Self-checking circuit and method for a backlight

Abstract

Provided are a self-checking circuit and method for a backlight, belonging to the field of display. In the self-checking circuit, the backlight control board can not only trigger the control chip to control the level of the backlight switch pin to control the power supply board to supply power to the backlight lamp board and perform a self-checking operation to detect whether there is an abnormally glowing backlight lamp board, but also trigger the control chip to control the level of the key control pin to light up the light emitting element in multiple intervals, and detect whether there is an abnormally glowing light emitting element through static picture display. Therefore, the defective position can be accurately located using controllable and sufficient detection time, thereby effectively intercepting defects and avoiding missed detection and false detection.

Description

Technical Field

[0001] This application relates to the field of display technology, and in particular to a self-test circuit and self-test method for a backlight. Background Technology

[0002] A backlight (BL) is a light source used to provide backlighting for the display panel in a liquid crystal display device. A backlight typically consists of multiple light-emitting elements. To ensure product yield, backlights are generally tested before leaving the factory to identify defective light-emitting elements in a timely manner.

[0003] In related technologies, during testing, communication with a host computer is typically used to control the backlight control board (BCON) to illuminate multiple light-emitting elements of the backlight in a sequential scrolling pattern. For example, multiple light-emitting elements are illuminated row by row from left to right. The purpose is to intercept defects such as open circuits, short circuits, uneven brightness, or uneven dimness.

[0004] However, because the marquee mode lights up quickly, it can easily lead to missed or false detections. Summary of the Invention

[0005] A self-test circuit and self-test method for a backlight are provided. The technical solution is as follows:

[0006] On one hand, a self-test circuit for a backlight is provided. The backlight includes: multiple backlight boards, each backlight board including multiple light-emitting elements; the self-test circuit includes: a fixture power board and a backlight control board, the backlight control board including a control chip, the control chip having backlight switch pins and key control pins; the fixture power board is connected to the power supply terminal of the backlight control board, and is also used to connect to the power supply terminals of the multiple backlight boards; the backlight control board is also used to connect to the multiple backlight boards.

[0007] The fixture power board is used to: output an enable power supply voltage to the power supply terminal of the backlight control board based on the input voltage from the external input, and output a backlight power supply voltage to the power supply terminal of the plurality of backlight boards based on the backlight turn-on signal output through the backlight switch pin.

[0008] The backlight control board is used to: trigger the control chip to output the backlight turn-on signal to the backlight switch pin based on the enable power supply voltage; trigger the control chip to control the multiple backlight panels to emit light and perform a self-test operation based on the backlight power supply voltage to detect whether there is a backlight panel emitting light abnormally; and trigger the control chip to control the multiple light-emitting elements included in the multiple backlight panels to emit light sequentially multiple times according to the display order based on the static screen lighting signal input through the key control pin, so as to detect whether there is a light-emitting element emitting light abnormally, wherein the light-emitting elements emitting light each time are different, and the light-emitting elements emitting light each time include multiple light-emitting elements spaced apart.

[0009] Optionally, the backlight source further includes: a plurality of backlight driver boards, the backlight control board being connected to the plurality of backlight lamp boards via the plurality of backlight driver boards, and each of the backlight driver boards having an address configuration pin, a signal input pin, and a signal output pin; for each of the backlight lamp boards, the self-test program includes:

[0010] The address configuration pin is used to configure an address for the backlight driver board connected to the backlight board, so as to identify the backlight driver board of the backlight board;

[0011] The backlight driver board connected to the backlight panel outputs a uniform brightness signal through the signal input pin to control the backlight driver board of the backlight panel to light up the multiple light-emitting elements included in the backlight panel according to the brightness signal.

[0012] The test signal fed back from the backlight driver board of the backlight board is received through the signal output pin, so as to detect whether the backlight board emits light abnormally based on the test signal.

[0013] Optionally, the backlight control board is further configured to: when an abnormal backlight panel is detected, control the abnormal backlight panel to flash, and after the self-test is completed, control the multiple backlight panels to emit light simultaneously to a brightness threshold to indicate that the self-test is complete.

[0014] Optionally, the plurality of backlight panels include a plurality of light-emitting element arrays arranged in a manner;

[0015] The display sequence includes: first, controlling the light-emitting elements of the 3N+1, 3N+2, and 3N+3 rows to emit light sequentially, on a row-by-row basis; then, controlling the light-emitting elements of the 2K+1 and 2K+2 columns to emit light sequentially, on a column-by-column basis; where N is a positive integer greater than or equal to 0 and less than the total number of rows, and K is a positive integer greater than or equal to 0 and less than the total number of columns.

[0016] Optionally, the self-test circuit further includes: a switch; the switch is connected to the power supply terminal, the ground terminal and the keying pin respectively;

[0017] The switch is used to: control the keying pin to connect to the ground terminal based on the received on signal, so as to input the static screen lighting signal through the keying pin, and control the keying pin to disconnect from the ground terminal based on the received off signal.

[0018] Optionally, the enabling power supply voltage includes an enabling voltage and a power supply voltage; the self-test circuit further includes a linear regulator; the linear regulator is connected between the fixture power board and the backlight control board;

[0019] The fixture power board is used to: output the power supply voltage to the power supply terminal of the backlight control board and the linear regulator respectively;

[0020] The linear regulator is used to: step down the supply voltage to obtain the enable voltage, and output the enable voltage to the enable terminal of the backlight control board and the enable terminal of the fixture power board respectively, so as to drive the backlight control board to work and control the fixture power board to enter the standby state.

[0021] Optionally, the backlight control board is further configured to: trigger the control chip to output a backlight off signal to the backlight switch pin after the detection is completed;

[0022] The fixture power board is also used to: stop outputting backlight power supply voltage to the power supply terminals of the plurality of backlight panels based on the backlight off signal, so that the plurality of backlight panels stop emitting light;

[0023] Furthermore, the self-test circuit also includes a discharge circuit; the discharge circuit is connected to the power supply terminal of the plurality of backlight boards, the backlight switch pin, and the ground terminal respectively;

[0024] The discharge circuit is used to: control the power supply terminals of the plurality of backlight panels to be connected to the ground terminal based on the backlight off signal, so as to discharge residual charge; and control the power supply terminals of the plurality of backlight panels to be disconnected from the ground terminal based on the backlight on signal.

[0025] Optionally, the self-test circuit further includes: a discharge indicator light; the discharge indicator light is connected to the discharge circuit;

[0026] The discharge indicator light is used to: illuminate based on the backlight on signal, and gradually turn off based on the backlight off signal; wherein, the discharge indicator light stopping to illuminate is used to indicate that the residual charge discharge is complete.

[0027] Optionally, the self-test circuit further includes: an adapter board;

[0028] The fixture power board is connected to the backlight control board and the plurality of backlight boards via the adapter board.

[0029] Furthermore, all circuits in the self-test circuit, except for the fixture power board and the backlight control board, are located on the adapter board.

[0030] On the other hand, a self-testing method for a backlight is provided, applied to a backlight control board included in the self-testing circuit as described in the above aspect; the method includes:

[0031] Based on the received enable power supply voltage, the control chip outputs a backlight turn-on signal to the backlight switch pin to control the fixture power board to output backlight power supply voltage to the power supply terminals of multiple backlight boards. The enable power supply voltage is the voltage provided by the fixture power board based on the external input voltage.

[0032] Based on the backlight power supply voltage, the control chip is triggered to control the multiple backlight panels to emit light and perform a self-test operation to detect whether there are backlight panels emitting abnormal light.

[0033] Based on the static screen lighting signal input via the keying pin, the control chip is triggered to control the multiple backlight panels, including multiple light-emitting elements, to emit light sequentially in the display order according to a uniform brightness, in order to detect whether there are any abnormal light-emitting elements. The light-emitting elements that emit light each time are different, and the light-emitting elements that emit light each time include multiple light-emitting elements spaced apart.

[0034] In summary, the beneficial effects of the technical solution provided in this application can include at least the following:

[0035] A self-test circuit and method for a backlight are provided. In this self-test circuit, the backlight control board not only triggers the control chip to control the level of the backlight switch pins to control the power supply board of the fixture to supply power to the backlight board and further performs a self-test to detect the presence of abnormally emitting backlights, but also triggers the control chip to illuminate the light-emitting elements at multiple intervals based on the level of the key control pins, detecting the presence of abnormally emitting light-emitting elements through static image display. Therefore, by utilizing a controllable and sufficient detection time, the faulty location can be accurately located, effectively intercepting defects and avoiding missed or false detections. Attached Figure Description

[0036] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0037] Figure 1This is a schematic diagram of the system architecture used in a self-test circuit provided in an embodiment of this application;

[0038] Figure 2 This is a schematic diagram of the structure of a backlight provided in an embodiment of this application;

[0039] Figure 3 This is a schematic diagram of the structure of a self-test circuit for a backlight provided in an embodiment of this application;

[0040] Figure 4 This is a schematic diagram of the structure of a control chip for a backlight control board provided in an embodiment of this application;

[0041] Figure 5 This is a schematic diagram of the structure of an ESD protection circuit provided in an embodiment of this application;

[0042] Figure 6 This is a schematic diagram of the structure of a backlight control board provided in an embodiment of this application;

[0043] Figure 7 This is a schematic diagram illustrating a static image display provided in an embodiment of this application;

[0044] Figure 8 This is a schematic diagram of a discharge circuit and discharge indicator light provided in an embodiment of this application;

[0045] Figure 9 This is a flowchart illustrating a self-testing method for a backlight provided in an embodiment of this application;

[0046] Figure 10 This is a flowchart illustrating the self-test control logic of a backlight provided in an embodiment of this application. Detailed Implementation

[0047] To make the objectives, technical solutions, and advantages of this application clearer, the embodiments of this application will be described in further detail below with reference to the accompanying drawings.

[0048] A backlight typically comprises multiple light-emitting elements, such as light-emitting diodes (LEDs), i.e., LED lamps. Backlights can be used in various display products to provide backlighting. For example, multi-zone mini-LED backlight display products using active matrix (AM) control are also called AM multi-zone Mini backlight driver products. Multi-zone means dividing all the light-emitting elements (e.g., LED lamps) in the backlight of the display product into multiple zones, each zone containing multiple light-emitting elements. Furthermore, in many products, the backlight usually comprises multiple backlight panels, each of which can be divided into multiple zones.

[0049] In historical mass production projects and the design applications of Mini multi-zone products in some embodiments, a running light pattern is typically used to sequentially illuminate individual LEDs, such as scanning row by row from right to left, scanning multiple LEDs, or scanning vertically. Furthermore, this running light pattern is primarily implemented through communication with a host computer. However, on the one hand, because the running light pattern involves dynamic scanning with multiple LEDs illuminating rapidly, the inspection personnel have limited observation time, easily leading to missed defects. On the other hand, since anomalies cannot be immediately interrupted and stopped at the defect, multiple checks are required to locate the defect, resulting in false positives and low inspection efficiency. Moreover, if adjacent LEDs are brighter or dimmer than normal, the lack of brightness references from other LEDs due to the dynamic scanning also easily leads to missed detections. In short, the current inspection method is prone to missed and false positives, and has low inspection efficiency.

[0050] Based on this, the present application provides a self-testing circuit and a self-testing method for a backlight. The self-testing circuit, in conjunction with the self-testing method, can accurately locate the defect in the backlight, and the detection time is controllable, which can efficiently intercept defects such as lamp malfunction, excessive brightness, and excessive dimness.

[0051] First, let's take TV products with backlights applied to AM multi-zone Mini backlight drivers as an example. Figure 1 First, a schematic diagram of a system structure in which a self-test circuit is applied is shown. (Reference) Figure 1 It can be seen that:

[0052] ① This refers to the motherboard, which is the control center of the TV product. The motherboard typically includes a system-on-chip (SOC), which can acquire the brightness signal of the video image and transmit the brightness control information required by the backlight to the backlight control board (BCON) via the serial peripheral interface (SPI) protocol. In addition to brightness control information, the signals transmitted by the SOC can also include inter-integrated circuit (I2C) signals, function signals, and enable signals.

[0053] ② is the power supply board. This power supply board can provide power to the BCON board, backlight, or other boards. In addition, it can receive feedback and enable control from other boards.

[0054] ③ is the voltage conversion module of the BCON board. This voltage conversion module can convert the externally input voltage into the power supply voltage required by other modules.

[0055] ④ is the main control chip, or controller chip, of the BCON board. This main control chip can parse the brightness control information input via SPI into the current signal required by the backlight driver IC, and can then transmit the brightness information required by the driver IC to the driver chip on the link through a custom transmission protocol. It can also interact with other boards via I2C or an enable signal. The transmission protocol can be, for example, a serial peripheral bus (SPB) protocol or an open wireless connectivity (OWC) protocol.

[0056] ⑤ is a key pin in this embodiment. This key pin includes a backlight switch pin BLON and a keying pin KEY, both of which are general purpose input / output (GPIO) pins. That is, this key pin can include GPIO-KEY / BLON. In this embodiment, self-test control can be achieved by customizing the function of this GPIO port.

[0057] ⑥ is the BCON board's buffer driver. This buffer enhances the driving capability of signals transmitted via the SPB / OWC transmission protocol.

[0058] ⑦ is the external connector from the BCON board to the backlight board, which includes the backlight panel. This external connector is capable of transmitting the power and control signals required by the backlight board to the backlight board.

[0059] ⑧ is a flat flexible cable (FFC) used to connect the BCON board and multiple backlight boards.

[0060] ⑨ is the driver IC for the backlight panel. Typically, a display product includes multiple driver ICs, and each driver IC can have 8 channels (CH) to control 8 zones respectively. The driver IC can configure the driving current used to drive the light-emitting elements in the backlight panel to emit light based on the received brightness information.

[0061] ⑩ refers to the light source selected for the backlight panel. For example, the light source can be an LED lamp as described above. VLED+ can serve as the power supply terminal of the backlight panel to provide positive voltage to the LED lamp, and the Driver IC can control the negative terminal connected to the LED lamp, so that the LED lamp can reliably emit light under the voltage difference between the positive and negative terminals.

[0062] Optionally, combined Figure 2The AM multi-zone Mini backlight driver product provided in this application embodiment may include, for example: Figure 2 The diagram shows seven backlight panels on the top and seven on the bottom, which can be considered as 14 backlight panels. Each backlight panel is divided into 360 zones. Therefore, the backlight of this product can be divided into 5040 zones. Since one driver IC can control eight zones, it is understood that one backlight panel requires 45 driver ICs, and 14 backlight panels would require 630 driver ICs. Furthermore, combining... Figure 2 It can also be seen that the BCON board can be connected to one backlight board via two sockets. One socket can connect to 23 driver ICs, and the other socket can connect to 22 driver ICs. Therefore, the BCON board can have 28 sockets. Of course, these numbers are only for illustrative purposes. Based on this structure, Figure 3 A schematic diagram of the structure of a self-test circuit for a backlight provided in an embodiment of this application is shown.

[0063] First, combined Figure 2 As can be seen, the backlight source includes: multiple backlight panels (referred to as panels in the figure), each backlight panel includes multiple light-emitting elements (not shown in the figure), and the light-emitting elements can be, for example, LEDs.

[0064] Secondly, combining Figure 3 As can be seen, the self-test circuit includes: a fixture power board 01 and a backlight control board 02, also known as the BCON board 02. The backlight control board 02 includes a control chip, for example... Figure 3 The microcontroller unit (MCU) shown is the BCON chip (MCU).

[0065] Combined Figure 4 As can be seen, the control chip MCU has a backlight switch pin GPIO_BLON and a keying pin GPIO_KEY, which correspond to pins 92 and 94 respectively. These are extension pins for the MCU.

[0066] The fixture power board 01 is connected to the 12V+ / DC_EN power supply terminal of the backlight control board 02, and is also used to connect to the VLED+ (i.e., positive) power supply terminal of multiple backlight panels. The backlight control board 02 is also used to connect to multiple backlight panels (not shown in the figure). It can be understood that the backlight control board 02 can be connected to the backlight panels through a backlight driver board (i.e., Driver IC). Figure 4 Other pins are also shown, but will not be described in detail here.

[0067] The fixture power board 01 is used to: output an enable power supply voltage to the power supply terminal 12V+ / DC_EN of the backlight control board 02 based on the input voltage from the external input, and output a backlight power supply voltage to the power supply terminal VLED+ of multiple backlight boards based on the backlight turn-on signal output through the backlight switch pin GPIO_BLON.

[0068] For example, the input voltage of the external input can be... Figure 3 The power supply shown is 220V AC mains power. The fixture power board 01 can convert this 220V AC mains power into the power supply voltage required by the backlight control board 02 and the backlight panel, thereby driving the backlight control board 02 to operate and illuminating the backlight panel. Furthermore, the fixture power board 01 can also output a backlight power supply voltage to the backlight panel under the control of the backlight turn-on signal output from the backlight switch pin GPIO_BLON of the control chip MCU, thus illuminating the backlight panel. Of course, the input voltage can also come from other power sources besides AC mains power.

[0069] The backlight control board 02 is used to: trigger the control chip MCU to output a backlight-on signal to the backlight switch pin GPIO_BLON based on the enable power supply voltage; trigger the control chip MCU to control multiple backlight panels to emit light and perform self-test operations based on the backlight power supply voltage to detect whether there are any abnormally emitting backlight panels; and trigger the control chip MCU to control multiple backlight panels, including multiple light-emitting elements, to emit light sequentially in multiple stages according to the display order, based on the static screen lighting signal input via the keying pin GPIO_KEY, to detect whether there are any abnormally emitting light-emitting elements. The light-emitting elements that emit light each time are different, and each time the light-emitting elements include multiple light-emitting elements spaced apart.

[0070] That is, the backlight control board 02 can enter the working state after receiving the enable power supply voltage provided by the fixture power supply board 01, and supply power to the control chip MCU to trigger the control chip MCU to output a backlight turn-on signal to the backlight switch pin GPIO_BLON. For example, the level of the backlight switch pin GPIO_BLON can be pulled high to represent the backlight turn-on signal. Based on this, the fixture power supply board 01 can be further instructed to output the backlight supply voltage to the power supply terminal VLED+ of the backlight board to start the power supply to the backlight board. Of course, the high level here is only illustrative. For example, in some other embodiments, the level can also be pulled low to represent the backlight turn-on signal.

[0071] At this point, the backlight control board 02 can enter a self-test state, running a pre-configured self-test program via the control chip MCU to perform the self-test operation. For example, the control chip MCU can output a drive signal to the backlight driver board, causing the backlight driver board to drive the light-emitting elements in the backlight board to emit light, and receive the detection signal fed back from the backlight driver board to complete the self-test, thereby detecting whether there are any backlight boards with abnormal light emission and which specific backlight board is malfunctioning. After the self-test is completed, a static screen lighting signal can be input through the keying pin GPIO_KEY. For example, the level of the keying pin GPIO_KEY can be pulled low to represent the static screen lighting signal. Of course, pulling low here is only for illustrative purposes. For example, in some other embodiments, the level can also be pulled high to represent the static screen lighting signal.

[0072] At this point, the control chip (MCU) can switch to a static screen and sequentially illuminate multiple light-emitting elements according to the display order until all light-emitting elements have been illuminated. This allows for further detection of any abnormally emitting light-emitting elements and identifying which specific element is malfunctioning. Each time, different light-emitting elements are illuminated, and each illumination includes multiple elements spaced apart. For example, it could be done column-by-column: first, the odd-numbered columns of light-emitting elements are illuminated, while the even-numbered columns remain off; then, the even-numbered columns are illuminated, while the odd-numbered columns remain off. This intermittent illumination is not glaring and facilitates comparison with other light-emitting elements, making it easier for inspectors to spot defects. Furthermore, because it is a static screen, the detection time is fully controllable.

[0073] In summary, this application provides a self-test circuit for a backlight. In this self-test circuit, the backlight control board can not only trigger the control chip to control the level of the backlight switch pins to control the power supply board of the fixture to supply power to the backlight board and perform a self-test to detect the presence of abnormally emitting backlights, but also trigger the control chip to illuminate the light-emitting elements at multiple intervals based on the level of the key control pins, detecting the presence of abnormally emitting light-emitting elements through static image display. Therefore, it can utilize a controllable and sufficient detection time to accurately locate the defective position, thereby effectively intercepting defects and avoiding missed or false detections.

[0074] Optionally, in some embodiments, electrostatic discharge (ESD) protection circuits can be provided on the backlight switch pin GPIO_BLON and the keying pin GPIO_KEY to protect the backlight switch pin GPIO_BLON and the keying pin GPIO_KEY.

[0075] For example, refer to Figure 5The diagram illustrates an ESD protection circuit. This circuit may include resistors R68 and R69 with a resistance of approximately 22 ohms (Ω), and transient voltage suppressors (TVS) D78 and D79. Based on this structure, when ESD is introduced into the backlight switch pin GPIO_BLON and / or the keying pin GPIO_KEY, the TVS can break down in reverse, thereby discharging the ESD to ground (GND) nearby. Resistors R68 and R69 can limit current without affecting signal functionality, thus preventing ESD from entering.

[0076] Optionally, continue to combine Figure 3 It can also be seen that the backlight may include: multiple backlight driver boards 03 (i.e., Driver ICs), and a backlight control board 02 that can be connected to multiple backlight panels through the multiple backlight driver boards 03. Each backlight driver board may have an address configuration pin DIS, a signal input pin DIP, and a signal output pin DOS. For each backlight panel, the self-test operation may include:

[0077] Configure an address for the backlight driver board 03 connected to the backlight board via the address configuration pin DIS to identify the backlight driver board 03 of the backlight board.

[0078] The backlight driver board 03, which is connected to the backlight board, outputs a uniform brightness signal through the signal input pin DIP to control the backlight driver board 03 to light up the multiple light-emitting elements included in the backlight board according to the brightness signal.

[0079] The test signal fed back from the backlight driver board 03 of the backlight board is received through the signal output pin DOS, so as to detect whether the backlight board is emitting abnormal light based on the test signal.

[0080] Optionally, the backlight control board 02 can also be used to: control the abnormally emitting backlight board to flash when an abnormally emitting backlight board is detected, and control multiple backlight boards to emit light simultaneously to the brightness threshold after the self-test is completed, so as to indicate that the self-test is completed.

[0081] For example, refer to Figure 3 and Figure 6The enlarged schematic of the backlight control board 02 shows that, for 14 backlight boards and 28 sockets, four address configuration pins (DIS_1 to DIS_4) can be set, 28 signal input pins (DIP_1 to DIP_28) can be set, and 28 signal output pins (DOS_1 to DOS_28) can be set. Based on this, firstly, the Driver IC addresses can be configured via DIS_1 to DIS_4 using a binary-like identifier to identify different Driver ICs. Then, the brightness data of the self-test screen LED array can be configured one-to-one for each Driver IC connected to the backlight boards via DIP_1 to DIP_28, illuminating each backlight board. Next, feedback signals from each Driver IC connected to the backlight boards via DOS_1 to DOS_28 can be received, and the system can detect any abnormal signals from the Driver ICs on the link based on the received feedback signals. If any of the DOS feedback channels malfunctions, the MCU can use the corresponding channel to make the backlight panel indicated by the malfunctioning DOS blink, thus indicating the backlight panel malfunction. During the entire self-test process, the GPIO ports do not need to respond to any other controls. After the self-test is complete, the MCU can also control the overall brightness of each backlight panel to indicate that the self-test is complete.

[0082] Optionally, a feedback anomaly can refer to a feedback signal voltage exceeding a voltage threshold, which can be a fixed value pre-stored in the control chip MCU. Of course, this is merely illustrative. Furthermore, the number of address configuration pins DIS, the control of the backlight board flashing to indicate a backlight board anomaly, and the control of the overall brightness increase of each backlight board to indicate self-test completion are all illustrative. For example, in some other embodiments, six address configuration pins DIS can be set, the backlight board can be kept constantly lit to indicate a backlight board anomaly, and other prompting devices (such as individual indicator lights or sounds) can be used to issue relevant information to indicate self-test completion. This application does not limit these aspects.

[0083] Optionally, the multiple backlight panels may include multiple light-emitting elements arranged in an array. That is, the backlight may include multiple rows and columns of light-emitting elements. Based on this, the display sequence may include:

[0084] First, control the light-emitting elements in rows 3N+1, 3N+2, and 3N+3 to light up sequentially. Then, control the light-emitting elements in columns 2K+1 and 2K+2 to light up sequentially. Here, N is a positive integer greater than or equal to 0 and less than the total number of rows, and K is a positive integer greater than or equal to 0 and less than the total number of columns.

[0085] That is, combining Figure 7 After the MCU performs a self-test and ends the self-test, once it detects a static screen lighting signal input through the key pin GPIO_KEY, if it detects that the level of the key pin GPIO_KEY is pulled low, it can first control all the light-emitting elements in the 3N+1th row to light up according to the preset brightness. That is, it controls the light-emitting elements in the 1st, 4th, 7th to 3N+1st rows to be lit up, so that the light-emitting elements in 1 / 3 of the entire screen are lit up at intervals, making it easier for inspectors to find defects.

[0086] After the static screen inspection is completed with the 3N+1 rows of LEDs lit, if the GPIO_KEY key pin is pulled low, the LEDs in the 3N+2 rows can be controlled to light up at a preset brightness. This means the LEDs in rows 2, 5, 8, and up to 3N+2 can be lit, resulting in intermittent lighting across one-third of the screen. This allows the system to switch back to the static screen with the 3N+2 rows of LEDs lit, making it easier for inspectors to spot defects.

[0087] After the static screen detection of the illuminated elements in rows 3N+2 is completed, when the level of the key control pin GPIO_KEY is detected to be pulled low, the illuminated elements in row 3N+3 can be controlled to light up all of them according to the preset brightness. That is, the illuminated elements in rows 3, 6, 9 to 3N+3 can be controlled to light up, so that the illuminated elements in 1 / 3 of the entire screen are lit at intervals. In other words, the static screen can be switched back to the state where the illuminated elements in rows 3N+3 are lit, making it easier for inspectors to find defects. This completes the detection of the illumination of all rows of illuminated elements.

[0088] Subsequently, when the GPIO_KEY key pin is detected to be pulled low, the LEDs in column 2K+1 can be controlled to light up at a preset brightness. This means that the LEDs in columns 1, 3, 5 through 2K+1 (odd-numbered columns) are illuminated, causing half a column of LEDs on the screen to light up intermittently. This allows the screen to switch back to a static display with column 2K+1 LEDs illuminated, making it easier for inspectors to spot defects.

[0089] After the static screen detection of 2K+1 columns of LEDs being lit is completed, when the level of the key control pin GPIO_KEY is detected to be pulled low, the LEDs of the 2K+2 columns can be controlled to light up all the LEDs according to the preset brightness. That is, the LEDs of the 2nd, 4th, 6th to 2K+6th columns (i.e., even-numbered columns) can be controlled to light up, so that half a column of LEDs on the screen are lit at intervals. In other words, the static screen can be switched back to the 2K+2 columns of LEDs being lit, making it easier for inspectors to find defects. At this point, the lighting detection of all columns of LEDs is completed.

[0090] In other words, it can be done according to Figure 7 The sequence shown is as follows: (1) Light up row 3N+1; (2) Light up row 3N+2; (3) Light up row 3N+3; (4) Light up column 2K+1; (5) Light up column 2K+2. This completes the lighting of all rows and all columns, achieving comprehensive defect detection. Optionally, a defect could be, for example, a light-emitting element not lighting up, being too bright, too dim, or an area that should display black being found to have lights on, etc.

[0091] Of course, the above display order is only illustrative. For example, in some other embodiments, for rows, detection can be achieved by lighting up odd-numbered rows and even-numbered rows separately. For columns, detection can be achieved by lighting up columns at intervals of 1 / 3 of a row. This application does not limit the display order.

[0092] Understandably, because the detection is achieved by illuminating a static screen, and there is an interval between two different static screen detections, such as detection in odd and even columns, it can effectively intercept defects, and the detection time is fully controllable, resulting in good detection reliability.

[0093] Optionally, continue to refer to Figure 3 As can be seen, the self-test circuit may also include: switch K1. Switch K1 can be connected to the power supply terminal 3V3, the ground terminal GND, and the keying pin GPIO_KEY.

[0094] Switch K1 can be used to: control the keying pin GPIO_KEY to connect to ground GND based on a received on signal, so as to input a static image lighting signal through the keying pin GPIO_KEY; and control the keying pin GPIO_KEY to disconnect from ground GND based on a received off signal. That is, switch K1 can be used to control the keying pin GPIO_KEY to ground, thereby pulling down the level of the keying pin GPIO_KEY, and thus instructing the light-emitting elements to light up and display a static image according to the display sequence described in the above embodiment.

[0095] Optionally, the 3V3 power supply can refer to a 3.3V power signal, which can come from the fixture power board 01. The on and off signals can be triggered by the inspector. For example, switch K1 can be a push-button switch, allowing the inspector to switch between static screen detection by toggling switch K1. For instance, when the inspector closes switch K1, switch K1 receives an on signal and grounds the key control pin GPIO_KEY. When the inspector opens switch K1, switch K1 receives an off signal and disconnects the key control pin GPIO_KEY from ground, thus breaking the connection between GPIO_KEY and ground. This allows the inspector to switch the static screen at intervals according to actual conditions, achieving controllable detection time. Of course, it is not limited to being triggered by the inspector. For example, at preset time intervals, other control circuits can automatically pull the level of the key control pin GPIO_KEY low to achieve fully automatic detection. Furthermore, it is not limited to a push-button switch. For example, in some other embodiments, it can also be a transistor switch.

[0096] Optionally, continue to refer to Figure 3 It can be seen that the enable supply voltage can include: enable voltage DC_EN and supply voltage 12V.

[0097] Correspondingly, the self-test circuit may also include a low dropout regulator (LDO). This LDO can be connected between the fixture power board 01 and the backlight control board 02.

[0098] The fixture power board 01 can be used to output the power supply voltage to the power supply terminal 12V+ of the backlight control board 02 and the linear regulator LDO.

[0099] The linear regulator (LDO) can be used to step down the supply voltage to an enable voltage and output it to the enable terminal of the backlight control board 02 and the fixture power board 01 to drive the backlight control board 02 to work and control the fixture power board 01 to enter the standby (STB) state.

[0100] Optionally, the supply voltage can be 12V, and the enable voltage DC_EN or STB_EN after the step-down process can be 3.3V. Of course, in some embodiments, before the step-down process, the supply voltage output to the power supply terminal of the backlight control board 02 can be 12V, while the supply voltage output to the fixture power board 01 can be 10.5V.

[0101] In other words, in this embodiment, the BCON board 02 can serve as a control platform, used in conjunction with the fixture power board 01 to control GPIO_BLON and STB. The MCU control chip of the BCON board 02 can act as a processing center. After AC power is supplied, both GPIO_BLON and STB_EN can be enabled. For example, the level of the backlight switch pin GPIO_BLON and the level of the enable pin STB_EN of the fixture power board 01 can both be pulled high to indicate that the backlight is turned on and that the fixture power board 01 enters standby mode. After the level of the backlight switch pin GPIO_BLON is pulled high, the MCU control chip of the BCON board 02 can internally run an initialization program and then enter a self-test state to begin performing a self-test operation.

[0102] Optionally, the backlight control board 02 can also be used to: trigger the control chip MCU to output a backlight off signal to the backlight switch pin GPIO_BLON after detection is completed. For example, the level of the backlight switch pin GPIO_BLON can be pulled low to represent the backlight off signal.

[0103] The fixture power board 01 can also be used to: stop outputting backlight power supply voltage to the power supply terminal VLED+ of multiple backlight boards based on the backlight off signal, so that the multiple backlight boards stop emitting light. That is, after the self-test is completed and the static image detection is completed, the control chip MCU of the BCON board 02 can configure the backlight switch pin GPIO_BLON to a low level, so that the fixture power board 01 stops driving the multiple backlight boards to emit light, and turns off the power supply terminal VLED+ of the multiple backlight boards.

[0104] Optionally, continue to refer to Figure 3 As can be seen, the self-test circuit also includes a discharge circuit 04. Discharge circuit 04 can be connected to the power supply terminal VLED+, the backlight switch pin GPIO_BLON, and the ground terminal GND of multiple backlight boards. Of course, discharge circuit 04 can also be connected to a power supply terminal (e.g., 12V).

[0105] The discharge circuit 04 can be used to: control the power supply terminal VLED+ of multiple backlight boards to conduct with the ground terminal GND based on the backlight off signal, so as to discharge residual charge; and control the power supply terminal VLED+ of multiple backlight boards to disconnect from the ground terminal GND based on the backlight on signal.

[0106] In other words, for example, the discharge circuit 04 can control the power supply terminal VLED+ of the backlight board to be grounded after the level of the backlight switch pin GPIO_BLON is pulled low, so as to discharge the residual charge in the backlight board to the ground terminal; and the discharge circuit 04 can also control the power supply terminal VLED+ of the backlight board to be disconnected from the ground terminal GND after the level of the backlight switch pin GPIO_BLON is pulled high, so as to stop discharging the residual charge. After the residual charge is discharged, the connecting wires between the various parts can be disconnected to complete the online test.

[0107] Understandably, by setting up a discharge circuit 04 to release residual charge after testing, the risk of hot-swapping can be effectively monitored and avoided. This ensures good production yield, first-pass yield, and UPH for both the backlight board and BCON board 02. Hot-swapping risk refers to the risk of damage or data loss caused by directly inserting or removing external circuits without following the normal shutdown procedure during product operation. Production yield refers to the proportion of qualified products produced within a certain period of time out of the total number of products produced. First-pass yield can be the proportion of products that meet quality standards in the first production run without rework or repair. UPH can be the number of units produced per hour.

[0108] Optionally, continue to refer to Figure 3 As can be seen, the self-test circuit may also include a discharge indicator light 05. The discharge indicator light 05 can be connected to the discharge circuit 04. For example, it can be connected to the 12V power supply terminal and the VLED+ power supply terminal of the discharge circuit 04, and it can also be grounded.

[0109] The discharge indicator light 05 can be used to: illuminate based on a backlight on signal and gradually dim based on a backlight off signal. When the discharge indicator light 05 stops illuminating, it indicates that the discharge of residual charge is complete.

[0110] That is, for example, after the level of the backlight switch pin GPIO_BLON is pulled high, the discharge circuit 04 can stop working, and at the same time, the discharge indicator light 05 can remain constantly lit. When the level of the backlight switch pin GPIO_BLON is pulled low, the discharge circuit 04 can begin to discharge residual charge, and at the same time, the discharge indicator light 05 can gradually turn off. The complete extinguishing of the discharge indicator light 05 indicates that the residual charge discharge is complete. Of course, the indication of residual charge discharge is not limited to the discharge indicator light 05. For example, in some other embodiments, a buzzer can be used to indicate the residual charge discharge status.

[0111] Optionally, Figure 8 This diagram schematically illustrates the circuit structure of a discharge circuit 04 and a discharge indicator light 05. (Reference) Figure 8It can be seen that the bleeder circuit 04 may include: a first part that controls the level of the input terminal DRV_IN based on the level of the backlight switch pin GPIO_BLON, and a second part that controls the connection and disconnection between the power supply terminal VLED+ and the ground terminal GND based on the level of the input terminal DRV_IN.

[0112] The first part may include eight resistors RP25 to RP32, two capacitors CB42 and CP2, three transistors QP4 to QP6, and one diode D2. The second part may include eight current-limiting resistors R1 to R8, one load resistor RL24, and one transistor QB3. The connection methods and parameters of each component in the discharge circuit 04 can be found in [reference needed]. Figure 8 This will not be elaborated upon here. The discharge indicator 05 may include one blue LED1 (i.e., blue light) and one green LED2 (i.e., green light). LED1 can be connected in series between the 12V_MOS power supply terminal and the ground terminal GND through a load resistor RL3, and LED2 can be connected in series between the VLED+ power supply terminal and the ground terminal GND through a load resistor RL26. Combined with... Figure 8 The working principle of the discharge circuit 04 and the discharge indicator light 05 is explained as follows:

[0113] Scenario 1: When both BCON board 02 and the backlight board are in self-test mode, if the level of the backlight switch pin GPIO_BLON is high, resistor RP29 can charge capacitor CB42. This makes the base (B) of transistor QP6 high, thus turning on transistor QP6 and lowering the collector (C). In other words, the anode of diode D2 can be low. This makes the bases (B) of transistors QP4 and QP5 both low, thus turning them off. At this time, the input terminal DRV_IN can be low, turning off transistor QB3. Therefore, in Scenario 1, the bleeder circuit 04 can be inactive. At the same time, both blue LED1 and green LED2 can be in the ON state, with blue LED1 emitting blue light and green LED2 emitting green light, indicating that a self-test is in progress.

[0114] Scenario 2: After the detection is complete, the MCU control chip of BCON board 02 can pull the level of the backlight switch pin GPIO_BLON from high to low. At this time, capacitor CB42 can discharge through resistor RP29, causing the base B of transistor QP6 to gradually become low. This cuts off transistor QP6. Then, the three resistors RP26, RP30, and RP31 connected to the 12V power supply divide the voltage, causing the anode of diode D2 to become high. This turns diode D2 on, which in turn turns the base B of transistors QP4 and QP5 high, turning them on. At this time, the input DRV_IN can be high. This turns transistor QB3 on, allowing the power supply VLED+ to form a discharge channel through resistors R1 to R8 and transistor QB3 to ground, discharging residual charge. At the same time, the blue LED1 and green LED2 can gradually turn off. After they are completely turned off, it indicates that the residual charge of the bypass electrolytic capacitor and other energy storage devices of 12V and VLED+ has been completely discharged.

[0115] Optionally, the transistor may be, for example, a metal-oxide-semiconductor (MOS) field-effect transistor, also known as a MOSFET. Furthermore, the discharge circuit 04 and the discharge indicator light 05 are not limited to... Figure 8 The circuit structure shown can be applied to any circuit that meets the requirements in the embodiments of this application.

[0116] Optionally, continue to refer to Figure 3 It can be seen that the self-test circuit may also include: adapter board 06.

[0117] The fixture power board 01 can be connected to the backlight control board 02 and multiple backlight boards via an adapter board 06. Furthermore, all circuits in the self-test circuit, except for the fixture power board 01 and the backlight control board 02, are housed on the adapter board. These other circuits include, for example, a linear regulator (LDO), a switch (K1), a bleed circuit 04, and a bleed indicator light 05. This ensures connection stability and simplifies the structure and size. Of course, in some other embodiments, these other circuits can be designed independently of the adapter board.

[0118] As can be seen from the above embodiments, this application provides a backlight self-test control platform. The backlight self-test control platform includes: (1) a BCON self-test control platform including a BCON board 02; (2) a fixture power supply, i.e., a fixture power supply board 01; and (3) an adapter board 06 for online testing of auxiliary module segments.

[0119] (1) The BCON self-test control platform can include 28 sockets to output power and control signals to the backlight board. The Driver IC address can be configured through DIS_1 to DIS_4; the brightness data of the self-test screen light array (i.e., the light-emitting elements included in the backlight board) can be configured through DIP_1 to DIP_28; and feedback signals can be received through DOS_1 to DOS_28 to confirm whether there is an abnormal signal feedback from the Driver IC on the link. The control chip MCU of the BCON board 02 can embed the self-test control software, and bring out the key control pin GPIO_KEY and the backlight switch pin GPIO_BLON through the custom GPIO port. The backlight switch pin GPIO_BLON can control the power-on and power-off of the fixture power board 01. The key control pin GPIO_KEY can be connected to the external adapter board 06 and, together with the button switch K1, control the switching of the static test screen.

[0120] (2) The fixture power supply can assist in online testing and provide power for the backlight driver. During the module assembly stage, it can primarily assemble the backlight board and BCON board 02, as well as the FFC connection between them. This ensures the yield rate of the FFC connection and lamp array before the LCD panel OC is applied, preventing secondary damage caused by discovering defects at the finished product stage after OC is applied, which would otherwise result in rework during the cleanroom process. For example, foreign objects, OC fragments, or other raw materials may be discarded. In other words, using the self-test circuit of this application embodiment, defect detection can be completed before OC is applied, preventing defects from flowing into the finished product.

[0121] (3) The adapter board 06, equipped with a linear regulator LDO, converts 12V to 3.3V and powers on the BCON board 02 and the fixture power board 01. Afterward, the BCON board 02 starts working and initializes, triggering the control chip MCU to pull the level of the backlight switch pin GPIO_BLON high. Then, the fixture power board 01 supplies power to the power supply terminal VLED+, and the control chip MCU runs a self-test program to perform the self-test. After the self-test is complete, the overall brightness of the backlight can be increased to indicate that the self-test is complete. Next, the testing personnel can toggle the button switch K1 to switch to static image testing. At this time, the control chip MCU can be triggered to pull the level of the key control pin GPIO_KEY low, thereby switching sequentially as follows... Figure 7The images shown are 3N+1 rows, 3N+2 rows, 3N+3 rows, 2K+1 odd-numbered columns, and 2K+2 even-numbered columns. After static image detection is complete, the control chip MCU can configure the backlight switch pin GPIO_BLON to a low level, causing the fixture power board 01 to stop supplying power to the power supply terminal VLED+, and causing transistor QB3 in the discharge circuit 04 to turn on and ground the power supply terminal VLED+ to discharge residual charge. The discharge indicator 05 will turn off when the residual charge is completely discharged. Finally, disconnect the connecting wires to complete the online test.

[0122] As described in the above embodiments, this application mainly relates to the implementation of a self-test circuit for a Mini backlight solution. This self-test circuit uses the MCU of the AM driver solution as a control platform, implementing logic control and detection schemes through software compilation, ensuring the yield of backlight products and reducing the design and manufacturing costs of additional testing equipment. This application mainly utilizes the MCU's GPIO ports to customize the control method of the self-test circuit, devising a self-test scheme and logic control timing. Through the combination of hardware and software technologies, an internally embedded self-test program enables rapid startup and achieves efficient product self-testing.

[0123] Furthermore, the self-testing circuit provided in this application embodiment can perform testing at the assembly stage, before the OC (Out-of-Concept) cover is applied. This effective interception measure can accurately locate defective backlight boards, facilitating production line repair and replacement, and improving production efficiency. Compared to similar mass-produced Mini testing solutions that can only locate defects at the assembly stage, this avoids the back-and-forth handling of defective products in the module or assembly workshops, thereby solving problems such as foreign objects during OC disassembly and material waste, and significantly saving operating and material costs.

[0124] Currently, mass-produced Mini-LED products typically employ a sequential inspection process using LEDs, either individually or in rows, relying on human visual inspection. This method is prone to missing problems on the entire production line and makes it difficult to pinpoint defects. Furthermore, even if a defect is observed visually during the sequential inspection process, it cannot be interrupted in time to stop the program at the corresponding defect location, making it impossible to accurately identify which LED board the defect occurred on. Relying on inspection memory for judgment and manual marking is prone to misjudgment and repeated repairs. Moreover, the transportation of disassembled defective products between the module and assembly sections can easily cause secondary defects, resulting in very high operating and material costs.

[0125] On the one hand, the embodiments of this application can accurately locate LED defects through self-testing circuits and methods, facilitating replacement and repair in a cleanroom environment. On the other hand, the static LED display configured in the embodiments of this application allows for time-controlled interception of defects such as stray lights, excessively bright lights, excessively dim lights, and no lights. Furthermore, the embodiments of this application use the BCON board as a control platform, resulting in fast system program startup and improved production testing efficiency. Moreover, the embodiments of this application simplify module production testing tooling, saving investment costs in production testing equipment. Furthermore, the embodiments of this application can effectively intercept defects before the module section is OC-covered, preventing defects from flowing into the complete machine. Furthermore, the embodiments of this application can also discharge residual charge through circuit control logic, effectively avoiding hot-swapping and ESD risks. In addition, the embodiments of this application also eliminate the need for repeated testing, LED board replacement, and handling during the back-and-forth transfer of products between module and complete machine workshops, as well as effectively solve the problems of loss during maintenance and disassembly OC, foreign object issues, and material scrap, significantly saving operating and material costs. In other words, the embodiments of this application can effectively solve the above problems, enabling timely repair of modules with poor positioning, improving production efficiency, and reducing manufacturing costs.

[0126] For example, taking multiple testing aspects such as lamp bridging (i.e., solder bridging), lamp open / short circuit, lamp on / off, faulty positioning, ESD / hot-plugging, and production testing efficiency as examples, the effects of the traditional LED display method and the self-testing method described in the embodiments of this application are explained as follows:

[0127] In traditional LED scrolling displays, issues arise such as: LEDs lighting sequentially in dynamic scrolling mode, with rapid image switching, making it easy for inspectors to miss defects. Furthermore, defects are only detected during the final assembly stage, requiring rework after OC (Over-Conversion) and disassembly, which can easily introduce secondary defects, and repeated operation can also introduce secondary defects, resulting in high operating costs. Similarly, in dynamic scrolling mode, LEDs light up individually without a reference brightness, making it difficult to effectively intercept brightness differences and easily leading to missed defects. Again, defects are only detected during the final assembly stage, requiring rework after OC and disassembly, which can easily introduce secondary defects, and repeated operation can also introduce secondary defects, resulting in high operating costs. Finally, in dynamic scrolling mode, LEDs light up sequentially, controlled by software serial commands, relying on human visual inspection to detect defects. It's impossible to interrupt the program in time and stop at the corresponding defect, making location difficult and easily leading to repeated exchanges and rework, further increasing operating costs. ESD / Hot-Swapping: The dynamic LED display mode uses the motherboard and power board as production test fixtures to illuminate the LEDs. There is no residual charge discharge circuit or discharge control logic, making it prone to hot-swapping, causing ESD / hot-swapping, secondary damage, and higher operating costs. Production Test Efficiency: The dynamic LED display mode, using the motherboard and power board as production test fixtures to illuminate the LEDs, involves plugging and unplugging, resulting in a long motherboard initialization time, lower test station efficiency, and reduced UPH (Uptime Per Hour).

[0128] In this embodiment, for the LED lighting: the self-test circuit, combined with the self-test method, illuminates the LEDs in odd and even static displays, effectively preventing LEDs from malfunctioning. The GPIO port is controllable, and the testing time is sufficient. For LED open / short circuit, LED on / off, and fault location: the BCON board, as the control center, initializes and self-tests the backlight board. With the initialization self-test program and set voltage range, when an abnormal signal is received from a certain path, the faulty backlight board is controlled to flash, accurately locating the fault and facilitating production line replacement and repair. Similarly, the odd / even static display illumination effectively prevents LEDs from malfunctioning, and the testing time is sufficient and controllable. For ESD / hot-swapping: the BCON board has reserved ports for expanding the discharge circuit, effectively solving residual charge discharge and hot-swapping issues. For production testing efficiency: the BCON board, as the control center, has simple software and fast initialization time, resulting in high testing station efficiency.

[0129] It is understood that the specific circuit structures and component parameters (such as resistance and voltage values) provided in the embodiments of this application are all illustrative.

[0130] Optionally, in some embodiments, other self-testing architectures can also be used. For example, a motherboard (MB) or MCU development board supporting SPI protocol communication control can be set up, along with a host computer, a display (i.e., a host computer), and a software testing tool. The host computer testing tool can send commands to the MB motherboard or MCU development board, which then controls the BCON board 02 via the SPI protocol interface. This causes the MCU control chip in the BCON board 02 to parse the received brightness signal and drive the light-emitting elements in the backlight board to emit light through a custom protocol such as SPB / OWC. Afterward, the host computer, MB motherboard, or MCU development board can then detect the presence of faulty light-emitting elements.

[0131] In summary, this application provides a self-test circuit for a backlight. In this self-test circuit, the backlight control board can not only trigger the control chip to control the level of the backlight switch pins to control the power supply board of the fixture to supply power to the backlight board and perform a self-test to detect the presence of abnormally emitting backlights, but also trigger the control chip to illuminate the light-emitting elements at multiple intervals based on the level of the key control pins, detecting the presence of abnormally emitting light-emitting elements through static image display. Therefore, it can utilize a controllable and sufficient detection time to accurately locate the defective position, thereby effectively intercepting defects and avoiding missed or false detections.

[0132] This application also provides a self-test method for a backlight, which can be applied to a backlight control board included in the self-test circuit described in the above embodiments. Figure 9 As shown, the method includes:

[0133] Step 901: Based on the received enable power supply voltage, trigger the control chip to output a backlight turn-on signal to the backlight switch pin, so as to control the fixture power board to output backlight power supply voltage to the power supply terminals of multiple backlight boards.

[0134] The enable supply voltage is the voltage provided by the fixture power board based on the input voltage from the external input.

[0135] Step 902: Based on the backlight power supply voltage trigger control chip, control multiple backlight boards to emit light and perform self-test operations to detect whether there are backlight boards emitting light abnormally.

[0136] Step 903: Based on the static screen lighting signal input via the keying pin, the control chip is triggered to control the multiple backlight boards, including multiple light-emitting elements, to emit light sequentially in the display order according to a uniform brightness, in order to detect whether there are any abnormal light-emitting elements.

[0137] Each time the light is emitted, the light-emitting element is different, and each time the light-emitting element includes multiple light-emitting elements spaced apart.

[0138] Optionally, in combination with the foregoing records and Figure 3 , Figure 10 A schematic diagram of a software control logic is shown. (Combined with...) Figure 10 It can be seen that:

[0139] First, AC power is applied. After AC power is applied, the fixture power board 01 can enter standby mode, i.e., power standby. The fixture power board 01 can output 12V and 10.5V voltages based on 220V AC mains power. The 12V and 10.5V voltages can be used as input voltages to drive the linear regulator LDO. The linear regulator LDO can convert the 12V voltage to 3.3V and output it to the BCON board 02 as the enable voltage DC_EN, driving the BCON board 02 to start and operate. The linear regulator LDO can also convert the 10.5V voltage to 3.3V and output it to the fixture power board 01 as the enable voltage STB_EN, driving the fixture power board 01 to stabilize in standby mode.

[0140] Afterwards, BCON board 02 can output 3.3V and 3.6V voltages to the control chip MCU and Driver IC respectively to drive them. Once BCON board 02 is powered on, it triggers the initialization of the control chip MCU. After initialization, the control chip MCU can pull the level of the backlight switch pin GPIO_BLON high, enabling GPIO_BLON. At this time, after receiving the high level of GPIO_BLON, the fixture power board 01 can supply power to the backlight board's power supply terminal VLED+, and the VLED+ circuit will operate, outputting the backlight power supply voltage. Next, the control chip MCU can configure the address and brightness information of the Driver IC, configure the backlight board to light up, and run a self-test program to perform a self-test operation. If any DOS feedback is abnormal, the control chip MCU can control the corresponding backlight board to blink. During the self-test, the GPIO port does not respond to other controls. After the self-test is completed, the control chip MCU can control the overall brightness of each backlight board to indicate that the self-test is complete.

[0141] After the self-test is complete, the GPIO_KEY key pin can begin to respond to control commands. For example, the operator can pull the GPIO_KEY key pin low by toggling switch K1. At this time, the control chip MCU can configure the Driver IC to sequentially light up the light-emitting elements according to the set uniform brightness and display order, switching the static test screen. For example, according to... Figure 7 The display sequence shown is as follows: 3N+1 rows, 3N+2 rows, 3N+3 rows, 2K+1 odd columns, and 2K+2 even columns.

[0142] After the static image detection is complete (OK), the control chip MCU can pull the level of the backlight switch pin GPIO_BLON low, causing the fixture power board 01 to stop supplying power to the backlight board's power supply terminal VLED+, i.e., power off. Furthermore, pulling the level of the backlight switch pin GPIO_BLON low can also trigger the transistor QB3 in the discharge circuit 04 to conduct, thereby discharging residual charge. During the discharge of residual charge, the discharge indicator lights 05 (e.g., LED1 and LED2) can gradually turn off; once completely off, it indicates that the residual charge has been completely discharged. At this point, the online test is complete; power off and disconnect the relevant test cables.

[0143] It is understood that since the self-test method can have the same technical effect as the self-test circuit described in the previous embodiment, the technical effect of the self-test method will not be described again here for the sake of brevity.

[0144] It should be noted that the terminology used in the embodiments of this application is for illustrative purposes only and is not intended to limit the application. Unless otherwise defined, the technical or scientific terms used in the implementation of this application should have the ordinary meaning understood by one of ordinary skill in the art to which this application pertains.

[0145] For example, the terms "first," "second," or "third," and similar words used in the patent application specification and claims do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Similarly, "an" or "a," and similar words do not indicate a quantity limitation, but rather indicate the presence of at least one. Terms such as "comprising" or "including" mean that the element or object preceding "comprising" covers the element or object listed after "comprising" or "including," and does not exclude other elements or objects. "Above," "below," "left," or "right," etc., are only used to indicate relative positional relationships; when the absolute position of the described object changes, the relative positional relationship may also change accordingly. "Connected" or "coupled" refers to an electrical connection. "And / or" indicates that three relationships can exist; for example, A and / or B can represent: A alone, A and B simultaneously, and B alone. The character " / " generally indicates that the preceding and following objects are in an "or" relationship.

[0146] The above description is merely an optional embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A self-test circuit for a backlight, characterized in that, The backlight source includes: multiple backlight panels, each backlight panel including multiple light-emitting elements; the self-test circuit includes: a fixture power board and a backlight control board, the backlight control board including a control chip, the control chip having backlight switch pins and key control pins; the fixture power board is connected to the power supply terminal of the backlight control board, and is also used to connect to the power supply terminals of the multiple backlight panels; the backlight control board is also used to connect to the multiple backlight panels; The fixture power board is used to: output an enable power supply voltage to the power supply terminal of the backlight control board based on the input voltage from the external input, and output a backlight power supply voltage to the power supply terminal of the plurality of backlight boards based on the backlight turn-on signal output through the backlight switch pin. The backlight control board is used to: trigger the control chip to output the backlight turn-on signal to the backlight switch pin based on the enable power supply voltage; trigger the control chip to control the multiple backlight panels to emit light and perform a self-test operation based on the backlight power supply voltage to detect whether there is a backlight panel emitting light abnormally; and trigger the control chip to control the multiple light-emitting elements included in the multiple backlight panels to emit light sequentially multiple times according to the display order based on the static screen lighting signal input through the key control pin, so as to detect whether there is a light-emitting element emitting light abnormally, wherein the light-emitting elements emitting light each time are different, and the light-emitting elements emitting light each time include multiple light-emitting elements spaced apart.

2. The self-test circuit according to claim 1, characterized in that, The backlight source further includes: multiple backlight driver boards, the backlight control board being connected to the multiple backlight lamp boards via the multiple backlight driver boards, and each of the multiple backlight driver boards having an address configuration pin, a signal input pin, and a signal output pin; for each of the backlight lamp boards, the self-test operation includes: The address configuration pin is used to configure an address for the backlight driver board connected to the backlight board, so as to identify the backlight driver board of the backlight board; The backlight driver board connected to the backlight panel outputs a uniform brightness signal through the signal input pin to control the backlight driver board of the backlight panel to light up the multiple light-emitting elements included in the backlight panel according to the brightness signal. The test signal fed back from the backlight driver board of the backlight board is received through the signal output pin, so as to detect whether the backlight board emits light abnormally based on the test signal.

3. The self-test circuit according to claim 1, characterized in that, The backlight control board is also used to: when an abnormal backlight board is detected, control the abnormal backlight board to flash, and after the self-test is completed, control the multiple backlight boards to emit light simultaneously to the brightness threshold to indicate that the self-test is complete.

4. The self-test circuit according to any one of claims 1 to 3, characterized in that, The multiple backlight panels include multiple light-emitting element arrays arranged in a single configuration. The display sequence includes: first, controlling the light-emitting elements of the 3N+1, 3N+2, and 3N+3 rows to emit light sequentially, on a row-by-row basis; then, controlling the light-emitting elements of the 2K+1 and 2K+2 columns to emit light sequentially, on a column-by-column basis; where N is a positive integer greater than or equal to 0 and less than the total number of rows, and K is a positive integer greater than or equal to 0 and less than the total number of columns.

5. The self-test circuit according to any one of claims 1 to 3, characterized in that, The self-test circuit further includes a switch; the switch is connected to the power supply terminal, the ground terminal and the keying pin respectively. The switch is used to: control the keying pin to connect to the ground terminal based on the received on signal, so as to input the static screen lighting signal through the keying pin, and control the keying pin to disconnect from the ground terminal based on the received off signal.

6. The self-test circuit according to any one of claims 1 to 3, characterized in that, The enabling power supply voltage includes: an enabling voltage and a power supply voltage; the self-test circuit further includes: a linear regulator; the linear regulator is connected between the fixture power board and the backlight control board; The fixture power board is used to: output the power supply voltage to the power supply terminal of the backlight control board and the linear regulator respectively; The linear regulator is used to: step down the supply voltage to obtain the enable voltage, and output the enable voltage to the enable terminal of the backlight control board and the enable terminal of the fixture power board respectively, so as to drive the backlight control board to work and control the fixture power board to enter the standby state.

7. The self-test circuit according to any one of claims 1 to 3, characterized in that, The backlight control board is also used to: trigger the control chip to output a backlight off signal to the backlight switch pin after the detection is completed; The fixture power board is also used to: stop outputting backlight power supply voltage to the power supply terminals of the plurality of backlight panels based on the backlight off signal, so that the plurality of backlight panels stop emitting light; Furthermore, the self-test circuit also includes a discharge circuit; the discharge circuit is connected to the power supply terminal of the plurality of backlight boards, the backlight switch pin, and the ground terminal respectively; The discharge circuit is used to: control the power supply terminals of the plurality of backlight panels to be connected to the ground terminal based on the backlight off signal, so as to discharge residual charge; and control the power supply terminals of the plurality of backlight panels to be disconnected from the ground terminal based on the backlight on signal.

8. The self-test circuit according to claim 7, characterized in that, The self-test circuit further includes: a discharge indicator light; the discharge indicator light is connected to the discharge circuit. The discharge indicator light is used to: illuminate based on the backlight on signal, and gradually turn off based on the backlight off signal; wherein, the discharge indicator light stopping to illuminate is used to indicate that the residual charge discharge is complete.

9. The self-test circuit according to any one of claims 1 to 3, characterized in that, The self-test circuit also includes: an adapter board; The fixture power board is connected to the backlight control board and the plurality of backlight boards via the adapter board. Furthermore, all circuits in the self-test circuit, except for the fixture power board and the backlight control board, are located on the adapter board.

10. A self-testing method for a backlight, characterized in that, The method is applied to a backlight control board included in the self-test circuit as described in any one of claims 1 to 9; the method includes: Based on the received enable power supply voltage, the control chip outputs a backlight turn-on signal to the backlight switch pin to control the fixture power board to output backlight power supply voltage to the power supply terminals of multiple backlight boards. The enable power supply voltage is the voltage provided by the fixture power board based on the external input voltage. Based on the backlight power supply voltage, the control chip is triggered to control the multiple backlight panels to emit light and perform a self-test operation to detect whether there are backlight panels emitting abnormal light. Based on the static screen lighting signal input via the keying pin, the control chip is triggered to control the multiple backlight panels, including multiple light-emitting elements, to emit light sequentially in the display order according to a uniform brightness, in order to detect whether there are any abnormal light-emitting elements. The light-emitting elements that emit light each time are different, and the light-emitting elements that emit light each time include multiple light-emitting elements spaced apart.

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