LED backlight control system and backlight driving chip used therein

Abstract

The invention provides an LED backlight control system and a backlight driving chip used in the LED backlight control system. The backlight driving chip used in the LED backlight control system comprises two communication ports with the same circuit structure and a port control unit, and the port control unit is configured to control a preset waveform signal to be transmitted to any one of the two communication ports when the preset waveform signal is received through any one of the two communication ports. One of the two communication ports is set as a main communication port of the backlight driving chip, and the other one of the two communication ports is set as a slave communication port of the backlight driving chip.

Description

Technical Field

[0001] The present invention generally relates to the field of integrated circuits, and particularly to an LED backlight control system and a backlight driving chip used therein. Background Art

[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 screen display to improve the picture effect, and thus are increasingly favored.

[0003] Figure 1 A schematic block diagram showing the system architecture of a conventional LED backlight control system is shown. As Figure 1 shown, the LED backlight control system 100 includes a backlight controller 102 and backlight driving chips 104-1 to 104-n (n is an integer greater than 1) cascaded through a single-wire link. Among them, each backlight driving chip has a main communication port and a slave communication port. The main communication port is connected to the backlight controller or the previous-stage backlight driving chip and is used to receive signals from the backlight controller or the previous-stage backlight driving chip. The slave communication port is connected to the next-stage backlight driving chip or the backlight controller and is used to output signals to the next-stage backlight driving chip or the backlight controller. When the positions of the two communication ports on the backlight driving chip are fixed, when routing the wiring between the backlight driving chips, it may not be possible to ensure that the slave communication port of the previous-stage backlight driving chip is always closer to the main communication port of the next-stage backlight driving chip. At this time, it is necessary to rotate the backlight driving chip or change the routing method, which may lead to an increase in additional jumpers, resulting in increased application difficulty and cost. Summary of the Invention

[0004] A backlight driving chip used in an LED backlight control system according to an embodiment of the present invention includes two communication ports with the same circuit structure and a port control unit. Among them, the port control unit is configured to, when a preset waveform signal is received through any one of the two communication ports, set this communication port as the main communication port of the backlight driving chip and set the other communication port of the two communication ports as the slave communication port of the backlight driving 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 above-mentioned backlight driving chips. Description of the Drawings

[0006] The present invention can be better understood from the following description of the specific embodiments of the present invention in conjunction with the drawings, wherein:

[0007] Figure 1A schematic block diagram showing the system architecture of a conventional LED backlight control system is shown.

[0008] Figure 2 A schematic block diagram showing an example structure of a backlight driving chip used in an LED backlight control system according to an embodiment of the present invention is shown.

[0009] Figure 3 Shown is used in Figure 2 A schematic block diagram showing an example structure of a communication port in the backlight driving chip shown.

[0010] Figure 4 Shown is Figure 2 A schematic flowchart showing the port setting process executed by the backlight driving chip shown.

[0011] Figure 5 A schematic block diagram showing the system architecture of an LED backlight control system according to an embodiment of the present invention is shown.

[0012] Figure 6A And Figure 6B Shown is used in Figure 5 An example waveform diagram of a preset waveform signal in the LED backlight control system shown. Detailed Description of the Invention

[0013] The features and exemplary embodiments of various aspects of the present invention will be described in detail below. In the following detailed description, many specific details are set forth in order to provide a thorough understanding of the present invention. However, it will be apparent to those skilled in the art that the present invention may be practiced without some of these specific details. The following description of the embodiments is only intended to provide a better understanding of the present invention by showing examples of the present invention. The present invention is in no way limited to any specific configuration and algorithm set forth below, but covers any modification, replacement, and improvement of elements, components, and algorithms without departing from the spirit of the present invention. Well-known structures and technologies are not shown in the drawings and the following description in order to avoid unnecessarily obscuring the present invention. Additionally, it should be noted that the term "A is connected to B" used herein may mean "A is directly connected to B" or "A is indirectly connected to B via one or more other elements".

[0014] In view of one or more problems existing in traditional LED backlight control systems, an LED backlight control system according to an embodiment of the present invention and a backlight driving chip used therein are provided. The backlight driving chip includes two communication ports (for example, input / output (IO) ports) having the same circuit structure. A user can, according to the actual layout situation, use any one of the communication ports as the main communication port for connecting to a previous-stage backlight driving chip or a backlight controller, and use the other communication port as the slave communication port for connecting to a subsequent-stage backlight driving chip or a backlight controller. It should be noted that, in actual applications, the last-stage backlight driving chip in the LED backlight control system may not be connected to other devices to form a unidirectional link, or may be connected to a backlight controller to form a link loop that connects the head and the tail.

[0015] Figure 2 FIG. shows a schematic block diagram of an exemplary structure of a backlight driving chip used in an LED backlight control system according to an embodiment of the present invention. As Figure 2 shown, the backlight driving chip 200 used in the LED backlight control system includes a first communication port 202, a second communication port 204, and a port control unit 206. The first communication port 202 and the second communication port 204 are two input / output ports having the same circuit structure. The port control unit 206 is configured to, when receiving a preset waveform signal through any one of the first communication port 202 and the second communication port 204, set this communication port as the main communication port of the backlight driving chip 200 and set the other communication port as the slave communication port of the backlight driving chip 200. That is to say, if the port control unit 206 receives a preset waveform signal through the first communication port 202, the first communication port 202 is set as the main communication port and the second communication port 204 is set as the slave communication port; if the port control unit 206 receives a preset waveform signal through the second communication port 204, the second communication port 204 is set as the main communication port and the first communication port 202 is set as the slave communication port.

[0016] In some embodiments, the port control unit 206 may be further configured to set both the first communication port 202 and the second communication port 204 to an input state (for example, a high-impedance state) before starting to work after the backlight driving chip 200 is powered on. At this time, the port control unit 206 does not distinguish between the main / slave communication ports.

[0017] In some embodiments, the port control unit 206 may be further configured to output a preset waveform signal to a subsequent-stage backlight driving chip in the LED backlight control system through the slave communication port after completing the setting of the main communication port and the slave communication port.

[0018] In some embodiments, the port control unit 206 may be further configured to perform one or more of the following processes when setting the main communication port to an input state and setting the slave communication port to an output state: receiving a first control signal from a previous-stage backlight driving chip or a backlight controller in the LED backlight control system through the main communication port, and outputting a second control signal to a subsequent-stage backlight driving chip in the LED backlight control system through the slave communication port, wherein the first control signal and the second control signal are generated based on the backlight control signal issued by the backlight controller.

[0019] In some embodiments, the port control unit 206 may be further configured to perform one or more of the following processes when setting the main communication port to an input state and setting the slave communication port to an output state: receiving a first feedback signal from a previous-stage backlight driving chip in the LED backlight control system through the main communication port, and outputting a second feedback signal to a subsequent-stage backlight driving chip or a backlight controller in the LED backlight control system through the slave communication port, wherein the first feedback signal and the second feedback signal are generated based on the backlight feedback signal provided by one or more backlight driving chips in the LED backlight control system.

[0020] In some embodiments, the port control unit 206 may be further configured to perform one or more of the following processes when setting the main communication port to an output state and setting the slave communication port to an input state: receiving a first feedback signal from a subsequent-stage backlight driving chip in the LED backlight control system through the slave communication port, and outputting a second feedback signal to a previous-stage backlight driving chip or a backlight controller in the LED backlight control system through the main communication port, wherein the first feedback signal and the second feedback signal are generated based on the backlight feedback signal provided by one or more backlight driving chips in the LED backlight control system.

[0021] Figure 3 is shown in Figure 2 A schematic block diagram showing an example structure of a communication port in the backlight driving chip shown. As Figure 3 shown, in some embodiments, the communication port 300 that can be used as Figure 2 shown, the first communication port 202 and the second communication port 204 includes a first buffer 302 and a second buffer 304, wherein the input end of the first buffer 302 is connected to the signal output end OUTPUT of the port control unit 206, the enable end is connected to the port enable end PORT_EN of the port control unit 206, the output end is connected to the input end of the second buffer 304, the output end of the second buffer 304 is connected to the signal input end INPUT of the port control unit 206, and the output end of the first buffer 302 and the input end of the second buffer 304 are connected to the input / output terminal of the communication port 300.

[0022] As Figure 3 shown, in some embodiments, the communication port 300 may further 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 supply voltage VDD of the backlight driving chip 200 through the pull-up resistor R1 or grounded through the pull-down resistor R2, so that the communication port 300 can maintain an initial potential when there is no input / output signal.

[0023] As Figure 3 shown, in some embodiments, the port control unit 206 may be further configured to set the communication 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 port 300 is in an output state, and when the output enable signal Output_en is invalid, the communication port 300 is in an input state.

[0024] Figure 4 shows Figure 2 a schematic flowchart of the port setting process executed by the backlight driving chip shown. As Figure 4 shown, in some embodiments, Figure 2 the port setting process executed by the backlight driving chip 200 shown includes: S402, when the backlight driving chip 200 is powered on, the port control unit 206 sets both communication ports to an input state and detects the input signals of the two communication ports; S404, when the port control unit 206 detects a preset waveform signal through any one of the communication ports, it sets this communication port as the main communication port and sets the other communication port as the slave communication port; S406, the port control unit 206 actively sends a preset waveform signal through the slave communication port once; S408, the backlight driving chip 200 enters the normal working mode, and the port control unit 206 performs signal transceiver processing according to the settings of the main communication port and the slave communication port.

[0025] 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 Figure 5 shown, the LED backlight control system 500 includes a backlight controller 502 and backlight driving chips 504-1 to 504-n. Wherein, the backlight driving chips 504-1 to 504-n can be implemented as the backlight driving chip 200 described above in combination with Figures 2 to 4 the description. The backlight controller 502 and the backlight driving chips 504-1 to 504-n can be cascaded through a single-wire link, and the last-stage backlight driving chip 504-1 may or may not be connected to the backlight controller 502.

[0026] Figure 6A and Figure 6B shows an example waveform diagram of a preset waveform signal used in the Figure 5 LED backlight control system shown, where D01 represents the signal between the backlight controller 502 and the first-stage backlight driver chip 504-1 in the LED backlight control system 500, D12 represents the signal between the first-stage backlight driver chip 504-1 and the second-stage backlight driver chip 504-2 in the LED backlight control system 500, D23 represents the signal between the second-stage backlight driver chip 504-2 and the third-stage 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-stage backlight driver chip 504-(n-1) and the nth-stage backlight driver chip 504-n in the LED backlight control system 500. As Figure 6A and Figure 6B shown, in some embodiments, the preset waveform signal can be a level flip that occurs a preset number of times (greater than or equal to once) within a certain time according to a preset period or duty cycle, or a combination of level flips that occurs a preset number of times (greater than or equal to once) according to a preset time or frequency (the interval time 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 port, it sets that communication port as the main communication port and sets the other communication port as the slave communication port, and then outputs the preset waveform signal to the next-stage backlight driver chip through the slave communication port; after all the backlight driver chips in the LED backlight control system have set their main communication ports and slave communication ports, the LED backlight control system enters the normal working mode.

[0027] The present invention may be embodied in other specific forms without departing from its spirit and essential characteristics. For example, the algorithms described in specific embodiments may be modified without the system architecture departing from the basic spirit of the present invention. Therefore, the current embodiments are to be considered in all respects as illustrative and not restrictive, and the scope of the present invention is defined by the appended claims rather than the above description, and all changes falling within the meaning and equivalents of the claims are thus included in the scope of the present invention.

Claims

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

2. The backlight driver chip according to claim 1, wherein: The port control unit is further configured to set the two communication ports to an input state before the backlight driving chip starts working after being powered on.

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

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

6. The backlight driver chip according to claim 1, wherein: Each of the two communication ports includes a first buffer and a second buffer, wherein the input end of the first buffer is connected to the signal output end of the port control unit, the enable end is connected to the port enable end of the port control unit, and the output end is connected to the input end of the second buffer, the output end of the second buffer is connected to the signal input end of the port control unit, and the output end of the first buffer and the input end of the second buffer are connected to the input and output terminals of the communication port.

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

8. The backlight driver chip according to claim 6, wherein: The port control unit is further configured to set the communication 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 port is in an output state, and when the output enable signal is invalid, the communication port is in an input state.

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

10. The LED backlight control system according to claim 9, wherein: The backlight controller and the one or more backlight driver chips are cascaded via a single-line link.

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