CN114217213A

CN114217213A - Test method for active LED matrix panel

Info

Publication number: CN114217213A
Application number: CN202111538075.1A
Authority: CN
Inventors: 张建良
Original assignee: Beijing Xingeno Microelectronics Co ltd
Current assignee: Beijing Xingeno Microelectronics Co ltd
Priority date: 2021-12-15
Filing date: 2021-12-15
Publication date: 2022-03-22
Anticipated expiration: 2041-12-15
Also published as: CN114217213B

Abstract

The invention discloses a test method for an active LED matrix panel, which comprises the following steps: after the active LED matrix panel is electrified, starting a timer; the driving controller outputs a test data message on the communication bus at an interval less than a preset time interval; when the message received by the drive IC within the preset time interval is a test data message, the drive IC drives the LED to display according to a first display mode specified by the test data message; when the driving IC does not receive the message information within the preset time interval T, the driving IC enters a communication fault state, and the driving IC outputs a fault data message at a frequency less than the preset time interval T and drives the LED to display in a preset second display mode; and when the driving IC receives the message information within the preset time interval T and the message information is a fault data message, the driving IC enters a preceding stage communication fault state and drives the LED to display in a preset third display mode.

Description

Test method for active LED matrix panel

Technical Field

The invention relates to the technical field of communication, in particular to a test method for an active LED matrix panel.

Background

With the development of display technology, LED array light sources have become the first choice for liquid crystal display devices. The use of the active matrix LED light source can enable the display effect to achieve wider color gamut and more accurate color accuracy, and meanwhile, the control is more accurate due to the narrow and constant color spectrum of the LED light source.

In order to improve the High Dynamic Range (HDR) display effect, a small LED (mini-LED) is widely used as a backlight source for a display panel. As shown in fig. 1, the LEDs are disposed on a PCB or a glass panel in a matrix arrangement, and the current of the LEDs is controlled independently or in groups to achieve the purpose of adjusting the display brightness. On a large panel, the number of LEDs can reach tens of thousands, and the LEDs are divided into thousands of partitions, each of which is controlled by a driving chip (driving IC). These driver chips are typically connected in series by a serial BUS (BUS1 and BUS2), with both ends of the BUS connected to the controller. There may be more than one similar serial bus to increase the efficiency of the communication. This control method is generally called Active Matrix (AM).

Fig. 1 schematically shows an implementation of controlling 4 partitions (D1-D4) per driver chip (IC), where D1-D4 are all independent partitions, and each partition may be an LED or a group of LEDs connected in series or in parallel. Each driver chip and its controlling D1-D4 form a group. Similarly, LEDs are also used for direct display (direct display), for example, micro-LEDs (micro-LEDs) can be directly used as display pixels, and millions of micro-LEDs are directly formed into one display panel in a matrix arrangement without an LCD screen. In applications where the LED matrix is used as a backlight or direct display, a large number of LEDs and driver chips (ICs) are used. During production or use, whether the LEDs and the driving chip work normally needs to be detected. In a conventional detection method, a controller sends an instruction through a serial communication bus, a driving chip lights up D1-D4 of each group, and whether D1-D4 are lighted up according to expected brightness is checked to judge whether the driving chip and D1-D4 work normally. The method has low efficiency, and if a certain group has a fault (causes such as poor driving chips) to cause communication interruption, the group needs to be checked and repaired to recover communication, and then the communication is detected again, so that whether the subsequent group works normally can be continuously checked. If a plurality of fault groups causing communication interruption exist on one bus, repeated detection is needed for many times, time and labor are consumed, and the cost is high.

Therefore, there is a need in the art for a detection method that can quickly and efficiently detect an active LED array panel.

Disclosure of Invention

One of the technical problems to be solved by the present invention is to provide a method for rapidly and effectively testing an active LED array panel, which can reduce the number of repeated detections, and determine a plurality of failure points on the active LED array panel by one-time detection.

In order to solve the above technical problem, the present invention provides a method for testing an active LED matrix panel, the method comprising:

after the active LED matrix panel is electrified, initializing each level of drive IC on the drive controller and the communication bus to enable the drive IC to enter a detection mode, and simultaneously starting the drive controller and a timer in each level of drive IC;

after initialization is completed, the drive controller outputs a test data message on the communication bus at a frequency less than a preset time interval T;

when the driver IC receives the message information in a preset time interval T, the driver IC identifies the message information, and if the message information is a test data message, the driver IC drives the LED to display according to a first display mode specified by the test data message; simultaneously transmitting the test data message to a next-stage drive IC;

when the driving IC does not receive the message information within the preset time interval T, the driving IC enters a communication fault state, and the driving IC outputs a fault data message at a frequency less than the preset time interval T and drives the LED to display in a preset second display mode; simultaneously transmitting the fault data message to a next-stage drive IC; the fault data message contains address information of the current drive IC;

when the driving IC receives message information in a preset time interval T and the message information is a fault data message, the driving IC enters a preceding stage communication fault state and drives the LED to display in a preset third display mode; meanwhile, forwarding the preceding-stage fault data message to a next-stage drive IC; the preceding-stage fault data message comprises third display mode data;

and detecting each level of driving IC on the communication bus to obtain the display modes of all LEDs.

In one embodiment, the data structures of the test data message, the fault data message and the preceding-stage fault data message comprise a command field, an address field and a data field; the address field includes display mode data in the data field for specifying a driver IC to display.

In one embodiment, the address field in the failure data message contains address information of the current driver IC that sent the failure data message.

In one embodiment, the first display mode, the second display mode, and the third display mode drive the LED elements to display in different lighting orders and brightness levels.

In one embodiment, the duration of the time interval T is greater than the time delay required for the drive controller to transfer a message from the first stage drive IC to the last stage drive IC.

In one embodiment, the frequency of the test data messages output by the drive controller is set to T/4, and the frequency of the fault data messages output by the drive IC is T/2.

In one embodiment, after the detection is completed, the drive controller sends an instruction to turn off the detection mode of all the drive ICs, so that the drive ICs enter the normal operation mode.

One or more embodiments of the present invention may have the following advantages over the prior art:

1. the technical purpose of simultaneously detecting a plurality of fault points on the active LED matrix panel is realized by setting a timer and a plurality of display modes.

2. The invention sets the lighting sequence and the brightness level of the LED in a plurality of display modes, so that the fault detection method can complete the fault detection of the LED element while detecting the driving IC.

Additional features and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objectives and other advantages of the invention will be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings.

Drawings

The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the principles of the invention and not to limit the invention. In the drawings:

FIG. 1 is a schematic diagram of an example of an active LED matrix panel in the prior art;

fig. 2 is a flow chart illustrating a method of detecting a failure of an active LED matrix panel according to the present invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is further described in detail below with reference to fig. 1-2.

Taking the arrangement of the active LED matrix panel in the prior art shown in fig. 1 as an example, each driver IC, i.e., the driver chip, controls an implementation of 4 LED partitions (D1-D4), where D1-D4 are all independent partitions, and each partition may be an LED or a group of LEDs connected in series or in parallel. Each driver chip and its controlling D1-D4 form a group. The testing method of the invention is implemented for the active LED matrix panel described above.

According to the schematic flow chart of the testing method of the active LED matrix panel shown in fig. 2, the fault detection method includes:

The test data message, the fault data message and the preceding-stage fault data message adopt a universal serial communication data structure in the prior art, and the test data message and the fault data message comprise a command field, an address field and a data field. The data field includes display mode data for specifying one of the first display mode, the second display mode, and the third display mode, which is display mode data for displaying by the driver IC.

According to the detection method of the embodiment, the failure condition of the driving IC on the communication bus can be known after the display mode of all the LEDs on the communication bus is obtained, and when the LEDs display in the first display mode, it indicates that all the front-stage LEDs and driving ICs including the stage of LEDs and driving ICs are working normally. When the LED displays in the second display mode, it is known that the stage driver IC does not receive the message information transmitted by the previous stage driver IC, and the communication between the stage driver IC and the previous stage driver IC is interrupted, and it is necessary to check the stage driver IC, the previous stage driver IC, and the communication line therebetween. When the LED displays in the third display mode, it indicates that there is a failure in the current stage LED or one of the previous stages of the driver ICs. In the invention, the message information transmitted back to the drive controller through the communication bus also carries the position information of a failed drive IC closest to the last drive IC.

In this embodiment, the first display mode, the second display mode, and the third display mode are defined at the same time, so that the display modes are displayed with different display effects, and the purpose of detecting the failure condition of the LED at the same time is achieved. For example, the first display mode is to light D1 to D4 at the luminance level L0 at the same time; the second display mode is to simultaneously light up D1 to D4 at the luminance level L1; the third display mode is to simultaneously light D1 to D4 at the luminance level L2.

Still alternatively, the first display mode is to light D1 to D4 at the same time at the luminance level L0; the second display mode is to sequentially light D1, D2, D3 and D4 at a brightness level of L1; the third display mode is to simultaneously light up D4, D3, D2, and D1 at the luminance level L2.

When the LED does not display according to the corresponding display mode, the LED element can be known to be in fault.

In this embodiment, the duration of the time interval T needs to be much longer than the time delay required for the driving controller to transmit the message from the first stage driving IC to the last stage driving IC. Meanwhile, the frequency of outputting the test data message by the driving controller can be set to be T/4, and the frequency of outputting the fault data message by the driving IC is T/2.

In this embodiment, after all the detection is completed, the driving controller sends an instruction to turn off the detection mode of all the driving ICs, so that the driving ICs enter the normal operating mode.

The above description is only an embodiment of the present invention, and the protection scope of the present invention is not limited thereto, and any person skilled in the art should modify or replace the present invention within the technical specification of the present invention.

Claims

1. A method for testing an active LED matrix panel, the method comprising:

when the driving IC does not receive the message information within the preset time interval T, the driving IC enters a communication fault state, and the driving IC outputs a fault data message at a frequency less than the preset time interval T and drives the LED to display in a preset second display mode; simultaneously transmitting the fault data message to a next-stage drive IC;

when the driving IC receives message information in a preset time interval T and the message information is a fault data message, the driving IC enters a preceding stage communication fault state and drives the LED to display in a preset third display mode; meanwhile, forwarding the preceding-stage fault data message to a next-stage drive IC;

2. The test method of claim 1, wherein the data structures of the test data message, the fault data message, and the preceding fault data message include a command field, an address field, and a data field; the address field includes display mode data in the data field for specifying a driver IC to display.

3. The test method according to claim 2, wherein the address field in the failure data packet contains address information of a current driver IC which issues the failure data packet.

4. The test method according to claim 1, wherein the first display mode, the second display mode, and the third display mode drive the LED elements to display in different lighting orders and brightness levels.

5. The test method of claim 1, wherein the duration of the time interval T is greater than a time delay required for the drive controller to transfer the message from the first stage drive IC to the last stage drive IC.

6. The test method of claim 1, wherein the frequency of outputting the test data messages by the driver controller is set to T/4, and the frequency of outputting the failure data messages by the driver IC is T/2.

7. The test method of claim 1, wherein after the completion of the test, the drive controller sends a command to turn off the test mode of all the drive ICs, so that the drive ICs enter a normal operation mode.

8. An active LED matrix panel comprising LED light emitting elements, driver ICs for driving the LED light emitting elements and a driver controller controlling all the driver ICs, wherein the driver controller and the driver ICs have stored therein instructions for implementing a test method according to one of claims 1 to 7.

9. A display device comprising the active LED matrix panel of claim 8.