阅读说明：本技术 用于调节用于发光二极管阵列的电源的方法和器件 (Method and device for regulating power supply for light emitting diode array ) 是由 D·耐特菲尔德 于 2019-07-23 设计创作，主要内容包括：本发明涉及一种具有由发光二极管(LED)组成的发光二极管阵列的布置系统,其中,每个发光二极管(LED)能够借助可控制的开关接通和断开；并且所述布置系统具有用于为发光二极管阵列供应电流的电源(Q),其中,所述布置系统具有接口(IF),在所述接口上能够施加具有有关可借助发光二极管阵列显示的图像的图像信息的输入信号并且所述接口(IF)将输入信号转换成数字信号(CLK、DATA、ENA、LD),在所述数字信号中包含有关接通和断开可控制开关的信息,以及所述布置系统具有计数器(COUNTER),借助所述计数器能够检测,在一个时钟节拍内多少开关是闭合的或者应当闭合,以及能够根据计数器读数控制由电源(Q)提供的电流。(The invention relates to an arrangement having a light-emitting diode array of light-emitting diodes (LEDs), wherein each light-emitting diode (LED) can be switched on and off by means of a controllable switch; and having a power supply (Q) for supplying current to the LED array, wherein the arrangement has an Interface (IF) on which an input signal with image information about an image displayable by means of the LED array can be applied and which converts the input signal into a digital signal (CLK, DATA, ENA, LD) in which information is contained to turn on and off the controllable switches, and a COUNTER (COUNTER) by means of which it can be detected how many switches are closed or should be closed within one clock cycle and the current supplied by the power supply (Q) can be controlled depending on the COUNTER reading.)

1. Arrangement having a light-emitting diode array of light-emitting diodes (LEDs), wherein each light-emitting diode (LED) can be switched on and off by means of a controllable switch, and having a power supply (Q) for supplying the light-emitting diode array with current, characterized in that,

-the arrangement system has an Interface (IF) on which an input signal with image information about an image displayable by means of the led array can be applied, and which converts the input signal into a digital signal (CLK, D, ENA, LD) in which information about the switching on and off of the controllable switches is contained, and

the arrangement system has a counter (C) by means of which it can be detected how many switches are closed or should be closed in a clock cycle, and

-the current supplied by the power supply (Q) can be controlled according to the counter reading.

2. The arrangement according to claim 1, characterized in that the counter (C) is a digital counter, which digitally provides a counter reading.

3. An arrangement as claimed in claim 2, characterized in that a register is connected to the counter, into which register a counter reading can be transferred and from which register a counter reading can be retrieved.

4. An arrangement as claimed in any one of claims 1 to 3, characterized in that the arrangement has a digital-to-analog converter (R2) for converting the counter reading into an analog signal for controlling the power supply (Q).

5. Arrangement according to one of claims 1 to 4, characterized in that the arrangement has means for regulating the switches (SR/L).

6. Arrangement according to claim 5, characterized in that the means (SR/L) for adjusting the switches have a first register into which the switch states of the switches can be input.

7. An arrangement as claimed in claim 6, characterized in that the first register is connected indirectly or directly to the control input of the controllable switch.

8. Arrangement according to one of claims 5 to 7, characterized in that the means (SR/L) for adjusting the switches comprise a second register, which is connected to the interface and to the first register.

9. An arrangement as claimed in any one of claims 1 to 8, characterized in that the digital signal of the Interface (IF) comprises a make and break signal (D) in which the switching state of the light-emitting diode (LED) that should be possessed by the light-emitting diode is specified.

10. Arrangement according to one of claims 1 to 9, characterized in that the digital signal of the interface comprises a clock signal (CLK) of a predefined clock cycle.

11. An arrangement as claimed in claim 10, characterized in that the switch states which the switches should have can be transmitted in turn in the make and break signal (D).

12. The arrangement according to claim 11, characterized in that the counter (C) is incremented or decremented from an initial value when the make and break signal indicates that the switching state of the light emitting diode is "on" or that the switching state is "off", or is incremented only when the make and break signal indicates that the switching state is "on", or is decremented when the make and break signal indicates that the switching state is "off".

13. An arrangement as claimed in claim 11 or 12, characterized in that the second register of the means (SR/L) for adjusting the switches is a shift register into which the switch states which the switches should have can be transmitted in turn by on and off signals entering the shift register.

14. Arrangement according to one of claims 3 to 13, characterized in that the digital signal comprises a received signal (LD) in the presence of which a current counter reading can be transferred into a register of a counter and/or in the presence of which the content of a second register should be transferred into a first register.

Technical Field

The present invention relates to a method and device for regulating the power supply for an array of light emitting diodes.

Background

A method and a device for regulating the power supply for supplying a light-emitting diode array are known from document DE 102010060857 a 1. An led array which receives an electrical energy supply by means of a current supply as described in DE 102010060857 a1 usually has a number of leds of up to 20, some of which have different current voltages, which leads to differences in the brightness of the leds for the same current. However, in order to obtain a uniform appearance of the led array, it is important that all leds of the led array leave the same brightness impression to the viewer. PWM (pulse width modulation) is used to achieve this goal. The switches are switched on and off in series with the LEDs by means of PWM, so that the average brightness of the light emitting diodes is the same. Due to the PWM control of the brightness of the light emitting diode, the current required by the light emitting diode array to achieve the desired brightness may fluctuate. Therefore, the power supply for powering the led array must be continuously adjusted according to the turned-on leds.

Light emitting diode arrays with significantly more light emitting diodes are used in newer applications. Therefore, light emitting diode arrays having more than one thousand light emitting diodes are no longer uncommon. In the case of such a large number of light-emitting diodes, the influence of the individual light-emitting diodes on the brightness impression of the light-emitting diode array is of less importance. The costly PWM control of the brightness of each individual led can therefore be dispensed with. A uniform brightness impression is ensured by the plurality of light-emitting diodes.

If the led array is operated in the rear region of the motor vehicle, this can be achieved with a lower current than in the case of use in the front region. Light-emitting diodes operated with low currents have a significantly higher differential resistance. Furthermore, due to the higher differential resistance, the difference in the current voltage of the individual light-emitting diodes of such a light-emitting diode array has a much smaller effect than in the case of light-emitting diodes which are operated with a higher current (for example 3A).

For this reason, light-emitting diodes known today are used in motor vehicles not only to provide functional lamps. Very often, the led array is a component of a so-called combination light, which in the case of motor vehicles assumes a multiplicity of lighting functions. For different functions of the light-emitting diode array (for example as a position light, a turn signal light, a brake light, a rear fog light, etc.), it is common to switch the individual light-emitting diodes of the light-emitting diode array on and off separately. It is thus also possible to display symbols by means of an array of light emitting diodes.

That is to say, even in the case of newer, larger arrays of light-emitting diodes, it must in principle still be possible to switch the individual light-emitting diodes on and off separately. Accordingly, in the case of the newer, larger light-emitting diode arrays, it is reasonable to be able to adjust the current for supplying the light-emitting diode array, which current achieves the desired brightness of the light-emitting diodes.

The invention proceeds from this.

Disclosure of Invention

The object of the present invention is to provide a simple method for regulating the power supply for supplying a light-emitting diode array.

According to the invention, this task is achieved by:

the arrangement system has an interface, to which an input signal with image information about an image displayable by means of the light-emitting diode array can be applied and which converts the input signal into a digital signal, in which information about the switching on and off of the controllable switches is contained, and

the arrangement system has a counter, by means of which it can be detected how many switches are closed or should be closed in a clock cycle, and

-the current supplied by the power supply can be controlled according to the counter reading.

The input signal with the image information specifies which light-emitting diodes of the light-emitting diode array should be switched on or off. The image contained in this information can be predefined that all or only some of the light-emitting diodes should be switched on. If only a part of the light emitting diodes of the light emitting diode array should be switched on, these light emitting diodes can be arranged in the associated area of the light emitting diode array. However, it is also possible for the image information to be predefined, for the pattern to be displayed by the led array and for the leds to be selected in particular to be switched on.

The input signal may be a video signal, such as an RGB signal or a monochrome signal. The interface can accordingly be a video interface. But it is also possible that the Interface is an SPI (Serial Peripheral Interface).

The counter may be a digital counter that digitally provides a counter reading.

Preferably, a register is connected downstream of the counter, into which register the counter reading can be transferred and from which register the counter reading can be retrieved. The counter reading can be left in the register for retrieval until the contents of the register are overwritten. The counter can be reset after the counter reading is transferred into the register and used for a new counting process.

The arrangement according to the invention can have a digital-to-analog converter in order to convert the counter reading into an analog signal for controlling the power supply. For this purpose, the digital-analog converter can be connected to the counter or to a register connected downstream of the counter.

Preferably, the arrangement according to the invention has a device for adjusting the switch. The device for adjusting the switch can have a first register into which the switching state of the switch can be input. The first register can be connected indirectly or directly to the control input of the controllable switch. The switch can thereby be switched on or off or maintain its state in accordance with the register content.

The device for adjusting the switch preferably has a second register, which is connected to the interface and to the first register.

The digital signal of the interface can comprise a make and break signal in which the switching state of the light emitting diode that should be possessed by the light emitting diode is stated.

The digital signal of the interface can comprise a clock signal of a predetermined clock cycle.

The switch states which the switches should have can be transmitted sequentially or in series in the on and off signals.

When the on and off signal indicates that the switching state of the light emitting diode is "on" or the switching state is "off", the counter can be incremented or decremented from an initial value.

The counter can be incremented or decremented from the initial value only if the on and off signal indicates that the switching state of the light emitting diode is "on" or that the switching state is "off".

The second register of the means for adjusting the switches may be a shift register into which the switch states which the switches should have can be transferred sequentially or serially by means of make and break signals entering the shift register.

The digital signal can comprise a received signal in the presence of which the current counter reading can be transferred into a register of the counter and/or in the presence of which the content of the second register should be transferred into the first register.

Drawings

The invention is explained in more detail below with reference to the drawings. The attached drawings are as follows:

fig. 1 shows a schematic view of an arrangement according to the invention.

Detailed Description

The arrangement according to the invention is used for controlling light-emitting diodes LEDs of a light-emitting diode array.

The arrangement according to the invention shown in fig. 1 has an interface to which an input signal containing image information can be applied. The interface converts an input signal into a digital signal including a turn-on and turn-off signal D, a reception signal LD, and a clock signal CLK. An activation and deactivation signal ENA can furthermore be provided, but this activation and deactivation signal is of no particular significance for the present example.

The digital signal is supplied to a device SR/L for adjusting the switches, which has a first register and a second register, which is a shift register. The switching states which the light-emitting diodes LEDs should have, coded in the on and off signal D, are in turn input into a shift register.

The contents of the shift register are transferred into the first register as soon as they are displayed in the received signal LD. The first register is connected to a control input of a controllable switch of the light-emitting diode array, by means of which control input the individual light-emitting diode LEDs can be switched on or off individually. The data word to be reserved in the first register then corresponds to the switching state of the light-emitting diode.

The on and off signal D is also transmitted in series to the counter, together with the switch states encoded therein. Upon transmission of the switch-on signal, the counter is incremented from an initial value, preferably zero. As soon as the received signal LD shows that the contents of the shift register should be transferred into the first register, the counter reading of the counter is transferred into a register connected downstream of the counter and the counter is reset to the initial value. The transmitted counter reading is then retained in a register for retrieval.

The register connected downstream of the counter is connected to a digital-to-analog converter R2R. Which converts the digitized counter reading into an analog signal corresponding to the counter reading. The analog signal is fed as a reference variable REF to the power supply and the power supply is controlled in such a way that it adjusts the current predefined by the reference variable in order to supply the current to the light-emitting diode LEDs of the light-emitting diode array connected to the power supply.

With the arrangement according to the invention it is ensured that the power supply always supplies the current required for the proper operation of the light-emitting diodes of the light-emitting diode array.

List of reference numerals

IF interface

CLK clock signal

D on and off signals

ENA activation signal

LD received signal

SR/L device for regulating switch

n number of light emitting diodes

Light emitting diode of LED array

C counter

m counter reading

R2R digital-to-analog converter

REF reference variable

Q power supply