LED backlight control system and the backlight driver chip used therein

Abstract

This invention provides an LED backlight control system and a backlight driver chip used therein. The backlight driver chip used in the LED backlight control system includes two communication connection ports having the same circuit structure and a port control unit. The port control unit is configured to, when receiving a preset waveform signal through either of the two communication connection ports, set that communication connection port as the master communication connection port of the backlight driver chip and set the other communication connection port as the slave communication connection port of the backlight driver chip.

Description

Technical Field

[0001] This invention relates generally to the field of integrated circuits, and more particularly to an LED backlight control system and a backlight driver chip used therein. Prior Technology

[0002] With the development of light-emitting diode (LED) display technology, mini LED (Mini LED) display devices can adjust the brightness of different Mini LEDs according to the image displayed on the screen to improve the picture effect, and are therefore becoming increasingly popular.

[0003] Figure 1 shows a schematic block diagram of the system architecture of a traditional LED backlight control system. As shown in Figure 1, the LED backlight control system 100 includes a backlight controller 102 and backlight driver chips 104-1 to 104-n (n is an integer greater than 1) cascaded via a single-line link. Each backlight driver chip has a main communication connection port and a slave communication connection port. The main communication connection port is connected to the backlight controller or the previous-level backlight driver chip and is used to receive signals from the backlight controller or the previous-level backlight driver chip. The slave communication connection port is connected to the next-level backlight driver chip or the backlight controller and is used to output signals to the next-level backlight driver chip or the backlight controller. When the positions of the two communication connection ports on the backlight driver chip are fixed, when laying out the wiring between the backlight driver chips, it may not be possible to guarantee that the slave communication connection port of the previous-level backlight driver chip is always closer to the main communication connection port of the next-level backlight driver chip. In this case, it is necessary to rotate the backlight driver chip or change the wiring method, which may result in additional jumpers, increasing the application difficulty and cost. Summary of the Invention

[0004] According to an embodiment of the present invention, a backlight driver chip for use in an LED backlight control system includes two communication connection ports having the same circuit structure and a port control unit. The port control unit is configured to, when receiving a preset waveform signal through either of the two communication connection ports, set that communication connection port as the main communication connection port of the backlight driver chip and set the other communication connection port as the slave communication connection port of the backlight driver chip.

[0005] An LED backlight control system according to an embodiment of the present invention includes a backlight controller; and one or more of the aforementioned backlight driver chips. Simple Explanation of the Diagram

[0006] The invention can be better understood from the following description of specific embodiments of the invention in conjunction with the accompanying drawings, wherein: Figure 1 shows a schematic block diagram of the system architecture of a traditional LED backlight control system. Figure 2 shows a schematic block diagram of an example structure of a backlight driver chip used in an LED backlight control system according to an embodiment of the present invention. Figure 3 shows a schematic block diagram of an example structure of a communication connection port used in the backlight driver chip shown in Figure 2. Figure 4 shows a schematic flowchart of the port setup process performed by the backlight driver chip shown in Figure 2. Figure 5 shows a schematic block diagram of the system architecture of the LED backlight control system according to an embodiment of the present invention. Figures 6A and 6B show example waveform diagrams of preset waveform signals used in the LED backlight control system shown in Figure 5. Implementation

[0007] The features and exemplary embodiments of various aspects of the present invention will now be described in detail. In the following detailed description, numerous specific details are set forth in order to provide a comprehensive understanding of the invention. However, it will be apparent to those skilled in the art that the invention may be practiced without requiring some of these specific details. The following description of embodiments is merely intended to provide a better understanding of the invention by illustrating examples of the invention. The invention is by no means limited to any specific configuration and algorithm presented below, but covers any modifications, substitutions, and improvements to elements, components, and algorithms without departing from the spirit of the invention. Well-known structures and techniques are not shown in the drawings and the following description in order to avoid unnecessarily obscuring the invention. Furthermore, it should be noted that the term "A connected to B" as used herein can mean "A and B are directly connected" or "A and B are indirectly connected via one or more other elements."

[0008] In view of one or more problems existing in traditional LED backlight control systems, an LED backlight control system and a backlight driver chip used therein are proposed according to embodiments of the present invention. The backlight driver chip includes two communication connection ports (e.g., input / output (IO) ports) with the same circuit structure. Users can, according to the actual layout, use either one communication connection port as the main communication connection port to connect to the previous stage backlight driver chip or backlight controller, and use the other communication connection port as the slave communication connection port to connect to the next stage backlight driver chip or backlight controller. It should be noted that, in practical applications, the last stage backlight driver chip in the LED backlight control system can either not be connected to other devices to form a unidirectional link, or it can be connected to the backlight controller to form a loop link.

[0009] Figure 2 shows a schematic block diagram of an example structure of a backlight driver chip used in an LED backlight control system according to an embodiment of the present invention. As shown in Figure 2, the backlight driver chip 200 used in the LED backlight control system includes a first communication connection port 202, a second communication connection port 204, and a port control unit 206. The first communication connection port 202 and the second communication connection port 204 are two input / output ports with the same circuit structure. The port control unit 206 is configured to, when a preset waveform signal is received through either the first communication connection port 202 or the second communication connection port 204, set that communication connection port as the main communication connection port of the backlight driver chip 200 and set the other communication connection port as the slave communication connection port of the backlight driver chip 200. In other words, if the port control unit 206 receives a preset waveform signal through the first communication connection port 202, then the first communication connection port 202 is set as the master communication connection port and the second communication connection port 204 is set as the slave communication connection port; if the port control unit 206 receives a preset waveform signal through the second communication connection port 204, then the second communication connection port 204 is set as the master communication connection port and the first communication connection port 202 is set as the slave communication connection port.

[0010] In some embodiments, the port control unit 206 may be further configured to set both the first communication connection port 202 and the second communication connection port 204 to an input state (e.g., a high impedance state) before the backlight driver chip 200 starts operating after power-on. In this case, the port control unit 206 does not distinguish between master and slave communication connection ports.

[0011] In some embodiments, the port control unit 206 may be further configured to output a preset waveform signal to the next-stage backlight driver chip in the LED backlight control system via the communication connection port after the main communication connection port and the slave communication connection port have been set.

[0012] In some embodiments, the port control unit 206 may be further configured to perform one or more of the following processes when the main communication connection port is set to an input state and the secondary communication connection port is set to an output state: receiving a first control signal from the previous stage backlight driver chip or backlight controller in the LED backlight control system through the main communication connection port, and outputting a second control signal to the next stage backlight driver chip in the LED backlight control system through the secondary communication connection port, wherein the first control signal and the second control signal are generated based on the backlight control signal issued by the backlight controller.

[0013] In some embodiments, the port control unit 206 may be further configured to perform one or more of the following processes when the main communication connection port is set to an input state and the secondary communication connection port is set to an output state: receiving a first feedback signal from the previous stage backlight driver chip in the LED backlight control system through the main communication connection port, and outputting a second feedback signal to the next stage backlight driver chip or backlight controller in the LED backlight control system through the secondary communication connection port, wherein the first feedback signal and the second feedback signal are generated based on backlight feedback signals provided by one or more backlight driver chips in the LED backlight control system.

[0014] In some embodiments, the port control unit 206 may be further configured to perform one or more of the following processes when the main communication connection port is set to an output state and the secondary communication connection port is set to an input state: receiving a first feedback signal from the next-stage backlight driver chip in the LED backlight control system via the secondary communication connection port, and outputting a second feedback signal to the previous-stage backlight driver chip or backlight controller in the LED backlight control system via the main communication connection port, wherein the first feedback signal and the second feedback signal are generated based on backlight feedback signals provided by one or more backlight driver chips in the LED backlight control system.

[0015] Figure 3 shows a schematic block diagram of an example structure of a communication connection port used in the backlight driver chip shown in Figure 2. As shown in Figure 3, in some embodiments, the communication connection port 300, which can be used as the first communication connection port 202 and the second communication connection port 204 shown in Figure 2, includes a first buffer 302 and a second buffer 304. The input terminal of the first buffer 302 is connected to the signal output terminal OUTPUT of the port control unit 206, the enable terminal is connected to the port enable terminal PORT_EN of the port control unit 206, and the output terminal is connected to the input terminal of the second buffer 304. The output terminal of the second buffer 304 is connected to the signal input terminal INPUT of the port control unit 206. The output terminal of the first buffer 302 and the input terminal of the second buffer 304 are connected to the input / output terminals of the communication connection port 300.

[0016] As shown in Figure 3, in some embodiments, the communication connection port 300 may also include a pull-up resistor R1 or a pull-down resistor R2, wherein the output terminal of the first buffer 302 and the input terminal of the second buffer 304 are connected to the chip power supply voltage VDD of the backlight driver chip 200 through the pull-up resistor R1 or grounded through the pull-down resistor R2, so that the communication connection port 300 can maintain an initial potential when there is no input / output signal.

[0017] As shown in Figure 3, in some embodiments, the port control unit 206 may be further configured to set the communication connection port 300 to an input or output state by sending an output enable signal Output_en to the first buffer 302, wherein when the output enable signal Output_en is valid, the communication connection port 300 is in an output state, and when the output enable signal Output_en is invalid, the communication connection port 300 is in an input state.

[0018] Figure 4 shows a schematic flowchart of the port setting process performed by the backlight driver chip shown in Figure 2. As shown in Figure 4, in some embodiments, the port setting process performed by the backlight driver chip 200 shown in Figure 2 includes: Step S402, when the backlight driver chip 200 is powered on, the port control unit 206 sets both communication connection ports to input state and detects the input signals of the two communication connection ports; Step S404, when the port control unit 206 detects a preset waveform signal through any one of the communication connection ports, it sets that communication connection port as the master communication connection port and sets the other communication connection port as the slave communication connection port; Step S406, the port control unit 206 actively sends a preset waveform signal through the slave communication connection port; Step S408, the backlight driver chip 200 enters the normal operation mode, and the port control unit 206 performs signal transmission and reception processing according to the settings of the master communication connection port and the slave communication connection port.

[0019] Figure 5 shows a schematic block diagram of the system architecture of the LED backlight control system according to an embodiment of the present invention. As shown in Figure 5, the LED backlight control system 500 includes a backlight controller 502 and backlight driver chips 504-1 to 504-n, wherein the backlight driver chips 504-1 to 504-n can be implemented as the backlight driver chip 200 described above in conjunction with Figures 2 to 4. The backlight controller 502 and the backlight driver chips 504-1 to 504-n can be cascaded through a single-wire link. The last-stage backlight driver chip 504-1 may or may not be connected to the backlight controller 502.

[0020] Figures 6A and 6B show example waveform diagrams of preset waveform signals used in the LED backlight control system shown in Figure 5, where D01 represents the signal between the backlight controller 502 and the first-level backlight driver chip 504-1 in the LED backlight control system 500, D12 represents the signal between the first-level backlight driver chip 504-1 and the second-level backlight driver chip 504-2 in the LED backlight control system 500, D23 represents the signal between the second-level backlight driver chip 504-2 and the third-level backlight driver chip 504-3 in the LED backlight control system 500, and D(n-1)n represents the signal between the (n-1)th level backlight driver chip 504-(n-1) and the nth level backlight driver chip 504-n in the LED backlight control system 500. As shown in Figures 6A and 6B, in some embodiments, the preset waveform signal can be a level flip performed at a preset number of times (greater than or equal to once) according to a preset period or duty cycle within a certain time, or it can be a combination of level flips performed at a preset time or frequency at a preset number of times (greater than or equal to once) (the interval between each level change (rising edge / falling edge) can be different); after each backlight driver chip receives the preset waveform signal through a certain communication connection port, it sets that communication connection port as the main communication connection port and sets another communication connection port as the slave communication connection port, and then outputs the preset waveform signal to the next level backlight driver chip through the slave communication connection port; after all the backlight driver chips in the LED backlight control system have set their main communication connection port and slave communication port, the LED backlight control system enters the normal operation mode.

[0021] This invention can be implemented in other specific forms without departing from its spirit and essential characteristics. For example, the algorithms described in a particular embodiment may be modified without departing from the basic spirit of the invention. Therefore, the present embodiments are to be regarded as exemplary rather than limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description, and all changes falling within the meaning of the claims and equivalents are thus included within the scope of the invention.

[0022] 100, 500: LED backlight control system 102, 502: Backlight controller 104-1, 104-2, …, 104-n, 200, 504-1, 504-2, 504-3, …, 504-(n-1), 504-n: Backlight driver chip 202: First communication connection port 204: Second communication connection port 206: Port Control Unit 300: Communication connection port 302: First Buffer 304: Second Buffer D01, D12, D23, D(n-1)n: Signals INPUT: Signal input terminal OUTPUT: Signal output terminal Output_en: Output enable signal PORT_EN: Port enable pin R1: Pull-up resistor R2: Pull-down resistor S402, S404, S406, S408: Steps VDD: Chip power supply voltage

Claims

1. A backlight driver chip used in an LED backlight control system, comprising two communication connection ports having the same circuit structure and a port control unit, wherein, The port control unit is configured to, when a preset waveform signal is received through either of the two communication connection ports, set one of the communication connection ports as the main communication connection port of the backlight driver chip and set the other of the two communication connection ports as the slave communication connection port of the backlight driver chip.

2. The backlight driver chip as described in claim 1, wherein, The port control unit is further configured to set the two communication connection ports to input state before the backlight driver chip starts working after being powered on.

3. The backlight driver chip as described in claim 1, wherein, The port control unit is further configured to perform one or more of the following processes when the main communication connection port is set to an input state and the secondary communication connection port is set to an output state: receiving a first control signal from the preceding backlight driver chip or backlight controller in the LED backlight control system through the main communication connection port, and outputting a second control signal to the following backlight driver chip in the LED backlight control system through the secondary communication connection port, wherein the first control signal and the second control signal are generated based on the backlight control signal issued by the backlight controller.

4. The backlight driver chip as described in claim 3, wherein, The port control unit is further configured to perform one or more of the following processes when the main communication connection port is set to an input state and the secondary communication connection port is set to an output state: receiving a first feedback signal from the preceding backlight driver chip in the LED backlight control system through the main communication connection port, and outputting a second feedback signal to the subsequent backlight driver chip or the backlight controller in the LED backlight control system through the secondary communication connection port, wherein the first feedback signal and the second feedback signal are generated based on backlight feedback signals provided by one or more backlight driver chips in the LED backlight control system.

5. The backlight driver chip as claimed in claim 1, wherein, The port control unit is further configured to perform one or more of the following processes when the main communication connection port is set to an output state and the slave communication connection port is set to an input state: receiving a first feedback signal from the subsequent backlight driver chip in the LED backlight control system through the slave communication connection port, and outputting a second feedback signal to the previous backlight driver chip or backlight controller in the LED backlight control system through the main communication connection port, wherein the first feedback signal and the second feedback signal are generated based on backlight feedback signals provided by one or more backlight driver chips in the LED backlight control system.

6. The backlight driver chip as claimed in claim 1, wherein, Each of the two communication connection ports includes a first buffer and a second buffer. The input terminal of the first buffer is connected to the signal output terminal of the port control unit, the enable terminal is connected to the port enable terminal of the port control unit, and the output terminal is connected to the input terminal of the second buffer. The output terminal of the second buffer is connected to the signal input terminal of the port control unit. The output terminal of the first buffer and the input terminal of the second buffer are connected to the input / output terminals of the communication connection port.

7. The backlight driver chip as described in claim 6, wherein, Each of the two communication connection ports further includes a pull-up resistor or a pull-down resistor. The output terminal of the first buffer and the input terminal of the second buffer are connected to the chip power supply voltage of the backlight driver chip through the pull-up resistor or grounded through the pull-down resistor.

8. The backlight driver chip as described in claim 6, wherein, The port control unit is further configured to set the communication connection port to an input or output state by sending an output enable signal to the first buffer. When the output enable signal is valid, the communication connection port is in an output state, and when the output enable signal is invalid, the communication connection port is in an input state.

9. An LED backlight control system, comprising: Backlight controller; And one or more backlight driver chips as described in any one of claims 1 to 8.

10. The LED backlight control system as described in claim 9, wherein, The backlight controller and the one or more backlight driver chips are cascaded via a single-wire link.

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