阅读说明：本技术 Oled光源驱动控制电路及oled灯具 (OLED light source drive control circuit and OLED lamp ) 是由 李佳颖 于 2018-09-13 设计创作，主要内容包括：本发明提供一种OLED光源驱动控制电路及OLED灯具,所述驱动控制电路包括：DC/DC恒压模块,外部收发器,第一内部收发器,微处理模块,线性恒流模块以及OLED屏体光源；微处理模块与第一内部收发器通讯,将检测的输出电压反馈至DC/DC恒压模块,并控制DC/DC恒压模块工作；第一内部收发器通过差分总线与线性恒流模块相连；线性恒流模块包含多个线性恒流芯片,各线性恒流芯片分别具有一第二内部收发器,第二内部收发器的差分总线接口分别连接于与所述第一内部收发器的差分总线接口相连的差分总线通讯线上。本发明具有更强的抗干扰能力,有效提高了整体驱动系统的电路转换效率。(The invention provides an OLED light source drive control circuit and an OLED lamp, wherein the drive control circuit comprises: the OLED screen comprises a DC/DC constant voltage module, an external transceiver, a first internal transceiver, a micro-processing module, a linear constant current module and an OLED screen body light source; the micro-processing module is communicated with the first internal transceiver, feeds back the detected output voltage to the DC/DC constant voltage module and controls the DC/DC constant voltage module to work; the first internal transceiver is connected with the linear constant current module through a differential bus; the linear constant current module comprises a plurality of linear constant current chips, each linear constant current chip is provided with a second internal transceiver, and differential bus interfaces of the second internal transceivers are connected to differential bus communication lines connected with the differential bus interfaces of the first internal transceivers. The invention has stronger anti-interference capability and effectively improves the circuit conversion efficiency of the whole driving system.)

1. An OLED light source driving control circuit, comprising: the OLED screen comprises a DC/DC constant voltage module, an external transceiver, a first internal transceiver, a micro-processing module, a linear constant current module and an OLED screen body light source;

the DC/DC constant voltage module is connected with the anode of an automobile power line and respectively outputs power to the external transceiver, the first internal transceiver, the microprocessor module and the linear constant current module;

one end of the external transceiver is connected with an automobile communication line, the other end of the external transceiver is connected with the micro-processing module, and the external transceiver receives a control signal transmitted by the automobile communication line and transmits the control signal to the micro-processing module so that the micro-processing module can execute a control instruction corresponding to the control signal;

the micro-processing module is communicated with the first internal transceiver, detects the output voltage of the linear constant current module, feeds the detected output voltage back to the DC/DC constant voltage module so that the DC/DC constant voltage module can regulate the output voltage output to the linear constant current module, and controls the DC/DC constant voltage module to work according to the detected voltage or the voltage fed back by the linear constant current module;

the first internal transceiver is connected with the linear constant current module through a differential bus and is used for transmitting signals between the micro-processing module and the linear constant current module;

the linear constant current module comprises a plurality of linear constant current chips, each linear constant current chip is provided with a second internal transceiver, and differential bus interfaces of the second internal transceivers are connected to differential bus communication lines connected with the differential bus interface of the first internal transceiver respectively so as to communicate with the differential bus interface of the first internal transceiver;

the OLED screen light source comprises a plurality of OLED screens corresponding to the linear constant current chips respectively, the output channels of the linear constant current chips are used for controlling the OLED screens to emit light, and each output channel corresponds to one OLED light emitting area;

the DC/DC constant voltage module, the external transceiver, the first internal transceiver, the micro-processing module, the linear constant current module and the ground end of the OLED screen light source are respectively connected with the negative electrode of an automobile power line.

2. The OLED light source driving control circuit of claim 1, wherein an anti-reverse connection circuit is further connected to a line between the DC/DC constant voltage module and a power line of the vehicle.

3. The OLED light source drive control circuit of claim 2, wherein the anti-reverse connection circuit comprises an anti-reverse connection diode or an anti-reverse connection PMOS circuit.

4. The OLED light source drive control circuit of claim 1, wherein the external transceiver is a LIN transceiver and the vehicle communication line is a LIN communication line; or the external transceiver is a CAN transceiver, and the automobile communication line is a CAN communication line.

5. The OLED light source driving control circuit of claim 1, wherein the external transceiver is integrated in the microprocessor module, and further integrated with a voltage regulator LDO.

6. The OLED light source driving control circuit of claim 1, wherein each of the linear constant current chips has a plurality of output channels correspondingly connected to a plurality of light emitting areas in one OLED screen.

7. The OLED light source driving control circuit of claim 6, wherein the number of linear constant current chips multiplied by the number of output channels on one linear constant current chip is greater than or equal to the number of OLED screen bodies multiplied by the number of light emitting areas on one OLED screen body.

8. The OLED light source driving control circuit of claim 6, wherein an over-temperature detection circuit is disposed near the OLED screen light source and connected to the micro-processing module for detecting the temperature of the OLED screen light source and transmitting the detected temperature to the micro-processing module.

9. The OLED light source driving control circuit of claim 8, wherein the over-temperature detection circuit comprises a PCB circuit board, a thermistor, a pull-up voltage divider resistor and an A/D sampling circuit mounted on the PCB circuit board; the thermistor is connected with the pull-up voltage-dividing resistor, one end of the A/D sampling circuit is connected to a line between the thermistor and the pull-up voltage-dividing resistor, and the other end of the A/D sampling circuit is connected with an A/D sampling port of the micro-processing module.

10. The OLED light source driving control circuit of claim 1, wherein the dynamic effect of the OLED light source is controlled via the differential bus; the differential bus adopts a differential bus protocol which is a high-speed digital communication bus protocol based on the combination of a UART protocol and a local differential bus physical layer structure.

11. The OLED light source driving control circuit of claim 1, wherein the first internal transceiver transmits control signals to a second internal transceiver provided inside each linear constant current chip, and the first internal transceiver transmits control signals to the micro-processing module and the linear constant current module.

12. The OLED light source driving control circuit of claim 1, wherein the differential bus communication line is used for collecting the voltage of the OLED screen corresponding to the OLED light emitting area on each channel in each linear constant current chip, and when the voltage of the OLED screen is increased within a preset range, the micro-processing module outputs a feedback signal to adjust the output voltage of the DC/DC constant voltage module, so that each linear constant current chip has enough voltage to increase the voltage of the OLED screen; when the voltage of the OLED screen body rises beyond the preset range, the micro-processing module outputs a feedback signal to increase the output voltage of the DC/DC constant voltage module to a preset limit voltage so as to maintain the preset constant output limit power to provide drive for the OLED screen body light source.

13. An OLED lighting device using the OLED light source driving control circuit as claimed in any one of claims 1 to 12.

Technical Field

The invention relates to the technical field of automobile lamps, in particular to the technical field of automobile OLED lamps, and particularly relates to an OLED light source driving control circuit and an OLED lamp.

Background

As a first light source of an automobile signal lamp, the LED has been widely and mature to be applied to various functional automobile signal lamps. However, when the LED is used as a point light source and applied to a signal lamp with a certain function in a rear lamp of an automobile, a plurality of LEDs are generally required to realize one function, and the light emitting effect of the plurality of LEDs is not dependent on the cooperation of a good optical reflection system and a light distribution lens, so that good light emitting uniformity is difficult to achieve. Organic Light Emitting Diode (OLED) products have two major advantages: on one hand, the self-luminous property of the LED tail lamp is realized, the support of any light source system is not needed, the thickness of the OLED luminous body is only 1.4 mm, the future tail lamp can be pasted on a parking space even like a sticker, the space of a trunk is not needed to be occupied, and the LED tail lamp has larger advantages in volume compared with a common LED product; on the other hand, compared with the point light source of the LED, the OLED has the characteristics of a surface light source and diffuse reflection, has uniform light quality, can realize stepless dimming and cannot cast any shadow. Because the OLED has the advantages of being light, thin, soft, good in light quality and the like, the OLED can be well played in the field of automobile illumination no matter in energy conservation or design. The OLED panel is thinner and thinner, the color of the screen body is from single color to multiple colors, and from a rigid panel to a flexible panel, and the like, so that the OLED lighting technology is mature continuously.

In the existing car lamp OLED drive control system, a pure linear constant current mode is adopted in a drive part, and a PWM dimming port of a multi-path linear constant current chip is switched on and off by directly connecting an IO port of a single chip microcomputer with a switch group in an independent light source control mode, specifically refer to a patent with the patent number of ZL 201720614078.1. The driving mode is low in driving efficiency, occupies a plurality of IO ports of single chip microcomputer resources, is complex in connection harness and is not beneficial to expansibility and platformization. And EMC interference killing feature is poor, and when there is stronger electromagnetic interference in the external world, OLED drive and control circuit receives the interference easily and leads to OLED can the abnormal light-emitting.

Disclosure of Invention

To solve the above and other potential technical problems, an embodiment of the present invention provides an OLED light source driving control circuit, including: the OLED screen comprises a DC/DC constant voltage module, an external transceiver, a first internal transceiver, a micro-processing module, a linear constant current module and an OLED screen body light source; the DC/DC constant voltage module is connected with the anode of an automobile power line and respectively outputs power to the external transceiver, the first internal transceiver, the microprocessor module and the linear constant current module; one end of the external transceiver is connected with an automobile communication line, the other end of the external transceiver is connected with the micro-processing module, and the external transceiver receives a control signal transmitted by the automobile communication line and transmits the control signal to the micro-processing module so that the micro-processing module can execute a control instruction corresponding to the control signal; the micro-processing module is communicated with the first internal transceiver, detects the output voltage of the linear constant current module, feeds the detected output voltage back to the DC/DC constant voltage module so that the DC/DC constant voltage module can regulate the output voltage output to the linear constant current module, and controls the DC/DC constant voltage module to work according to the detected voltage or the voltage fed back by the linear constant current module; the first internal transceiver is connected with the linear constant current module through a differential bus and is used for transmitting signals between the micro-processing module and the linear constant current module; the linear constant current module comprises a plurality of linear constant current chips, each linear constant current chip is provided with a second internal transceiver, and differential bus interfaces of the second internal transceivers are connected to differential bus communication lines connected with the differential bus interface of the first internal transceiver respectively so as to communicate with the differential bus interface of the first internal transceiver; the OLED screen light source comprises a plurality of OLED screens corresponding to the linear constant current chips respectively, the output channels of the linear constant current chips are used for controlling the OLED screens to emit light, and each output channel corresponds to one OLED light emitting area; the DC/DC constant voltage module, the external transceiver, the first internal transceiver, the micro-processing module, the linear constant current module and the ground end of the OLED screen light source are respectively connected with the negative electrode of an automobile power line.

In an embodiment of the invention, an anti-reverse connection circuit is further connected to a line between the DC/DC constant voltage module and the power line of the vehicle.

In an embodiment of the invention, the reverse connection preventing circuit includes a reverse connection preventing diode or a reverse connection preventing PMOS circuit.

In an embodiment of the present invention, the external transceiver is an LIN transceiver, and the vehicle communication line is an LIN communication line; or the external transceiver is a CAN transceiver, and the automobile communication line is a CAN communication line.

In an embodiment of the invention, the external transceiver is integrated in the microprocessor module, and the microprocessor module is further integrated with a regulator LDO.

In an embodiment of the invention, each of the linear constant current chips has a plurality of output channels, and is correspondingly connected to a plurality of light emitting areas in an OLED panel.

In an embodiment of the invention, the number of the linear constant current chips multiplied by the number of the output channels on one linear constant current chip is greater than or equal to the number of the OLED screens multiplied by the number of the light emitting areas on one OLED screen.

In an embodiment of the invention, an over-temperature detection circuit is disposed near the OLED screen light source, and is connected to the microprocessor module, and configured to detect a temperature of the OLED screen light source and transmit the detected temperature to the microprocessor module.

In an embodiment of the present invention, the over-temperature detecting circuit includes a PCB circuit board, a thermistor, a pull-up voltage-dividing resistor and an a/D sampling circuit mounted on the PCB circuit board; the thermistor is connected with the pull-up voltage-dividing resistor, one end of the A/D sampling circuit is connected to a line between the thermistor and the pull-up voltage-dividing resistor, and the other end of the A/D sampling circuit is connected with an A/D sampling port of the micro-processing module.

In an embodiment of the invention, the dynamic effect of the OLED light source is controlled by the differential bus; the differential bus adopts a differential bus protocol which is a high-speed digital communication bus protocol based on the combination of a UART protocol and a local differential bus physical layer structure.

In an embodiment of the invention, the first internal transceiver and the second internal transceiver of each of the linear constant current chips transmit control signals, and the first internal transceiver enables the microprocessor module and the linear constant current module to transmit control signals.

In an embodiment of the invention, the differential bus communication line is used for acquiring the voltage of the OLED screen body corresponding to the OLED light-emitting area on each channel in each linear constant current chip, and when the voltage of the OLED screen body is increased within a preset range, the micro-processing module outputs a feedback signal to adjust the output voltage of the DC/DC constant voltage module, so that each linear constant current chip has enough voltage for increasing the voltage of the OLED screen body; when the voltage of the OLED screen body rises beyond the preset range, the micro-processing module outputs a feedback signal to increase the output voltage of the DC/DC constant voltage module to a preset limit voltage so as to maintain the preset constant output limit power to provide drive for the OLED screen body light source.

The embodiment of the invention also provides an OLED lamp which adopts the OLED light source driving control circuit.

As described above, the OLED light source driving control circuit and the OLED lamp of the present invention have the following beneficial effects:

1. the invention adopts a differential bus communication mode, and the differential bus protocol is an optimized improved high-speed digital communication bus protocol based on the combination of a UART protocol and a local differential bus physical layer structure. Compared with the traditional I2C or SPI communication line, the differential bus communication protocol and the differential bus communication mode have stronger anti-jamming capability because signals in the form of voltage difference similar to 2 differential lines are adopted as transmission signals. The anti-interference capability can bring convenience to the circuit layout of the driving control circuit, the original communication mode of I2C and SPI needs to arrange the linear constant current module with the communication interface and the micro-processing module on the same PCB to avoid external interference caused by overlong communication lines due to weaker anti-interference capability, and the linear constant current module with the communication interface and the micro-processing module can be distributed on different PCBs to be arranged by applying the differential bus communication protocol, so that the control circuit of the automobile lamp with a compact structure can be conveniently designed and arranged.

2. According to the invention, the DC/DC constant voltage module is adopted to preprocess the vehicle body voltage, so that the circuit conversion efficiency of the whole driving system is effectively improved, the power consumption and heat consumed by driving are reduced, and the area of the driving plate can be effectively reduced.

3. The invention adopts a circuit form of combining the front end DC/DC constant voltage module and the rear end linear constant current module, can effectively reduce the external radiation interference of the switching power supply type circuit, and enables the EMC electromagnetic compatibility test to pass more easily.

4. The invention adopts the first internal transceiver and the linear constant current module with the second internal transceiver to communicate through the differential bus, simplifies the control circuit structure, thereby reducing the PCB occupation rate and saving the required number of I/O ports or PWM ports of the MCU.

5. According to the invention, when the OLED has a fault, the EN enabling signal is adopted to close the DC/DC constant voltage module, so that the fault turn-off current of the OLED can be reduced, and the current requirement of the BCM of the body of the whole vehicle factory on fault diagnosis can be more easily met by the lamp.

6. The invention can avoid the phenomenon that the OLED current is reduced due to insufficient output voltage (insufficient voltage difference) supplied to the linear constant current drive at the rear end originally set after the voltage of the OLED screen body is increased due to the aging problem, thereby maintaining the constant luminous flux output of the OLED, maintaining the limit power of a certain preset constant output to provide drive for the OLED light source and avoiding the excessive overheating of the whole lamp system.

7. The invention can reduce the current flowing through the OLED or close the OLED light source, thereby avoiding the damage of high temperature to the OLED.

8. The invention can realize independent control of a plurality of OLED light source light-emitting areas or a plurality of LED light sources through a simpler control circuit framework, and realize functions of rich dynamic effect, character information display and the like.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings needed to be used in the description of the embodiments will be briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.

Fig. 1 is a schematic diagram of the OLED light source driving control circuit according to the present invention.

Fig. 2 is a schematic diagram showing a specific circuit structure of the OLED light source driving control circuit according to the present invention, which employs LIN communication.

Fig. 3 is a schematic diagram showing a specific circuit structure of the OLED light source driving control circuit according to the present invention, in which CAN communication is adopted.

Fig. 4 to 7 are schematic circuit diagrams showing another circuit structure of the OLED light source driving control circuit of the present invention with the same effect.

Fig. 8 is a schematic layout diagram of an OLED panel in the OLED light source driving control circuit according to the present invention.

FIG. 9 is a schematic diagram of the connection of the over-temperature detection circuit in the OLED light source driving control circuit according to the present invention.

Fig. 10 is a schematic circuit diagram of an over-temperature detection circuit in the OLED light source driving control circuit according to the present invention.

Fig. 11 is a diagram illustrating an exemplary DC/DC constant voltage module in the OLED light source driving control circuit according to the present invention.

FIG. 12 is a diagram of an exemplary hardware implementation of the OLED light source driving control circuit according to the present invention.

Fig. 13-1 and 13-2 are schematic diagrams respectively showing the overall structure of the OLED light source driving control circuit according to the present invention when an LED light source is used.

Description of the element reference numerals

110 DC/DC constant voltage module

120 external transceiver

121 LIN transceiver

122 CAN transceiver

130 micro-processing module

140 first internal transceiver

150 linear constant current module

151 second internal transceiver

160 OLED screen light source

170 over-temperature detection circuit

171 PCB circuit board

172A/D sampling circuit

180 lamp control module

190 LED light source

Detailed Description

The embodiments of the present invention are described below with reference to specific embodiments, and other advantages and effects of the present invention will be easily understood by those skilled in the art from the disclosure of the present specification. The invention is capable of other and different embodiments and of being practiced or of being carried out in various ways, and its several details are capable of modification in various respects, all without departing from the spirit and scope of the present invention. It is to be noted that the features in the following embodiments and examples may be combined with each other without conflict.

Please refer to fig. 1 to 13. It should be understood that the structures, ratios, sizes, and the like shown in the drawings and described in the specification are only used for matching with the disclosure of the specification, so as to be understood and read by those skilled in the art, and are not used to limit the conditions under which the present invention can be implemented, so that the present invention has no technical significance, and any structural modification, ratio relationship change, or size adjustment should still fall within the scope of the present invention without affecting the efficacy and the achievable purpose of the present invention. In addition, the terms "upper", "lower", "left", "right", "middle" and "one" used in the present specification are for clarity of description, and are not intended to limit the scope of the present invention, and the relative relationship between the terms and the terms is not to be construed as a scope of the present invention.

The embodiment aims to provide an OLED light source driving control circuit and an OLED lamp, which can be widely applied to an electronic power supply driving and control system of an automobile OLED lamp, can improve the problems of large heat quantity, large required area of a control panel and poor EMC anti-interference capability of an original linear driving system of the OLED lamp, can independently control the light emitting areas of a plurality of blocks in a plurality of complex OLED light sources in an OLED car lamp so as to meet the requirement of a dynamic OLED display effect, can simplify the control system in the OLED lamp, simplify a connecting wire harness on a control loop, and facilitate cascading expansion, can directly cascade and expand the number of rear-end OLED linear constant current driving chips without changing models on the selection of a single chip microcomputer for increasing the light emitting areas of the independently controllable OLED, and is favorable for the platform of an OLED control part.

The invention overcomes the defects that the traditional OLED lamp driving circuit for the vehicle uses a single type linear driving circuit: if the linear constant current type driving is singly used, the driving circuit has low working efficiency, overlarge heat, overlarge area of a driving control panel and poor anti-jamming capability; in order to improve the driving conversion efficiency and reduce the ambient temperature in the whole lamp, a brand new circuit architecture with front end DC/DC + rear end linearity is adopted: the front end is in a DC/DC constant voltage mode, the output voltage is controlled to be about a numerical value slightly higher than the voltage of the OLED, and the power is supplied to the linear drive of the multi-path rear end, so that the working efficiency of the whole system driving circuit is improved, and the heat of OLED driving is reduced.

The principle and the embodiment of the OLED light source driving control circuit and the OLED lamp of the present invention will be described in detail below, so that those skilled in the art can understand the OLED light source driving control circuit and the OLED lamp without creative work.

An embodiment of the present invention provides an OLED light source driving control circuit, including: a DC/DC constant voltage module 110, an external transceiver 120, a first internal transceiver 140, a microprocessor module 130, a linear constant current module 150, and an OLED screen light source 160.

In this embodiment, the DC/DC constant voltage module 110 is connected to the positive electrode of the power line of the vehicle, and outputs power to the external transceiver 120, the first internal transceiver 140, the microprocessor module 130, and the linear constant current module 150, respectively.

The DC/DC constant voltage module 110 not only outputs power to the linear constant current module 150, but also the DC/DC constant voltage module 110 simultaneously outputs power VCC to the external transceiver 120, the microprocessor module 130, and the first internal transceiver 140.

In this embodiment, the interface between the vehicle body and the OLED lamp is a power line VBat, a ground line GND, a LIN communication line, or two CAN communication lines (CANH line and CANL line).

In this embodiment, an anti-reverse connection circuit is further connected to a line between the DC/DC constant voltage module 110 and the power line of the vehicle.

The reverse connection prevention circuit comprises but is not limited to a reverse connection prevention diode or a reverse connection prevention PMOS circuit. For example, the anti-reverse connection circuit adopts an anti-reverse connection diode D1, one end of the anti-reverse connection diode D1 is connected to the power line VBat, and the other end is connected to the input end of the DC/DC constant voltage module 110.

In this embodiment, one end of the external transceiver 120 is connected to a vehicle communication line, and the other end is connected to the microprocessor 130, and receives the control signal transmitted by the vehicle communication line and transmits the control signal to the microprocessor 130, so that the microprocessor 130 can execute the control command corresponding to the control signal.

The external transceiver 120 communicates with a micro processing unit (MCU) 130 through an Rx communication port and a Tx communication port.

Specifically, in this embodiment, as shown in fig. 2, the external transceiver 120 is a LIN transceiver 121, the vehicle communication line is a LIN communication line, and the communication between the OLED lamp and the vehicle body follows a LIN communication protocol; or as shown in fig. 3, the external transceiver 120 is a CAN transceiver 122, the vehicle communication line is a CAN communication line (CANH line and CANL line), and the communication between the OLED lamp and the vehicle body follows a CAN communication protocol.

In this embodiment, the microprocessor module 130 communicates with the first internal transceiver 140, detects the output voltage of the linear constant current module 150, feeds back the detected output voltage to the DC/DC constant voltage module 110 to allow the DC/DC constant voltage module 110 to regulate the output voltage output to the linear constant current module 150, and controls the DC/DC constant voltage module 110 to operate according to the detected voltage or the voltage fed back by the linear constant current module 150.

Specifically, the micro processing module 130 performs an algorithm process according to the detected output voltage of each channel of the linear constant current module 150, selects a highest voltage uout (max) of a plurality of output channels, and then sets a feedback signal FB according to the highest voltage to output the feedback signal FB to the DC/DC constant voltage module 110 so that the DC/DC constant voltage module 110 can adjust the output voltage output to the linear constant current module 150, and controls the DC/DC constant voltage module 110 to operate according to the detected output voltage of the linear constant current module 150. The feedback signal FB may be in the form of: analog voltage values, PWM signals, etc.

In this embodiment, as shown in fig. 4 and 5, the external transceiver 120 may be integrated into the microprocessor module 130, and the microprocessor module 130 further integrates a regulator LDO. When the transceiver is integrated in the microprocessor module 130, an anti-reverse diode D2 for performing anti-reverse protection is added to form an anti-reverse circuit for performing anti-reverse protection on the microprocessor module 130.

As shown in fig. 6 and 7, only the regulator LDO may be integrated in the microprocessor module 130, and the external transceiver 120 is connected to the outside of the microprocessor module 130.

In this embodiment, the first internal transceiver 140 is connected to the linear constant current module 150 through a differential bus, and is configured to transmit signals between the microprocessor module 130 and the linear constant current module 150. Wherein the first internal transceiver 140 is an internal CAN transceiver.

Wherein the dynamic effect of the OLED light source is controlled through the differential bus; the differential bus adopts a differential bus protocol which is a high-speed digital communication bus protocol based on the combination of a UART protocol and a local differential bus physical layer structure.

The micro processing module 130 communicates with the first internal transceiver 140 through Rx and Tx communication ports, and the first internal transceiver 140 is connected to the communication ports of the linear constant current chips in the rear-end linear constant current module 150 through a differential bus, so as to control the switching, dimming and delay of the OLED light source of each channel.

The micro-processing module 130 can output a feedback signal FB to transmit to the DC/DC constant voltage module to adjust the output voltage of the DC/DC constant voltage module 110 at a proper time, and the micro-processing module 130 can output an enable signal EN to transmit to the DC/DC constant voltage module 110 to turn off the operation of the DC/DC constant voltage module 110.

In this embodiment, the linear constant current module 150 includes a plurality of linear constant current chips, each of the linear constant current chips has a second internal transceiver 151, and differential bus interfaces of the second internal transceivers 151 are connected to differential bus communication lines connected to the differential bus interface of the first internal transceiver 140, respectively, so as to communicate with the differential bus interface of the first internal transceiver 140.

The first internal transceiver 140 transmits control signals with the second internal transceiver 151 of each linear constant current chip, and the first internal transceiver 140 transmits control signals with the microprocessor module 130 and the linear constant current module 150.

Wherein the second internal transceiver 151 is also an internal CAN transceiver.

Therefore, in the OLED light source driving control circuit in this embodiment, the DC/DC constant voltage circuit is used as a front-end primary circuit, the input voltage is first adjusted to a range suitable for the rear-end OLED voltage through a high-efficiency driving manner (for example, 12V is reduced to 6V, and the conversion efficiency is about 80% higher than the simple linear constant current conversion efficiency by 30% through DC/DC driving), and then the input voltage is connected to each linear constant current driving chip for accurately controlling the current flowing through the OLED, so that the circuit conversion efficiency of the whole driving system is effectively improved, the power consumption and heat consumption of driving are reduced, and the area of the driving board can be effectively reduced; and because the hybrid circuit of front end DC/DC constant voltage type drive and rear end linear constant current drive is adopted, the rear end second-stage linear constant current circuit can effectively relieve the external radiation interference of the front-stage DC/DC constant voltage type circuit, and compared with the traditional DC/DC type constant current drive, the external radiation interference of the switching power supply type circuit can be effectively reduced, so that the external radiation and external conduction tests in the EMC electromagnetic compatibility test are easier to pass.

OLED is as tail lamp light source, and its purpose is felt in order to embody science and technology, and the super sense of dazzling can realize that single OLED figure region independent control lights respectively, and if the OLED number of pieces is more, just bring the burden to singlechip pin demand. The first generation of driving adopts a shift register chip for converting serial ports into parallel ports for output, so that the number of I/O ports is expanded by converting one-way SPI communication into a plurality of ways of parallel output control, the control architecture needs to additionally increase a plurality of shift register chips and peripheral circuits besides linear constant current driving, and the complexity and the board occupation area of a control circuit are increased. The OLED light source driving control circuit in this embodiment adopts a linear constant current driving chip with a communication function, and utilizes a differential bus communication protocol of the linear constant current driving chip to communicate with the micro-processing module 130 through the first internal transceiver 140 (internal CAN transceiver), so as to achieve diversified OLED graphic display effects through a few simple communication lines, thereby simplifying the structure of the control circuit, reducing the board occupation rate of the PCB, and saving the required number of I/O ports or PWM ports of the MCU. Compared with the communication line mode of I2C or SPI, the differential bus protocol is an optimized improved high-speed digital communication bus protocol based on the combination of UART protocol and local differential bus physical layer structure, has the characteristic of strong anti-electromagnetic interference capability, is particularly beneficial to a dynamic control system of OLED automobile lamps, which needs to independently control each light-emitting area, and the strong anti-interference capability is beneficial to the dynamic OLED automobile lamps to implement dynamic effect according to a preset state, so that the functions of rich dynamic effect, character information display and the like are realized.

Therefore, the original OLED driving and controlling system adopts a shift register chip for converting a serial port into a parallel port for output to realize conversion from one-path SPI communication to a plurality of-path parallel output control so as to expand the number of I/O ports, and the control architecture needs to additionally increase a plurality of shift register chips and peripheral circuits besides linear constant current driving, thereby increasing the complexity of a control circuit and the occupied board area. The OLED light source driving control circuit in the embodiment adopts the linear constant current driving chip with the communication function, the differential bus communication port of the linear constant current driving chip is used for transmitting control signals with the internal CAN transceiver, the control signals are converted by the internal CAN transceiver and then communicated with the micro-processing module 130, diversified OLED graphic display effects are achieved through a few simple communication lines, the structure of the control circuit is simplified, the PCB occupation rate is reduced, and the quantity of I/O ports or PWM ports of the micro-processing module 130 is saved. Compared with the traditional I2C or SPI communication line, the differential bus communication mode has stronger interference resistance. Meanwhile, an open circuit or short circuit fault of an OLED load CAN be fed back to the micro-processing module 130 through a communication interface of an internal CAN transceiver through a differential bus communication interface of the linear constant current driving chip, and then the micro-processing module 130 outputs an enable EN signal to turn off the previous DC/DC constant voltage module 110, so that the OLED fault turn-off current is reduced, and the current requirement of the body BCM of the whole vehicle factory on fault diagnosis CAN be met more easily by the lamp.

In this embodiment, each of the linear constant current chips in the linear constant current module 150 has 1 to n output channels (e.g., n is 12) for connecting the anode of the OLED light source, and the cathode of the OLED light source is connected to GND (the OLED light source is a common cathode, and the required linear constant current chip must be driven at a high side). The linear constant current chips 1-N can be completely hung on a differential bus communication line (the differential bus protocol is an optimized and improved high-speed digital communication bus protocol based on the combination of a UART protocol and a local differential bus physical layer structure), and the number of channels for controlling the OLED light source (the number of OLED single controllable light-emitting areas according to actual requirements) is expanded by cascading in such a way. The linear constant current chip collects the voltage value of the OLED light source on each channel, and transmits the voltage value to the first internal transceiver 140 through the second internal transceiver and the differential bus communication line, the first internal transceiver 140 converts the signal and transmits the signal to the micro-processing module 130, if the voltage abnormality is detected, it can be determined that the OLED is short-circuited or open-circuited, and the micro-processing module 130 can output an EN signal to close the front-end DC/DC constant voltage module 110 to stop supplying power to the rear-end linear constant current module 150. On the other hand, the micro processing module 130 may also collect the OLED light source voltage through the differential bus communication line, for example, the OLED voltage changes within a certain range (non-short circuit and open circuit), and the MCU may output an FB feedback signal to the DC/DC constant voltage module 110 to appropriately adjust the output voltage value of the DC/DC constant voltage module 110 to adapt to the voltage change of the rear-end OLED due to aging, so as to compensate the darkening or lightening of the OLED due to aging.

In this embodiment, the OLED panel light source 160 includes a plurality of OLED panels corresponding to the linear constant current chips, and the output channels of the linear constant current chips control the light emission of the OLED panels.

In this embodiment, each of the linear constant current chips has a plurality of output channels, and is correspondingly connected to a plurality of light emitting areas in an OLED panel.

The output end of each linear constant current chip is respectively connected with the anode led out from each OLED light-emitting area according to each channel number (CH 1-CHn), and the cathode polarity led out from each OLED light-emitting area is all connected with GND.

In this embodiment, the differential bus communication line is used to collect the voltage of the OLED panel corresponding to the OLED light-emitting area on each channel in each linear constant current chip, and when the voltage of the OLED panel rises within a preset range, the micro-processing module 130 outputs a feedback signal to adjust the output voltage of the DC/DC constant voltage module 110, so that each linear constant current chip has enough voltage to raise the voltage of the OLED panel; when the voltage of the OLED panel rises beyond the preset range, the microprocessor 130 outputs a feedback signal to increase the output voltage of the DC/DC constant voltage module 110 to a preset limit voltage, so as to maintain a preset constant output limit power to drive the OLED panel light source.

Specifically, in order to adapt to the change of the electrical characteristic parameters of the screen body of the OLED screen body after aging due to high temperature and solar irradiation and avoid the darkening of the OLED lamp due to environmental factors, the OLED light source driving control circuit in the embodiment adopts the following design: in this embodiment, the micro-processing module 130 of the OLED light source driving control circuit is connected to a first internal transceiver 140 (internal CAN transceiver), the first internal transceiver 140 is connected to the communication port of each linear constant current chip, the micro-processing module 130 converts the signal via the first internal transceiver 140 (internal CAN transceiver), collects the voltage of the OLED screen corresponding to the OLED light emitting area on each channel of the linear constant current chip via a differential bus communication line (the differential bus protocol is an optimized and improved high-speed digital communication bus protocol based on the UART protocol and the physical layer structure of the local differential bus), when the voltage of the OLED screen rises within a certain range (which CAN be defined by user, for example, + 30%), the micro-processing module 130 outputs a feedback signal to adjust the output voltage (follow-up voltage control) driven by the front-end DC/DC constant voltage module, so that the rear-end linear constant current module 150 has enough voltage to keep the OLED with the rising screen voltage to turn on at the original current value, the problem that the voltage of the screen body is increased due to aging is avoided, the OLED current is reduced due to the fact that the originally set output voltage supplied to the rear linear constant current drive is insufficient (the voltage difference is insufficient), and therefore the constant luminous flux output of the OLED is maintained, namely the phenomenon that the whole lamp is darkened after the electrical characteristics of the OLED screen body are changed due to environmental factors is avoided; when the voltage of the OLED screen rises beyond the certain range, the micro-processing module 130 outputs a feedback signal to adjust the driving output of the front-end DC/DC constant voltage module, so that the front-end DC/DC constant voltage module can output a voltage floating up to a certain set proportion as a limit, so as to maintain a certain preset constant output limit power to provide driving for the OLED light source, thereby avoiding excessive overheating of the whole lamp system.

If the OLED light source participates in the regulation and examination of the light distribution of the whole lamp, if a single light emitting area in the OLED light source is damaged, the regulation and regulation compliance of the light distribution of the whole lamp can be possibly influenced, and at the moment, the single light emitting area is damaged and all OLED screen bodies are closed to display the damaged function of the lamp. The original traditional OLED drive control circuit does not have the fault turn-off function. In the OLED light source driving control circuit in this embodiment, the output terminal voltage of each channel, which is supplied by each linear constant current chip to the OLED, is transmitted back to the internal CAN transceiver through the differential bus interface of the linear constant current chip itself, and then the internal CAN transceiver converts the signal and transmits the signal to the micro processing module 130, if the voltage change has the characteristics of OLED short circuit or open circuit, the signal CAN be detected by the micro processing module 130, the micro processing module 130 then outputs an enable EN signal to the front end DC/DC constant voltage module 110 for turning off the DC/DC constant voltage module 110, and stops supplying power to the rear end linear constant current module 150 to turn off all OLEDs, and meanwhile, the micro processing module 130 provides a fault alarm signal and transmits the fault alarm signal to the vehicle body through the CAN/LIN communication line.

In this embodiment, the number of the linear constant current chips multiplied by the number of output channels on one linear constant current chip is greater than or equal to the number of the OLED screens multiplied by the number of light emitting areas on one OLED screen.

Specifically, fig. 8 is an exemplary schematic diagram for explaining the correspondence between the OLED screen and the light emitting region corresponding to the OLED light source in the OLED light source driving control circuit in the embodiment (but not limited to this figure, this figure is only an example). Assuming that M OLED screens of fig. 8 are shared in a vehicle lamp, M independently controllable light-emitting regions are provided in each OLED screen (where M is 3 in fig. 8, that is, 3 independently controllable light-emitting regions are provided in each OLED screen), OLED1-1 represents the leftmost light-emitting region of the first OLED screen, OLED1-2 represents the middle light-emitting region of the first OLED screen, and OLED1-3 represents the rightmost light-emitting region of the first OLED screen; of course m can be larger than 3, then there can be more than 3 m independent light emitting areas in each OLED panel. It should be noted that: wherein N stands for there are N linear constant current chips, and N stands for the output channel quantity in every linear constant current chip, and its relation is: nxn is not less than Mxm, namely the total output channel number of the linear constant current chip set is not less than the light emitting area of all OLED screens needing to be controlled independently.

In this embodiment, as shown in fig. 9, an over-temperature detection circuit 170 is disposed in the OLED panel light source 160, and is connected to the micro-processing module 130, for detecting the temperature of the OLED panel light source 160 and transmitting the detected temperature to the micro-processing module 130.

The over-temperature detection circuit 170 can be arranged in the hottest area in the lamp body, the temperature change in the lamp body is transmitted to the micro-processing module 130 through the over-temperature detection circuit 170, and the micro-processing module 130 can adjust the output control strategy in due time so as to reduce the current flowing through the OLED light source or close the OLED light source, thereby avoiding the damage of high temperature to the OLED light source.

Specifically, as shown in fig. 10, in the present embodiment, the over-temperature detection circuit 170 includes a PCB 171, a thermistor, a pull-up voltage divider resistor and an a/D sampling circuit 172 mounted on the PCB 171; the thermistor is connected to the pull-up voltage-dividing resistor, one end of the a/D sampling circuit 172 is connected to a line between the thermistor and the pull-up voltage-dividing resistor, and the other end is connected to the microprocessor module 130.

In this embodiment, the over-temperature protection principle is as follows:

the thermistor is welded on a PCB board, an electric polarity leads out the wiring, and the PCB board is arranged in an area close to the OLED screen body and fixed at a physical position and used for sensing the temperature of the area close to the OLED. In terms of circuit structure, the over-temperature detection circuit 170 is composed of a pull-up voltage-dividing resistor, a thermistor and an A/D sampling circuit 172, the pull-up voltage-dividing resistor is connected with a pull-up constant voltage VCC, the lower end of the pull-up voltage-dividing resistor is connected with the thermistor, the other end of the thermistor is connected with ground GND, the voltage of the voltage-dividing point which is the connection point between the thermistor and the pull-up resistor is sampled into the microprocessing module 130(MCU) by the A/D sampling circuit 172 of the microprocessing module 130(MCU), when the resistance value of the thermistor changes due to the temperature change, the micro processing unit (MCU) 130 can sense the change of the voltage division point, therefore, the micro processing unit 130(MCU) outputs an FB feedback signal (which may be a 0% -100% PWM signal) to the front-end DC/DC constant voltage module 110 for timely adjustment, so as to reduce the current flowing through the OLED light source or directly turn off the OLED light source.

The DC/DC constant voltage module 110, the external transceiver 120, the first internal transceiver 140, the microprocessor module 130, the linear constant current module 150, and the OLED screen light source 160 are connected to the ground of the vehicle power line.

In this embodiment, the operating principle of the OLED light source driving control circuit is as follows:

the vehicle body inputs signals of two types into the OLED light source driving control circuit, wherein one type is a power line of VBat and GND, VBat is a positive pole of the power line, GND is a negative pole of the power line, and the positive pole and the negative pole form a current loop of the whole OLED light source driving control circuit and are responsible for power supply of the power source of the whole OLED light source driving control circuit; the other one is a communication signal line LIN (1 LIN line input) or CAN (CANH and CANL two line inputs), which is responsible for the control functions of the OLED light source driving control circuit, for example: whether the power supply of the OLED needs to be turned on or not is transmitted through the LIN or CAN communication line, or a certain preset signal is input into the vehicle body through the LIN or CAN communication line, different light-emitting areas of the OLED respectively execute dynamic display according to a certain specific dynamic effect to represent a certain special scene definition of the vehicle body (such as a welcome mode, when a vehicle key approaches, the OLED rear lamp CAN meet the vehicle owner through the display of the certain preset dynamic effect).

The reverse connection preventing circuit provides reverse connection prevention for the whole OLED light source driving control circuit, can be composed of a diode or a PMOS reverse connection preventing circuit with the same effect, and is used for preventing damage to a system after the positive electrode and the negative electrode of a power supply are reversely connected. The DC/DC constant voltage module 110 may be, for example, a BUCK DC/DC and E522.10 chip model, or may be composed of a BUCK SEPIC and ZETA constant voltage circuit and other DC/DC chips of similar function.

As shown in fig. 11, an exemplary diagram of the DC/DC constant voltage module 110 is shown. The DC/DC constant voltage module 110 may be composed of an input filter circuit, a DC/DC driver chip (taking E522.10 of ELMOS manufacturer as an example), and a peripheral circuit (see the circuit structure of the DC/DC constant voltage module 110 in fig. 11 for details) constituting a constant voltage topology architecture (BUCK topology, SEPIC BUCK-boost topology, or ZETA-form BUCK topology), and an output filter circuit: the input filter circuit is used to mitigate the ripple of the DC/DC switching power supply circuit, fig. 11 is a DC/DC BUCK constant voltage circuit (fig. 11 is an example of this type, but the example is not limited to this BUCK type, and can be extended to a BUCK-boost type SEPIC or ZETA type constant voltage circuit): in fig. 11, C1, L1, and C2 form an input filter circuit; u1, D1, L2 and C5 form a DC/DC type BUCK voltage reduction topological structure; c8, C6 and C7 form an output filter circuit; the remaining devices in fig. 11 constitute peripheral circuits of the DC/DC constant voltage BUCK circuit. The negative electrode of D1 in the OLED light source driving control circuit is connected to the VIN-D1 port in fig. 11, the power output of the DC/DC constant voltage output module in the OLED light source driving control circuit is the DC/DC-VOUT port in fig. 11, and this port is connected to the power input end of the rear linear constant current chipset. The DC/DC constant voltage module 110 outputs a constant voltage to the power input terminal of the rear linear constant current module 150, and the voltage applied to both ends of the secondary linear constant current chipset can be reduced by the primary constant voltage at the front end, so as to reduce the power consumption on the secondary linear constant current chip.

The communication signal of the internal transceiver of each linear constant current chip (for example, TPS929XX series of TI) in the linear constant current module 150 is connected to the communication port of the first internal transceiver 140 (internal CAN transceiver) through differential bus lines (ICANH and ICANL lines) to transmit a control signal; an input signal port of the first internal transceiver 140 is connected to a communication port of the microprocessor module 130 to receive a control signal transmitted by the microprocessor module 130, so that the microprocessor module 130 CAN convert the signal through the internal CAN transceiver and independently control a power supply output channel of each linear constant current chip through a differential bus output instruction, and the control method includes: switching each channel and individual dimming, switching, and time delay or interval control of each channel. Each linear constant current chip is provided with n power supply output channels CH 1-n, each output channel is connected with the anode led out from the lead of one OLED independent control light-emitting area to provide constant current for the OLED to emit light, and the cathodes of all the OLED independent light-emitting areas are connected with the ground GND. The DC/DC constant voltage module 110 CAN also provide a power supply with a constant voltage VCC to supply power to the microprocessor module 130 and the LIN transceiver 121, the LIN transceiver 121 receives a communication signal LIN of a vehicle body, transmits a vehicle body instruction to the microprocessor module 130 through conversion of the LIN transceiver 121, the microprocessor module 130 receives the signal instruction, converts the signal through the internal CAN transceiver 122, and transmits a control signal to each linear constant current chip at the rear end through the differential bus, thereby realizing independent control of each channel, i.e., independent control of each light emitting area.

In addition, the micro processing module 130 collects the voltage value output by each channel of each linear constant current chip through the internal CAN transceiver through the differential bus, for example, if the voltage value is abnormal, such as an OLED open circuit or a short circuit, the micro processing module 130 CAN collect the abnormal value and correspondingly output an enable signal EN to shut down the operation of the front end DC/DC constant voltage module 110; if the voltage value collected by the micro-processing module 130 through the internal CAN transceiver via the differential bus increases or decreases within a certain preset value range, the micro-processing module 130 may output the feedback signal FB to adjust the output voltage of the DC/DC constant voltage module 110, thereby compensating for the decrease or increase of the OLED current caused by the screen voltage change due to the aging of the OLED.

As shown in fig. 12, since the front-end DC/DC constant voltage module is used for voltage preprocessing and the differential bus with strong anti-interference capability is used for control signal transmission in the present embodiment, the anti-reverse diode D1, the DC/DC constant voltage module 110, the external transceiver 120, the micro-processing module 130 and the first internal transceiver 140 are combined into a lamp control module 180, the lamp control module 180 can be designed into a standardized and platform independent control module, the lamp control module 180 is independent from the OLED light source driving control circuit architecture to form a physically independent control module, the hardware circuit design of the lamp control module 180 can be suitable for different lamps of the vehicle, and different software can be programmed into the control module according to different light control effects. The lamp control module 180 can be arranged outside the automobile lamp as a standard Master control module Master, while the linear constant current module 150 and the OLED screen body light source 160 in the OLED light source driving control circuit architecture in the embodiment can be independently arranged inside the lamp together, and the linear constant current module 150 is used as a Slave driving circuit Slave, and different circuit designs are made according to different lamp models.

Note that, as shown in fig. 13-1 and 13-2, the above OLED light source drive control circuit is also applicable to the LED light source 190. For example: when the automobile lamp formed by the plurality of LED light sources has the functional requirements of dynamically displaying or independently controlling the independent on-off, dimming and text or information display of each LED light source, the light source driving control circuit scheme of the invention can be used for realizing the functions. As shown in fig. 13-1 and 13-2, the linear constant current chip in fig. 13-1 is driven at the high side, and the linear constant current chip in fig. 13-2 is driven at the low side, both of which are suitable for the LED light source 190.

The embodiment of the invention also provides an OLED lamp which adopts the OLED light source driving control circuit. The OLED light source driving control circuit has already been described in detail above, and is not described herein again.

In summary, the present invention adopts a differential bus communication manner, which has stronger anti-interference capability compared to the conventional I2C or SPI communication line; the invention adopts a circuit mode of combining the front-end DC/DC constant voltage module and the rear-end linear constant current module, thereby effectively improving the circuit conversion efficiency of the whole driving system, reducing the power consumption and heat consumed by driving and effectively reducing the area of the driving plate; the invention can effectively reduce the external radiation interference of the switching power supply type circuit, and enables the EMC electromagnetic compatibility test to pass more easily; the invention simplifies the control circuit framework, thereby reducing the PCB occupation rate, saving the required quantity of I/O ports or PWM ports of the MCU, and reducing the OLED fault turn-off current, so that the lamp can more easily meet the current requirement of the body BCM of the whole vehicle factory on fault diagnosis; according to the invention, the phenomenon that the OLED current is reduced due to insufficient output voltage (insufficient voltage difference) supplied to the rear-end linear constant current drive originally set after the voltage of the screen body is increased due to the aging problem can be avoided, so that the constant luminous flux output of the OLED is maintained, a certain preset constant output limit power can be maintained to provide drive for an OLED light source, and the excessive overheating of the whole lamp system is avoided; the invention can reduce the current flowing through the OLED or close the OLED light source, thereby avoiding the damage of high temperature to the OLED. Therefore, the invention effectively overcomes various defects in the prior art and has high industrial utilization value.

The foregoing embodiments are merely illustrative of the principles and utilities of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or change the above-mentioned embodiments without departing from the spirit and scope of the present invention. Accordingly, it is intended that all equivalent modifications or changes which can be made by those skilled in the art without departing from the spirit and technical spirit of the present invention shall be covered by the claims of the present invention.