A method and device for detecting weak abnormal points of a display panel

Abstract

The present invention discloses a method for detecting weak abnormal points of a display panel, the method comprising: importing a test image into a display panel, photographing the display panel as a first test result, and marking a first area; importing a monochrome image into a display panel, photographing the display panel as a second test result; in the second test result, marking the area corresponding to the first area as a second area, and marking a third area, calculating the ratio of the third area to the second area; when the ratio is greater than a second threshold, it is considered that the point formed by the first area is an abnormal point of the color corresponding to the monochrome image. The present invention calculates the proportion of different color areas in the abnormal point, divides the abnormal point into points of different colors, and improves the efficiency of abnormal point classification.

Description

Technical Field

[0001] The present invention relates to the field of display panel detection technology, and more specifically, to a method and device for detecting weak abnormal points of a display panel. Background Art

[0002] With the rapid development of the industrial field, the inspection tasks of LCD and OLED panels have gradually changed from manual inspection to machine inspection. In the process of machine inspection, the system commonly used is the AOI system (Automated Optical Inspection), which plays the role of manual inspection to perform a series of high-intensity and high-precision inspection tasks, greatly improving production efficiency and liberating productivity.

[0003] The most common detection items in panel detection are bright spot and dark spot detection. Bright spots refer to spots that appear bright in a black screen, while dark spots refer to spots that appear black in a white screen. Each pixel in the panel is composed of several pixel units according to certain rules. When bright spots or dark spots appear in the panel, it is necessary to further analyze the causes of the bright spots and dark spots, which involves a classification method for bright spots or dark spots. However, the prior art lacks a classification method for bright spots or dark spots. Summary of the invention

[0004] In response to at least one defect or improvement need in the prior art, the present invention provides a method, device and storage medium for detecting faint abnormal points in a display panel. By calculating the proportion of different color areas in the abnormal points, the abnormal points are divided into points of different colors, thereby improving the efficiency of abnormal point classification.

[0005] To achieve the above object, according to a first aspect of the present invention, a method for detecting weak abnormal points of a display panel is provided, the method comprising:

[0006] S1. importing a test pattern into a display panel, photographing the display panel as a first test result, and marking a first area; wherein the first area is an area where the difference between the grayscale value actually photographed in the first test result and the grayscale value theoretically obtained in the first test result is greater than a first threshold value;

[0007] S2. The monochrome image is imported into the display panel, and the display panel is photographed as a second test result;

[0008] S3. In the second test result, mark the area corresponding to the first area as the second area, and mark the third area, and calculate the ratio of the third area to the second area; when the ratio is greater than a second threshold, it is considered that the points constituted by the first area are abnormal points of the corresponding colors of the monochrome image; wherein the third area refers to an area where the absolute value of the difference between the grayscale value in the second area and the average grayscale value of the second area is greater than the third threshold.

[0009] Furthermore, the method for detecting weak abnormal points of the display panel further includes:

[0010] The monochrome image is an image composed of colors corresponding to pixel units of the display panel.

[0011] Furthermore, the method for detecting weak abnormal points of the display panel further includes:

[0012] When the pixel units of the display panel are red, green and blue, the monochrome images are (255, 0, 0), (0, 255, 0) and (0, 0, 255) respectively.

[0013] Furthermore, the method for detecting weak abnormal points of the display panel further includes:

[0014] S4. Replace the monochrome image, and repeat steps S2-S3 until the monochrome images of all colors are tested.

[0015] Furthermore, the method for detecting weak abnormal points of the display panel further includes:

[0016] According to the test result, the points formed by the first area are one of single-color abnormal points or multi-color abnormal points.

[0017] Furthermore, the method for detecting weak abnormal points of the display panel further includes:

[0018] The second threshold is set according to the pixel unit arrangement mode of the display panel and / or the test requirement.

[0019] Furthermore, the method for detecting weak abnormal points of the display panel further includes:

[0020] The second threshold is preferably a ratio of the area occupied by the color corresponding to the pixel unit of the display panel in all the pixel units of the display panel.

[0021] Furthermore, the method for detecting weak abnormal points of the display panel further includes:

[0022] The third threshold is specifically set according to the different monochrome images.

[0023] According to a second aspect of the present invention, there is also provided a device for detecting weak abnormal points of a display panel, comprising:

[0024] a camera module configured to obtain a display photo of the display panel;

[0025] A display panel control module configured to input a test pattern or a monochrome pattern to the display panel;

[0026] A calculation and analysis module is configured to obtain the shooting results of the camera and classify the abnormal points of the display panel according to the steps of any of the above methods.

[0027] According to the third aspect of the present invention, there is also provided a device for detecting faint abnormal points of a display panel, which includes at least one processing unit and at least one storage unit, wherein the storage unit stores a computer program, and when the computer program is executed by the processing unit, the processing unit executes the steps of any one of the above-mentioned methods.

[0028] According to a fourth aspect of the present invention, there is also provided a storage medium storing a computer program executable by an access authentication device, wherein when the computer program runs on the access authentication device, the access authentication device executes the steps of any one of the above methods.

[0029] In general, the above technical solutions conceived by the present invention can achieve the following beneficial effects compared with the prior art:

[0030] The present invention provides a method for detecting weak abnormal points of a display panel, which classifies the abnormal points into points of different colors by calculating the proportions of different color areas in the abnormal points, thereby improving the efficiency of abnormal point classification. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the embodiments will be briefly introduced below. 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 these drawings without paying creative work.

[0032] Figure 1 A schematic diagram of a flow chart of a method for detecting weak abnormal points of a display panel provided by an embodiment of the present invention;

[0033] Figure 2 A schematic diagram of shooting for bright spot detection provided by an embodiment of the present invention;

[0034] Figure 3 A schematic diagram of a bright spot provided by an embodiment of the present invention;

[0035] Figure 4 An enlarged schematic diagram of a bright spot provided by an embodiment of the present invention;

[0036] Figure 5 A schematic diagram showing the comparison of highlights in different pictures provided by an embodiment of the present invention;

[0037] Figure 6 A schematic diagram of taking a photo when a red image is imported into the display panel provided by an embodiment of the present invention;

[0038] Figure 7 A schematic diagram of taking a photo when a green image is imported into the display panel provided by an embodiment of the present invention;

[0039] Figure 8 A schematic diagram of taking photos when a blue image is imported into the display panel provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0040] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0041] The terms "first", "second", "third", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish different objects, rather than to describe a specific order. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or units is not limited to the listed steps or units, but optionally includes steps or units that are not listed, or optionally includes other steps or units inherent to these processes, methods, products or devices.

[0042] Common abnormal points on display panels are bright spots and dark spots. Bright spots are points that appear bright on a black screen. The reason for their occurrence is that some pixel units emit light when they should not. Dark spots are the opposite of bright spots. They appear black on a white screen. They are points that some pixel units do not emit light when they should. Both bright spots and dark spots are defects in display panels. Therefore, it is necessary to detect bright spots and dark spots before leaving the factory.

[0043] Different display panels use different pixel unit arrangements. For example, the most common arrangement for LCD screens is the RGB arrangement, while there are many different arrangements for OLED screens, such as Pentile arrangement, Diamond arrangement, or Delta arrangement. Under different arrangements, the color type, size, and arrangement of pixel units are different, so the causes of bright spots and dark spots are also different, and the methods of solving bright spots and dark spots are also different. Therefore, it is necessary to classify the bright spots and dark spots of different display panels, such as red bright spots, blue dark spots, etc., to help with their subsequent repair and adjustment.

[0044] like Figure 1 As shown in FIG. 1 , as the first embodiment of the present invention, a method for detecting weak abnormal points on a display panel is provided. In this embodiment, the common RGB arrangement of an LCD screen is taken as an example. Taking the classification of bright spots as an example, firstly, an image with a gray value of 10, that is, an image with an RGB value of (10, 10, 10) is imported into the display panel to be tested. At this time, the display panel should theoretically display nearly black, such as Figure 2 When the camera is used to shoot the display panel, the image obtained should be close to completely black. When a bright spot appears, the grayscale value of the bright spot area will be significantly higher than that of other areas of the panel, such as Figure 3-4 As shown. Figure 3 This is a partial picture of the panel bright spot detection. You can see that there is a bright spot in the white circle. Figure 4 It is a partial enlarged image of the area. It can be seen that the bright spot is displayed as multiple pixels in the camera. There are many methods for bright spot detection. In this embodiment, the method of gray value comparison is selected to delineate the bright spot area. The screen photo taken by the above camera is recorded as the first test result L0, and the bright spot area is the first area.

[0045] Because the LCD screen is arranged in RGB format, its pixel units only have three types: red, green and blue. Therefore, it is only necessary to prepare red, blue and green color images for testing. Here, we take the import of the red image, that is, the image with RGB value (255,0,0) as an example. After importing the red image, take a photo with a camera to get a new image, recorded as R255. When the distance between the panel and the camera and the parameters of the camera remain unchanged, it is easy to obtain the position of the bright spot area in the L0 image in R255. When the RGB-arranged LCD screen displays red, the red pixel unit should emit light, and the green and blue pixel units should not emit light.

[0046] The object of application of the present invention is a weak abnormal point. After the red image is imported, the red pixel unit will emit light at the maximum brightness. Therefore, in the R255 image, the abnormal pixel unit emits light very weakly and can be ignored. Figure 5The images of the same area of ​​the L0 image and the R255 image taken by the camera are given. It can be seen that the bright spot area can be distinguished in the L0 image, but it is difficult to judge the bright spot area by the grayscale value in the R255 image. Therefore, the bright spot area in the R255 image, the luminous part is caused by the red pixel unit. After the photo is taken and becomes the R255 image, the grayscale value of the luminous part and the grayscale value of the non-luminous part will be very different. At this time, you only need to calculate the ratio of the luminous part to the entire bright spot area. When the ratio exceeds a certain threshold, the bright spot is considered to be a red bright spot.

[0047] Similarly, repeat the above steps, use the (0,255,0) image to get the G255 image to determine whether the bright spot is a green bright spot; use the (0,0,255) image to get the B255 image to determine whether the bright spot is a blue bright spot. When the bright spot belongs to three colors at the same time, it is considered a white bright spot. If it is a two-color bright spot, it is considered a two-color bright spot.

[0048] The abnormal point detection method described in the present invention can also use only a single monochrome image. If a complete classification detection of bright spots or dark spots is to be performed, it is necessary to import a map of the corresponding colors of all its pixel units. If only the bright spot / dark spot is to be determined whether it is a red bright spot / dark spot, only the monochrome image can be imported.

[0049] The second threshold used to determine whether it belongs to a certain color bright spot can be set according to the needs. As a setting method, for example, for an LCD screen with RGB arrangement, because its RGB pixel units are evenly arranged and the classification requirements are not high, the second threshold can be set to 33.3% (i.e. 1 / 3), then the color greater than 33.3% (i.e. 1 / 3) is the classification described by the bright spot. For other types of screens, the color corresponding to the pixel unit and the area corresponding to the pixel unit can be calculated, and the area ratio of each color on the entire screen can be calculated in theory, and the area ratio is used as the second threshold.

[0050] For example, in some application scenarios, the classification requirements for bright spot colors are relatively strict. In this case, a smaller threshold can be set, such as 10%. That is, taking the above detection as an example, when the red luminous area accounts for 10% of the total bright spot area, the area is considered to be a red bright spot.

[0051] Even if the same camera is used, the effects of taking red, blue and green images will be different, and the final grayscale images will be different. Therefore, the third threshold used to determine the luminous area, that is, the third area, also needs to be set according to the actual situation. Figure 6-8The R255, G255 and B255 images are shown in sequence, that is, the grayscale value of each pixel in the camera imaging screen when the camera shooting panel displays red, green and blue images. Those skilled in the art can set the threshold value for determining the third area through experiments and test requirements.

[0052] Similarly, when the test item is the dark spot of the display panel, that is, when the dark spot of the display panel is to be classified, it is only necessary to change the image initially imported from a grayscale value of 10 to a grayscale value of 255, repeat the subsequent steps and adjust the corresponding parameters. Those skilled in the art can also understand that the grayscale values ​​of the test images used for the bright spot test and the dark spot test are preferably (10, 10, 10) and (255, 255, 255) as in the above embodiment, and other settings may also be possible.

[0053] Furthermore, even if the camera resolution and the pixels of the display panel do not correspond one to one, the method in this embodiment can be used to classify abnormal points. The judgment basis adopted by the present invention is the area ratio. Even if there is a situation where the pixels cannot correspond one to one, the ratio can still be calculated normally. Adaptive adjustment is used to determine whether the second threshold value belongs to a certain color bright spot.

[0054] The detection method used as an example in this embodiment is applied to an LCD screen with an RGB arrangement. For those skilled in the art, when the display panel to be tested is another display panel with other arrangements, such as an OLED display panel with a Pentile arrangement, a Diamond arrangement, or a Delta arrangement, the method described in the present invention can also achieve the effect of abnormal point classification by simply adjusting the corresponding parameters.

[0055] By using the method described in the present invention to classify abnormal points, no complicated calculation method is required. Only a simple area ratio calculation is needed to classify the bright spots or dark spots of the display panel, which can effectively improve the efficiency of classification.

[0056] Furthermore, it is easy for a person skilled in the art to apply the detection method described in the present invention only to a part of the display panel, or to apply the detection method described in the present invention to the local areas in sequence to complete the bright spot / dark spot detection of the entire panel. In other words, the detection method described in the present invention is not limited to testing and classifying the entire display panel, and can also be implemented by taking pictures of a local area of ​​the panel.

[0057] As a second embodiment of the present invention, a device for detecting a weak abnormal point of a display panel is provided, comprising:

[0058] a camera module configured to obtain a display photo of the display panel;

[0059] A display panel control module configured to input a test pattern or a monochrome pattern to the display panel;

[0060] A calculation and analysis module is configured to obtain the shooting results of the camera and classify the abnormal points of the display panel according to the steps of any of the above methods.

[0061] As a third embodiment of the present invention, a device for detecting faint abnormal points of a display panel is also provided, which includes at least one processing unit and at least one storage unit, wherein the storage unit stores a computer program, and when the computer program is executed by the processing unit, the processing unit executes the steps of any one of the above-mentioned methods.

[0062] The present invention also provides a computer-readable storage medium having a computer program stored thereon, which implements the steps of the above method when executed by a processor. The computer-readable storage medium may include, but is not limited to, any type of disk, including a floppy disk, an optical disk, a DVD, a CD-ROM, a micro drive, and a magneto-optical disk, a ROM, a RAM, an EPROM, an EEPROM, a DRAM, a VRAM, a flash memory device, a magnetic card or an optical card, a nanosystem (including a molecular memory IC), or any type of medium or device suitable for storing instructions and / or data.

[0063] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0064] It will be easily understood by those skilled in the art that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for detecting weak abnormal points of a display panel, characterized in that: include: S1. importing a test pattern into a display panel, photographing the display panel as a first test result, and marking a first area; wherein the first area is an area where the difference between the grayscale value actually photographed in the first test result and the grayscale value theoretically obtained in the first test result is greater than a first threshold value; S2. The monochrome image is imported into the display panel, and the display panel is photographed as a second test result; S3. In the second test result, mark the area corresponding to the first area as the second area, and mark the third area, and calculate the ratio of the third area to the second area; when the ratio is greater than a second threshold, it is considered that the points constituted by the first area are abnormal points of the corresponding colors of the monochrome image; wherein the third area refers to an area where the absolute value of the difference between the grayscale value in the second area and the average grayscale value of the second area is greater than the third threshold.

2. The method for detecting weak abnormal points of a display panel according to claim 1, characterized in that: The monochrome image is an image composed of colors corresponding to pixel units of the display panel.

3. The method for detecting weak abnormal points of a display panel as claimed in claim 2, characterized in that: When the pixel units of the display panel are red, green and blue, the monochrome images are (255, 0, 0), (0, 255, 0) and (0, 0, 255) respectively.

4. The method for detecting weak abnormal points of a display panel as claimed in claim 3, characterized in that: S4. Replace the monochrome image, and repeat steps S2-S3 until the monochrome images of all colors are tested.

5. The method for detecting weak abnormal points of a display panel as claimed in claim 4, characterized in that: According to the test result, the points formed by the first area are one of single-color abnormal points or multi-color abnormal points.

6. The method for detecting weak abnormal points of a display panel as claimed in claim 2, characterized in that: The second threshold is set according to the pixel unit arrangement mode of the display panel and / or the test requirement.

7. The method for detecting weak abnormal points of a display panel according to claim 6, characterized in that: The second threshold is preferably a ratio of the area occupied by the color corresponding to the pixel unit of the display panel in all the pixel units of the display panel.

8. The method for detecting weak abnormal points of a display panel as claimed in claim 1, characterized in that: The third threshold is specifically set according to the different monochrome images.

9. A device for detecting weak abnormal points of a display panel, characterized in that: The method comprises at least one processing unit and at least one storage unit, wherein the storage unit stores a computer program, and when the computer program is executed by the processing unit, the processing unit executes the steps of the method according to any one of claims 1 to 8.

10. A storage medium, characterized in that: It stores a computer program executable by an access authentication device. When the computer program runs on the access authentication device, the access authentication device executes the steps of the method according to any one of claims 1 to 8.

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