Backlight panel photoelectric performance testing device and testing method

Abstract

The present invention discloses a backlight panel photoelectric performance detection device and a detection method thereof, comprising a cabinet, an adsorption device, and a detection device. An installation cavity is formed inside the cabinet, and a mounting seat is provided on the top of the cabinet. The adsorption device comprises an adsorption workbench mounted on the mounting seat. The detection device comprises an optical vision module and an image processing module. The optical vision module is movably mounted above the adsorption workbench and has a motion stroke along the XYZ direction, and scans the backlight panel during movement. The image processing module is installed in the installation cavity, and the image processing module is electrically connected to the optical vision module. The image processing module uses an edge detection algorithm to identify the detection image transmitted by the optical vision module. While matching backlight panels of different materials, sizes and models for detection, the present invention can also quickly identify unqualified areas through image comparison, and can also transport materials through connecting tracks, shortening the manufacturing cycle and improving production efficiency.

Description

Technical Field

[0001] The present invention relates to the technical field of photoelectric performance detection, and in particular to a backlight panel photoelectric performance detection device and a detection method thereof. Background Art

[0002] Direct-lit Mini-LED backlight modules, made with millimeter-scale chips, can enhance the visual fidelity of images perceived by the human eye. Combined with local dimming, they can achieve superior contrast and HDR display effects. Mini-LED backlight panels typically utilize tens of thousands of millimeter-scale LED chips to achieve superior backlighting performance.

[0003] Visually inspecting the photoelectric characteristics of Mini-LED backlight panels can lead to missed or incorrect detection of photoelectric defects such as dimmed or dimmed LED chips due to factors such as the large number of small LED chips used, as well as warping and unevenness in panels made of different materials. If these defects go undetected, uneven and inconsistent light output from the subsequent Mini-LED backlight panels, when assembled into modules or displays, can occur. This mura defect directly impacts the final image, diminishing the user's viewing experience and, in more serious cases, hindering device performance or functionality.

[0004] Mini-LED backlight is an emerging display technology on the market, but the means for testing its photoelectric performance are limited. In the early verification stage, Mini-LED backlights are diverse and most are customized products. Existing technologies mostly use visual inspection or manual optical inspection, which is inefficient and directly affects the accuracy of test results due to human fatigue and emotional influences. Summary of the Invention

[0005] The main purpose of the present invention is to provide a backlight panel photoelectric performance detection device, aiming to improve the technical problem of poor detection accuracy in the prior art.

[0006] To achieve the above-mentioned object, the present invention provides a backlight panel photoelectric performance testing device, comprising:

[0007] A cabinet body, wherein a mounting cavity is formed inside the cabinet body, and a mounting seat is provided on the top of the cabinet body;

[0008] The adsorption device comprises an adsorption workbench, the adsorption workbench is fixedly mounted on the mounting base, and the adsorption workbench is used to adsorb and fix the backlight panel;

[0009] The detection device includes an optical vision module and an image processing module. The optical vision module is movably installed above the adsorption workbench. The optical vision module has a motion range along the XYZ direction to scan the backlight panel during movement. The image processing module is installed in the installation cavity. The image processing module is electrically connected to the optical vision module. The image processing module uses an edge detection algorithm to judge the detection picture transmitted by the optical vision module.

[0010] Optionally, the backlight panel photoelectric performance testing equipment also includes a moving device, which includes two first guide rails extending along the Y direction, a second guide rail extending along the X direction, and a third guide rail extending along the Z direction. The two first guide rails are respectively fixedly installed on both sides of the mounting seat, the second guide rail can be slidably installed on the two first guide rails along the Y direction, the third guide rail is fixedly installed on the second guide rail, and the optical vision module can be slidably installed on the third guide rail along the Z direction.

[0011] Optionally, the mobile device also includes a first drive motor, a second drive motor, a third drive motor, a first transmission chain, a second transmission chain, and a third transmission chain. The first transmission chain is unfolded along the Y direction and is driven and connected to the second guide rail and the first drive motor. The second transmission chain is unfolded along the X direction and is driven and connected to the third guide rail and the second drive motor. The third transmission chain is unfolded along the Z direction and is driven and connected to the optical vision module and the third drive motor.

[0012] Optionally, the adsorption device also includes a vacuum pump, which is fixedly installed in the installation cavity. The adsorption workbench includes an adsorption surface and a base. The base is fixedly installed on the mounting seat. The adsorption surface is arranged on the base. A plurality of evenly distributed adsorption holes are formed on the adsorption surface. The vacuum pump is connected to the adsorption surface through an air pipe.

[0013] Optionally, the backlight panel photoelectric performance testing equipment further includes a transmission device, which includes a transmission track, one end of which is connected to the adsorption workbench, and the transmission track is used to transmit the backlight panel to the adsorption workbench.

[0014] Optionally, the transmission device further includes a barcode scanner, which is installed on the transmission track and is used to scan and mark the backlight panel.

[0015] Optionally, the detection device further includes a controller, which is electrically connected to the optical vision module and the image processing module.

[0016] Optionally, the backlight panel photoelectric performance detection equipment also includes a connecting device, which includes an adapter board, a connecting line, and a flexible cable. The adapter board is connected to the controller through the connecting line, and the adapter board is connected to the backlight panel through the flexible cable.

[0017] In addition, in order to achieve the above-mentioned purpose, the present invention also provides a method for detecting the photoelectric performance of a backlight panel, comprising the following steps:

[0018] Place the backlight panel on the adsorption workbench, turn on the vacuum adsorption and start the detection equipment;

[0019] Electrically connect the backlight panel to the detection device and set the positive and negative poles, current, and voltage of each path to light up the backlight panel;

[0020] Control the optical vision module to capture the backlight panel's illuminated image in different areas according to the set path diagram and transmit the images to the image processing module;

[0021] The image processing module performs analysis and judgment through edge detection algorithm.

[0022] Optionally, the image processing module performs analysis and discrimination using an edge detection algorithm, including the following steps:

[0023] Adjust the input current and voltage so that the industrial optical vision module can capture the halo of LED light;

[0024] In the single-tone image mode, an image without abnormalities is selected as the standard image for overall judgment;

[0025] The detection images are analyzed, and the captured detection images are spliced ​​to form an image of the entire backlight panel being lit, and then a coordinate system is established.

[0026] In the technical solution provided by the present invention, an online Mini-LED backlight board photoelectric performance inspection device and method thereof can be used to inspect a variety of Mini-LED backlight boards of different materials, sizes and models. The warping of the light board can be reduced by an adsorption device. After the Mini-LED light board is connected and lit by a connecting device, edge analysis is performed using a visual module and an image processing module. NG is identified by comparing the similarity between the quantitative detection image and the standard image. This can quickly and accurately determine whether the Mini-LED backlight board has any defective areas that are not bright, and subsequently, materials can be transported through a connecting track, shortening the manufacturing cycle and improving production efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying any creative work.

[0028] Figure 1 A front view of an embodiment of a device for testing the photoelectric performance of a backlight panel provided by the present invention;

[0029] Figure 2 for Figure 1 Schematic diagram of the structure of the adsorption device in the photoelectric performance testing equipment of the backlight panel;

[0030] Figure 3 for Figure 1 Schematic diagram of the structure of the mobile device in the backlight panel photoelectric performance testing equipment;

[0031] Figure 4 A schematic flow chart of a method for detecting photoelectric performance of a backlight panel provided by the present invention;

[0032] Figure 5 This is a flow chart of the method for detecting the photoelectric performance of a backlight panel provided by the present invention.

[0033] Description of Figure Numbers:

[0034] Label name Label name 1 Cabinet 21 Adsorption workbench 2 Adsorption device 22 Adsorption surface 3 Optical vision module 23 Adsorption holes 4 Image processing module 100 Backlight panel photoelectric performance testing equipment 5 mobile devices 51 First guide rail 52 Second guide rail 53 The third rail

[0035] The purpose, features and advantages of the present invention will be further described with reference to the accompanying drawings and in conjunction with the embodiments. DETAILED DESCRIPTION

[0036] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0037] It should be noted that if a directional indication is involved in an embodiment of the present invention, the directional indication is only used to explain the relative position relationship, movement status, etc. between the components in a certain specific posture. If the specific posture changes, the directional indication will also change accordingly.

[0038] In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the present invention, the descriptions of "first", "second", etc. are only for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of such features. In addition, the meaning of "and / or" appearing throughout the text includes three parallel schemes. Taking "A and / or B" as an example, it includes scheme A, or scheme B, or a scheme in which A and B are satisfied at the same time. In addition, the technical solutions between the various embodiments can be combined with each other, but it must be based on the ability of ordinary technicians in this field to implement it. When the combination of technical solutions is mutually contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0039] Mini-LED backlight is an emerging display technology on the market, but the means for testing its photoelectric performance are limited. In the early verification stage, Mini-LED backlights are diverse and most are customized products. Existing technologies mostly use visual inspection or manual optical inspection, which is inefficient and directly affects the accuracy of test results due to human fatigue and emotional influences.

[0040] In view of this, the present invention provides a backlight panel photoelectric performance detection device, which aims to improve the technical problem of poor detection accuracy in the existing technology. Figures 1 to 5 This is an embodiment of the backlight panel photoelectric performance detection device provided by the present invention.

[0041] See also Figure 1 The present embodiment provides a backlight panel photoelectric performance testing device 100, comprising:

[0042] A cabinet 1 is provided with a mounting cavity formed inside the cabinet 1 and a mounting seat provided on the top of the cabinet 1;

[0043] The adsorption device 2 includes an adsorption workbench 21, which is fixedly mounted on the mounting base and is used to adsorb and fix the backlight panel;

[0044] The detection device includes an optical vision module 3 and an image processing module 4. The optical vision module 3 is movably installed above the adsorption workbench 21. The optical vision module 3 has a motion stroke along the XYZ direction to scan the backlight board during movement. The image processing module 4 is installed in the installation cavity. The image processing module 4 is electrically connected to the optical vision module 3. The image processing module 4 uses an edge detection algorithm to judge the detection picture transmitted by the optical vision module 3.

[0045] In this embodiment, the backlight panel photoelectric performance testing device 100 includes a rectangular cabinet 1, which is similar to the cabinet of the equipment. The interior of the cabinet 1 is hollow, forming a mounting cavity that can install many components; the top of the cabinet 1, that is, the upper end face of the cabinet 1 is provided with a mounting seat, which is used to support and install the adsorption device 2 and the detection device. The adsorption device 2 includes an adsorption workbench 21, which is fixedly installed on the upper end face of the cabinet 1. The backlight panel is placed on the adsorption workbench 21. When the adsorption device 2 is working, the backlight panel is adsorbed by vacuum to ensure that the backlight panel does not warp during the detection process, thereby improving the accuracy of the detection results.

[0046] In this embodiment, the detection device includes an optical vision module 3 and an image processing module 4. The optical vision module 3 can be an industrial CMOS camera, which can perform path scanning on the backlight board according to the MAP diagram set by the operator during the detection process. The optical vision module 3 is movably installed above the adsorption workbench 21 and has a motion stroke along the XYZ direction, that is, the optical vision module 3 can move along the X direction (i.e., front and back direction), Y direction (i.e., left and right direction), and Z direction (i.e., vertical direction) to scan different areas of the backlight board. The image processing module 4 is fixedly installed in the mounting cavity, and the image processing module 4 is electrically connected to the optical vision module 3. The image processing module 4 uses an edge detection algorithm to identify the detection picture transmitted by the optical vision module 3 and store the data.

[0047] The present invention provides a backlight board photoelectric performance testing device 100, which can test a variety of backlight boards of different materials, sizes and models. In this embodiment, a vacuum adsorption workbench 21 is used to reduce the warping of the backlight board. After the backlight board is illuminated by input current, an industrial camera is used to photograph the backlight board in different areas for edge analysis. By comparing and judging the similarity between the quantitative detection image and the standard image, it is possible to quickly and accurately determine whether there are any defective areas of the backlight board that are not bright.

[0048] Further, see Figure 3In this embodiment, the backlight panel photoelectric performance testing equipment 100 also includes a moving device 5, which includes two first guide rails 51 extending along the Y direction, a second guide rail 52 extending along the X direction, and a third guide rail 53 extending along the Z direction. The two first guide rails 51 are respectively fixedly installed on both sides of the mounting seat, that is, next to the adsorption workbench 21. The second guide rail 52 can be slidably installed on the two first guide rails 51 along the Y direction. The two first guide rails 51 are equivalent to the slide rails of the second guide rails 52, thereby realizing the movable stroke in the Y direction. The third guide rail 53 is fixedly installed on the second guide rail 52. The second guide rail 52 is equivalent to the slide rail of the third guide rail 53, thereby realizing the movable stroke in the X direction. The optical vision module 3 can be slidably installed on the third guide rail 53 along the Z direction. The third guide rail 53 is the slide rail of the optical vision module 3, thereby realizing the movable stroke in the Z direction.

[0049] Specifically, in this embodiment, the moving device 5 further includes a first drive motor, a second drive motor, a third drive motor, a first transmission chain, a second transmission chain, and a third transmission chain. The first transmission chain is extended along the Y direction and is connected to the second guide rail 52 and the first drive motor. The first drive motor and the first transmission chain can be engaged by gears, and the first transmission chain and the second guide rail 52 can be engaged by racks. Driven by the first drive motor, the first transmission chain rotates and drives the second guide rail 52 to move along the Y direction. The second transmission chain is extended along the X direction and is connected to the third guide rail 53 and the second drive motor. The second drive motor and the second transmission chain can be engaged by gears, and the second transmission chain and the third guide rail 53 can be engaged by racks. Driven by the second drive motor, the second transmission chain rotates and drives the third guide rail 53 to move along the X direction. The third transmission chain is extended along the Z direction and is connected to the optical vision module 3 and the third drive motor. The third drive motor and the third transmission chain can be engaged through gears, and the third transmission chain and the optical vision module 3 can be engaged through racks. Driven by the third drive motor, the third transmission chain rotates and drives the second guide rail 52 to move along the Z direction.

[0050] Furthermore, in this embodiment, the adsorption device 2 also includes a vacuum pump, and the vacuum pump is fixedly installed in the installation cavity. The adsorption workbench 21 includes an adsorption surface 22 and a base, and the base is fixedly installed on the mounting seat. The adsorption surface 22 is provided on the base, and a plurality of evenly distributed adsorption holes 23 are formed on the adsorption surface 22. The vacuum pump is connected to the adsorption surface 22 through an air pipe. The vacuum pump evacuates the adsorption workbench 21, and the backlight panel can be adsorbed on the adsorption surface 22 under the action of atmospheric pressure, thereby ensuring that the backlight panel does not warp during the detection process, thereby ensuring the accuracy of the detection results. In addition, the vacuum degree can be controlled by adjusting the knob to prevent the backlight panel from being damaged due to excessive vacuum.

[0051] Furthermore, in this embodiment, the detection device also includes a controller electrically connected to the optical vision module 3 and the image processing module 4. It is understood that the controller's functions include connecting various mechanisms for operation, determining detection results using an image comparison algorithm, and storing data. It should be noted that the controller's structure and control system are both state-of-the-art and will not be further elaborated upon here.

[0052] Furthermore, in this embodiment, the backlight panel photoelectric performance testing equipment 100 also includes a connection device, comprising an adapter board, a connecting cable, and a flexible flat cable. The adapter board is electrically connected to the controller via the connecting cable, and the adapter board is electrically connected to the backlight panel via the flexible flat cable. It is understood that the universal connection device in this photoelectric performance testing equipment specifically functions to provide electrical connection between the device and different backlight panel models. The connection device comprises an adapter board, a connecting cable, and an FFC / FPC flexible flat cable. The universal adapter board has conductive vias corresponding to the pin positions of the Mini-LED backlight panel, which connect to the probe sockets of the photoelectric performance testing equipment through the conductive vias to provide electrical connection. The adapter board also has a connector, which connects to one end of the FFC or FPC flexible flat cable, the other end of which connects to the connector on the Mini-LED backlight panel. For Mini-LED backlight panels made of FPC with gold fingers, the FPC gold fingers are used to connect directly to the adapter board. Each path of the connector is controlled separately, and the electrical properties of each connected path are set according to the positive and negative poles of the Mini-LED backlight board. After power is turned on, the Mini-LED backlight board is electrically connected to the photoelectric performance test equipment, thereby lighting up the Mini-LED backlight board.

[0053] Furthermore, in this embodiment, the backlight panel photoelectric performance testing device 100 also includes a transport device, which includes a transport track and a scanner. One end of the transport track is connected to the adsorption workbench, and the transport track is used to transport the backlight panel to the adsorption workbench 21. The barcode scanner is installed on the transport track to scan and mark the backlight panel.

[0054] It should be noted that Mini-LED backlight panel production lines are limited by the speed and yield of large-scale transfers, resulting in low production efficiency and a yield rate that rarely reaches above 99.99%. Therefore, to maximize Mini-LED backlight panel production efficiency and product yield, equipment in various processes, such as printing, die bonding, testing, and rework, can be connected through a transmission device.

[0055] At the starting position of the printing section, the operator places the backlight board (PCB) with a QR code on the back on the conveyor track. After the infrared code is scanned to read the data, it is transferred from the starting position through the conveyor track to the printer workbench for SMT solder paste printing. After printing, the backlight board (PCB) is transferred to the SPI inspection station through the conveyor track. After passing the inspection, the product is transferred to the next process of crystal bonding section through the conveyor track, fixed to the crystal bonding machine workbench for crystal bonding, and then transferred to the AOI inspection station through the conveyor track. The products that pass the inspection are soldered through reflow soldering and then transferred to the backlight board optoelectronic performance testing equipment 100 for inspection through the conveyor track. After the inspection, the products are transferred to the rework station through the conveyor track for rework. After the rework is completed, the products are returned to the backlight board optoelectronic performance testing equipment 100 through the conveyor track for re-inspection before proceeding to the next production step.

[0056] In addition, in order to improve the technical problem of detection accuracy, the present application also provides a method for detecting the photoelectric performance of a backlight panel, comprising the following steps:

[0057] Step S101: placing the backlight panel on the adsorption workbench 21, turning on the vacuum adsorption and starting the detection equipment;

[0058] Step S102: electrically connecting the backlight panel to the detection device, and setting the positive and negative poles, current, and voltage of each path to light up the backlight panel;

[0059] Step S103: Control the optical vision module 3 to capture the backlight panel's illuminated image in different regions according to the set path diagram and transmit the captured images to the image processing module 4;

[0060] Step S104: the image processing module 4 performs analysis and judgment using an edge detection algorithm.

[0061] In this embodiment, the operator places the Mini-LED backlight board on the fixed area of ​​the adsorption workbench 21 (that is, the adsorption area), turns on the vacuum adsorption, and starts the detection equipment. For FR4 / BT / aluminum-based Mini-LED backlight boards that require connectors, a matching adapter board is selected according to the connector of the backlight board and connected to the female socket, and the Mini-LED backlight board is connected to the connector on the machine through the FFC / FPC flexible cable. For FPC / glass-based Mini-LED backlight boards that do not require connectors, a matching adapter board is selected according to the gold fingers of the backlight board, and the gold fingers are connected to the connector of the adapter board.

[0062] For example, a 27-inch, 384-zone Mini-LED backlight board for MNT backlighting has four 60-pin connectors with a 0.5mm pitch on its back. Therefore, a matching adapter board should be selected and plugged into the device's female connector, then connected to the backlight board via an FFC / FPC flexible cable. The principle of this backlight board is that pins 1-11 are positive and pins 13-60 are negative. Therefore, on the machine, pins 1-11 are connected in parallel as the positive pole, and pins 1-60 are connected in parallel as the negative pole, and the backlight board is illuminated for testing. When testing a 16-inch, 576-zone Mini-LED backlight board for notebook backlighting, which has three 110-pin connectors with a 0.4mm pitch on its back, the original adapter board is removed from the device's female connector and replaced with a matching adapter board, plugged into the device's female connector, for testing.

[0063] In this embodiment, the light panel is illuminated by setting the positive and negative poles of each connector path and setting appropriate current and voltage values. The three-axis mobile platform of mobile device 5 uses a track to move an industrial CMOS camera along a map set by the operator, capturing images of the illuminated Mini-LED backlight panel in sections and transmitting the image data to the backend. The backend analyzes the captured images using an edge detection algorithm to determine whether they are OK or NG. Furthermore, after the test is complete, the positive and negative inputs of the Mini-LED backlight panel are turned off, the panel is disconnected from the device's connector, the vacuum suction is turned off, and the panel is removed, completing the test.

[0064] Furthermore, in this embodiment, step S104 further includes the following steps:

[0065] Step S1041: Adjust the input current and voltage so that the industrial optical vision module 3 can capture the halo of the LED light.

[0066] It should be noted that the current and voltage are adjusted according to the circuit design of different light boards. For example, if a 15.6-inch light board has 336 evenly distributed zones, and each zone has 4 LEDs connected in series, then the voltage required to light up this 15.6-inch light board is 12V. The current can be gradually increased from 0mA until the LEDs are fully lit for testing.

[0067] Step S1042: Selecting an image without abnormalities in the single-tone image mode as a standard image for overall judgment.

[0068] It should be noted that in grayscale, or single-tone image mode, using a common 8-bit screen as an example, a single tone is used to display an image. Each sub-pixel can display 2 to the power of 8, or 256 shades of gray. This eliminates color interference and makes the image display clearer. Convert a color image to grayscale.

[0069] Step S1043: Analyze the detection picture, and splice the captured detection picture to form a picture of the entire backlight panel being lit, and establish a coordinate system.

[0070] In this embodiment, the edge detection algorithm is used to analyze and determine whether it is qualified or not. The specific steps are as follows:

[0071] ① Image preprocessing: Image processing is based on digital signals and is performed digitally through calculations and comparisons. Therefore, the image data must be digitized and then the pixel values ​​of the standard image and the reference image are compared. First, the captured image is converted to a grayscale image. At this point, each pixel in the image can be represented by a grayscale value from 0 to 255, ranging from completely black to completely white.

[0072] ② Contour Analysis: Select the LED brightness image at a point in the image as the reference image and use an algorithm to determine the edge contour. (For details on the algorithm, see the algorithm calculation process.) Compare the contours with other points and output a similarity value. Typically, values ​​below 85 are considered unqualified. You can also select a baseline similarity value, with values ​​above the baseline considered acceptable.

[0073] ③ Detection judgment: Set the similarity percentage standard. Generally, 85 can be selected, or you can select the similarity benchmark yourself. When the threshold of the comparison image exceeds or equals the similarity percentage set by the standard image threshold, the detection image can be considered qualified.

[0074] 1. Convert the color image to grayscale. The calculation formula for converting the color image to grayscale is:

[0075] Gray=R*0.299+G*0.587+B*0.114G

[0076] Among them, Gray represents a grayscale image, and R, G, and B represent the grayscale values ​​of the red (red), green (green), and blue (blue) channels of a color image.

[0077] 2. Filtering: Extract image features, simplify the image, use edge lines to represent the information carried by the image, and eliminate the noise mixed in when the image is digitized. Use a 3*3 matrix filter to traverse the image from top to bottom and from left to right, perform dot product operations on the image and assign the value to the image. The specific formula is

[0078]

[0079] Where R represents the current pixel, Rk and Gk represent the value of the current pixel multiplied by the corresponding filter value, and n is the filter size. The filtered image should appear blurred, and the larger the filter size, the more obvious the blurring effect.

[0080] 3. Edge detection: Use the Marr-Hildreth edge detection operator.

[0081] 3.1 Gaussian filtering: Smoothing the image G(x, y). The principle is to perform a weighted average based on the grayscale values ​​of the pixel to be filtered and its neighboring points according to the parameter rule generated by the Gaussian formula. This can effectively filter out high-frequency noise superimposed on the ideal image. The two-dimensional Gaussian formula G(x, y) is as follows:

[0082]

[0083] 3.2 Enhancement: Perform Laplace operation on the smoothed image after Gaussian filtering. The Laplace second-order derivative formula is:

[0084]

[0085] Among them, the calibration coefficients are generated so that the sum of the coefficients is zero, and the image to be calculated is obtained.

[0086] 3.3 Detection: Find the zero crossings of the image after the Karplus filter, search for edge pixels, extract the boundary using the most appropriate threshold, and obtain the image edge continuity curve. Set a similarity percentage standard. When the threshold of the comparison image exceeds or equals the similarity percentage set by the standard image threshold, the detection image is considered a pass.

[0087] After the Mini-LED backlight panel is electrically lit through the probe, the input current and voltage are adjusted to enable the industrial CMOS camera to clearly capture the halo of the LED light. An image with no abnormalities at one point in the grayscale image is selected as the standard image for overall judgment.

[0088] To ensure inspection accuracy, the device's optical vision structure uses an industrial CMOS camera capable of capturing a maximum image size of 60*60mm. A three-axis mobile platform drives the camera from its origin, capturing images sequentially along a map path set by the operator, within the 60*60mm maximum image size. These images are then transmitted to the backend. For example, a 15.6-inch Mini-LED backlight panel measures 345.6*194.4mm in length and width, and the camera's maximum capture size is 60*60mm. Therefore, the capture size can be set to 57.6*60mm. Starting from the upper left corner, the camera captures Frame 1, Frame 2, Frame 3, and so on. When the capture reaches the rightmost edge of the panel, the camera continues along the adjacent edge, capturing Frame 7, Frame 8, and so on, until all captures are complete, for a total of 24 frames.

[0089] The backend analyzes the inspection images captured and transmitted by the COMS camera, and splices the inspection images set according to the MAP diagram to form an image of the entire Mini-LED backlight panel being lit. The row and column numbers X / Y are marked in sequence above and to the left of the overall lit image according to the origin of the three-axis mobile platform. The inspection image and the standard image are compared for correlation based on the similarity of the LED halo contours. The correlation value ranges from 0 to 100, with 100 representing complete consistency and 0 representing complete inconsistency. By setting a critical correlation value such as 85, it is determined whether the inspection image has changed. If the value is less than 85, the backend can surround the halo edge of the unqualified area with a red line. The operator can then quickly find the unqualified area of ​​the Mini-LED backlight panel for repair through the row and column X / Y values ​​corresponding to the image.

[0090] The above descriptions are merely optional embodiments of the present invention and do not limit the patent scope of the present invention. All equivalent structural transformations made using the contents of the present invention's description and drawings, or direct / indirect applications in other related technical fields, within the scope of the present invention are included in the patent protection scope of the present invention.

Claims

1. A backlight panel photoelectric performance testing device, characterized in that: The backlight panel photoelectric performance testing device is used to test the Mini-LED backlight panel, which includes a millimeter-level LED chip. The backlight panel photoelectric performance testing device includes: A cabinet body, wherein a mounting cavity is formed inside the cabinet body, and a mounting seat is provided on the top of the cabinet body; The adsorption device comprises an adsorption workbench, the adsorption workbench is fixedly mounted on the mounting base, and the adsorption workbench is used to adsorb and fix the backlight panel; The detection device includes an optical vision module and an image processing module. The optical vision module is movably mounted above the adsorption workbench. The optical vision module has a motion range along the XYZ directions, so as to capture the illuminated image of the backlight panel in different regions during movement and transmit the captured image to the image processing module. The captured image of each region is less than or equal to 60*60mm. The image processing module is installed in the installation cavity, and the image processing module is electrically connected to the optical vision module. The image processing module judges the detection picture transmitted by the optical vision module through an edge detection algorithm. The image processing module compares the detection picture with the standard picture through the similarity of the LED halo contour, and identifies the unqualified area in the image by enclosing the LED halo edge with a red line, so that the operator can find the unqualified area of ​​the Mini-LED backlight board for repair through the row and column X / Y values ​​corresponding to the image.

2. The backlight panel photoelectric performance testing device according to claim 1, characterized in that: The backlight panel photoelectric performance testing equipment also includes a moving device, which includes two first guide rails extending along the Y direction, a second guide rail extending along the X direction, and a third guide rail extending along the Z direction. The two first guide rails are respectively fixedly installed on both sides of the mounting seat, the second guide rail can be slidably installed on the two first guide rails along the Y direction, the third guide rail is fixedly installed on the second guide rail, and the optical vision module can be slidably installed on the third guide rail along the Z direction.

3. The backlight panel photoelectric performance testing device according to claim 2, characterized in that: The mobile device also includes a first drive motor, a second drive motor, a third drive motor, a first transmission chain, a second transmission chain, and a third transmission chain. The first transmission chain is unfolded along the Y direction and is driven and connected to the second guide rail and the first drive motor. The second transmission chain is unfolded along the X direction and is driven and connected to the third guide rail and the second drive motor. The third transmission chain is unfolded along the Z direction and is driven and connected to the optical vision module and the third drive motor.

4. The backlight panel photoelectric performance testing device according to claim 1, characterized in that: The adsorption device also includes a vacuum pump, which is fixedly installed in the installation cavity. The adsorption workbench includes an adsorption surface and a base. The base is fixedly installed on the mounting seat. The adsorption surface is provided on the base. A plurality of evenly distributed adsorption holes are formed on the adsorption surface. The vacuum pump is connected to the adsorption surface through an air pipe.

5. The backlight panel photoelectric performance testing device according to claim 1, wherein: The backlight panel photoelectric performance testing equipment further comprises a transmission device, which comprises a transmission track, one end of which is connected to the adsorption workbench, and the transmission track is used to transmit the backlight panel to the adsorption workbench.

6. The backlight panel photoelectric performance testing device according to claim 5, characterized in that: The transmission device also includes a code scanner, which is installed on the transmission track and is used to scan and mark the backlight panel.

7. The backlight panel photoelectric performance testing device according to claim 1, characterized in that: The detection device further includes a controller, which is electrically connected to the optical vision module and the image processing module.

8. The backlight panel photoelectric performance testing device according to claim 7, characterized in that: The backlight panel photoelectric performance detection equipment also includes a connecting device, which includes an adapter board, a connecting line, and a flexible cable. The adapter board is connected to the controller through the connecting line, and the adapter board is connected to the backlight panel through the flexible cable.

9. A method for testing the photoelectric performance of a backlight panel, characterized in that: The backlight panel photoelectric performance detection method is used to detect a Mini-LED backlight panel, wherein the Mini-LED backlight panel includes a millimeter-level LED chip. The backlight panel photoelectric performance detection method includes the following steps: Place the backlight panel on the adsorption workbench, turn on the vacuum adsorption and start the detection equipment; Electrically connect the backlight panel to the detection device and set the positive and negative poles, current, and voltage of each path to light up the backlight panel; Control the optical vision module to capture the backlight panel's illuminated image in different areas according to the set image path and transmit the captured image to the image processing module, wherein the image captured in each area is less than or equal to 60*60mm; The image processing module uses an edge detection algorithm for analysis and judgment, including: comparing the similarity of the LED halo outline between the detection image and the standard image, and marking the unqualified area in the image by enclosing the edge of the LED halo with a red line, so that the operator can find the unqualified area of ​​the Mini-LED backlight board through the corresponding row and column X / Y values ​​of the image for repair.

10. The method for testing the photoelectric performance of a backlight panel according to claim 9, wherein: The image processing module uses edge detection algorithm to analyze and judge, including the following steps: Adjust the input current and voltage so that the industrial optical vision module can capture the halo of LED light; In the single-tone image mode, an image without abnormalities is selected as the standard image for overall judgment; The detection images are analyzed, and the captured detection images are spliced ​​to form an image of the entire backlight panel being lit, and then a coordinate system is established.

Images