, a different shape, or other form of identifier, configured to communicate the polarity and mounting location of LED package 26 on the outer surface.

Fig. 3A is a bottom view of a representative LED package 58 including a plurality of conductive traces 60-1 through 60-7, wherein portions of the conductive traces 60-1 through 60-4 form package bond pads 62-1 through 62-4 for the LED package 58. FIG. 3B is a cross-sectional view taken along section line E-E of FIG. 3A. The LED package 58 may include the substrate 32, encapsulant layer 40, a plurality of LEDs 28-1 to 28-3 having cathode contacts 34-1 to 34-3 and anode contacts 36-1 to 36-3, and an active electrical element 30 having contact pads 38, as previously described. After planarizing encapsulant layer 40 to expose cathode contacts 34-1 through 34-3, anode contacts 36-1 through 36-3, and contact pads 38, a plurality of conductive traces 60-1 through 60-7 are formed on encapsulant layer 40 in a manner similar to plurality of conductive traces 42-1 through 42-7 of fig. 2C, as previously described. As shown in fig. 3A, portions of some of the conductive traces 60-1 through 60-4 are configured to have a wider area across the LED package 58. An insulating material 64, such as a solder mask, is then formed over portions of the conductive traces 60-1 through 60-7. Notably, the insulating material 64 does not extend completely over all of the conductive traces 60-1 through 60-7. Specifically, portions of the conductive traces 60-1 through 60-4 are not covered by the insulating material 64 to form package bond pads 62-1 through 62-4 of the LED package 58. In this regard, package bond pads 62-1 through 62-4 may be bonded or soldered to another surface, and insulating material 64 may prevent electrical shorting between different ones of conductive traces 60-1 through 60-7.

FIG. 4 is a view showing a first horizontal plane P along the LED packages 66₁A cross-sectional view of the LED package 66 mounting the one or more LEDs 28-1 and the configuration of the active electrical component 30. In FIG. 4, only the LED28-1 is shown, but it should be understood that the LED package 66 may include a plurality of LEDs mounted in a similar manner as the LED28-1 of FIG. 4. As shown, the LEDs 28-1 and the active electrical components 30 are along a first horizontal plane P defined by the mounting surface of the substrate 32₁Mounting or engaging. In some embodiments, the LED28-1 and the active electrical component 30 may include different dimensions, such as different thicknesses or heights relative to the substrate 32. In addition, bonding layers of different thicknesses may be provided to respectively bond the LED28-1 and the active electrical element 30 to the substrate 32. Along a first horizontal plane P₁After bonding LED28-1 and active electrical element 30, electrical connector 44, encapsulant layer 40, additional electrical connectors 50, conductive traces 42-1 through 42-3, additional encapsulant layer 46, and package bond pads 48-1 may be formed as previously described.

FIG. 5 is a view showing the first horizontal plane P₁Mounting one or more LEDs 28-1 and along a first horizontal plane P different from the LED packages 68₁Second level P of₂A cross-sectional view of an LED package 68 of an arrangement mounting the active electrical component 30. In FIG. 5, only LED28-1 is shown, but it should be understood that LED package 68 may include a plurality of LEDs mounted in a similar manner as LED28-1 of FIG. 5. As shown, the LEDs 28-1 are along a first horizontal plane P defined by the mounting surface of the substrate 32 ₁Mounting or engaging. And then formed as previously describedElectrical connector 44, encapsulant layer 40, and a plurality of conductive traces 42-1 through 42-3. Then, along a second horizontal plane P defined by the faces of the plurality of conductive traces 42-1 through 42-3 opposite the LED 28-1₂The active electrical component 30 is mounted. In this manner, the plurality of conductive traces 42-1 through 42-2 are thus disposed between the LED 28-1 and the active electrical component 30. Additional electrical connectors 50, additional encapsulant layer 46, and package bond pads 48-1 may then be formed as previously described. It is noted that in this configuration, the active electrical element 30 may be at least partially embedded in the additional encapsulant layer 46. Accordingly, the additional encapsulant layer 46 and the at least one additional electrical connector 50 may include a greater thickness than in the previously described embodiments. In certain embodiments, the additional encapsulant layer 46 may include a second substrate, and the active electrical elements 30 are embedded within or mounted to the second substrate. This arrangement may be referred to as a chip scale configuration.

FIG. 6 is a cross-sectional view of an LED package 70 showing a configuration in which one or more LEDs 28-1 and an active electrical component 30 are mounted on opposite sides of a substrate 32. In FIG. 6, only LED 28-1 is shown, but it should be understood that LED package 70 may include a plurality of LEDs mounted in a similar manner as LED 28-1 of FIG. 6. As shown, a plurality of conductive traces 42-1, 42-2 are formed on the second side 32 "of the substrate 32, and additional electrical traces 71-1, 71-2 are formed on the first side 32' of the substrate 32. The LED 28-1 is mounted or bonded to the conductive traces 42-1, 42-2 by the electrical connector 44 and the active electrical component 30 is mounted or bonded to the additional electrical traces 71-1, 71-2 by the additional electrical connector 50. Encapsulant layer 40 is formed over LEDs 28-1 and second face 32 "of substrate 32. In certain embodiments, portions of the encapsulant layer 40 form the primary emission surface 52 of the LED package 70. As previously described, the encapsulant layer 40 may include a black material to provide improved contrast between the LEDs 28-1 and other LEDs that may be mounted in the LED package 70. In certain embodiments, another layer or extension of the encapsulant layer 40 may extend over the LED 28-1 to provide an encapsulant for the LED 28-1. In such embodiments, another layer or extension of the encapsulant layer 40 over the LEDs 28-1 may include a light transmissive material, additional layers, or texturing. An additional encapsulant layer 46 may be formed on the first side 32' of the substrate 32 to provide a hermetic seal to the active electrical elements 30. In this regard, the additional sealant layer 46 may or may not extend over the entire first side 32' of the substrate 32. Notably, as previously described, the portions of additional conductive traces 71-2 not covered by additional encapsulant layer 46 may form package bond pads 48. To facilitate bonding to the outer surface, the conductive bonding material 72 may include a thickness relative to the substrate 32 that is greater than or nearly equal to the thickness of the active electrical component 30 and the additional sealing material 46. To provide electrical communication between the conductive trace 42-2 and the additional conductive trace 71-1, one or more conductive interconnects 73, such as metal patches, vias, or traces, may be provided through the substrate 32 as shown in fig. 6, or the conductive interconnects 73 may be wrapped around the side edges of the substrate 32.

Fig. 7 is a bottom view of an LED package 74 including a plurality of LED pixels according to embodiments disclosed herein. The LED package 74 is similar to the LED package 26 of fig. 2E, but includes a plurality of LED chips 75-1 to 75-3, 76-1 to 76-3, 77-1 to 77-3, 78-1 to 78-3, respectively, which form a plurality of LED pixels spaced apart from each other and packaged together in the same LED package 74. As shown, LED chips 75-1 through 75-3 form a first LED pixel, LED chips 76-1 through 76-3 form a second LED pixel, LED chips 77-1 through 77-3 form a third LED pixel, and LED chips 78-1 through 78-3 form a fourth LED pixel. In certain embodiments, each LED pixel includes a red LED chip, a blue LED chip, and a green LED chip. The LED package 74 further includes an active electrical element 30' configured to electrically connect with the plurality of pixels, the plurality of conductive traces 42-1 through 42-16, and the plurality of package bond pads 48-1 through 48-4 as previously described. Notably, the LED package 74 may be configured with the same number of package bond pads 48-1 through 48-4 as previously described for a single pixel LED package (e.g., LED package 26 of fig. 2H). As shown, LED package 74 includes four package bond pads 48-1 to 48-4 configured to receive various combinations of input signals or connections, such as a supply voltage (Vdd), ground (Vss), a color selection signal, a brightness level (or grayscale) signal, an analog signal, an encoded color selection signal, an encoded brightness level selection signal, a digital signal, a clock signal, and an asynchronous data signal, as will be described in more detail later. Thus, the active electrical component 30' includes four input/output and power connections; however, as will be described later, the active electrical element 30' is configured to independently change the driving conditions of each of the plurality of LED chips 75-1 to 75-3, 76-1 to 76-3, 77-1 to 77-3, 78-1 to 78-3. Notably, the conductive trace 42-1 may be electrically connected to the anode of each of the LED chips 75-1 through 75-3, 76-1 through 76-3, 77-1 through 77-3, and 78-1 through 78-3 for common anode control. Conductive trace 42-1 is also electrically connected between package bond pad 48-1 and active electrical component 30'. Conductive trace 42-2 is electrically connected between package bond pad 48-4 and active electrical component 30', conductive trace 42-9 is electrically connected between package bond pad 48-3 and active electrical component 30', and conductive trace 42-10 is electrically connected between package bond pad 48-2 and active electrical component 30 '. In other embodiments, the LED packages 74 may be configured for common cathode control as previously described. To provide electrical communication with an increased number of LED pixels within the LED package 74, the active electrical element 30' may include an increased number of contact pads 38 for communicating with an increased number of conductive traces 42-1 through 42-16. As described above, four contact pads 38 are electrically connected to package bond pads 48-1 to 48-4, and the remaining contact pads 38 are electrically connected to different ones of LED chips 75-1 to 75-3, 76-1 to 76-3, 77-1 to 77-3, and 78-1 to 78-3. In order for the LED package 74 to control a plurality of LED pixels with a reduced number of input signal connections, the active electrical element 30 may include circuitry configured to receive the input communication signal and perform a sub-pixel selection function to independently communicate the operating state individually to each LED chip 75-1 to 75-3, 76-1 to 76-3, 77-1 to 77-3, and 78-1 to 78-3 of each LED pixel. In this regard, when a plurality of LED packages 74 are arranged together to form an array of LED pixels for display applications, the resulting display will have a reduced number of LED packages 74 as compared to a similarly sized display in which each LED package includes only a single LED pixel. In this regard, the total number of communication signals between the external source (e.g., control element 18 of fig. 1B) and the LED pixels may be reduced. As with the single pixel embodiment (e.g., fig. 2E), an almost limitless combination of routes for communication signals is within the scope of the present disclosure, including a simple variation in which one or more metal traces are configured along the same plane as previously described with respect to fig. 3A and 3B.

Fig. 8 is a block diagram schematically illustrating components of the active electrical element 30 (or the active electrical element 30' of fig. 7) according to embodiments disclosed herein. As previously described, active electrical elements 30 may be incorporated into LED packages to enable active matrix addressing for corresponding LED displays. The active electrical element 30 is configured to receive an input signal from an external source (e.g., the control element 18 of fig. 1B) and independently maintain and/or change the driving conditions of one or more LEDs within the LED package. As will be described in more detail later, the input signal may comprise a single communication line or multiple communication lines in analog, digital, or a combination of analog and digital formats. In certain embodiments, the active electrical component 30 includes a memory component 80, which may include one or more of volatile and non-volatile memory components. The memory elements 80 may include one or more of bipolar transistors, field effect transistors, inverters, logic gates, Dynamic Random Access Memory (DRAM), Static Random Access Memory (SRAM), Programmable Read Only Memory (PROM), Erasable Programmable Read Only Memory (EPROM), Electrically Erasable Programmable Read Only Memory (EEPROM), flash memory, operational amplifiers, capacitors, lookup tables, and the like. In some embodiments, the memory element 80 includes at least one of a sample and hold circuit, a latch circuit, and a flip-flop circuit. In certain embodiments, the memory element 80 comprises a volatile memory element configured to store the operating state of one or more LEDs based on an input signal. In operation, whenever the active electrical element 30 receives an updated input signal, the volatile memory element is updated to a new operating state for the one or more LEDs, and the one or more LEDs are activated and maintained accordingly according to the new operating state. In this regard, the volatile memory element may be configured to store the temporarily stored operating state, and the active electrical element 30 is thereby configured to change the driving conditions of the one or more LEDs in accordance with the temporarily stored operating state. In some embodiments, the volatile memory element may additionally be configured to store other states or conditions that may not be considered temporary, such as a calibration factor, or an electronic transfer function such as gain. In this regard, one or more of the temporary operating state and the non-temporary state or condition may be used together to generate a driving condition for one or more LEDs. In certain embodiments, the memory element 80 comprises a non-volatile memory element configured to store preset data or information that may also be used to change the operating state of one or more LEDs. A non-volatile memory element (e.g., a look-up table or a hash table) may be provided to change the operating state based on the operating conditions or environment of the LED package. For example, a thermal management element as shown in fig. 8 may be incorporated within the active electrical element 30, which monitors the operating temperature of the LED package, and may adjust the operating state of one or more LEDs based on a comparison of the operating temperature to a value stored by the non-volatile memory element accordingly. In certain embodiments, the thermal management element includes a temperature sensor or a temperature sensor input from an external temperature sensor. In other embodiments, ambient light level information from the light sensor may be compared to values stored in the non-volatile memory element to change the brightness level of one or more LEDs. In further embodiments, the non-volatile memory element can be programmed to store position setting data for the LEDs or LED pixels of the display, including predetermined position setting data or later programmed position setting data. The position settings may be programmed before or after the LED display is installed. The positional arrangement may include positional arrangements for individual LED chips, individual LED packages comprising LED pixels, and individual LED panels that may collectively form an LED display. In this regard, a common control line may be connected to more than one LED, LED pixel, or LED package, and the positional settings may be used to interpret the input signal and drive only the intended LEDs connected by the common control line.

The active electrical element 30 may additionally include one or more ESD protection elements configured between the input signal and other components within the active electrical element 30. In certain embodiments, a decoder or control logic element is provided within the active electrical element 30 to receive one or more input signals and convert them into a unique combination of output signals that in turn are used to change the different operating states of one or more LEDs. In particular, the decoder or control logic element may output a combination of output signals that may be stored and periodically updated in the volatile memory element. The operating state of one or more LEDs is changed or updated by the driver element 82 each time the volatile memory element is updated. In some embodiments, the decoder element is configured to provide row or column selection information for one or more LEDs, or to provide brightness or gray scale for each LED. For LED package configurations including multiple LED pixels, the decoder element may be configured to provide pixel or sub-pixel selection within the LED package to the memory element 80. The decoder element may be configured to provide programming, set point information, or calibration information to the memory element 80. In some embodiments, the decoder element may be configured to select certain pixels of the shared control lines by decoding predetermined location settings of the certain pixels on the shared control lines so that only certain pixels will respond to the control signals. The predetermined location setting may be programmed and stored in a memory element 80, such as a non-volatile memory element. In some embodiments, the driver elements 82 (or buffer elements) include source driver elements, sink driver elements, or both source and sink driver elements. The source driver element is typically used when the LEDs are configured for common cathode control, while the sink driver is typically used when the LEDs are configured for common anode control. In some embodiments, the source driver and the sink driver may be included within the active electrical element 30, and thus, the source driver and the sink driver may be configured to provide a differential voltage output to control the one or more LEDs. In some embodiments, the active electrical element 30 may also include one or more signal conditioning elements configured to convert, manipulate, or otherwise transform the control signals before they are received by the source driver or sink driver. The signal conditioning element may be configured to transform an analog signal or a digital signal for applications such as gamma correction, or to apply other non-linear transfer functions. In some embodiments, the decoder/control logic communicates directly with the signal conditioning elements, while in other embodiments, the decoder/control logic undertakes the tasks or functions of the signal conditioning elements in the digital domain. In such an embodiment, the signal conditioning element may simply comprise wiring when the decoder/control logic assumes the role. The signal conditioning element may be configured or electrically connected between the memory element 80 and the driver element 82 such that signals exiting the memory element 80 may be switched or manipulated before reaching the driver element 82. The signal conditioning element may be configured or electrically connected between the input signal and the memory element 80 such that the input signal may be converted or manipulated before reaching the memory element 80. Since the division of the various elements of the active electrical element 30 may be made in other ways, various other arrangements are contemplated. For example, the decoder/control logic along with the signal conditioning and memory elements may be considered a single processor unit. Further, depending on the particular application, the active electrical elements 30 may include multiple ESD elements, and/or multiple decoder/control logic elements, and/or multiple memory elements 80, and/or multiple signal conditioning elements, and/or multiple thermal management elements and/or multiple driver elements 82. Each of the decoder/control logic elements, memory elements 80, signal conditioning elements, thermal management elements and driver elements may be configured as analog elements, digital elements, and combinations of analog and digital elements, including software and firmware, etc.

Fig. 9 is a block diagram schematically illustrating components of an active electrical element 30 according to embodiments disclosed herein. In fig. 9, the active electrical element 30 may include many of the same components as previously described with respect to fig. 8, including ESD protection elements, decoder/control logic, volatile memory elements, non-volatile memory elements, and thermal management elements. As further shown in FIG. 9, for each LED (LED 1-LED 3), a volatile memory cellThe output of the element may be split into individual signal lines 84-1 to 84-3. Each individual signal line 84-1 to 84-3 may include a different one of the signal conditioning elements, source driver elements, and sink driver elements described previously. In this regard, each LED (LED 1-LED 3) may be independently driven and varied based on one or more control signals into the active electrical element 30. Furthermore, in the case of different colored LEDs, it may be necessary to configure the different LEDs at different supply lines or supply voltage inputs V₁、V₂The above. For example, red LEDs typically have a lower turn-on or forward voltage (e.g., 1.8-2.4 volts (V)) compared to blue or green LEDs (e.g., 3-3.3V) due to the lower bandgap of the different material systems typically used to form red LEDs (e.g., GaAs, AIGalnP, GaP based) compared to blue or green LEDs (e.g., GaN based). in this regard, active control element 30 may be configured with a separate connection (e.g., contact pad 38 of FIG. 2A) configured to receive a separate power line or input (e.g., V between about 1.8-2.4V) for red LEDs ₁) And a common power line or input for both the blue and green LEDs (e.g., V between about 3-3.3V₂)。

In addition to various digital memory elements, analog memory elements may also be used. FIG. 10 is a schematic diagram illustrating an example structure including an analog volatile memory element that can be included within an active electrical element according to embodiments disclosed herein. In fig. 10, an exemplary sample and hold circuit 86 is shown that includes a switching device 88, a capacitor 90, an operational amplifier 92, and an optional operational amplifier buffer 94 between the input and the capacitor 90. To sample the input signal, the switching device 88 connects the input signal to the capacitor 90 through the operational amplifier buffer 94, and the capacitor 90 stores a charge. After sampling the input signal, the switching device 88 turns off the capacitor 90 and the stored charge of the capacitor 90 is discharged through the operational amplifier 92 to provide an operating state for the particular LED that remains until the input signal is sampled again. In this manner, the optional operational amplifier buffer 94 and switching device 88 may be considered components of the decoder/control logic (fig. 8 and 9), the capacitor 90 may be considered a component of the memory element (fig. 8 and 9), and the operational amplifier 92 may be considered a component of the signal conditioning element (fig. 8 and 9), which may be linear or non-linear, depending on the system configuration.

Fig. 11A-11F are schematic diagrams illustrating exemplary structures of driver elements that may be included within active electrical elements according to embodiments disclosed herein. For video display applications, it may be desirable for the driver element to include a non-inverting circuit configured to drive each LED in a linear fashion from a fully off state of about 0 microamperes (uA) or about 0V to a low power consumption of about 1 milliamp (mA) or about 3V. Fig. 11A shows an embodiment in which the driver element 96 comprises a voltage controlled current source circuit (e.g., a transconductance amplifier). For a transconductance amplifier, a differential input voltage is converted to an output current to drive an LED. In the simplified schematic of fig. 11A, the driver element 96 includes a non-inverting circuit, but the driver element 96 needs to be connected to both terminals of the LED for operation, resulting in a more complex device layout. Therefore, the driver element 96 is not a sink driver element for common anode control or a source driver element for common cathode control. In addition, a resistor R₁It needs to be so large as to reduce the input voltage sensitivity, which reduces the efficiency of the driver element 96. Furthermore, when the LED needs to be turned off, the output current may be difficult to reach a sufficiently low value (0uA) to achieve the turn-off. Fig. 11B shows an embodiment in which the driver element 98 comprises a transconductance amplifier arranged with an active cascode configuration comprising a transistor, e.g. a Metal Oxide Semiconductor Field Effect Transistor (MOSFET) M ₁And an additional resistor R₂Which may facilitate complete turn-off of the LED. As previously described with respect to fig. 11A, the voltage sensitivity of the driver element 98 may be too high. When the LED is fully on, or about 1mA, the driver element 98 may result in a low voltage input, for example about 0.05V, and therefore, the active cascode configuration may experience an undesirable signal-to-noise ratio.

FIG. 11C shows drivingAn embodiment of the device element 100, a driver element that adds an input amplifier to the driver element 98, the driver element comprising a transconductance amplifier having the active cascode configuration of fig. 11B. The added input amplifier can be used to de-amplify the voltage to achieve lower signal sensitivity and provide improved signal-to-noise ratio. Further, the driver element 100 provides a drain (sinking) or common anode configuration for the LED; however, the input voltage becomes inverted. Fig. 11D shows an embodiment of the driver element 102, which is similar to the embodiment of fig. 11C, but with reversed polarity connections. In this regard, the driver element 102 includes an input amplifier between the input voltage and the driver element 98', the driver element 98' being an inverted polarity version of the driver element 98 that includes a transconductance amplifier having the active cascode configuration of fig. 11B. As shown, the driver element 102 represented in fig. 11D provides the advantage of non-inversion; however, it does result in a source or common cathode configuration for the LED. Other driver element arrangements are possible, such as the Howland current pump configurations 104, 106 shown in fig. 11E and 11F. In fig. 11E, the Howland current pump 104 includes an operational amplifier and a resistor bridge configured to drive the LEDs. In FIG. 11F, the Howland current pump 106 additionally includes a voltage divider comprising a resistor R ₅And R₆Added to the Howland current pump 104 of fig. 11E to improve performance when little to no current flows. In addition, an additional operational amplifier is provided at the voltage input to form a non-inverting voltage follower (e.g., a preamplifier) to provide the high input resistance required for the output buffer of the sample and hold circuit to ensure adequate hold time.

When a plurality of LED packages as disclosed herein are arranged to form an array of LED pixels for LED display applications, it may be advantageous if the location of each individual LED package within its respective active electrical element is known, or each LED package has a specific address associated with it. In certain embodiments, each active electrical element within each LED package is configured to store location or address specific information, such as the particular row and column in which the LED package is recorded. In this regard, the display control unit may send signals across the LED pixel array that are encoded for particular locations within the LED pixel array, and each active electrical element of each individual LED package is thereby configured to interpret the signals and determine whether to respond or ignore the particular signals based on the location or address information. In certain embodiments, the active electrical element of each LED package includes a detector element configured to detect the position of the LED package in the array of LED packages in the display and, in cooperation with a master controller (e.g., control element 18 of fig. 1B and other hardware/software configurations), relay this information for storage in a memory within the active electrical element. This task may be performed after PCB assembly, when a specific configuration program is run to properly set and store the address and calibration information into the non-volatile memory of the active electrical component, into one or more remote memory devices, or both.

Fig. 12A is a block diagram schematically illustrating an embodiment of an active electrical element 30 comprising a detector/signal conditioning element. As previously described, the active electrical element 30 may be incorporated into an LED package to achieve an LED display configured for active matrix addressing. The active electrical element 30 is configured to receive an input signal from an external source (e.g., the control element 18 of fig. 1B) and independently vary the driving conditions of one or more LEDs within the LED package. The block diagram of fig. 12A is similar to that of fig. 8 and includes a memory element 80 and a driver element 82 as previously described. As shown, ESD protection elements, decoder/control logic elements, thermal management elements, and signal conditioning elements may also be included, as previously described. In certain embodiments, one or more LEDs may be used as light detectors to generate signals that are received by the detector/signal conditioning element. For example, after multiple LED packages are mounted in an LED pixel array, all LED packages connected to a common data bus may lack a single unique address. In this regard, an initial setup process (or position setup process) may be performed in which each LED package may be scanned with a light beam, and at least one LED within each LED package may function as a photodiode that provides a corresponding voltage and/or current signal corresponding to a particular position of the LED package. In this way, during the initial setup process, at least one of the LEDs may be operated in a photovoltaic mode or a light guide mode. The signal generated by the light beam is used in conjunction with an electrical signal provided from a master controller (e.g., control element 18 of fig. 1B and other hardware/software configurations) over a data bus to cause the component to record its address. When the encoded signal for each pixel location is sent across the LED pixel array, each LED package can thus be configured to know which signal the LED package should respond to. For such embodiments, the LED driver element 82 may be configured with a high impedance output to support the photodetector mode of one or more LEDs during the initial setup process. In some embodiments, the detector/signal conditioning element may include a voltage detector, a current sensor, or even wiring that conveys the position signal to a decoder/control logic element. In this way, the active electrical element 30 may be configured to be addressed and the operating state of the at least one LED may be changed in a manner dependent on information such as an address stored in the local memory. In some embodiments, a separate photodiode that is not one of the LEDs within the LED package may be configured within the LED package to provide a position signal to the active electrical element 30. In certain embodiments, the detector/signal conditioning element may be configured to monitor the operating voltage or current of the LED and store such information in the memory element. In this regard, the active electrical element 30 is configured to store monitoring information including operating temperature from the thermal management element, location information, or voltage or current information from the LEDs via the detector/signal conditioning element. In certain embodiments, the active electrical element 30 may be configured to communicate such monitoring information with an external source (e.g., the control element 18 of fig. 1B or a separate device) such that the LED display may be configured to self-monitor various operating conditions and generate a report or visual indication if any of the monitored operating conditions are outside of the target window. In this regard, the active electrical element 30 may be configured for bidirectional communication with an external source.

Fig. 12B is a bottom view of an LED package 108 including a photodiode 110 according to embodiments disclosed herein. The LED package 108 is similar to the LED package 74 of fig. 7 and includes a plurality of LED chips 75-1 to 75-3, 76-1 to 76-3, 77-1 to 77-3, 78-1 to 78-3, which respectively form a plurality of LED pixels and an active electrical element 30' as previously described. The LED package 108 may also include package bond pads 48-1 through 48-4 and conductive traces (42-1 through 42-16 of FIG. 7). As shown, the LED package 108 includes a photodiode 110 configured to detect and transmit optical signals to other components of the active electrical element 30' as described in fig. 12A. In certain embodiments, the active electrical component 30' includes a photodiode 110. In certain embodiments, the photodiode 110 is disposed on the active electrical component 30. In other embodiments, the photodiode 110 is disposed outside of the active electrical component 30'. For example, in some embodiments, the LED package 108 includes a black encapsulant covering the LED package 108 except for the regions where each of the LED chips 75-1 to 75-3, 76-1 to 76-3, 77-1 to 77-3, and 78-1 to 78-3 is registered. In this regard, the photodiode 110 may be disposed adjacent to one of the LED chips 75-1 to 75-3, 76-1 to 76-3, 77-1 to 77-3, and 78-1 to 78-3 such that a sufficient amount of optical signal may reach the photodiode 110 without being absorbed by the black encapsulant. In other embodiments, the photodiode may be incorporated within other LED packages, including the LED package 26 of fig. 2H, the LED package 58 of fig. 3A, the LED package 66 of fig. 4, the LED package 68 of fig. 5, the LED package 70 of fig. 6, and so forth. As previously described, the photodiode 110 may be omitted in some embodiments, and one or more of the LED chips 75-1 through 75-3, 76-1 through 76-3, 77-1 through 77-3, and 78-1 through 78-3 may be used as a photodiode when scanning with a light beam during initial setup.

FIG. 13 is a block diagram that schematically illustrates various components that may be included in a system level control scheme for an LED display panel, in accordance with embodiments disclosed herein. In some embodiments, the components of the system level control scheme may be included on the back of the display panel, as previously shown in FIG. 1B. In operation, the LED display panel receives an input signal from an external video source. As previously mentioned, video sources such as VGA, DVI, HDMI, HUB75, USB, etc. are provided through appropriate electrical connectors. A signal decoder, such as a DVI/HDMI decoder, may be configured to provide conversion of the input signal to other formats, such as 24-bit transistor-to-transistor logic (TTL) or Complementary Metal Oxide Semiconductor (CMOS) color pixel data. For example, the signal decoder may convert the input signal into a 24-wire data bus along with other control signals, such as pixel clock, vertical synchronization, and horizontal synchronization, which are then routed to the control elements. As previously mentioned, the control elements may include one or more of an ASIC, a microcontroller, a programmable control element, and a field programmable gate array FPGA. For example, the control element may include an FPGA programmed to scale, offset, or otherwise transform the converted data from the signal decoder and provide data buffering for the control lines that ultimately deliver the various signals to the LED packages and the corresponding LED pixels of the LED display panel. In some embodiments, the control element is further configured to receive an additional input for transforming the input signal. For example, additional inputs may include horizontal and vertical panel position information for an LED display panel within a larger LED display. When multiple LED display panels are assembled together to form a larger LED display, each LED display panel may be configured with a unique location identifier that is relayed to the control element. The unique identifier may be pre-assigned before or during installation, such as a serial number or location coordinates, or may simply be assigned according to the order in which they are connected when the LED display panel is assembled. In the latter configuration, each LED display panel may be configured to communicate with each other via a shift register or the like such that during installation, as the LED display panels are arranged adjacent to each other in a daisy-chain configuration, the positional information is relayed from one LED display panel to the next in the installation order in a manner similar to a HUB75 compatible panel. The additional inputs may also include calibration tables, such as hash tables, that provide information so that the control element can transform the input signal in a manner that compensates for any non-uniform performance characteristics between the LED chips of the LED display panel. For example, after assembling the LED display panel, the intensity of each LED pixel may be measured, and the calibration table may then be configured to provide information to the control element to scale the drive signal differently based on the initial measured brightness levels of the different LED pixels.

Thus, the control element may be configured to receive the input signal and additional input including panel position or calibration information via the signal decoder. As previously mentioned, the control element may comprise one or more integrated circuits of various types. In certain embodiments, the control element comprises an ASIC preconfigured for application in an LED display panel. In other embodiments, the control element comprises an FPGA that provides the ability to be programmed and reprogrammed after installation. Therefore, other support devices are implied, such as power inputs and regulators, programming interfaces, volatile and non-volatile memory elements, and so forth. The control element is configured to process the input signal and any additional input and output control signals sent to the active electrical elements of each LED pixel. In some embodiments, the plurality of DACs may be arranged to convert signals from the control element before routing the signals to the LED pixels. The control element may also be configured to output column, row and LED color selection information to the LED pixels that determines when each LED pixel and each LED chip within each LED pixel responds to control signals from the plurality of DACs. In some embodiments, one or more column, row, or color selection decoders may be configured to receive and transform the output column, row, and/or LED color selection information from the control element before routing to the LED pixels. For example, the control element may comprise an FPGA that outputs digital signal codes of 0 and 1 for column, row or color selection information. In turn, a column, row, or color selection decoder may be configured to receive and decode the digital signal so that the active control element of a particular LED pixel within the LED display panel may be activated.

For display applications, an LED display panel may include a plurality of LED packages arranged in columns and rows to form an LED pixel array. Each LED package may include one or more LED pixels including a first LED chip (e.g., a red LED chip), a second LED chip (e.g., a blue LED chip), and a third LED chip (e.g., a green LED chip) and an active electrical element as previously described. The number of control lines and the number of row, column, color selection lines connected between the control element and each LED package may vary according to the driving configuration between the control element and the LED package.

Fig. 14 is a schematic diagram showing a configuration in which an active electrical element 30 corresponding to a specific LED pixel is configured to receive a row selection signal line and individual control signals for each of red, green, and blue LED chips included in the LED pixel. In this regard, a row select signal activates each active electrical element 30 of a particular row of LED pixels, and each column of LED pixels is configured to receive three separate control signals for each of the red, green, and blue LED chips. The three separate control signals may correspond to three separate DACs per column, or analog control signals. The control signals may control the brightness level or gray scale of each of the red, green, and blue LED chips within a particular LED pixel. Thus, when a control signal is passed along a particular column, the row select signal determines which LED pixel responds to the signal. As previously described, the active electrical element 30 corresponding to each LED pixel is configured to store red, green and blue level signal information and drive the LED chip accordingly in a constant manner until the next time the active electrical element 30 is activated to refresh or update the signal information. Thus, for the configuration of fig. 14, in addition to ground and voltage input connections, the active electrical element 30 is configured with connections to receive four different signal lines (row select, red level, green color level, blue level). Thus, this configuration requires at least six connections, increasing PCB path complexity. In some embodiments, it may be desirable to have fewer connections, such as the 4-connection embodiment shown in the previous embodiments (e.g., fig. 2E).

Fig. 15 is a schematic diagram showing a configuration in which an active electrical element 30 corresponding to a particular LED pixel is configured to receive a separate row select signal line for each LED chip of the LED pixel and a single color level signal line for all LED chips within the LED pixel. In fig. 15, three separate row select signals (red row select, green row select, blue row select) activate each of the red, green, blue LED chips within the LED pixel, respectively. Thus, a single color level (e.g., brightness level or gray scale) may be provided for each of the red, green, and blue LED chips within an LED pixel. In this regard, each column may be configured with a single DAC as previously described. In other embodiments, the active electrical element 30 may be configured to receive selectable column select lines, thereby allowing a single DAC to provide color level signals to a plurality of columns of LED pixels. In operation, a particular row select signal activates a particular LED chip in response to a color level signal at a particular time. As with the previous embodiment, the active electrical element 30 is configured to store color level signal information and drive each LED chip accordingly until the next time the active electrical element 30 is activated to refresh or update the color level information. Thus, for the configuration of FIG. 15, in addition to ground and voltage input connections, the active electrical element 30 is configured with connections to receive four to five different signal lines (red row select, blue row select, green row select, color rank select, and select column select). While overall system complexity is reduced by reducing the DAC, for some applications, it may be undesirable to require at least six connections.

Fig. 16 is a schematic diagram showing a configuration in which the active electrical element 30 corresponding to a particular LED pixel is configured to receive an encoded row selection signal for each LED chip of the LED pixel and a single color level signal line for all the LED chips within the LED pixel. In FIG. 16, the color rank and optional column select lines may be configured the same as previously described for FIG. 15; however, the row select signal is reduced to two row select lines (row select RS0, row select RS 1). In this regard, the row select lines are configured to provide a coded digital signal (combination of 0 and 1) that determines which LED chip should respond to a particular color level signal. As a non-limiting example, two row select lines may provide a "00" digital signal corresponding to an operating state to which no LED chip should respond, a "01" digital signal corresponding to activation of a red LED chip, a "10" signal corresponding to activation of a blue LED chip, and an "11" signal corresponding to activation of a green LED chip. As with the previous embodiment, the active electrical element 30 is configured to store color level signal information and drive each LED chip in a constant manner accordingly until the next time the active electrical element 30 is activated to refresh or update the color level information. Thus, for the configuration of fig. 16, in addition to ground and voltage input connections, the active electrical element 30 is configured with connections to receive three to four different signal lines (row select RS0, row select RS1, color rank, and optional column select). Thus, the reduction of at least one connection represents an improvement in the reduction of PCB complexity compared to the embodiments of fig. 14 and 15.

Fig. 17 is a schematic diagram showing a configuration in which the active electrical element 30 of a particular LED pixel is configured to receive row selection signals, color level signals, and one or more color selection signals for the red, green, and blue LED chips included in the LED pixel. In fig. 17, the row selection signal is configured to be the same as the configuration of fig. 14; however, the signal of the color level (e.g., brightness or gray level) of each LED chip is controlled by a single signal line. In this regard, each column may be configured with a single DAC as previously described. In other embodiments, a single DAC may be configured to provide signals regarding color levels to a plurality of columns of LED pixels. To determine which LED chip within an LED pixel should respond to a particular color level signal, two color select lines (color select 0, color select 1) are configured to provide a coded digital signal (combination of 0 and 1) that determines which LED chip should respond to the particular color level signal. As a non-limiting example, two color select lines may provide a "00" digital signal corresponding to an operating state to which no LED chip should respond, a "01" digital signal corresponding to activation of a red LED chip, a "10" signal corresponding to activation of a blue LED chip, and a "11" signal corresponding to activation of a green LED chip. Thus, for the configuration of fig. 17, in addition to ground and voltage input connections, the active electrical element 30 is configured with connections to receive four different signal lines (row select, color level, color select 0, color select 1).

Fig. 18 is a schematic diagram showing a configuration similar to that of fig. 16 and 17. Specifically, fig. 18 represents an independent symbol configuration that may represent either of the configurations of fig. 16 or 17. In fig. 18, the active electric element 30 includes the same color gradation lines as those in fig. 16 and 17. The active electrical element 30 of fig. 18 additionally includes a Device Select (DS) line and two color select lines (CS0 and CS 1). The DS line is configured to provide a device selection signal, which may include at least one of a row selection signal and a column selection signal. The CS0 and CS1 lines are configured to provide encoding signals that may correspond to the row select RS0 and row select RS1 lines of fig. 16 or the color select 0 and color select 1 lines of fig. 17. In this regard, the active electrical component 30 may be configured to control a number of operating conditions with a small number of connections. The DS lines correspond to the column select lines of FIG. 16 or the row select lines of FIG. 17.

Fig. 19 is a schematic diagram showing a configuration in which an active electrical element 30 corresponding to a particular LED pixel is configured to receive a single row selection signal line and a single color level signal line for all LED chips of the LED pixel. In FIG. 19, the color rank and optional column select lines may be configured the same as previously described for FIG. 15; however, the row selection signals are combined into signal row selection lines. In this regard, a single row select line may be configured to transmit a coded signal that individually corresponds to each LED chip within an LED pixel. The encoded signal may comprise an analog signal comprising at least one of a variable amplitude signal, a variable frequency signal, or a variable phase signal. The encoded signal may also comprise a multiplexed or multilevel logic signal. In some embodiments, the row select lines may be configured to provide signals having different voltage states corresponding to different LED chips. For example, the row select line may be configured as a four-level signal line, where each of the four signal levels corresponds to one of the following operating conditions: unselected LED chips, selected red LEDs, selected blue LEDs, and selected green LEDs. In some embodiments, additional active electrical components may be provided to further facilitate processing of the four-level signal lines. Additional active electrical components may be disposed within or separate from each LED package. As with the previous embodiment, the active electrical element 30 is configured to store color level signal information and drive each LED chip in a constant manner accordingly until the next time the active electrical element 30 is activated to refresh or update the color level information. Thus, for the configuration of fig. 19, in addition to ground and voltage input connections, the active electrical element 30 is configured with connections to receive two to three different signal lines (row select (multi-level), color rank, and option select). This configuration is desirable for applications with reduced complexity, such as the 4-connection configuration previously described (e.g., fig. 2E).

Fig. 20 is a schematic diagram showing a configuration in which an active electrical element 30 corresponding to a particular LED pixel is configured to receive a single row selection signal line and a single color level signal line for all LED chips of the LED pixel. FIG. 20 is similar to the configuration of FIG. 19 and includes color levels and optional column select lines as previously described. In fig. 20, the row select signal line may be configured to transmit an encoded signal, e.g., an asynchronous encoded digital signal, a portion of which corresponds to each LED chip within an LED pixel, respectively. In certain embodiments, the encoded signal includes different pulses corresponding to each of a red LED select, a blue LED select, a green LED select, and a no LED select operating condition. Other operating states may also be addressed by extending the coding scheme. In this manner, the active electrical element 30 may include a shift register that cycles through each operating state (e.g., no select, red select, blue select, green select) in turn with each pulse of the encoded signal. To prevent the shift registers from being unsynchronized, the encoding signal may also include a pulse code at the end of each cycle to reset the shift registers to the beginning of the next cycle. In addition to sequential pulses, the row select lines may include other coded signals that identify and correspond to different ones of the four or more operating states described above. Thus, for the configuration of fig. 20, in addition to ground and voltage input connections, the active electrical element 30 is configured with connections (e.g., contact pads 38 of fig. 2A) to receive two to three different signal lines (row select (encode), color level, and optional column select). As with the configuration of fig. 19, the configuration of fig. 20 is desirable for applications with reduced complexity, such as the 4-connection configuration previously described (e.g., fig. 2E).

FIG. 21 is a block diagram schematically illustrating a system level control scheme for the LED display panel in which each active electrical element of the LED pixel array is configured to receive a signal line, according to the embodiment of FIG. 20. In fig. 21, input signals, signal decoders, control elements, row/column decoders, panel position input, calibration table input, and multiple DACs may be provided, as previously described with respect to fig. 13. In fig. 21, the column select lines are not included, and the optional DAC decoder elements are arranged to allow selection of the appropriate DAC elements to receive data provided by the common data bus. In other embodiments, the control element may be configured to include DAC decoding capabilities, and thus, a DAC decoder element may not be required. Depending on the number of output pins available on a particular FPGA or other control element, a separate row/color decoder may also not be required.

Fig. 22 is a partial plan view showing a path configuration of the LED panel 112 configured to operate according to the configuration of fig. 20 and 21. In fig. 22, a plurality of LED packages 26 are arranged in rows and columns to form an LED pixel array. Each LED package 26 may include a plurality of LEDs (e.g., 28-1 through 28-3 of fig. 2), an active electrical element (30 of fig. 2), and a plurality of package bond pads 48-1 through 48-4 forming an LED pixel as previously described. As shown in fig. 22, the plurality of LED packages 26 are connected to a plurality of color gradation control lines 114-1 to 114-4 corresponding to the color gradation selection lines of fig. 20 and a plurality of row selection control lines 116-1 to 116-3 corresponding to the row selection lines of fig. 20. For the LED package 26 labeled in FIG. 22, package bond pad 48-1 is connected to color level control line 114-1 and package bond pad 48-3 is connected to row select control line 116-3. Package bond pad 48-2 is connected to a voltage input line 118-1 of the plurality of voltage input lines 118-1 through 118-4, and package bond pad 48-4 is connected to a ground plane (not shown). In some embodiments, the plurality of color-level control lines 114-1 through 114-4 and the plurality of row select control lines 116-1 through 116-3 may be arranged on different levels or planes of the multi-layered connector interface with one or more dielectric layers arranged between the multi-layered connector interface for electrical isolation. For example, the row select control lines 116-1 to 116-3 may be arranged along a first plane closest to the plurality of LED packages 26. The plurality of color gradation control lines 114-1 to 114-4 and the plurality of voltage input lines 118-1 to 118-4 may be arranged along different planes at a greater distance from the plurality of LED packages 26. Finally, a ground connection plane (not shown) may be disposed along a different plane that is further from the plurality of LED packages 26 than the plurality of color-level control lines 114-1 through 114-4 and the plurality of voltage input lines 118-1 through 118-4. A plurality of vias 120 may be disposed through the multilayer connector interface to provide corresponding connections to package bond pads 48-1 to 48-4. Fig. 22 shows only one of many configurations of path configurations for the LED panel 112. In other embodiments, the various lines 114-1 through 114-4, 116-1 through 116-3, and 118-1 through 118-4 may be provided in different arrangements in vertical and horizontal configurations, including but not limited to all vertical and all horizontal configurations.

Fig. 23 is a schematic diagram representing a configuration in which the active electrical elements 30 corresponding to a particular LED pixel are configured to receive all-digital communication of row, column and/or color selection signals. Further, two-way communication may be achieved through one of many standard or custom protocols. Thus, many additional tasks are enabled, such as communication handshaking, addressing, status reporting, and a broader command structure. In other words, the active electrical element includes a serial communication element. In this manner, the serial input/output lines are configured to provide digital signals to the active electrical elements 30 in accordance with one of a variety of serial communication link techniques. Serial communication techniques typically involve sending or streaming data in a single bit order over time. An optional clock input may be configured to receive a clock signal that provides cycle information for the LED pixels. In some embodiments, serial communication (e.g., transmission or reception) may include a high ratio with differential signalingFeatures including, but not limited to, Low Voltage Differential Signaling (LVDS), transition minimum differential signaling (TDMS), Current Mode Logic (CML), and Source Coupled Logic (SCL). In this regard, the active electrical component 30 may be configured to receive a selectable differential input/output line and a selectable clock differential input/output line. Some serial communication technologies may be configured with a self-clocking configuration or a configuration for receiving a self-clocking signal and, therefore, may not require a clock input. Such a self-clocking configuration may include decoder elements within the active electrical elements that include various decoding capabilities for clock recovery, such as 8b/10b encoding, manchester encoding, phase encoding, pulse counting with or without timing reset, isochronous signal encoding or non-isochronous signal encoding. Other communication techniques may include inter-integrated circuit (I) ²C) Protocols, I3C protocol, Serial Peripheral Interface (SPI), ethernet, Fibre Channel (FC), Universal Serial Bus (USB), IEEE1394 or firewire, HyperTransport (HT), Infiniband (IB), Digital Multiplex (DMX), DC-BUS or other power line communication protocols, Avionics Digital Video BUS (ADVB), Serial input/output (SIO), Controller Area Network (CAN), ccTalk protocol, CoaXPres (CXP), Musical Instrument Digital Interface (MIDI), MIL-STD-1553, peripheral component interconnect express (PCIexpress), Fieldbus, RS-232, RS-422, RS-423, RS-485, Serial Digital Interface (SDI), Serial AT attachment (Serial ATA), Serial attached (SCSI), Synchronous Optical Network (SONET), synchronous digital hierarchy (SDFI), space line (SpaceWire), UNI/O BUS, and 1-line, and the like. For some configurations, the active control element 30 is configured to operate (e.g., transmit or receive) using at least one subset of signals compatible with one of the protocols described above, including but not limited to I²And C, protocol. When arranged for all-digital communication, the active electrical elements 30 are configured to latch input data, implement other logic, and provide color levels or gray scales to the LED pixels of the display. In certain embodiments, the active electrical elements 30 may include DAC-controlled current drivers, wherein one or more DACs are included within the active electrical elements 30, having current drive outputs. In certain embodiments, the active electrical component 30 comprises a PWM driver or current source, which Configured to independently drive each LED of the LED pixels based on a digital input signal. When the active electrical element 30 is arranged for all digital communication, the path for the LED pixel array can be simplified. In this regard, in some embodiments, each active electrical component 30 may only need to be configured to receive as few as one communication or signal line, such as the serial input/output lines shown in FIG. 23.

FIG. 24 is a block diagram schematically illustrating a system level control scheme for the LED display panel in which each active electrical element of the LED pixel array is configured to receive a signal line, according to the embodiment of FIG. 23. In fig. 24, an input signal, a signal decoder, a panel position input, and a calibration table input may be provided, as previously described with respect to fig. 13. In certain embodiments, the control element includes one or more serial communication interfaces or serial communication elements as previously described. Therefore, a DAC element is not required, thereby providing a simplified configuration compared to the block diagram of fig. 21. Depending on the number of output pins available on a particular FPGA or other control element, a separate row/color decoder may also not be required. As shown, the output of the control element may be in direct communication with the LED array, with multiple serial outputs in communication with multiple serial lines or LED strings of the LED array. In fig. 24, each LED string is shown with two columns for illustrative purposes. In practice, the LED strings may be arranged in different sizes and numbers of rows and columns, or the electrical connections of each string may not follow the rows and columns shown.

Fig. 25 is a partial plan view showing a path configuration of an LED panel configured to operate according to the configuration of fig. 23. In fig. 25, a plurality of LED packages 26 are arranged in rows and columns to form an LED pixel array. Each LED package 26 may include a plurality of LEDs (e.g., 28-1 through 28-3 of fig. 2), an active electrical element (e.g., 30 of fig. 2), and a plurality of package bond pads 48-1 through 48-4 forming an LED pixel as previously described. In this configuration, the control lines 116-1 to 116-4 correspond to the serial input/output lines, the first and second voltage input lines 118-1 to 118-4 and 120-1 to 120-4, and the illustrated ground connection lines 122-1 to 122-4 of FIG. 23. As shown, no color level control lines from the DACs (e.g., 114-1 through 114-4 of FIG. 22) are required, thereby providing a simplified PCB path configuration. In FIG. 25, the input electrical connections including the control lines 116-1 through 116-4, the voltage lines 118-1 through 118-4, 120-1 through 120-4, and the ground lines 122-1 through 122-4 are all arranged along the same plane or layer of the LED panel. This configuration provides simpler structure and manufacturing process, and reduced cost. In other embodiments, the control lines 116-1 through 116-4, the voltage lines 118-1 through 118-4, 120-1 through 120-4, and the ground lines 122-1 through 122-4 may be configured on different planes having different dielectric layers and via arrangements to form various connections to each LED package 26. In FIG. 25, the control lines 116-1 through 116-4, voltage lines 118-1 through 118-4, 120-1 through 120-4, and ground lines 122-1 through 122-4 are shown in long linear segments across the LED panel. In some embodiments, the control lines 116-1 through 116-4, the voltage lines 118-1 through 118-4, 120-1 through 120-4, and the ground lines 122-1 through 122-4 may be arranged in other configurations, such as comb-like wiring or other chained configurations that may reduce crosstalk between the various lines. In some embodiments, the control lines 116-1 through 116-4, the voltage lines 118-1 through 118-4, 120-1 through 120-4, and the ground lines 122-1 through 122-4 may not be registered with a particular row and column of the LED packages 26. For example, the control lines 116-1 to 116-4, the voltage lines 118-1 to 118-4, 120-1 to 120-4, and the ground lines 122-1 to 122-4 may be configured to connect and communicate with a subset of the LED packages 26 arranged in a block or other shape across the LED panel.

In certain embodiments, the signal communication between the control element and the LED packages of the LED display may include sending a control signal including a plurality of data packets from the control element. The specific data packet may include control information, such as color selection data and brightness level data for the individual LED packages of the array. In some embodiments, the data packets may include file sizes ranging from as low as a single bit of data to very large file sizes (e.g., large video files). Each data packet may also include a command code configured as an identifier or a series of identifiers that enable each LED package of the array to receive the command code and respond to the data packet or pass the data packet to the next LED package. In this way, the LED packages may be arranged to receive different data packets from the control signal in a cascaded manner.

Fig. 26A and 26B are schematic diagrams illustrating an arrangement of exemplary data packets 124 according to embodiments disclosed herein. The data packet 124 is included in a data stream 126 that is sent from the control element 18 to the active electrical element 30 of the LED package 26 via the control line. In certain embodiments, the data stream 126 may include a plurality of data streams, including a cascading approach in which the data stream 126 includes a plurality of sub-data streams. In certain embodiments, the LED packages 26 form one or more pixels (e.g., 12 of fig. 1A) as previously described. There may be additional LED packages disposed before or after the LED package 26 that are configured to receive the data stream 126. In this manner, the LED package 26 may receive the data packet 124 directly from the control element 18, or through another LED package disposed in the data stream 126 and between the control element 18 and the LED package 26. The data packet 124 may include an information or data portion (indicated as "data") for selecting and operating one or more LED chips of the LED package 26, including individual color selection and brightness level data for each LED chip disposed within the LED package 26. The information or data may also include setup data, calibration data, temperature compensation data, option selection data, and the like. In addition, the data packet 124 may include instructions for turning on or off one or more LED chips of the LED package 26. In certain embodiments, at least some of the information or data from the data packet 124 may be stored in a register within the LED package 26 for later use. For applications in which the LED packages 26 form one or more LED pixels including multiple LED chips (e.g., red, green, and blue LED chips), the information or data may include a subset of data corresponding to a single one of the LED chips. The data packet 124 may also include a portion that includes a command code (indicated as a "command") configured as an identifier or series of identifiers for the data packet 124 that identifies how the active electrical component 30 should respond to the data packet 124. In particular, the command code is configured to identify an action to be taken by the active electrical element 30. In certain embodiments, the action includes passing the data packet 124 through the LED package 26, or sending or retransmitting the data packet 124 through an output port of the LED package 26. In certain embodiments, the action includes performing an internal action within the LED package 26, such as driving one or more LED chips within the LED package 26 and sending a data packet 124 through the LED package 26. As used herein, internal actions on the LED package 26 may include setting or changing a persistent state for a time frame defined by the data packet 124 or any other associated data packet of a given time frame. The persistent state may include one or more of turning on or off one or more LED chips, changing a color or brightness level of an LED chip, or setting or updating calibration data, etc. In certain embodiments, the action includes driving one or more LED chips within the LED package 26 without sending the data packet 124 through the LED package 26. In some embodiments, this action includes sending the data packet 124 without performing any other action inside the LED package 26. Such an action may be based, at least in part, on one or more other data packets previously received by the LED package 26. In further embodiments, the other or second data packet received by the LED package 26 may include a second command code identifying a second action to be taken, the second action including sending the second data packet through the LED package 26. In other embodiments, the second action includes driving one or more LED chips within the LED package 26, and sending a second data packet through the LED package 26. In this manner, the packet 124 is configured with a self-identification. In certain embodiments, the data packet 124 may include information configured to provide a data handshake with another LED package in the data stream 126. The data handshaking capability may include a beginning of packet portion (indicated as "BOP") and/or an end of packet portion (indicated as "EOP") of the data packet 124 such that the LED package 26 may acknowledge receipt and/or transmission of the data packet 124. In some embodiments, the data stream 126 may include a null space portion (denoted "space") that is a period of no data or a null transmission period disposed before or after the data packet 124 in the data stream 126. The no data transfer period may be configured to control the communication speed and prevent buffer overflow of the control signal for the LED package 26. For example, if multiple LED packages 26 having different communication speeds or clock configurations are arranged to receive different data packets from the data stream 126 in a cascaded manner, data overflow may occur. Accordingly, periods of no data transfer may be provided to ensure that communications are effectively run at a controlled or slower speed to avoid or reduce buffer overflow. The no data transfer period may also be configured to signal a reset or restart condition, or to signal a next frame condition. The no data transmission period may be configured at a different location relative to the data packet 124, for example, after the data packet 124 as shown in fig. 26A, or before the data packet 124 as shown in fig. 26B. In certain embodiments, the data packet 124 may include other commands, such as basic on or off instructions for the LED package 26.

FIG. 27 is a diagram showing a plurality of packets DP₁、DP₂…DP_nA schematic diagram of a cascading flow from the control element 18 to the plurality of LED packages 26-1, 26-2 … 26-n. In certain embodiments, any number (n) of LED packages may be provided to form an LED display. As shown, the control element 18 is configured to route a plurality of data packets DP along the data stream 126₁、DP₂…DP_nTo the plurality of LED packages 26-1, 26-2 … 26-n. For example, each data packet DP₁、DP₂…DP_nMay be configured as described for the data packet 124 of fig. 26A or 26B. Data packets (e.g. DP)₁、DP₂…DP_nOne or more combinations of) may form one of a plurality of data sets 128-1, 128-2 … 128-n corresponding to the data packet DP₁、DP₂…DP_nWhich is received by a particular LED package 26-1, 26-2 … 26-n. For example, data set 128-1 corresponds to data packet DP₁、DP₂…DP_nIs received by the first LED package 26-1, and data set 128-2 corresponds to data packet DP₂…DP_nIs received by the second LED package 26-2, and so on. In some embodiments, a particular data packet (e.g., the first data packet DP)₁) QuiltConfigured for a corresponding LED package (e.g., first LED package 26-1). Thus, the data packet DP₁、DP₂…DP_nReceived by the first LED package 26-1, which is configured to be based on the first data packet DP ₁Takes action to remove the first data packet DP from the data stream 126₁And pass or retransmit the data packet DP₂…DP_nTo adjacent LED packages 26-2. In a similar manner, the LED package 26-2 is configured to take action and remove the data packet DP₂And passes or retransmits the remaining data packet DP_n. The sequence continues until the remaining data packet DP of the data set 128-n_nUntil received by the remaining LED packages 26-n. For some display applications, each LED package 26-1, 26-2 … 26-n will be based on its corresponding data packet DP₁、DP₂…DP_nThe operational state is maintained until the control element 18 sends a new data set 128-1 for the corresponding LED package 26-1, 26-2 … 26-n. In some embodiments, the control element 18 may be configured to provide a portion of the data stream 126, such as a bit pattern/code or transmission delay, that indicates to the LED packages 26-1, 26-2 … 26-n that the previous data set 128-1, 128-2 … 128-n is complete and looks for the next data set 128-1, 128-2 … 128-n. For transmission delays between different data sets 128-1, 128-2 … 128-n, the time delay may include a range from 1 microsecond to 0.1 seconds, which provides the LED package 26-1, 26-2 … 26-n with sufficient timeout to begin looking for the next data set 128-1, 128-2 … 128-n. For LED display applications, each data set 128-1, 128-2 … 128-n may correspond to a frame of data or a frame of video for an LED display. For other LED applications, each data set 128-1, 128-2 … 128-n may correspond to an operating state, such as a general illumination color point and/or brightness level, or a static image collectively provided by the LED packages 26-1, 26-2 … 26-n. In certain embodiments, a first data packet DP configured for the first LED package 26-1 ₁May comprise a second data packet DP₂The same data length. In other embodiments, the first data packet DP₁May comprise more than the second data packet DP₂Of the data length of so as toMore information, such as color selection data, brightness level data, setting data, calibration data, temperature compensation data, and/or option selection data, is communicated to the first LED package 26-1.

FIG. 28 is a diagram showing a plurality of packets DP₁、DP₂…DP_nA schematic diagram of a cascading flow from the control element 18 to the plurality of LED packages 26-1, 26-2 … 26-n and one or more talk-back packets TB₁、TB₂… TBn to the control element 18. As described with respect to FIG. 27, the control element 18 and data stream 126 provide data packets DP to the data sets 128-1, 128-2 … 128-n₁、DP₂…DP_nTo the LED packages 26-1, 26-2 … 26-n. In FIG. 28, the first LED package 26-1 is configured to receive and take action to remove the first data packet DP from the data stream 126₁And then using the first talk-over packet TB in the data set 128-2₁Or the data stream 126 leaving the first LED package 26-1 replaces the first data packet DP₁. In a similar manner, the remaining LED packages 26-2 … 26-n may be configured to receive a corresponding data packet DP ₂…DP_nAnd subsequently with the corresponding talk-back data packet TB₂…TB_nReplacing them. Intercommunication data packet TB₁、TB₂…TB_nA data set 128-c may then be formed that is configured to communicate information about the LED packages 26-1, 26-2 … 26-n back to the control element 18 for monitoring. In some embodiments, the talk-back packet TB₁、TB₂…TB_nConfigured to communicate one or more states of the LED packages 26-1, 26-2 … 26-n, such as one or more of operating temperature, operating current, or other operating state, such that the control element 18 may base its operation on one or more talk-back packets TB₁、TB₂…TB_nAdditional data is changed or added to the subsequent data sets 128-1, 128-2 … 128-n. Intercommunication data packet TB₁,TB₂…TB_nAnd may also be configured to provide data checking and parity checking or other data validation to control element 18. In such an embodiment, one or more data packets DP₁、DP₂…DP_nThe main points ofThe signaling code may include active electrical elements configured to direct or prompt the respective LED packages 26-1, 26-2 … 26-n to provide the talk-back data packet TB₁,TB₂…TB_nCode or signal. Thus, the one or more LED packages 26-1, 26-2 … 26-n and the respective active electrical elements within each LED package 26-1, 26-2 … 26-n may be configured to receive input data (e.g., one or more data packets DP ₁、DP₂…DP_n) And introducing additional data (e.g. one or more talk-back packets TB)₁、TB₂…TB_n) To data stream 126.

FIG. 29 is a diagram showing a plurality of data packets DP from the control element 18₁、DP₂…DP_nIn a cascade flow additionally comprising data packets DP_ALL-1、DP_ALL-2Data packet DP_ALL-1、DP_ALL-2Configured to provide information to all of the LED packages 26-1, 26-2 … 26-n receiving the data stream 126. As described with respect to FIG. 27, the control element 18 and data stream 126 provide data sets 128-1, 128-2 … 128-n to the LED packages 26-1, 26-2 … 26-n, which data sets include data packets DP₁、DP₂…DP_nTo (3) is performed. In certain embodiments, the data sets 128-1, 128-2 … 128-n additionally include one or more data packets DP_ALL-1、DP_ALL-2Data packet DP_ALL-1、DP_ALL-2Configured as a common or broadcast data packet for all of the LED packages 26-1, 26-2 … 26-n. In this regard, the first LED package 26-1 is configured to receive and respond to the data packet DP_ALL-1、DP_ALL-2And additionally delivers or retransmits data packets DP along the data stream 126_ALL-1、DP_ALL-2Such that the remaining LED packages 26-2 … 26-n may also receive and respond accordingly. In some embodiments, the data packet DP_ALL-1、DP_ALL-2Direct all of the LED packages 26-1, 26-2 … 26-n to turn on or off, or provide a brightness level for all of the LED packages 26-1, 26-2 … 26-n in response to user input or ambient light sensing. In other embodiments, the data packet DP _ALL-1、DP_ALL-2One or more ofA plurality of LED packages 26-1, 26-2 … 26-n may be configured to direct LED packages 26-1, 26-2 to provide talk-back data packet TB as described in FIG. 28₁、TB₂…TB_n. In some embodiments, the same data set 128-1, 128-2 … 128-n may include a first data packet DP_ALL-1And a second data packet DP_ALL-2Each data packet provides a different common instruction, such as DP, to the LED packages 26-1, 26-2 … 26-n_ALL-1Indicating LED packages 26-1, 26-2 … 26-n are on and DP_ALL-2A common brightness setting for the LED packages 26-1, 26-2 … 26-n is provided. In FIG. 29, the data packet DP is shown at the beginning and end of the data sets 128-1, 128-2 … 128-n_ALL-1、DP_ALL-2(ii) a However, in other embodiments, the data packet DP_ALL-1、DP_ALL-2May be disposed anywhere within the data sets 128-1, 128-2 … 128-n. In some embodiments, the data packet DP_ALL-1，DP_ALL-2May be retransmitted by the LED packages 26-n to form the data set 128-c received by the control element 18.

FIG. 30 is a diagram showing a plurality of data packets DP from the control element 18₁、DP₂…DP_nIn a cascade flow additionally comprising one or more consecutive data packets CDP₂Configured to provide additional information to at least one of the LED packages 26-1, 26-2 … 26-n. As described with respect to FIG. 27, the control element 18 is configured to provide the LED packages 26-1, 26-2 … 26-n with data sets 128-1, 128-2 … 128-n, including data packets DP ₁、DP₂…DP_n. In certain embodiments, the data sets 128-1, 128-2 … 128-n additionally include consecutive data packets CDP₂Configured to provide additional data or information to at least one of the LED packages 26-1, 26-2 … 26-n (e.g., the second LED package 26-2 in fig. 30). In this regard, in the data sets 128-1, 128-2 … 128-n of the data stream 126, successive data packets CDP₂Is arranged in a data packet DP₂Later sum data packet DP₃Before. In addition, a continuous packet CDP may be configured₂Such that the first LED package 26-1 transmits successive data packets CDP₂And the second LED package 26-2 is removed and responds to the data packet DP₂Thereafter removing and responding to the continuous data packet CDP₂. In some embodiments, the continuous data packet CDP₂Comprising color selection data and/or brightness level data, which may be derived from the data packet DP₂Complement of received color selection data and/or brightness level data. In some embodiments, the continuous data packet CDP₂Including at least one of setup data, option selection data, and calibration data. For example, in certain embodiments, the active electrical elements 30 of one or more of the LED packages 26-1, 26-2 … 26-n may be arranged without flash memory and as disclosed herein in a continuous data packet CDP ₂May be configured to provide one or more transfer functions after a reset or initial start-up condition. The transfer function may include temperature compensation information, a gamma function, and the like.

According to embodiments disclosed herein, a plurality of LED packages may be arranged in series to receive a cascading stream of data packets. The plurality of LED packages may form an LED package array, which may form at least a portion of an LED display panel, an LED sign panel, or a general lighting panel. In such embodiments, one or more LED packages may include an active electrical element as previously described that receives and takes action on one or more data packets. In certain embodiments, the array of LED packages may be arranged on the panel in a serpentine arrangement configured to provide a cascading flow of data packets while also providing a reduced footprint of electrical paths or traces between the LED packages.

Fig. 31 is a partial plan view illustrating a path configuration of an LED panel 130 configured for operation in accordance with embodiments disclosed herein. In fig. 31, a plurality of LED packages 26 are arranged in rows and columns to form an LED pixel array. Each LED package 26 may include a plurality of LEDs (e.g., 28-1 through 28-3 of fig. 2), an active electrical element (e.g., 30 of fig. 2), and a plurality of package bond pads 48-1 through 48-4 forming an LED pixel as previously described. In fig. 31, package bond pads 48-1, 48-3 of each LED package 26 are configured as communication ports for sending and receiving a cascading stream of data packets of a data stream. Specifically, each package bond pad 48-3 is pre-assigned as an input port for a data flow (denoted "DIN" for data input) and each package bond pad 48-1 is pre-assigned as an output port for a data flow (denoted "DOUT" for data output). Each package bond pad 48-2 is configured as a voltage port (VDD) and each package bond pad 48-4 is configured as a ground port (GND). In this manner, a data stream (designated "input") may be received at package bond pad 48-3 of LED package 26 in the lower right corner of LED panel 130. At least a portion of the data stream may then exit LED package 26 via package bond pad 48-1 to be received by an adjacent LED package 26. A plurality of communication buses 132-1 through 132-3 for data flow are arranged to connect package bond pads 48-1 of one LED package 26 with package bond pads 48-3 of the next LED package 26. In certain embodiments, the communication buses 132-1 through 132-3 are arranged to connect the LED packages 26 in series in a serpentine manner. In FIG. 31, the communication buses 132-1 through 132-3 connect the LED packages 26 in series from right to left through the bottom row of the LED panel 130 and from left to right through the next row from bottom row up. This sequence is repeated for each additional row of the LED panel 130 to form a serpentine arrangement. Depending on the alternating direction of the series connection from row to row, different communication buses 132-1 through 132-3 may include different lengths to connect between package bond pads 48-1 and 48-3 of the series connected LED packages 26. For example, the communication bus 132-1 may comprise shorter lengths and alternate with the communication bus 132-3 having longer lengths row by row. As shown, the communication bus 132-2 is arranged to connect one row to another row and may comprise the same or similar length as the communication bus 132-1. In this manner, all of the communication buses 132-1 through 132-3 may be arranged on the same layer or plane of the LED panel 130 while providing a series connection for data flow to the LED packages 26. Although not shown, at least some of the power connections for the LED packages 26 may be arranged on a different layer or plane than the communication buses 132-1 through 132-3.

Fig. 32 is a partial plan view illustrating a routing configuration for an LED panel 134 including a plurality of LED packages 26 having selectively assignable or bi-directional communication ports according to embodiments disclosed herein. In fig. 32, a plurality of LED packages 26 are arranged and connected in a serpentine fashion in rows and columns to form an LED pixel array. Each LED package 26 may include a plurality of LEDs (e.g., 28-1 through 28-3 of fig. 2), an active electrical element (e.g., 30 of fig. 2), and a plurality of package bond pads 48-1 through 48-4 forming an LED pixel as previously described. In FIG. 32, package bond pads 48-2(VDD) and package bond pads 48-4(GND) are configured in a similar manner as in FIG. 32, while package bond pads 48-1(D2), 48-3(D1) of each LED package 26 are configured as communication ports for transmitting and receiving a cascaded stream of data packets of a data stream. As shown, in a similar manner to FIG. 31, each package bond pad 48-1 is disposed in the upper left corner of each LED package 26 and each package bond pad 48-3 is disposed in the lower right corner of each LED package 26. In fig. 32, package bond pads 48-1, 48-3 are configured as communication ports that are selectively assignable based on how communication buses 132-1 through 132-3 are arranged to input and output data streams through each LED package 26. In this regard, the communication buses 132-1 through 132-3 may be arranged to input or output data streams from any of the package bond pads 48-1, 48-3 of each LED package 26. Upon startup or after reset of the LED panel 134, when a certain LED package 26 initially receives a data stream, the active electrical elements of the LED package 26 are thus configured to identify a first one of the first and second communication ports (e.g., one of the package bond pads 48-1, 48-3) that receives an input signal from the data stream, selectively assign the first one of the first and second communication ports as an input port, and selectively assign a second one of the first and second communication ports (e.g., the other one of the package bond pads 48-1, 48-3) as an output port. In this manner, package bond pads 48-1, 48-3 may be configured as a bi-directional communication port within each LED package 26. Thus, some LED packages 26 may have package bond pads 48-1 assigned as input ports, while other LED packages 26 in the same LED panel 134 may have package bond pads 48-1 assigned as output ports. In certain embodiments, the active electrical elements of each LED package 26 may include circuitry configured to selectively distribute input and output communication portions. For example, the active electrical element may comprise a circuit comprising a tri-state buffer, such that when an input communication signal is received, the active electrical element may allocate an input port and an output port in a register. By providing such selectively assignable communication ports, the path of the communication buses 132-1 through 132-3 between the LED packages 26 may be simplified in reduced length, thereby providing lower cost and achieving higher resolution for the LED panel 134.

Fig. 33 is a partial plan view illustrating another routing configuration for an LED panel 136 including a plurality of LED packages 26 having selectively assignable communication ports according to embodiments disclosed herein. In fig. 33, a plurality of LED packages 26 are arranged and connected in a serpentine fashion in rows and columns to form an LED pixel array. Each LED package 26 may include a plurality of LEDs (e.g., 28-1 through 28-3 of fig. 2), an active electrical element (e.g., 30 of fig. 2), and a plurality of package bond pads 48-1 through 48-4 forming an LED pixel as previously described. In fig. 33, some of package bond pads 48-1 through 48-4 are provided with a different arrangement than that shown in fig. 32. Specifically, package bond pad 48-1 is configured as ground port (GND) in FIG. 33, package bond pad 48-2 holds voltage port (VDD), and package bond pads 48-3(D1), 48-4(D2) are configured as selectively assignable communication ports. In this manner, the selectively assignable communication ports are disposed proximate to each other within the same LED package 26 and closer to the selectively assignable communication ports of adjacent LED packages 26. Thus, the communication buses 132-1, 132-2 may be further simplified by reducing the length between the LED packages 26. In particular, the communication bus 132-1 may form a straight line between adjacent LED packages 26 along each row of the LED panel 136. The longer communication bus 132-2 connects one row to another and is disposed around the periphery of the LED panel 136.

Fig. 34 is a partial plan view illustrating a routing configuration of the LED panel 136 of fig. 33 with the addition of a voltage line 118 and a ground line 122, according to embodiments disclosed herein. The simplified routing of communication lines 132-1, 132-2 allows for simplified routing of voltage line 118 and ground line 122 for LED panel 136 by having multiple LED packages 26 with one or more selectively assignable communication ports (e.g., one or more of package bond pads 48-1 through 48-4). Specifically, this path configuration allows the communication lines 132-1, 132-2, the voltage line 118, and the ground line 122 to all be disposed on the same layer or plane of the LED panel 136. In some applications, it may be beneficial to arrange one or more of the voltage lines 118 or ground lines 122 on a different plane than the communication buses 132-1, 132-2 to improve power distribution, reduce voltage drops due to trace resistance, and reduce noise from crosstalk and other sources. In some embodiments, the communication buses 132-1, 132-2 and the voltage line 118 may be disposed on a first layer or plane of the LED panel 136, and the ground line 122 may be disposed on a second layer or plane of the LED panel 136, with the electrical vias connecting the ground line 122 to the package bond pads 48-1 of each LED package 26. A distribution of subsets on a second layer or plane of the LED panel 136 may be provided to reduce the number of electrical vias.

In each of fig. 31-34, LED package 26 is shown with four package bond pads 48-1 to 48-4. It should be understood that in some embodiments, the LED package 26 shown in any of fig. 31-34 may include an additional number of package bond pads. In some embodiments, the LED package 26 may have at least two additional package bond pads configured to provide a clock signal input and a clock signal output to provide a synchronization or other timing sequence for the LED package 26. In certain embodiments, the series-connected LED packages 26 may be configured with a self-clocking configuration or a configuration for receiving a self-clocking signal, and thus, may not require a clock input. In some embodiments, the additional package bond pads may be configured to receive additional voltage inputs to conserve power. For example, one or more red LED chips within the same LED package 26 may operate at a lower voltage with a different voltage input than one or more blue or green LED chips within the LED package 26. Furthermore, one or more logic circuit arrangements in the active electrical element 30 may operate at lower voltages with different voltage inputs.

As disclosed herein, the series connected LED packages 26 may be configured with temperature or other compensation, calibration, correction, or transfer function capabilities. Such capabilities or techniques may include the use of one or more look-up tables, transfer coefficient-based calculations, and combinations of look-up tables and transfer coefficient calculations that provide piecewise continuous transfer functions. In some embodiments, the data packet DP, the continuous data packet CDP or the public or broadcast data packet DP_ALLMay include command codes configured to prompt active electrical components in one or more of the LED packages 26 to allow communication from such look-up tables and/or transfer coefficients to be calculated to individual LED packages 26, subsets of LED packages 26, or all of the LED packages 26 in the data stream 126.

As disclosed herein, LED packages are disclosed that include an active electrical element configured to receive data from a data stream and take one or more actions at least partially in response to the received data. In certain embodiments, the active electrical element may take one or more actions based on commands identified by data received from the data stream in conjunction with one or more of a current state of the LED package or previous commands received by the active electrical element.

Fig. 35 is a schematic diagram illustrating various inputs and corresponding actions for an active electrical element, according to embodiments disclosed herein. As shown, the active electrical component 30 is configured to receive an input data stream 126A and take actions based on the data stream 126A and various inputs and internal states 138-1 through 138-n that identify one or more corresponding actions 140-1 through 140-n to be taken. Specifically, the one or more inputs and internal states 138-1 through 138-n are received by the control logic 141 of the active electrical element 30. The one or more input or internal states 138-1 through 138-n include a current state 138-1 of the active electrical element 30 (and corresponding LED package 26), a current command 138-2 corresponding to a command code received from a current portion of the input data stream 126A, a previous command 138-3 corresponding to a previous command code received from a previous portion of the input data stream 126A, and one or more additional inputs (… 138-n). The current state 138-1 may include a reset or start-up condition of the active electrical element 30, such as resetting a register to an initial state. If the LED package 26 is arranged with a bi-directional communication port, the initial state may include resetting the bi-directional communication port for an input signal. The current state 138-1 may also include waiting for data input from one or more communication ports. Upon receiving data from the input data stream 126A, the current state 138-1 may include maintaining the operating conditions of the LED package 26, or implementing a common or broadcast command and any corresponding continuous data commands. Upon receiving the current command 138-2, the control logic 141 of the active electrical element 30 may then identify one or more actions 140-1 through 140-n to take based on the control logic 141 input and one or more combinations of the internal states 138-1 through 138-n, and may include changing the current state 138-1. One or more actions 140-1 through 140-n may include transmitting or retransmitting data 140-1 from input data stream 126A to output data stream 126B, transmitting LED data 140-2 (e.g., a talk-over packet) to output data stream 126B, or any number of other actions 140-3, 140-4 … 140-n, including energizing the LED chip or other elements of the LED package 26, turning on or off the output of the LED package 26, sends data to the calibration registers based on the received input data stream 126A, identifies and assigns the bi-directional communication port of the LED package 26 as a different one of the input port and the output port, changing the data rate according to the input or output data stream 126A/126B, implementing a particular set of options for the LED package 26, or changing the driving conditions of the LED package 26. In this regard, the active electrical elements 30 may include a finite state machine configured to identify and take action based on current or previous input commands and one or more finite or current states of the LED packages 26.

Fig. 36 is a schematic diagram illustrating an active electrical element 30 including a finite state machine 142, according to embodiments disclosed herein. The active electrical component 30 may be configured according to any number of states 144-1 through 144-4 corresponding to the current state 138-1 of FIG. 35. The startup or reset state 144-1 may include an initial state for resetting registers and communication ports to the initial state. After the start-up or reset state 144-1, the active electrical component 30 can proceed to a communication port set state 144-2, wherein the active electrical component 30 waits for data input from a data stream. Upon receiving the data input, the active electrical element 30 may assign an input port and an output port to the respective LED package. The active electrical component 30 may advance to one of the command states 144-3, 144-4 based on command codes received from various input signals. The command status 144-3 corresponds to achieving and/or maintaining operating conditions of individual LED packages of the active electrical element 30 according to the received command code. The command status 144-4 corresponds to implementing and/or maintaining a common or broadcast operating condition in the data stream for all of the LED packages. In normal operation, the active electrical component 30 may advance from the enabled or reset state 144-1 to the communication port set state 144-2 before advancing and cycling between the command states 144-3, 144-4 depending on the various command codes received and other conditions such as timeout conditions. As shown, all of the various states 144-1 through 144-4 may cycle back to themselves until a condition or command is provided to change the active electrical element 30 to another of the various states 144-1 through 144-4. In some embodiments, the command or condition may change one of the various states 144-1 through 144-4 to a different one of the various states 144-1 through 144-4, as indicated by the dashed lines between the different ones of the various states 144-1 through 144-4. Although only four states 144-1 to 144-4 are shown, the active electrical element 30 and the finite state machine 142 may have additional states in accordance with embodiments disclosed herein. Accordingly, fig. 36 is provided as a high-level conceptual diagram of the basic operation of the active electrical component 30. It will be appreciated that the same operation may be represented in many different ways, such as combining command states into one and downgrading a first command condition to a slave state. In some embodiments, all of the states 144-1 through 144-4 may be configured with one or more timeout conditions that change a particular state 144-1 through 144-4 to a previous one of the states 144-1 through 144-4, which states 144-1 through 144-4 may eventually force a reset condition. In this regard, the active electrical component 30 may avoid being stuck in the unresponsive state 144-1 through 144-4.

In certain embodiments disclosed herein, an LED package includes an active electrical element configured to detect an adverse operating condition or a corresponding error signal of one or more LEDs within the LED package. In some embodiments, the active electrical element may be configured to provide forward and reverse bias conditions to and switch between one or more LEDs. A forward bias condition is provided to activate or turn on one or more LEDs, and a reverse bias condition may be provided separately to one or more LEDs for other capabilities, including current leakage measurements and reverse bias voltage measurements. In certain embodiments, the active electrical element may be configured to provide forward voltage monitoring and corresponding adjustment of the drive signal to the one or more LEDs. An LED panel is disclosed that includes a plurality of LED packages configured to provide forward and reverse bias conditions. The LED panel may be configured to enable one or more LED packages to run a self-test routine at startup or at other intervals or times. Such a self-test routine may include comparing a reverse leakage measurement to a reverse leakage requirement and a forward voltage measurement to a forward voltage requirement for any LED within each LED package. Such self-test routines may also include temperature assessment of any LEDs. In certain embodiments, reverse leakage measurements and forward voltage measurements may be added to or may replace data transmitted back to the control element (e.g., 18 of fig. 28). In response to an improper reverse leakage value, the active electrical element of a particular LED package may turn off a particular LED within the LED package, turn off an LED pixel within the LED package, or turn off the entire LED package during normal operation of the LED panel, so as not to draw current from other LEDs, LED pixels, or LED packages. In response to a deviation in the forward voltage measurement, the active electrical element of a particular LED package may responsively adjust a drive signal, e.g., a PWM signal, of one or more LEDs within the package. In some embodiments, an exemplary self-test routine may include cycling through each LED to perform an initial brightness measurement, perform an internal reverse leakage and/or forward voltage measurement, and provide one or more diagnostic signals via LED color or pulse sequences for external machine detection and decoding. In certain embodiments, the self-test routine may provide an output signal indicative of at least one of a pass or fail condition of an LED within the package. The output signal may be transmitted as a digital signal to the electrical port. In other embodiments, the output signal may be communicated as an optical signal through one or more LEDs within the package. In some embodiments, the self-test routine may repeat steps in which the LEDs are electrically activated in a slower manner to provide a visible signal to a human observer. In this manner, the light signal may include a code that may be interpreted from one or more LEDs in a predetermined color, duration, and/or count flash. In some embodiments, the optical signal may be transmitted first at a high speed that is undetectable or difficult to detect by a human observer, and then at a slower speed to provide a human-readable code for human detection. The LED package may be configured to automatically perform such a self-test routine upon power-up, or the LED package may be configured to perform such a self-test routine upon direct connection to a separate power source for testing. Further, a time delay may be provided between the high speed communication at power up and the low speed communication code, which is low enough that the controller has time to send a command to stop the self test routine before displaying or sending the low speed communication. Thus, when first powered up, the display screen may only blink according to higher speed communications, and the master controller may send a full off command almost immediately after power up. In this way, an initial blink at a higher speed during power-up will be difficult to detect by a human observer.

Fig. 37-42 are provided as general schematic and block diagrams illustrating concepts associated with the active electrical components described herein. While fig. 37-42 are illustrated as general schematic and block diagrams, various configurations and additional support elements and circuits may be present in various embodiments. In fig. 37-42, any of the lines connecting the various elements may comprise a single line or multiple lines, depending on the application and the type of signal (e.g., analog or digital) being transmitted. Also, these figures are intended to convey concepts in a general manner. Additional resistors, capacitors, and active elements may need to be added to achieve the desired functionality and performance. Other arrangements, such as source and/or sink drivers, are also contemplated. In addition, other arrangements, such as using one ADC with a multiplexer switch rather than separate ADC inputs for each node, are understood to be within the scope of the present disclosure. Likewise, separate voltage inputs may be used for LEDs of different voltage requirements (e.g., a separate voltage input for a red LED compared to a voltage input for a green or blue LED).

Fig. 37 is a schematic diagram illustrating an embodiment in which the active electrical element 30 is configured to detect a normal or poor operating condition of the at least one LED 146 in accordance with embodiments disclosed herein. As shown, the driver 148 of the active electrical element 30 is substantially an analog interface of the active electrical element 30 and includes a pull-up resistor R6 provided with a high resistor value (e.g., 10000-. Threshold detector 150 may include a comparator/op amp configuration for communicating an Error (ERR) signal to control logic 141. These error signals may include an electrical short or open circuit condition of the LED1, etc. Control logic 141 is a digital interface to active electrical components 30 and includes resistor Select (R-Select) and PWM circuitry coupled to driver 148. The cathode of the LED 146 is coupled to a pull-up resistor R6, a threshold detector 150, and a resistor network R1-R5. In normal operation, the selection switch FETs 1-3 allow selection of the resistors R3-R5 to provide a predetermined current limit, and the selection switch FET4 is coupled with the PWM circuit of the control logic 141 to provide brightness control of the LED 146. When the LED 146 is in an electrical short condition, an error is detected as a high voltage, e.g., above 2V or above 3V, and a corresponding error signal is transmitted to the control logic 141. When the LED 146 is in an electrically open state, the error is detected as a low voltage, e.g., below 0.5V, depending on the particular resistor selection. Although only LEDs 146 are shown, the concepts described herein are also applicable to multiple LED arrangements where a separate or multiplexed threshold detector 150 is configured with each LED. As with the previously described embodiments, the active electrical component 30 configured as in fig. 37 may be incorporated into the same LED package as one or more LEDs (e.g., LED 146). Additionally, the active electrical element 30 may be configured to communicate with and respond to commands from another control element (e.g., the control element 18 of fig. 1B).

Fig. 38 is a schematic diagram illustrating an embodiment in which the active electrical element 30 is configured to provide forward and reverse bias conditions to the at least one LED 146, according to embodiments disclosed herein. In some embodiments, control logic 141 includes a reverse bias control output signal configured, with appropriate active elements, to provide a near VSS or near VDD voltage level to LEDs 146 in accordance with the output signal. Since the term "reverse bias" means that a high level on the output of the control logic 141 creates a reverse bias condition, the output signal may simply be coupled to an inverter 152 provided in the driver 148. Thus, depending on the particular operating conditions, the LED 146 may be forward biased or reverse biased. The inverter 152 or inverter logic element may have sufficient output characteristics to drive the LED 146. As with other aspects, other elements may need to be added to meet all requirements. In fig. 38, the ADC 154 is configured to detect the voltage at the LED 146 that is related to the operating condition of the LED 146. Thus, the ADC 154 is arranged to replace the threshold detector 150 of fig. 37. In certain embodiments, the ADC 154 includes at least one of a resistor-capacitor (RC) circuit or analog filter disposed in the driver 148 and a digital filter circuit disposed in the control logic 141. The ADC 154 may further include a comparator, a sampling element with digital feedback, and additional filtering in the digital domain. Other arrangements/methods for analog-to-digital conversion are also contemplated. To measure an operating condition such as reverse leakage of the LED 146, the control logic 141 may apply a reverse bias to the LED 146 such that the anode of the LED 146 becomes close to 0V. In the reverse bias state with the PWM circuit off, if the LED 146 exhibits suitably low reverse leakage, the cathode of the LED 146 coupled to the pull-up resistor R6 will be near V _dd. If the LED 146 leaks in the reverse biased state, the cathode of the LED 146 will have a lower voltage. This may be sensed by the ADC 154 or limit sensor and caused by the control logic 141To take appropriate action, such as turning off the LED 146 and notifying the main control element 18 via the communication protocol. In this regard, the ADC 154 may form a level sensor configured to provide an error signal when the LED 146 is in a reverse biased state. Accordingly, the ADC 154 is configured to detect a voltage associated with an operating condition of the LED 146 when the LED 146 is in a reverse biased state.

In other embodiments, control logic 141 may turn off one or more LEDs within an LED package in response to a detected reverse leak, or control logic 141 may turn off the entire LED package. In other embodiments, control logic 141 may adjust the control signal to LED 146 in response to a detected reverse leakage. As shown, the driver 148 may include a resistor network R1-R5 and selection switch FETs 1-FET4, and the control logic 141 may include an R selection circuit and a PWM circuit, as described in fig. 37. As described above, during the reverse bias state of the LED 146, the PWM circuit will be turned off. In certain embodiments, such a configuration of the active electrical element 30 may allow for adjustment and improved control of the operating conditions of the LED 146, rather than merely detecting the voltage level and responding only to pass (pass) and fail conditions. The resistor network R1-R5 acts as a current limiting circuit for the LED 146 and in this way, without active feedback, does not accurately control the current of the LED 146 in response to small LED voltage variations. These variations are typically observed over the lifetime of the LED 146. The forward voltage level feedback from the ADC 154 to the LED 146 may be used as part of the calculation to determine and/or adjust the PWM duty cycle of the LED 146. For example, if the ADC 154 detects a decrease in the forward voltage level of the LED 146, the control logic 141 may responsively increase the PWM duty cycle of the LED 146 to compensate for the brightness difference that would otherwise be observed. This pseudo-current control may be advantageous over other current control methods because it requires less resources (e.g., additional chip space and power) to implement. Along with the forward voltage level feedback of the LED 146, the transmission curve, temperature compensation data, and input brightness level data may also be part of the calculations used to determine and adjust the PWM duty cycle. Additionally, since the ADC 154 may provide voltage level monitoring of the LED 146 to the control logic 141, an electrical short or an electrical open condition of the LED 146 may also be detected. In this manner, the ADC 154 is configured to detect a voltage, e.g., a forward voltage level, associated with an operating condition of the LED 146 when the LED 146 is in a forward biased state. According to embodiments disclosed herein, the ADC 154 may be configured to send measurement data (e.g., reverse leakage and forward voltage measurements) to the active electrical element 30 for serial output to a main control element (e.g., the control element 18 of fig. 1B). Although only LEDs 146 are shown in fig. 38, the concepts described herein are also applicable to multiple LED arrangements where a separate ADC 154 is configured with each LED, or a switching network (e.g., a multiplexer) allows one ADC 154 to make voltage measurements from multiple LEDs. As with the previously described embodiments, the active electrical component 30 configured as in fig. 38 may be incorporated into the same LED package as one or more LEDs (e.g., LED 146).

Fig. 39 is a schematic diagram illustrating an embodiment of replacing the resistor network R1-R5 and the respective select switch FETs 1-3 of fig. 38 with a current source 156 in the active electrical element 30 according to an embodiment disclosed herein. In fig. 39, pull-up resistor R6 and inverter 152 are coupled to LED 146 as described in fig. 38. The current source 156 is configured to provide a selectable (e.g., several levels) or adjustable (e.g., many levels) current to the LEDs 146. Since the schematic of the current source 156 is more versatile than the resistor network R1-R5 and corresponding select switch FETs 1-FET3 of FIG. 38, the subsequent figures will use the current source 156 to represent any method for controlling LED current, including the resistor network R1-R5 and corresponding select switch FETs 1-FET3 of FIG. 38. Control logic 141 includes a current selection circuit (or resistor selection circuit of fig. 37) that is typically used to set the maximum current or brightness level based on the chip size of LED 146, etc. Such a selection can generally be made at initial setup, and does not have to be changed thereafter. In some embodiments, the PWM may be omitted and the LED 146 may be operated solely by the current source 156, as previously described with the Howland current pump of fig. 11E. In some embodiments, the current source 156 is equipped with built-in feedback, and thus, feedback from the ADC 154 may not be required. In some embodiments, temperature measurement feedback may be provided to the current source 156 by one or more components of the ADC 154. Although only LED 146 is shown in fig. 39, the concepts described herein are also applicable to multiple LED arrangements. As with the previously described embodiments, the active electrical component 30 configured as in fig. 39 may be incorporated into the same LED package as one or more LEDs (e.g., LED 146).

Fig. 40 is a schematic diagram showing a multiple LED embodiment similar to the schematic diagram of fig. 39. As shown, individual ones of the pull-up resistors R6-1 through R6-3 in the active electrical element 30 are coupled to respective ones of the plurality of LEDs 146-1 through 146-3. In addition, each of the LEDs 146-1 to 146-3 is coupled to a corresponding ADC 154-1 to 154-3 and a corresponding current source 156-1 to 156-3. In FIG. 40, the inverter 152 is configured to change or switch from a forward biased state to a reverse biased state for each of the LEDs 146-1 to 146-3. In other embodiments, the active electrical component 30 may include a separate inverter 152 for each of the LEDs 146-1 to 146-3. As before, V alone_ddThe voltage input may be used to save power by driving the LEDs 146-1 to 146-3 with less power dissipation at their respective voltage levels within the active electrical component 30. Although current sources 156-1 to 156-3 are shown, a resistor network (e.g., R1-R5 of FIG. 38) and a selection switch (e.g., FET1-FET3 of FIG. 38) may also be configured for each of the LEDs 146-1 to 146-3. Thus, the active electrical component 30 of FIG. 40 is configured to provide electrical open detection, electrical short detection, forward voltage monitoring, and reverse leakage monitoring for each LED 146-1 to 146-3, and to responsively adjust or turn off individual LEDs or groups of LEDs 146-1 to 146-3. As with the previously described embodiments, the active electrical component 30 configured as in FIG. 40 can be incorporated into the same LED package as the LEDs 146-1 to 146-3. Although multiple ADCs 154-1 to 154-3 are shown, a single ADC may be provided to detect the voltage or voltage level at multiple nodes, such that the single ADC is configured to provide at least one of a reverse leakage measurement and a forward voltage measurement of the multiple LEDs 146-1 to 146-3.

FIG. 41 is a diagram illustrating the active electrical of FIG. 40 configured with multiple ports according to embodiments disclosed hereinSchematic diagram of element 30, the plurality of ports including a supply voltage V_ddEarth connection V_ssAnd bidirectional communication ports (input/output (I/O) port 1 and I/O port 2). In FIG. 41, except for V on the left side of the diagram_dd、V_ssThe active electrical component 30 includes, in addition to the four ports of I/O port 1 and I/O port 2, four ports on the right side of the schematic that are coupled to the LEDs 146-1 to 146-3. As shown, LEDs 146-1 to 146-3 are electrically coupled to inverter 152, pull-up resistors R6-1 to R6-3, ADCs 154-1 to 154-3, and current sources 156-1 to 156-3, as previously described. In other embodiments, the current sources 156-1 to 156-3 may be replaced with respective resistor networks and selection switches, as previously described. Bidirectional communication ports I/O port 1 and I/O port 2 are electrically coupled to one or more I/O buffers 158. The I/O buffer 158 includes circuitry (e.g., various buffers and tri-state buffers) that, together with the control logic 141, is configured to assign the bi-directional communication ports I/O port 1 and I/O port 2 as either input (data in) or output (data out) communication ports based on the manner in which the active electrical component 30 is connected within the system. In response to an incoming data connection at either of the bidirectional communication ports I/O port 1 and I/O port 2, control logic 141 will assign an input port direction and an output port direction accordingly. The control logic 141 may include one or more additional elements, shown generally in fig. 41, such as a memory element, a clock or oscillator, and/or a filter and ADC, connected to a temperature sensor and resistor-capacitor to provide thermal management capabilities. In certain embodiments, one or more of the ADCs 154-1 through 154-3 or individual ADCs may be configured to provide a temperature measurement by measuring a voltage provided by a temperature sensor.

Fig. 42 is a schematic diagram illustrating the active electrical element 30 of fig. 41 configured with polarity agnostic or polarity independent input capability according to embodiments disclosed herein. As shown, a switching network 160, such as an active switching network, may be arranged to receive or connect with multiple connections (e.g., ports P1-P4) from an input port or pin and configure individual signal lines as V_dd、V_ssOne of the data input and data output signal lines. Thus, it is possible to provideThe ports P1-P4 form a plurality of polarity agnostic connection ports arranged to receive or transmit various signals. In certain embodiments, the switch network 160 includes circuitry configured to be self-configuring regardless of the order of connection of the ports P1-P4. An exemplary circuit for the switching network 160 may include a network of actively controlled switches, such as a plurality of MOSFETs with gates biased according to a voltage level sensed at the input. In some embodiments, switch network 160 may provide some of the functionality for I/O buffer 158 of FIG. 41. Thus, in some embodiments, it may be desirable to combine the functionality of the I/O buffer 158 of FIG. 41 into the switching network 160. As shown by the dashed lines within the active switching network 160 of FIG. 42, each individual one of the ports P1-P4 can be connected as V _dd、V_ssAny one of the data input and data output signal lines. In this manner, the active electrical component 30 of the LED package may include the switching network 160 and one or more bi-directional communication ports such that the package bond pads (e.g., 48-1 to 48-4 of FIG. 2I) of the LED package are formed connectable to V_dd、V_ssA polarity agnostic connection port for any one of an input communication and an output communication. For outgoing communications, at least one of the plurality of ports (e.g., ports P1-P4) may be configured accordingly as an outgoing communications port. Since the switching network 160 also includes a power supply, the power supply pin must first be designated and switched to the appropriate node. Such power input may be achieved through passive circuitry (e.g., an RC network that controls the gate of the FET). As an example, fig. 43 is a general schematic diagram illustrating a four-input rectifier 162 that may be used to provide initial power to the switching network 160 of fig. 42. As shown, each of the ports P1-P4 is coupled with a pair of low voltage components such as bipolar diodes, Schottky diodes, etc. Because such diodes may consume too much power due to their voltage drop (especially for low voltage LED assemblies), the four-input rectifier 162 may only be used to initially power the switching network 160 of fig. 42, after which the final switching connections may be made using active elements and logic. In this manner, the power switching network of fig. 42 can then be provided using low voltage switches such as MOSFETs The low resistance path of the power supply pin bypasses the diode rectifier (e.g., 162 of fig. 43). In some embodiments, MOSFETs may be included in the active rectifier of the switching network 160 used in combination with the four-input rectifier 162. In other embodiments, an active rectifier may be used in place of the 4-input rectifier 162 by replacing each diode shown in fig. 43 with an actively controlled switch (e.g., a transistor comprising a MOSFET and/or a bipolar junction transistor).

As previously mentioned, an active electrical component of an LED package is disclosed that is configured to receive a digital code, such as a compressed digital code or encoded signal, from a control component of an LED display. For example, the active electrical component may be configured to receive an encoded digital signal (e.g., fig. 20) that conveys a greater number of command codes with reduced data bits in the data stream. In this regard, the active electrical component may be configured to receive the compressed digital code and subsequently decompress the digital code of the data stream received by the active electrical component. Thus, decompression of the received digital code may include any non-linear function or algorithm for expanding the received data stream, including an exponential inverse power function that may increase the dynamic range of the data stream. The dynamic range of a digital signal may refer to the range of signal levels (e.g., upper and lower values) that are typically described by the number of bits. One form of compression is only relevant to how the bits are used. Bits are typically used to generate current or power input to the LED in a linear fashion. For display systems, this can be an inefficient use of bit depth (e.g., dynamic range) because a human observer recognizes light in a non-linear manner more similar to a logarithmic or power law function such as that used for gamma correction. The dynamic range for a given number of bits may be small (e.g., 255 times the highest level of an 8-bit code, excluding zeros) but may extend by several orders of magnitude when transforming the data to match the non-linear response of the eye. As an example, instead of having a dynamic range 255 of 8 bits, by applying a gamma of 2.2 we get a dynamic range of nearly 200000, while still using only 8 bits. Without compression, 18 bits are needed to achieve the same level of dynamic range. In this manner, dynamic range may refer to the useful number of bits, samples, or resolution of the data stream of the active electrical element. Accordingly, the active electrical elements disclosed herein may be configured to receive compressed data and decompress the data to provide a greater observed and useful dynamic range. As just described, certain embodiments, the compression and decompression schemes may follow a power law expression (e.g., gamma correction) to increase the dynamic range between digital images and human observer-perceived images. In other embodiments, the compression and decompression scheme may include grouping adjacent LED pixels/packages or LED pixels/packages in close proximity to each other. Such grouping of LED pixels may be applicable to embodiments in which the groups of LED pixels are under control of a common electrical element in the LED display matrix. In particular, the LED package may include two or more adjacent LED pixels, and compressing the data codes and subsequently decompressing the data codes reduces data inefficiencies by eliminating redundancies within the data that may be expected between adjacent pixels of the two or more adjacent LED pixels. Thus, the common code is decoded or decompressed to provide a code for two or more adjacent LED pixels or sub-pixels.

As described above with respect to fig. 41 and 42, an LED package is disclosed that is capable of receiving compressed digital data at any one of several bi-directional communication ports or at any one of polarity agnostic package bond pads (e.g., 48-1 to 48-4 of fig. 2I) and decompressing such digital data. Further, an LED package is disclosed that is capable of receiving a transfer function or a transfer function value to be applied within the LED package to any of a plurality of bidirectional communication ports or any of polarity agnostic package bond pads (e.g., 48-1 to 48-4 of fig. 2I). The transfer function may include one or more subsets of transfer function coefficients for the active electrical component to interpolate. In this way, the transfer function can be calculated in the digital domain. In some embodiments, the transfer function may comprise a piecewise transfer function. According to embodiments disclosed herein, the transfer function may be applied to direct or control one or more of a temperature measurement of one or more LEDs within the LED package or a brightness output of one or more LEDs within the LED package to an ADC input (e.g., ADC 154 of fig. 38), to a PWM output (e.g., PWM circuit of fig. 38), and to a DAC controlled output of the active electrical element. As used herein, "transfer function" refers to any type of function that may be implemented in any number of ways to convert input data into output data such that the output data is different from the input data. In some embodiments, the transfer function may be configured to transform the data according to a linear function (e.g., addition, multiplication, etc.). In some embodiments, the transfer function may be configured to transform the data according to a non-linear function (e.g., exponential, logarithmic, transcendental, algorithmic, fourier transform (e.g., discrete fourier transform), etc.). The transfer function may be applied to temperature control by transforming the temperature sensor values to generate corresponding control signals for the LEDs for temperature, brightness or voltage adjustment, and combinations thereof. In certain embodiments, the transfer function may be configured to receive and transform multiple inputs of data values from multiple sources, the inputs from the control element (18 of FIG. 1B), from the temperature sensor, and inputs including a forward voltage measurement or a reverse leakage measurement of the LED. Inputs from control elements external to the LED package may be configured as serial communications or serial inputs, including desired brightness, calibration and transfer coefficients, etc. Inputs from temperature sensors, or inputs including forward voltage and/or reverse leakage measurements, may be generated internally within a particular LED package. In this manner, an LED package is disclosed herein that includes an active electrical element configured to receive a data value and transform the data value according to a transfer function. In certain embodiments, the data value comprises a compressed data code received by the active electrical element, and the active electrical element is configured to transform the compressed data code into a decompressed data code. The decompressed data codes may include signals for brightness level or other control of the LEDs within the LED package.

In certain embodiments disclosed herein, the active electrical element of the LED package is configured to receive data from a data stream comprising user selectable color depth data. Color depth may refer to the number of data bits used to indicate or represent the color of an LED or LED pixel. For example, a 1-bit color depth may include single color colors, such as black and white, and a 24-bit color depth may include 8 bits for each of the red, blue, and green LEDs within a particular LED package. Depending on the application, the user selectable color depth data may include color depths ranging from 1-bit color depth to 100-bit color depth. In certain embodiments, a user may select a color depth for one or more LED packages within an LED display, which may be selected from any of 24-bit, 30-bit, 36-bit, and 48-bit color depths. In some embodiments, a particular bit depth (e.g., one of 24-bit, 30-bit, 36-bit, and 48-bit color depths) may be achieved by selecting a next higher bit depth and zero-padding a number of least significant bits associated with the difference. Depending on the selected color depth, the data stream received by the active electrical element of a particular LED package may be adjusted according to the bit size corresponding to the selected color depth. For example, when changing from a larger color depth to a smaller color depth, the corresponding number of bits and transmission time is reduced. In this way, the bit size of the selectable color depth data is adjustable. At different communication speeds of the data stream, a trade-off can be made between bit size or depth in relation to color depth, frame rate and the number of pixels or sub-pixels in the control chain.

As disclosed herein, the active electrical element of the LED package can be configured to receive various data signals, including compressed or encoded signals and color depth data corresponding to any number of command codes. As previously described, the command code may be included as part of a data packet of the data stream. In certain embodiments, the command code for a particular LED or LED pixel may include an identifier signal that indicates to the active electrical element how the particular LED or LED pixel should respond to the command code. For example, the identifier signal may include: a "0" digital signal indicating that the command code is a single pixel command code for a single LED or a single LED pixel; or a "1" digital signal indicating that the command code is a full pixel command code for all LEDs or all LED pixels. In some embodiments, single pixel data is removed from the data stream by receiving a particular pixel of data, and the single pixel data may be replaced with talkback data or talkback packets as previously described. The single pixel command code may include any one of skip pixel, set brightness return voltage, set brightness return temperature and status, and return or talk-back reverse leakage command, etc. The skip pixel command code allows a particular LED or LED pixel in the chain to be addressed without affecting other LEDs or LED pixels upstream. The full pixel command code may include any of the set brightness of all LEDs or LED pixels or the end of the frame command code. In some embodiments, a frame command code end is provided to indicate that the LED or LED pixel should respond to the next single pixel command code. In some embodiments, single pixel command codes may be sent or retransmitted along the chain for addressing specific LEDs or LED pixels. In this regard, the active electrical element of the LED package that is responsive to the single pixel command code may responsively transmit the single pixel command code with the code changed to indicate an "executed" command code, then wait until the end of the frame command code is received before responding to the next single pixel command code. Such an active electrical element may be referred to as a pseudo-repeater in tandem communication because it receives and retransmits data, but sometimes changes or replaces data, and always does not return the same data as the received data.

Examples of command codes (e.g., 0 or 1 for "ALL" command bits) that may be single pixel command codes or full pixel command codes may include any of reset, set options, set RGB calibration, set RGB transfer coefficients, set RGB thermal coefficient command codes, load (load) data, and a loader. The loading data and the loading program may be used to send and/or receive any data or program to/from the memory element of the active electrical element. In some embodiments, the set option command code may be followed by an additional data byte, where each bit represents one of the following options: red LED off, green LED off, blue LED off, disable thermal off, disable red LED off, disable green LED off, disable blue LED off, communication speed 0, communication speed 1, color depth 0, color depth 1, off/on parity failure, PWM type 0, PWM type 1, resistor select 0, resistor select 1, resistor select 2, not turn off shorted LEDs, use thermal compensation, set validation to confirm that the power on reset condition has been resolved, and use voltage compensation to set a mode for adjusting the PWM duty cycle using forward voltage feedback. Communication speed 0 and 1 options may provide up to four communication speeds for the output or may provide a communication speed for detecting the input. In this regard, an LED package is disclosed that includes an active electrical element configured to change or adapt the communication speed of data without a transmitted clock signal. The color depth 0 and 1 options may be configured to switch between color depths including 24 bit depth, 30 bit depth, 36 bit depth, and 48 bit depth.

As described above, some embodiments may include controlling the brightness and/or gray scale output of the LEDs by a pulsed method, such as PWM. Under general PWM control, the LED may be electrically activated for a portion of a PWM cycle or duty cycle. The PWM period may be referred to as a PWM ratio or PWM frequency and corresponds to a length of time to complete each PWM period. For LED display applications with PWM control, higher PWM frequencies are typically required. Below 60Hz, the human eye may be able to detect the flickering of the LED, while between 60Hz and 1000Hz, jumps with respect to other cyclic (PWM or scanning) sources or recording devices may occur. In this regard, there is provided an LED display as disclosed herein that is capable of PWM operation at an effective PWM frequency of at least 60Hz, or at least 1000Hz, or at least 10000Hz, or within a range including 60Hz and 1000Hz, or within a range including 1000Hz and 10000 Hz.

Higher PWM frequencies may lead to performance tradeoffs, including increased power consumption and reduced linearity. Furthermore, the PWM frequency of a display application may be limited by the color or bit depth of the display and the clock or counter rate. Specifically, the PWM period is equal to the bit depth divided by the clock frequency. In this regard, for High Dynamic Range (HDR) displays, as the bit depth increases, the PWM frequency decreases proportionally to the clock frequency. Thus, the PWM frequency is increased Conventional approaches to rate involve increasing the clock frequency, however, the actual clock frequency may be limited to a range including 1MHz and 50MHz, with some exemplary display applications operating at a clock frequency of 3 MHz. The bit depth corresponds to the number of bits used to represent a particular color in the display. Each bit has two possible values, 0 or 1, so the total number of bits for a particular bit depth is calculated by increasing the number of possible values (2) to a power corresponding to the bit depth. In this manner, 2 bits deep (e.g., 2)²) Corresponding to a total number of bits of 4, 4 bits deep (e.g., 2)⁴) Corresponding to a total number of bits of 16, 16 bits deep (e.g., 2)¹⁶) Corresponding to a total number of bits of 65536, and so on. Thus, for display applications with higher bit depths, it may be difficult to achieve higher PWM frequencies within an acceptable clock frequency range.

According to embodiments disclosed herein, the effective PWM frequency of an LED display is increased by segmenting the duty cycle, wherein the LEDs are electrically activated in each PWM cycle. In other words, the effective PWM frequency is achieved without changing the clock or bit depth, but still remains the same PWM period (e.g., the PWM period remains equal to the bit depth divided by the clock frequency, but the effective PWM frequency becomes the clock frequency multiplied by the number of segments and divided by the bit depth). One way to segment the duty cycle within a PWM period is to shift or reorder a sequence of clock counters, which are compared to the desired stage, resulting in an output control signal for a driver operating at least one LED. In this manner, the duty cycle within each PWM cycle may be segmented over a series of pulses that electrically activate and turn off the LED multiple times within each PWM cycle, rather than continuously maintaining the LED in an electrically activated state for the duration of the duty cycle. In certain embodiments, an active electrical element as disclosed herein incorporated into one or more LED packages of an LED display can be individually segmented for the duty cycle of one or more groups of one or more LEDs.

Fig. 44A is a schematic diagram illustrating an embodiment in which the active electrical element 30 is configured to segment the duty cycle for one or more LEDs. Although fig. 44A includes the components described below, the active electrical element 30 may include many other components as previously described, which are not reproduced in fig. 44A for illustrative purposes. In this regard, fig. 44A may represent an example of an implementation of a sub-block of potentially more complex elements. As previously described, the active electrical element 30 is configured to receive a data stream and responsively send a driving or control signal to one or more LEDs. The data stream may be received by the active electrical element 30 and optionally stored in the memory element 164 or a register. Memory element 164 may include any of the memory elements, register elements, and/or chips previously described for memory element 80 of fig. 8. Additionally, the one or more signal conditioning elements 166 may be configured to convert, manipulate, or otherwise transform the control signals from the data stream before the drive signals are sent to the one or more LEDs, as described for the signal conditioning elements of fig. 8. A separate signal conditioning element input may be provided to introduce the previously described transfer coefficients, etc., into signal conditioning element 166. In some embodiments, signal conditioning element 166 may be optional. In other embodiments, the signal conditioning element 166 may be implemented by hard logic built into the active electrical element 30 for a particular task. In other embodiments, a programmable device such as a microcontroller may be used to transform data by calculation or by other means of program instructions. When present, comparator 168 is configured to receive command signals from the data stream by way of memory element 164 and signal conditioning element 166. The comparator 168 is also configured to receive a clock or counter signal via the clock 170 and the counter 171 and output a control signal based on a comparison of the command signal from the data stream and the counter signal accordingly. Clock 170 and counter 171 may comprise any of the previously described clock configurations. In fig. 44A, the clock 170 and the counter 171 are shown within the active electrical component 30, while in other embodiments the clock 170 may be located external to the active electrical component 30. In addition, inputs for data flow, signal conditioning, and counter translation are shown within the active electrical element 30, as in practice, external inputs may be routed through intermediate components within the active electrical element 30 as previously described.

During operation, clock 170 and counter 171 provide a sequential count corresponding to the desired bit depth for the LED display. In this manner, the counter 171 sequentially counts the total number of bits of the bit depth and then resets or flips to zero. As used herein, sequential counting refers to counting the total number of bits in a numerical order (e.g., 0, 1, 2, 3, 4, …), while non-sequential counting refers to sorting the total number of bits according to a numerical sequence in a non-numerical order while including all of the same total number of bits within one PWM period. Thus, comparator 168 compares bits from the data stream after any signal conditioning/conversion with the count value provided by counter 171 after any counter conversion as described below, and responsively provides a control signal to driver 172. For an exemplary PWM period or cycle, a data value corresponding to a number of bits depending on the bit depth is received from the data stream and compared to a counter value. When the counter value is less than the data value, the comparator 168 may responsively provide a control signal to the driver 172 to electrically activate the corresponding one or more LEDs. As the count value increases, the comparator 168 may responsively provide a control signal to the driver 172 to electrically disconnect the corresponding one or more LEDs when the count value exceeds the data value. In this manner, PWM control is provided to the LEDs, wherein the LEDs are electrically activated for the duty cycle of the PWM cycle and electrically deactivated for the remainder of the PWM cycle. The driver 172 may comprise any of the driver devices and elements previously described, including the driver element 82 as described in fig. 8. In some embodiments, the comparator 168 may be configured to perform a simple comparison of the data value to the counter value, such as less than, less than or equal to, greater than or equal to, and/or not equal to. In other embodiments, the comparator 168 may be configured to perform the comparison based on other logical operations.

As further shown in fig. 44A, a counter translation device 174 or circuit may be provided to receive counter signals from the clock 170 and the counter 171 and responsively translate the counter signals prior to the comparator 168 receiving the counter signals. In this manner, the counter translation device 174 may be configured to rearrange the order of the counter signals such that the comparator 168 performs the above-described comparison with each data value in a non-sequential sequence (e.g., non-numerical order) within each PWM period. By applying the comparison in a non-sequential manner, the output of the comparator 168 may undergo multiple transitions during each PWM cycle. In this manner, depending on the data value, the duty cycle may be segmented into multiple electrically activated portions, rather than a single continuous duty cycle, thereby increasing the effective PWM frequency of the LED. In some embodiments, the counter inverter 174 may be configured to be selectable between a digitally ordered sequence and one or more non-digitally ordered sequences applied in each PWM cycle to selectively switch the active electrical component 30 between the segmented duty cycle and the single pulse duty cycle. In this regard, in some applications the same counter transformation device 174 may provide numeric sort counter values that are not transformed or changed from the counter 171, while in other applications it is also possible to provide transformed and non-numeric sort counter values. In some embodiments, a separate counter transformation input may be provided to the counter transformation device 174 to provide the ability to select between digitally ordered sequences and non-digitally ordered sequences.

Fig. 44B is a schematic diagram illustrating an embodiment in which the counter conversion device 174 of fig. 44A is configured to share respective duty cycles between a plurality of LEDs (LED 1 to LED 3) to segment the LEDs (LED 1 to LED 3). As with fig. 44A, fig. 44B may include many other components as previously described that are not reproduced in fig. 44B. In this regard, fig. 44B may represent an example of an implementation of a sub-block of potentially more complex elements. In fig. 44B, the clock 170 and the counter 171 are configured the same as in fig. 44A. However, the output of the counter conversion device 174 is shared by a plurality of LEDs (LED 1 to LED 3). In this manner, each of the LEDs (LED 1-LED 3) includes a corresponding and separate memory element 164-1-164-3, signal conditioning element 166-1-166-3, comparators 168-1-168-3, and drivers 172-1-172-3. Thus, the output of the counter translation device 174 is shared with each of the comparators 168-1 to 168-3 for comparison with the individual data signals of each of the LEDs (LED 1 to LED 3). In certain embodiments, the LEDs (LED 1-LED 3) may include any number of LEDs forming a plurality or matrix of sub-pixels served by a single counter transformation device 174.

Fig. 45-50 provide tabular views respectively representing the sequence and various non-sequential or modified counter sequences that may be provided by the counter translation device 174 of fig. 44A for PWM control. In certain embodiments, the counter translation device 174 of fig. 44A may have a select/control input to allow selection among any number of count sequences such as those shown in fig. 45-50. In each of fig. 45-50, each row of the table represents a data value that may be received from the data stream for a particular desired output power or LED brightness. These data values are represented in sequential decimal values (e.g., 1, 2, 3, etc.) and their corresponding binary values (e.g., 0000, 0001, 0010, etc.). For each step of the counter sequence, each column represents the counter value (sequential and/or modified) in binary values. For purposes of illustration, the examples shown in fig. 45-50 are provided for a 4-bit depth display application, where 16 possible values (e.g., 0, 1, 2, … 15) are provided for each color or gray level. In practice, the embodiments shown in fig. 45-50 may be extended to larger bit depth applications for higher resolution displays, including but not limited to 24 bit depth, 30 bit depth, 36 bit depth, and 48 bit depth configurations. Each of these bit depth configurations will be divided by 3 for the bit depth of each pixel (e.g., 8, 10, 12, or 16 bits). In the case of a three-color or other multi-subpixel composition, a single counter and transformed counter signal may be shared between all subpixels, each having its own data, comparator and driver, as previously described for fig. 44B.

Fig. 45 shows a tabular diagram for providing counter sequences to comparator 168 of fig. 44A in numerical order. In this regard, the comparator (168 of fig. 44A) compares the data value for a particular PWM period to a counter value that starts at 0 and increases to 15 in numerical order. Since FIG. 45 represents the untransformed linear counter values, the modified counter value portion of the table is left empty. When the data value is greater than the counter value, a control signal (e.g., "1") is provided to electrically activate the corresponding LED. When the data value is less than or equal to the counter value, a control signal (e.g., "0") is provided to electrically disconnect the corresponding LED. In this regard, a data value of 0 will cause the corresponding LED to be electrically turned off for the entire PWM cycle. A data value of 8 will cause the corresponding LED to be electrically activated in 8 consecutive counts of the 16 total counts of the counter sequence, thereby providing a duty cycle corresponding to 50% of the PWM period. As shown, for each of the data values 0 through 15, the corresponding LED is electrically activated once for the duration of the duty cycle in each PWM period. In other words, at most only one electrical pulse is delivered to the LED or at most one positive and one negative transition during each PWM period. At low frequencies, this may lead to significant flicker or flash, and may additionally provide jitter with respect to other light sources or imaging sources.

FIG. 46 shows a tabular representation for providing non-numerically ordered counter values to comparator 168 of FIG. 44A according to an all-bit reversed sequence. Rather than comparing the data values to the digitally ordered counter values provided by the counter 171 of fig. 44A, the counter transformation means 174 of fig. 44A may reorder the counter values by bit reversal to provide modified counter values. For example, when the counter sequence is 3, the sequential counter value 0011 is converted to the modified counter value 1100 that originally corresponds to the counter sequence 12 in the reverse order. For all-bit inversion, all sequential binary counter values are transformed in this manner. This is one of the simplest reordering methods, as it can be achieved by concatenating the bit outputs of the counters in reverse order, and does not require decision logic, computation or lookup. Thus, the comparator 168 of fig. 44A modifies the counter values according to the following non-numerical order: 0. 8, 4, 12, 2, 10, 6, 14, 1, 9, 5, 13, 3, 11, 7, 15 compare data values for a particular PWM cycle. When the data value is greater than the modified counter value, a control signal (e.g., "1") is provided to electrically activate the corresponding LED. When the data value is less than or equal to the modified counter value, a control signal (e.g., "0") is provided to electrically disconnect the corresponding LED. Depending on the particular bit depth and data value, the corresponding LED may be electrically activated and turned off multiple times to provide a particular net duty cycle. For example, a data value of 8 will cause the corresponding LED to be electrically activated in 8 discrete counts out of 16 total counts, cycling (or toggling) on and off 8 times to provide a duty cycle of 50% of the PWM cycle. In this way, the effective PWM frequency for the 50% duty cycle is 8 times higher than the ratio of fig. 45. For data values of 0, 1 and 15, the corresponding LEDs will be driven in a similar manner as shown in fig. 45. While the bit inversion method of fig. 46 provides an increased effective PWM rate for many data values, power consumption may also increase as the LEDs cycle on and off more times per PWM period. As shown, at the 50% data level, the full bit-reversed PWM provides a drive frequency of half the clock rate, which may be much higher than desired. Furthermore, linearity problems may occur because the driver may not accurately follow the high speed signal provided by the comparator.

FIG. 47 shows a tabular representation for providing the comparator 168 of FIG. 44A with modified counter values according to a partial bit reversal sequence. For partial bit inversion, only a portion of the counter bits are inverted. As an example, fig. 47 shows a modified counter value obtained by inverting the first two digits of the counter value. Thus, for a counter sequence of 4, the sequence counter value 0100 representing the decimal value 4 is converted to a modified binary counter value 1000 representing the decimal value 8. In this example, the number of transitions of the 50% stage is reduced by a quarter of the number of full bit reversals by only transitioning the first two digits. Thus, the comparator 168 of fig. 44A modifies the counter values according to the following non-numerical order: 0. 1, 2, 3, 8, 9, 10, 11, 4, 5, 6, 7, 12, 13, 14, 15, the data values for a particular PWM period are compared. By applying partial bit reversal, the corresponding LED may be electrically activated and turned off more times per PWM cycle than the digitally ordered sequence of FIG. 45, but less than the full bit reversal sequence of FIG. 46. For example, a data value of 8 will cause the corresponding LED to be electrically activated and turned off in successive increments of 4 counts to provide a 50% duty cycle. Thus, the corresponding LED will cycle on and off (or toggle) twice in each PWM period with a data value of 8, doubling the effective PWM frequency compared to fig. 45, but benefiting from less power consumption compared to the higher effective PWM frequency of fig. 46. In some embodiments, partial bit reversal may include other numbers that reverse the sequential binary counter value. In some embodiments, the number of bits from none to the total number of counter bits may be reversed. In some embodiments, the selection of how many bits to invert may be hard coded or hard wired in the system. In still further embodiments, adaptive bit reversal may be utilized, which allows changes to the bit reversed and/or partial bit reversed sequences to be accepted as input as user options and/or settings.

As described above, partial bit inversion provides more advantages than the original counter sequence by providing a higher switching frequency (significantly higher than one per PWM cycle), while also providing a switching frequency significantly lower than the clock frequency. However, as shown in the diagram in fig. 47, the data levels below 5 and above 11 are unchanged from the data levels of the original method (e.g., fig. 45). This can be further solved by bit field swapping. The previous embodiment inverts all or a portion of the counter bits. With bit segment swapping, the bit segments are swapped without inverting the bits within each segment. For example, to achieve y pulses in a PWM cycle, 2 may be used^xThe remaining bits of y are exchanged for the bit segment of the x most significant bits. As an example, an 8-bit counter 76543210 having a bit position may have bit position 7 as the most significant bit. If 4 PWM pulses are required per cycle for most data values, the most significant two bits (76) can be moved to the least significant position to provide the sequence 54321076. In this regard, the modification counter using the bit order may be transferred to the comparator 168 of fig. 44A.

FIG. 48 shows a tabular representation for providing the comparator 168 of FIG. 44A with modified counter values through bit field swapping according to a two field ordering. For a two-segment sequence, the modified counter value is obtained by rearranging the 16 values into two different segments, e.g. all even numbers in one segment followed by all odd numbers in the second segment. As previously described, this is accomplished by swapping the order of the counter bits so that the most significant bit is moved to the least significant bit position. Thus, the comparator 168 of fig. 44A modifies the counter values according to the following non-numerical order: 0. 2, 4, 6, 8, 10, 12, 14, 1, 3, 5, 7, 9, 11, 13, 15, the data values for a particular PWM period are compared. As shown, the increased number of data values compared to the partial bit inversion sequence of FIG. 47 may correspond to the LED being electrically activated and turned off twice per PWM cycle, thereby providing a higher effective PWM frequency for lower and higher data values and values of approximately 50%.

FIG. 49 shows a tabular representation for providing counter values modified by bit segment swapping according to a four segment ordering to comparator 168 of FIG. 44A. For a four segment sequence, the modified counter value is obtained by rearranging the 16 values into four different segments. In other words, rather than inverting the bits in each group, the upper two bits are swapped with the lower two bits. As a result, fig. 49 shows that four different segments are provided by: starting with 0, the modified counter value and counting 4 to provide the first four digits of the modified counter sequence, then setting the fifth digit to the modified counter value of 1 and counting 4 to provide the next four digits, and so on. Thus, the comparator 168 of fig. 44A modifies the counter values according to the following non-numerical order: 0. 4, 8, 12, 1, 5, 9, 13, 2, 6, 10, 14, 3, 7, 11, 15, the data values for a particular PWM period are compared. As shown, depending on the data value, the corresponding LED may be electrically activated and turned off anywhere from one to four times per PWM cycle.

FIG. 50 shows a tabular representation for providing counter values modified by bit field swapping according to eight field ordering to comparator 168 of FIG. 44A. For an eight segment sequence, the modified counter value is obtained by rearranging the 16 values into eight different segments. In other words, the upper three bits are swapped with the lower bits, rather than inverting the bits in each group. As a result, fig. 50 shows that up to eight different segments are provided by: the modified counter value starts at 0 and counts eight to provide the first two digits of the modified counter sequence, then sets the third digit to the modified counter value of 1 and counts eight to provide the next two digits, and so on. Thus, the comparator 168 of fig. 44A modifies the counter values according to the following non-numerical order: 0. 8, 1, 9, 2, 10, 3, 11, 4, 12, 5, 13, 6, 14, 7, 15, the data values for a particular PWM period are compared. As shown, depending on the data value, the corresponding LED may be electrically activated and turned off anywhere from one to eight times per PWM cycle. Although the above examples are provided for two, four, and eight segment ordering, these embodiments are extendable to larger bit depth applications for higher resolution displays, including but not limited to 24 bit depth, 30 bit depth, 36 bit depth, and 48 bit depth configurations. For such higher bit depth applications, the higher segment orderings may include sixteen segment, thirty-two segment, and sixty-four segment orderings, and so forth.

In each of fig. 45-50, the last column is zero, so that even for the highest brightness level, the LED is turned off for one clock pulse corresponding to the last counter sequence value. This is one representation of the various embodiments of fig. 45-50 in practice. If it is desired that the maximum level not transition so that the LED remains active for the entire PWM cycle, then the embodiment may omit the last counter value (i.e., the last column) and roll back to zero one cycle earlier than the previous embodiment. For clarity, all of FIGS. 45-50 show the last optional cycle, where the modified counter is the same as the decimal 15 (or binary 1111) sequential value.

By providing various non-numerically ordered and/or modified count sequences as shown in the examples of fig. 45-50, higher effective PWM frequencies can be achieved. In this regard, the active electrical components configured for PWM control may achieve an effective PWM frequency that is higher than a PWM frequency calculated by dividing the clock frequency by the bit depth of the particular application. By providing a higher effective PWM frequency, the LED display can advantageously avoid glitch effects while providing a higher dynamic range with precise high and low brightness levels and maintaining good linearity without having to increase clock rates or sacrifice power efficiency. Such non-numerically ordered and/or modified count sequences may be provided for any of the previously described embodiments, including the LED packages 26 of fig. 2A-2I having a plurality of LED chips forming a pixel, the LED packages 74 of fig. 7 and/or the LED packages 108 of fig. 12B including a plurality of sets of LED chips forming a plurality of pixels, and any of the active electrical element structures, related components, and related system-level configurations as described in fig. 8-12A and 14-35. In certain embodiments, the non-numerically ordered and/or modified count sequences described herein are applicable to a unitary multi-pixel display comprising a plurality of LED chips formed in groups of pixels formed on a common board comprising a common active electrical element, such as an ASIC or a plurality of individual ASICs. Such a unitary multi-pixel display may include one or more of a Chip On Glass (COG), Chip On Board (COB), Package On Package (POP), Package On Board (POB), or PCB assembly.

LED displays as described herein may sometimes require resetting due to various error conditions that may occur. As previously described, the period of no data transfer and/or a command code including a reset command code may be configured to signal a reset or restart condition. In some embodiments, the LED display and corresponding active electrical components may be configured to initiate reset and/or interrupt conditions without periods of no data transmission and/or reset command codes. In this regard, the reset and/or interrupt conditions may be initiated by a common data signal, such as a serial communication signal, by maintaining the line state in the high or low position for a time interval longer than expected for normal operation. Such a reset condition may be signaled, such a reset condition being configured to reset all active electrical elements in the display or one or more individual active electrical elements in the display. For one or more individual active electrical elements, the reset signal may be provided with different lengths and or pulses corresponding to certain active electrical elements. In this regard, an active electrical element that does not correspond to a reset signal may simply pass the reset signal to the next active electrical element. Another way to issue a reset signal to an individual active electrical element within a string is to configure the active electrical element to respond to a "next hard reset" command. In this way, commands may be directed to active electrical elements preceding the target active electrical element to be reset and to the reset signal to its output, thereby avoiding all previous active electrical elements from receiving a hard reset signal. In some embodiments, there may be two such commands: hard reset one and hard reset all commands. A "hard reset one" command will send a separate reset signal, e.g., the shorter of the two reset signals. A hard reset all command may direct a longer pulse at the output to signal a reset of all subsequent active electrical elements in the string. The ability to initiate a reset condition by embedding a reset signal in the data stream may be particularly advantageous for forcing a reset when the LED display and corresponding active electrical element are not responsive to other reset communications, including command codes or periods of no data transmission.

Fig. 51A shows a normal data flow 176 in return-to-zero (RZ) format that may be provided to active electrical components in accordance with the previously described embodiments. Fig. 51B shows a RZ formatted data stream 178 that includes a reset signal 180. As shown, the reset signal 180 corresponds to a time period of duration in which the data stream 178 remains in a high state (e.g., "1"), which is longer than a portion of the normal data stream 176 of fig. 51A. In this manner, the active electrical component for which the reset signal 180 is intended can responsively reset its operating state upon receipt of the reset signal 180. Furthermore, any active electrical element for which the reset signal 180 is not used may simply pass the reset signal 180 to the next active electrical element without initiating a reset action. Although the reset signal 180 is shown in a high state (e.g., "1"), the reset signal 180 may alternatively remain in a low state (e.g., "0"), or the reset signal 180 may include different lengths and/or multiple pulses without departing from the principles disclosed herein. In some embodiments, the data stream 178 may further include one or more commands or instructions indicating the type of reset or interrupt condition that should be initiated after receiving the reset signal 180. Further, data stream 178 may include additional commands indicating the next action to be taken after the reset or interrupt condition is initiated.

As previously described for fig. 8, a thermal management element may be incorporated within the LED package and/or LED display that monitors the operating temperature of the LED package and/or LED display. Accordingly, the operating state of one or more LEDs within the package and/or display may be adjusted based on the monitored temperature provided by the one or more thermal management elements. In some cases, the response time of the thermal management element may be slow, or the thermal management element may be located too far from a particular LED to provide timely thermal compensation. For example, in a three-chip LED package 26 as shown in fig. 2A, the corresponding thermal management element may provide a single operating temperature for the LED package 26 without identifying the individual contribution of each individual LED chip 28-1 to 28-3 to the overall operating temperature. In some cases, one of the LED chips (e.g., 28-1) may operate disproportionately hotter than the other LED chips (e.g., 28-2, 28-3). For this condition, the integrator may be incorporated into the active electrical element 30, which is configured to individually determine the thermal management compensation for each of the LED chips 28-1 through 28-3 within the package. For example, the integrator may compare the operating temperature measured by the thermal management element to one or more different brightness levels delivered to each of the LED chips 28-1 through 28-3 and any calibration constants to calculate an individual thermal compensation adjustment for each of the LED chips 28-1 through 28-3.

The color space or gamut that an LED pixel is capable of displaying may be defined by the individual color points of the LED chips that form the LED pixel. For example, the color space of an LED pixel comprising red, green and blue LED chips may be defined as a triangular area in a chromaticity diagram, wherein the vertices of the triangular area correspond to different color points of the LED chips. In some embodiments, the color space of the input video source may be different from the color space defined by the LED chips of the LED pixels. As a result, the colors displayed on different monitors may be different unless there is a data conversion. In some applications, the video processor may perform the conversion in real time before sending the data signal to the LED display. The LED display may include its own video processor to simulate one or a selection of standard color spaces or color gamuts depending on the video technology used. For example, an LED display capable of a relatively wide color gamut may be configured to display a narrower color gamut, such as the National Television Standards Committee (NTSC) color gamut of analog television based on a particular video source. Such video processors need to be relatively fast and powerful to do this in real time and, therefore, can be relatively expensive. In some embodiments, an active electrical element as previously described may be configured for digital signal processing, i.e., it performs digital signal processing by being able to accept input data from a color space or gamut and transform that data into a color space or gamut that more accurately represents the LED chip controlled by the active electrical element. Since the active electrical elements serve only a small number of sub-pixels (typically 3 for a single pixel RGB and 12 for a 2x2 pixel RGB), the task of color space conversion is significantly simpler, so that a high speed processor is not required to calculate the conversion for all pixels within the display.

In some embodiments, the active electrical element may be configured to control more than 3 LED chips per LED pixel. For example, the active electrical element may be configured to control 4 LED chips for a 4-point color gamut. In such an example, the active electrical element may be configured to receive 3-color input data and transform it to more accurately match the intended 4-point color gamut. In a further example, rather than simply turning on only the green LED, the controller for the LED display may send a green command, and the active electrical element may calculate a combination of drive signals to the LED chips to match the green shade expected by the source data within its respective color space. Thus, the active electrical element can convert the green input signal to a drive signal for all 3 or more LED chips in the LED pixel (e.g., significantly higher green LED emission combined with a smaller amount of blue LED and red LED emission). In certain embodiments, the active electrical components capable of digital signal processing may include one or more ASICs including one or more of arithmetic logic units, microcontrollers, execution controllers, and digital signal processing units.

The embodiments disclosed herein may be implemented in a number of applications, including the LED packages of fig. 2A-6 having a plurality of LED chips forming a plurality of pixels, and the LED packages 74 of fig. 7 and/or the LED packages 108 of fig. 12B including a plurality of sets of LED chips forming a plurality of pixels. Embodiments as described herein may also be applicable to unitary multi-pixel displays comprising a plurality of LED chips formed in groups of pixels formed on a common board comprising a common active electrical element, such as an ASIC or a plurality of individual ASICs. Such a unitary multi-pixel display may include one or more of a Chip On Glass (COG), Chip On Board (COB), Package On Package (POP), Package On Board (POB), or PCB assembly. In this regard, any of the active electrical element configurations, related component configurations, and related system-level configurations as described in fig. 8-12A and 14-51B may be applicable to LED packages and LED display systems.

In certain embodiments, any of the foregoing aspects and/or various individual aspects and features as described herein may be combined to obtain additional advantages. Any of the various features and elements disclosed herein may be combined with one or more other disclosed features and elements, unless the context indicates otherwise.

Those skilled in the art will recognize improvements and modifications to the preferred embodiments of the present disclosure. All such improvements and modifications are considered within the scope of the concepts disclosed herein and the claims that follow.