Mini LED backlight test method based on FCT test equipment

Abstract

The present invention discloses a Mini LED backlight source testing method based on FCT testing equipment, which relates to the field of backlight source testing and solves the problem of low backlight source testing efficiency at this stage. The method includes: performing an optical performance test on a Mini LED screen to generate a brightness abnormality signal or a color abnormality signal of the Mini LED screen; randomly sampling and selecting multiple lamp beads in the Mini LED screen as light-emitting diodes to be tested, connecting the multiple light-emitting diodes to be tested to obtain a light-emitting diode group to be tested and fixing it to an FCT testing machine; performing an electrical parameter test on the light-emitting diode group to be tested to generate a power supply abnormality signal or a short-circuit abnormality signal of the light-emitting diode group to be tested; and displaying the brightness abnormality signal, color abnormality signal, power supply abnormality signal and short-circuit abnormality signal of the Mini LED screen. The present invention realizes efficient and accurate testing of the Mini LED backlight source.

Description

Technical Field

[0001] The present invention belongs to the technical field of backlight source testing, and specifically is a Mini LED backlight source testing method based on FCT testing equipment. Background Art

[0002] Mini LED is an upgraded version of LED technology and a new type of LED display technology. Its full name is Mini Light-Emitting Diode. Its core technology is to reduce the size of LED chips to between 50-200 microns and achieve more precise backlight control through high-density arrangement. By detecting optical performance and defects, combined with automated equipment and industry standards, it can ensure the high image quality, high reliability and market compliance of Mini LED. With technological advancements, detection efficiency and accuracy will be further improved, promoting the popularization and application of Mini LED technology.

[0003] However, currently, when testing Mini LED screens, each Mini LED is usually tested in turn. Optical performance verification of the Mini LED screen is not combined with electrical parameter testing of the Mini LED lamp beads, resulting in low testing efficiency and extremely high testing costs.

[0004] To this end, the present invention proposes a Mini LED backlight source testing method based on FCT testing equipment. Summary of the Invention

[0005] The purpose of the present invention is to propose a Mini LED backlight source testing method based on FCT testing equipment to solve the problems raised in the above background technology.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions:

[0007] Mini LED backlight test method based on FCT test equipment, the method includes:

[0008] Step S1: Fix the Mini LED screen to the FCT test machine

[0009] Step S2: Perform an optical performance test on the Mini LED screen to generate a brightness abnormality signal or a color abnormality signal of the Mini LED screen;

[0010] Step S3: randomly sampling multiple LEDs from the Mini LED screen as light-emitting diodes to be tested, connecting the multiple light-emitting diodes to be tested to obtain a light-emitting diode group to be tested, and fixing the group to the FCT test machine;

[0011] Step S4, performing electrical parameter testing on the light emitting diode group to be tested, and generating a power supply abnormality signal or a short circuit abnormality signal of the light emitting diode group to be tested;

[0012] Step S5: Display the brightness abnormality signal, color abnormality signal, power supply abnormality signal and short circuit abnormality signal of the Mini LED screen.

[0013] Furthermore, the optical performance test includes a brightness test and a chromaticity test; the electrical parameter test includes a power supply parameter test and a short circuit test.

[0014] Furthermore, the test process of the brightness test is as follows:

[0015] Step S201: sending a white display signal to the Mini LED screen, which receives the white display signal and switches to a white display mode;

[0016] Step S202: The Mini LED screen performs brightness tests in sequence from brightness test level 1 to brightness test level Z; where Z is a positive integer, and different brightness levels correspond to white window displays of different sizes.

[0017] Step S203: Record the brightness values of the white window display center corresponding to different brightness test levels, and record them as the brightness values of the corresponding brightness test levels; select the maximum brightness value among all brightness test levels and record it as the peak brightness of the Mini LED screen;

[0018] In step S204, after the brightness test level Z is continuously displayed for a fixed time, the Mini LED display screen is divided into K display partitions, and the real-time brightness values of different pixels in each display partition are recorded; wherein the fixed time is greater than or equal to one minute, and K is a positive integer.

[0019] Furthermore, the brightness test process also includes:

[0020] Step S205: Add the real-time brightness values of all pixels in the same display partition and take the average value as the partition brightness value of the corresponding display partition; divide the minimum partition brightness value of all display partitions by the maximum partition brightness value and multiply by 100 to obtain the brightness uniformity of the Mini LED screen;

[0021] Step S206, compare the peak brightness with the peak brightness threshold, and compare the brightness uniformity with the brightness uniformity threshold. If the peak brightness is greater than or equal to the peak brightness threshold and the brightness uniformity is greater than or equal to the brightness uniformity threshold, then the brightness display of the Mini LED screen is deemed normal; if the peak brightness is less than the peak brightness threshold or the brightness uniformity is less than the brightness uniformity threshold, then the brightness display of the Mini LED screen is deemed abnormal, and a brightness abnormality signal is generated.

[0022] Furthermore, the testing process of the chromaticity test is specifically as follows:

[0023] Step S211: Sending a standard color display signal to the Mini LED screen, and switching the Mini LED screen to a standard color display mode; wherein the standard color display mode is used to display multiple colors;

[0024] Step S212: Divide the Mini LED display screen into multiple display partitions, and randomly select a pixel point in each display partition as a color test point;

[0025] Step S213: sequentially input a full red display signal, a full green display signal, and a full blue display signal to the Mini LED screen, and record the chromaticity coordinate value of the first color test point when the full red display signal is input as RZ1 (RX, RY), the chromaticity coordinate value of the first color test point when the full green display signal is input as GZ1 (GX, GY), and the chromaticity coordinate value of the first color test point when the full blue display signal is input as BZ1 (BX, BY);

[0026] In step S214, the color gamut triangle area MJ1 corresponding to the color test point is calculated using the following formula:

[0027] .

[0028] Furthermore, the chromaticity test process also includes:

[0029] Step S215, measuring the chromaticity coordinate values of the remaining color test points, and calculating the color gamut triangle areas of the remaining color test points to obtain MJ2 to MJK;

[0030] Step S216: Select the minimum value from MJ1 to MJK as the color gamut triangle area of the Mini LED screen; and obtain the color gamut coverage of the Mini LED screen by dividing the color gamut triangle area of the Mini LED screen by the standard color gamut area.

[0031] In step S217, the color gamut coverage is compared with the color gamut coverage threshold. If the color gamut coverage is greater than or equal to the color gamut coverage threshold, the Mini LED color test is deemed normal; if the color gamut coverage is less than the color gamut coverage threshold, the Mini LED color display is deemed abnormal and a color abnormality signal is generated.

[0032] Furthermore, the test process of the power supply parameter test is as follows:

[0033] Step S401: Connect the LED group to be tested to a programmable power supply, apply a rated voltage to the LED group to be tested through the programmable power supply of the FCT machine, and set a limit protection current for the LED group to be tested;

[0034] Step S402: If the real-time current value of the LED group under test is greater than or equal to the limit protection current, the programmable power supply will disconnect from the LED group under test; if the real-time current value of the LED group under test is less than the limit protection current, the subsequent steps will be executed;

[0035] Step S403 : sending a control instruction to make the light emitting diode group to be tested enter the maximum brightness mode, and collecting the real-time current value and real-time voltage value of the light emitting diode group to be tested through the data acquisition card.

[0036] Furthermore, the test process of the power supply parameter test also includes:

[0037] Step S404: multiply the rated current by the rated voltage to obtain the rated power, and multiply the real-time current by the real-time voltage to obtain the actual power; subtract the actual power from the rated power and take the absolute value to obtain the power deviation value;

[0038] In step S405, the electric power deviation value is compared with the electric power deviation threshold. If the electric power deviation value is less than the electric power deviation threshold, it is determined that the power supply parameters of the light-emitting diode to be tested are normal; if the electric power deviation value is greater than or equal to the electric power deviation threshold, it is determined that the power supply test of the light-emitting diode to be tested is abnormal, and a power supply abnormality signal is generated.

[0039] Furthermore, the test process of the short circuit test is specifically as follows:

[0040] Step S411: disconnecting the programmable power supply from the LED group to be tested; if the LED group to be tested has a parallel branch, isolating the other branches by physically disconnecting them, and selecting any one of the branches as the target circuit; if the LED group to be tested does not have a parallel branch, recording the circuit corresponding to the LED group to be tested as the target circuit;

[0041] Step S412 , selecting a current applying end and a voltage applying end, and connecting the probes of the current applying end and the voltage applying end to the positive and negative electrodes of the target circuit in sequence.

[0042] Furthermore, the short circuit test process also includes:

[0043] Step S413, measuring the measured resistance values at both ends of the target circuit by a resistance measuring device; reading the standard resistance value of each light-emitting diode to be measured in the target circuit, and summing the standard resistance values of all the light-emitting diodes to be measured to obtain the calculated resistance value of the target circuit;

[0044] Step S414: The resistance deviation value is obtained by subtracting the calculated resistance value from the measured resistance value, and the resistance deviation value is compared with the estimated line impedance. If the resistance deviation value is greater than or equal to the estimated line impedance, it is determined that a short circuit test anomaly exists in the target circuit and a short circuit anomaly signal is generated; if the resistance deviation value is greater than or equal to the estimated line impedance, no operation is performed.

[0045] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are:

[0046] 1. The present invention first fixes the Mini LED screen to the FCT test machine, then performs an optical performance test on the Mini LED screen to generate a brightness abnormality signal or a color abnormality signal of the Mini LED screen; the present invention realizes the optical performance test of the Mini LED screen;

[0047] 2. The present invention randomly samples multiple lamp beads in the Mini LED screen and records them as light-emitting diodes to be tested, connects the multiple light-emitting diodes to be tested to obtain a light-emitting diode group to be tested and fixes it to an FCT testing machine; then performs electrical parameter testing on the light-emitting diode group to be tested to generate a power supply abnormality signal or a short-circuit abnormality signal of the light-emitting diode group to be tested; finally, the brightness abnormality signal, color abnormality signal, power supply abnormality signal and short-circuit abnormality signal of the Mini LED screen are displayed. The present invention realizes efficient detection of Mini LED backlight sources. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] To facilitate understanding by those skilled in the art, the present invention is further described below with reference to the accompanying drawings.

[0049] Figure 1 A flowchart of the method of the present invention;

[0050] Figure 2 Schematic diagram of the color gamut triangle in the present invention;

[0051] Figure 3 It is a structural diagram of the computer device in the present invention. DETAILED DESCRIPTION

[0052] The technical solutions of the present invention will be clearly and completely described below in conjunction with the embodiments. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0053] Example 1, please refer to Figure 1 and Figure 2As shown, the technical solution provided by the present invention is: a Mini LED backlight source testing method based on FCT testing equipment, which first tests the optical performance of the entire Mini LED screen to determine the optical anomaly of the Mini LED, then detects the electrical parameters of the lamp beads in the Mini LED screen, and then determines the electrical anomaly of the Mini LED screen. Finally, the electrical and optical anomalies of the Mini LED screen are integrated and displayed;

[0054] It should be noted that the Mini LED screen refers to a layer structure in the Mini LED display, specifically the light-emitting layer composed of Mini LEDs;

[0055] Among them, FCT test equipment is functional circuit test equipment. Mini LED, also known as sub-millimeter light-emitting diode, refers to LED chips with a grain size of about 100 microns, which is between the size of small-pitch LED and Micro-LED;

[0056] In this embodiment, the Mini LED backlight test method is as follows:

[0057] Step S1, fixing the Mini LED screen to the FCT test machine;

[0058] Specifically, the FCT test machine integrates a programmable power supply, a data acquisition card, a probe matrix, and a photometer, etc., and is used to test the electrical parameters and optical performance of the light-emitting diode group under test;

[0059] Step S2: Perform an optical performance test on the Mini LED screen to generate a brightness abnormality signal or a color abnormality signal of the Mini LED screen; wherein the optical performance test includes a brightness test and a chromaticity test;

[0060] In this embodiment, the brightness test is specifically as follows:

[0061] Step S201: Send a white display signal to the Mini LED screen. The Mini LED screen receives the white display signal and switches to a white display mode. The white display mode can only display white, and the RGB value of the white display is (255, 255, 255).

[0062] Step S202: The Mini LED screen performs brightness tests in sequence from brightness test level 1 to brightness test level Z; where Z is a positive integer, and different brightness levels correspond to white window displays of different sizes.

[0063] For example, brightness test level 1 corresponds to P1×P1 white window display, brightness test level 2 corresponds to P2×P2 white window display, and so on, brightness test level Z corresponds to Pt×Pt white window display, where P1<P2<……<Pt;

[0064] Step S203: Record the brightness values of the white window display center corresponding to different brightness test levels, and record them as the brightness values of the corresponding brightness test levels; select the maximum brightness value among all brightness test levels and record it as the peak brightness of the Mini LED screen;

[0065] Step S204: After the brightness test level Z is continuously displayed for a fixed time, the Mini LED display screen is divided into K display partitions, and the real-time brightness values of different pixels in each display partition are recorded; wherein the fixed time is greater than or equal to one minute, and K is a positive integer; optionally, K is 9, 16, or 25;

[0066] Step S205: Add the real-time brightness values of all pixels in the same display partition and take the average value as the partition brightness value of the corresponding display partition; divide the minimum partition brightness value of all display partitions by the maximum partition brightness value and multiply by 100 to obtain the brightness uniformity of the Mini LED screen;

[0067] Step S206: Compare the peak brightness with the peak brightness threshold, and compare the brightness uniformity with the brightness uniformity threshold. If the peak brightness is greater than or equal to the peak brightness threshold and the brightness uniformity is greater than or equal to the brightness uniformity threshold, the Mini LED screen brightness display is considered normal. If the peak brightness is less than the peak brightness threshold or the brightness uniformity is less than the brightness uniformity threshold, the Mini LED screen brightness display is considered abnormal, and a brightness abnormality signal is generated.

[0068] In this embodiment, the chromaticity test is specifically as follows:

[0069] Step S211: Sending a standard color display signal to the Mini LED screen, and switching the Mini LED screen to a standard color display mode; wherein the standard color display mode is used to display multiple colors;

[0070] Step S212: Divide the Mini LED display screen into multiple display partitions, and randomly select a pixel point in each display partition as a color test point;

[0071] Step S213: sequentially input a full red display signal, a full green display signal, and a full blue display signal to the Mini LED screen, and record the chromaticity coordinate value of the first color test point when the full red display signal is input as RZ1 (RX, RY), the chromaticity coordinate value of the first color test point when the full green display signal is input as GZ1 (GX, GY), and the chromaticity coordinate value of the first color test point when the full blue display signal is input as BZ1 (BX, BY);

[0072] Among them, the chromaticity coordinate value is the color coordinate, which is a commonly used color coordinate, divided into a horizontal axis X and a vertical axis Y, and is measured by a spectrophotometer;

[0073] Step S214: Calculate the color gamut triangle area MJ1 corresponding to the color test point using the following formula:

[0074] ;

[0075] Step S215: Similarly, measure the chromaticity coordinates of the remaining color test points and calculate the color gamut triangle areas of the remaining color test points to obtain MJ2 to MJK;

[0076] In step S216, refer to Figure 2, which shows three different standard color gamut areas. The minimum value among MJ1 to MJK is selected as the color gamut triangle area of the Mini LED screen. The color gamut coverage of the Mini LED screen is obtained by dividing the color gamut triangle area of the Mini LED screen by the standard color gamut area.

[0077] In step S217, the color gamut coverage is compared with the color gamut coverage threshold. If the color gamut coverage is greater than or equal to the color gamut coverage threshold, the Mini LED color test is deemed normal; if the color gamut coverage is less than the color gamut coverage threshold, the Mini LED color display is deemed abnormal and a color abnormality signal is generated.

[0078] Step S3: randomly sampling multiple LEDs from the Mini LED screen as light-emitting diodes to be tested, connecting the multiple light-emitting diodes to be tested to obtain a light-emitting diode group to be tested, and fixing the group to the FCT test machine;

[0079] Among them, the connection methods are series and parallel.

[0080] Step S4, performing an electrical parameter test on the light emitting diode group to be tested, and generating a power supply abnormality signal or a short circuit abnormality signal of the light emitting diode group to be tested; the electrical parameter test includes a power supply parameter test and a short circuit test;

[0081] In this embodiment, the power supply parameter test is specifically as follows:

[0082] Step S401: Connect the LED group to be tested to a programmable power supply, apply a rated voltage to the LED group to be tested through the programmable power supply of the FCT machine, and set a limit protection current for the LED group to be tested;

[0083] Specifically, if the LED group under test includes 20 LEDs, with four LEDs connected in series to form a single branch, and all five branches connected in parallel in the FCT machine, and each LED has the same specifications, with a rated voltage of 3 volts and a rated current of 100 mAh, then the total rated voltage of the circuit is 4 × 3 = 12 volts, and the total rated current is 5 × 100 = 500 mAh, the rated current of the five branches in parallel. It should be noted that the above data is provided for ease of explanation and calculation only, and may vary in magnitude in actual operation.

[0084] Therefore, a rated voltage of 12 volts is applied between the VCC pin and the GND pin of the light-emitting diode group to be tested; when setting the limit protection current, it can be optionally set to 1.5 times the rated current corresponding to the light-emitting diode to be tested, that is, 750 mA;

[0085] Step S402: If the real-time current value of the LED group under test is greater than or equal to the limit protection current, the programmable power supply will disconnect from the LED group under test; if the real-time current value of the LED group under test is less than the limit protection current, the subsequent steps will be executed;

[0086] Step S403, sending a control instruction to make the light emitting diode group to be tested enter the maximum brightness mode, and collecting the real-time current value and real-time voltage value of the light emitting diode group to be tested through the data acquisition card;

[0087] Step S404: multiply the rated current by the rated voltage to obtain the rated power, and multiply the real-time current by the real-time voltage to obtain the actual power; subtract the actual power from the rated power and take the absolute value to obtain the power deviation value;

[0088] Step S405: Compare the electric power deviation value with the electric power deviation threshold. If the electric power deviation value is less than the electric power deviation threshold, it is determined that the power supply parameters of the light-emitting diode under test are normal; if the electric power deviation value is greater than or equal to the electric power deviation threshold, it is determined that the power supply test of the light-emitting diode under test is abnormal, and a power supply abnormality signal is generated.

[0089] In this embodiment, the short circuit test is specifically as follows:

[0090] Step S411: disconnecting the programmable power supply from the LED group to be tested; if the LED group to be tested has a parallel branch, isolating the other branches by physically disconnecting them, and selecting any one of the branches as the target circuit; if the LED group to be tested does not have a parallel branch, recording the circuit corresponding to the LED group to be tested as the target circuit;

[0091] Step S412, selecting a current applying end and a voltage applying end, and connecting the probes of the current applying end and the voltage applying end to the positive and negative electrodes of the target circuit in sequence;

[0092] It should be noted that the probes need to directly contact the metal pads to avoid touching the package of the target LED. The positive and negative poles must be connected correctly. Since the LED to be tested is unidirectional, incorrect positive and negative pole connections will result in infinite resistance. The current applied by the current application terminal should be less than the conduction current of the LED to be tested to avoid lighting the LED to be tested.

[0093] Step S413, measuring the measured resistance values at both ends of the target circuit by a resistance measuring device; reading the standard resistance value of each light-emitting diode to be measured in the target circuit, and summing the standard resistance values of all the light-emitting diodes to be measured to obtain the calculated resistance value of the target circuit;

[0094] Step S414: Subtract the calculated resistance value from the measured resistance value to obtain a resistance deviation value. The resistance deviation value is compared with the estimated line impedance. If the resistance deviation value is greater than or equal to the estimated line impedance, a short circuit test anomaly is determined to exist in the target circuit, and a short circuit anomaly signal is generated. If the resistance deviation value is greater than or equal to the estimated line impedance, no operation is performed.

[0095] The estimated line impedance is determined by the length, cross-sectional area, and material of the line in the target circuit. It is calculated by multiplying the resistivity of the corresponding material by the line length divided by the cross-sectional area.

[0096] Step S5: Display the brightness abnormality signal, color abnormality signal, power supply abnormality signal and short circuit abnormality signal of the Mini LED screen.

[0097] In this application, if a corresponding calculation formula appears, the above calculation formula is dimensionless and its numerical calculation is performed. The weight coefficient, proportional coefficient and other coefficients in the formula are set to a result value obtained by quantifying each parameter. Regarding the size of the weight coefficient and the proportional coefficient, as long as it does not affect the proportional relationship between the parameter and the result value, it is acceptable.

[0098] Example 2, Figure 3The present invention is a structural diagram of a computer device, which may include: a processor, a communication interface, a memory, and a communication bus, wherein the processor, the communication interface, and the memory communicate with each other via the communication bus. The processor may call logic instructions in the memory to execute a Mini LED backlight source test method based on an FCT test device, the method comprising: fixing a Mini LED screen to an FCT test machine; performing an optical performance test on the Mini LED screen to generate a brightness abnormality signal or a color abnormality signal of the Mini LED screen; randomly sampling a plurality of lamp beads in the Mini LED screen as light-emitting diodes to be tested, connecting the plurality of light-emitting diodes to be tested to obtain a light-emitting diode group to be tested and fixing the group to the FCT test machine; performing an electrical parameter test on the light-emitting diode group to be tested to generate a power supply abnormality signal or a short circuit abnormality signal of the light-emitting diode group to be tested; and displaying the brightness abnormality signal, color abnormality signal, power supply abnormality signal, and short circuit abnormality signal of the MiniLED screen.

[0099] In addition, the logical instructions in the above-mentioned memory can be implemented in the form of a software functional unit and can be stored in a computer-readable storage medium when sold or used as an independent product. Based on this understanding, the technical solution of the present application, or the part that contributes to the existing technology, or the part of the technical solution, can be embodied in the form of a software product. The computer software product is stored in a storage medium and includes several instructions for enabling a computer device (which can be a personal computer, server, or network device, etc.) to execute all or part of the steps of the method described in each embodiment of the present application. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), disk or optical disk, and other media that can store program code.

[0100] On the other hand, the present application also provides a computer program product, which includes a computer program stored on a computer-readable storage medium, and the computer program includes program instructions. When the program instructions are executed by a computer, the computer can execute the Mini LED backlight source test method based on the FCT test equipment provided by the above methods, the method including: fixing the Mini LED screen to the FCT test machine; performing an optical performance test on the Mini LED screen to generate a brightness abnormality signal or a color abnormality signal of the Mini LED screen; randomly sampling a plurality of lamp beads in the Mini LED screen as light-emitting diodes to be tested, connecting the plurality of light-emitting diodes to be tested to obtain a light-emitting diode group to be tested and fixing it to the FCT test machine; performing an electrical parameter test on the light-emitting diode group to be tested to generate a power supply abnormality signal or a short circuit abnormality signal of the light-emitting diode group to be tested; and displaying the brightness abnormality signal, color abnormality signal, power supply abnormality signal and short circuit abnormality signal of the Mini LED screen.

[0101] On the other hand, the present application also provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, is implemented to execute the above-mentioned Mini LED backlight source test method based on the FCT test equipment, the method comprising: fixing the Mini LED screen to the FCT test machine; performing an optical performance test on the Mini LED screen to generate a brightness abnormality signal or a color abnormality signal of the Mini LED screen; randomly sampling a plurality of lamp beads in the Mini LED screen as light-emitting diodes to be tested, connecting the plurality of light-emitting diodes to be tested to obtain a light-emitting diode group to be tested and fixing it to the FCT test machine; performing an electrical parameter test on the light-emitting diode group to be tested to generate a power supply abnormality signal or a short circuit abnormality signal of the light-emitting diode group to be tested; and displaying the brightness abnormality signal, color abnormality signal, power supply abnormality signal and short circuit abnormality signal of the Mini LED screen.

[0102] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units, i.e., they may be located in one location or distributed across multiple network units. Some or all of the modules may be selected based on actual needs to achieve the objectives of the present embodiment. Persons of ordinary skill in the art will be able to understand and implement the present invention without inventive effort.

[0103] Through the description of the above embodiments, those skilled in the art will clearly understand that each embodiment can be implemented using software plus a necessary general-purpose hardware platform, or of course, hardware. Based on this understanding, the essence of the above technical solution, or the portion that contributes to the prior art, can be embodied in the form of a software product. This computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, a magnetic disk, or an optical disk, and includes a number of instructions for causing a computer device (such as a personal computer, server, or network device) to execute the methods described in each embodiment or certain portions of the embodiments.

[0104] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A Mini LED backlight testing method based on FCT testing equipment, characterized in that: Methods include: Step S1, fixing the Mini LED screen to the FCT test machine; Step S2: Perform an optical performance test on the Mini LED screen to generate a brightness abnormality signal or a color abnormality signal of the Mini LED screen; the optical performance test includes a brightness test and a chromaticity test; The test process of the brightness test is as follows: Step S201: Send a white display signal to the Mini LED screen, and the Mini LED screen receives the white display signal and switches to a white display mode; Step S202: The Mini LED screen performs brightness tests in sequence from brightness test level 1 to brightness test level Z; where Z is a positive integer, and different brightness levels correspond to white window displays of different sizes. Step S203: Record the brightness values of the white window display center corresponding to different brightness test levels, and record them as the brightness values of the corresponding brightness test levels; select the maximum brightness value among all brightness test levels and record it as the peak brightness of the Mini LED screen; Step S204: After the brightness test level Z is continuously displayed for a fixed time, the Mini LED display screen is divided into K display partitions, and the real-time brightness values of different pixels in each display partition are recorded; wherein the fixed time is greater than or equal to one minute, and K is a positive integer; Step S205: Add the real-time brightness values of all pixels in the same display partition and take the average value as the partition brightness value of the corresponding display partition; divide the minimum partition brightness value of all display partitions by the maximum partition brightness value and multiply by 100 to obtain the brightness uniformity of the Mini LED screen; Step S206: Compare the peak brightness with the peak brightness threshold, and compare the brightness uniformity with the brightness uniformity threshold. If the peak brightness is greater than or equal to the peak brightness threshold and the brightness uniformity is greater than or equal to the brightness uniformity threshold, the Mini LED screen brightness display is considered normal. If the peak brightness is less than the peak brightness threshold or the brightness uniformity is less than the brightness uniformity threshold, the Mini LED screen brightness display is considered abnormal, and a brightness abnormality signal is generated. Step S3: randomly sampling multiple LEDs from the Mini LED screen as light-emitting diodes to be tested, connecting the multiple light-emitting diodes to be tested to obtain a light-emitting diode group to be tested, and fixing the group to the FCT test machine; Step S4, performing electrical parameter testing on the light emitting diode group to be tested, and generating a power supply abnormality signal or a short circuit abnormality signal of the light emitting diode group to be tested; Step S5: Display the brightness abnormality signal, color abnormality signal, power supply abnormality signal and short circuit abnormality signal of the Mini LED screen.

2. The Mini LED backlight source testing method based on the FCT testing equipment according to claim 1, characterized in that: The electrical parameter test includes a power supply parameter test and a short circuit test.

3. The Mini LED backlight source testing method based on the FCT testing equipment according to claim 1, characterized in that: The testing process of the chromaticity test is as follows: Step S211: Sending a standard color display signal to the Mini LED screen, and switching the Mini LED screen to a standard color display mode; wherein the standard color display mode is used to display multiple colors; Step S212: Divide the Mini LED display screen into multiple display partitions, and randomly select a pixel point in each display partition as a color test point; Step S213: sequentially input a full red display signal, a full green display signal, and a full blue display signal to the Mini LED screen, and record the chromaticity coordinate value of the first color test point when the full red display signal is input as RZ1 (RX, RY), the chromaticity coordinate value of the first color test point when the full green display signal is input as GZ1 (GX, GY), and the chromaticity coordinate value of the first color test point when the full blue display signal is input as BZ1 (BX, BY); In step S214, the color gamut triangle area MJ1 corresponding to the color test point is calculated using the following formula: 。 4. The Mini LED backlight source testing method based on the FCT testing equipment according to claim 3, characterized in that: The testing process of the colorimetric test also includes: Step S215, measuring the chromaticity coordinate values of the remaining color test points, and calculating the color gamut triangle areas of the remaining color test points to obtain MJ2 to MJK; Step S216: Select the minimum value among MJ1 to MJK as the color gamut triangle area of the Mini LED screen; and obtain the color gamut coverage of the Mini LED screen by dividing the color gamut triangle area of the Mini LED screen by the standard color gamut area. In step S217, the color gamut coverage is compared with the color gamut coverage threshold. If the color gamut coverage is greater than or equal to the color gamut coverage threshold, the Mini LED color test is deemed normal; if the color gamut coverage is less than the color gamut coverage threshold, the Mini LED color display is deemed abnormal and a color abnormality signal is generated.

5. The Mini LED backlight source testing method based on the FCT testing equipment according to claim 2, characterized in that: The test process of the power supply parameter test is as follows: Step S401: Connect the LED group to be tested to a programmable power supply, apply a rated voltage to the LED group to be tested through the programmable power supply of the FCT machine, and set a limit protection current for the LED group to be tested; Step S402 , if the real-time current value of the LED group to be tested is greater than or equal to the limit protection current, the programmable power supply will be disconnected from the LED group to be tested; If the real-time current value of the light-emitting diode group to be tested is less than the limiting protection current, the subsequent steps are executed; Step S403 : sending a control instruction to make the light emitting diode group to be tested enter the maximum brightness mode, and collecting the real-time current value and real-time voltage value of the light emitting diode group to be tested through the data acquisition card.

6. The Mini LED backlight testing method based on the FCT testing equipment according to claim 5, characterized in that: The test process of the power supply parameter test also includes: Step S404: multiply the rated current by the rated voltage to obtain the rated power, and multiply the real-time current by the real-time voltage to obtain the actual power; subtract the actual power from the rated power and take the absolute value to obtain the power deviation value; In step S405, the electric power deviation value is compared with the electric power deviation threshold. If the electric power deviation value is less than the electric power deviation threshold, it is determined that the power supply parameters of the light-emitting diode to be tested are normal; if the electric power deviation value is greater than or equal to the electric power deviation threshold, it is determined that the power supply test of the light-emitting diode to be tested is abnormal, and a power supply abnormality signal is generated.

7. The Mini LED backlight source testing method based on the FCT testing equipment according to claim 2, characterized in that: The test process of the short circuit test is as follows: Step S411: disconnecting the programmable power supply from the LED group to be tested; if the LED group to be tested has parallel branches, isolating the other branches by physically disconnecting them, and selecting any one branch as the target circuit; If the light emitting diode group to be tested does not have a parallel branch, the circuit corresponding to the light emitting diode group to be tested is recorded as the target circuit; Step S412 , selecting a current applying end and a voltage applying end, and connecting the probes of the current applying end and the voltage applying end to the positive and negative electrodes of the target circuit in sequence.

8. The Mini LED backlight source testing method based on the FCT testing equipment according to claim 7, characterized in that: The testing process of the short circuit test also includes: Step S413, measuring the measured resistance values at both ends of the target circuit by a resistance measuring device; reading the standard resistance value of each light-emitting diode to be measured in the target circuit, and summing the standard resistance values of all the light-emitting diodes to be measured to obtain the calculated resistance value of the target circuit; Step S414: The resistance deviation value is obtained by subtracting the calculated resistance value from the measured resistance value, and the resistance deviation value is compared with the estimated line impedance. If the resistance deviation value is greater than or equal to the estimated line impedance, it is determined that a short circuit test anomaly exists in the target circuit and a short circuit anomaly signal is generated; if the resistance deviation value is greater than or equal to the estimated line impedance, no operation is performed.

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