A detection method and detection system for display panel

Abstract

The present invention provides a detection method and detection system for a display panel, wherein the detection method comprises: obtaining a dark state image of the display panel when displaying a dark state picture; detecting the bright spot of the display panel according to the dark state image; obtaining a bright state image of the display panel when displaying a bright state picture; detecting the dark spot of the display panel according to the bright state image, so as to improve the detection efficiency of the bright and dark spots of the display panel.

Description

Technical Field

[0001] The present invention relates to the field of display technology, and in particular to a detection method and a detection system for a display panel. Background Art

[0002] In order to ensure the factory quality of display panels, it is often necessary to perform light and dark spot detection on display panels. At present, the light and dark spot detection of display panels mainly relies on manual detection. Specifically, for display panels, a device such as a magnifying glass is moved to a certain position each time, and the light and dark spot detection is performed by the human eye. The entire detection process is prone to missed detections, and the detection efficiency is not high. Summary of the invention

[0003] The present invention provides a display panel detection method and a detection system, which are used to improve the detection efficiency of bright and dark points of the display panel.

[0004] In a first aspect, an embodiment of the present invention provides a method for detecting a display panel, comprising:

[0005] Acquire a dark state image when the display panel displays a dark state picture;

[0006] Detecting a bright spot of the display panel according to the dark state image;

[0007] Acquire a bright state image of the display panel when displaying a bright state picture;

[0008] According to the bright state image, dark spots of the display panel are detected.

[0009] In a possible implementation manner, before detecting the bright spot of the display panel, the method further includes:

[0010] When at least one side light source located around the display panel is turned on, acquiring a black screen image of the display panel when the display panel is in a black screen state;

[0011] Dust spots on the display panel are detected according to the black screen image.

[0012] In a possible implementation manner, detecting dust spots on the display panel according to the black screen image includes:

[0013] For each pixel of the black screen image, execute:

[0014] Determine the grayscale value of the pixel point, and multiple grayscale values ​​corresponding to multiple pixels within a first preset neighborhood of the pixel point;

[0015] removing a maximum value among the plurality of grayscale values, and taking an average value of other grayscale values ​​among the plurality of grayscale values ​​as a first reference value;

[0016] The sum of the first reference value and the first preset grayscale difference is used as the first grayscale threshold of the pixel;

[0017] The grayscale value of the pixel is compared with the first grayscale threshold. If the grayscale value of the pixel is greater than the first grayscale threshold, the pixel and the pixels within a second preset neighborhood of the pixel are regarded as dust points, wherein the first preset neighborhood surrounds the second preset neighborhood.

[0018] In a possible implementation manner, after detecting the bright spot of the display panel according to the dark state image, the method further includes:

[0019] Pixels in the bright spots except the dust spots are regarded as bad spots.

[0020] In a possible implementation manner, detecting the bright spot of the display panel according to the dark state image includes:

[0021] For each pixel of the dark state image, execute:

[0022] Determine a grayscale value of the pixel in the dark state image, and a plurality of grayscale values ​​corresponding to a plurality of pixels within a third preset neighborhood of the pixel;

[0023] removing the maximum value among the plurality of grayscale values ​​and taking the average value of the other grayscale values ​​as the second reference value;

[0024] taking the sum of the second reference value and the second preset grayscale difference as a second grayscale threshold;

[0025] The grayscale value of the pixel is compared with the second grayscale threshold, and if the grayscale value of the pixel is greater than the second grayscale threshold, the pixel is regarded as a bright spot.

[0026] In a possible implementation manner, after detecting the bright spot of the display panel according to the dark state image, the method further includes:

[0027] Determine the grayscale value of the bright spot in the dark state image, the connected domain where the adjacent bright spots are located, and the maximum grayscale value in the connected domain;

[0028] Acquiring a reference image when the display panel displays a reference picture;

[0029] Determine, from the reference image, a cumulative histogram of the pixel points corresponding to the bright spot within a fourth preset neighborhood;

[0030] Determining the boundary grayscale of the pixel points corresponding to the bright spot according to the cumulative histogram;

[0031] The maximum grayscale value is compared with the boundary grayscale to determine the brightness level of the bright spot.

[0032] In a possible implementation manner, detecting a dark spot of the display panel according to the bright state image includes:

[0033] Inverting the bright state image to obtain an inverted image;

[0034] For each pixel in the inverted image, execute:

[0035] Determine the grayscale value of the pixel point, and multiple grayscale values ​​corresponding to multiple pixels within a fifth preset neighborhood of the pixel point;

[0036] removing the maximum value among the plurality of grayscale values, and taking the average value of the other grayscale values ​​as the third reference value;

[0037] taking the sum of the third reference value and the third preset grayscale difference as a third grayscale threshold;

[0038] The grayscale value of the pixel is compared with the third grayscale threshold. If the grayscale value of the pixel is greater than the third grayscale threshold, the pixel is regarded as a dark point.

[0039] In a possible implementation manner, after detecting the dark spot of the display panel according to the bright state image, the method further includes:

[0040] The pixel points in the dark spots except the dust points are regarded as bad pixels;

[0041] Determine the grayscale value of the bad pixel in the inverted image and the connected domain where the adjacent bad pixels are located;

[0042] If the contrast, area and center of gravity grayscale value of each pixel point in the connected domain meet the preset conditions, the connected domain is determined to be a scratch;

[0043] The pixel points corresponding to the scratches in the bad pixels are removed.

[0044] In a possible implementation manner, if the display panel is a panel corresponding to a VR device, the method further includes:

[0045] Acquire a bright screen image of the display panel when the screen is bright;

[0046] Determining a plurality of detection areas of the display panel according to the bright screen image;

[0047] Bright spot and dark spot detection are performed for each of the detection areas.

[0048] In a second aspect, an embodiment of the present invention provides a display panel detection system, including:

[0049] An industrial computer, and an image acquisition unit electrically connected to the industrial computer; wherein:

[0050] The image acquisition unit is used to acquire a dark state image when the display panel displays a dark state image, and to acquire a bright state image when the display panel displays a bright state image;

[0051] The industrial computer is used to detect the bright spots of the display panel according to the dark state image, and to detect the dark spots of the display panel according to the bright state image.

[0052] In one possible implementation, the detection system also includes at least one side light source located around the display panel, the industrial computer is electrically connected to the at least one side light source, and controls whether the at least one side light source is turned on or off, and the industrial computer is used to obtain a black screen image of the display panel when the at least one side light source located around the display panel is turned on; and detect dust spots on the display panel based on the black screen image.

[0053] In a possible implementation, the industrial computer is used to execute, for each pixel of the black screen image:

[0054] Determine the grayscale value of the pixel point, and multiple grayscale values ​​corresponding to multiple pixels within a first preset neighborhood of the pixel point;

[0055] removing a maximum value among the plurality of grayscale values, and taking an average value of other grayscale values ​​among the plurality of grayscale values ​​as a first reference value;

[0056] The sum of the first reference value and the first preset grayscale difference is used as the first grayscale threshold of the pixel;

[0057] The grayscale value of the pixel is compared with the first grayscale threshold. If the grayscale value of the pixel is greater than the first grayscale threshold, the pixel and the pixels within a second preset neighborhood of the pixel are regarded as dust points, wherein the first preset neighborhood surrounds the second preset neighborhood.

[0058] In a possible implementation, the industrial computer is further configured to treat pixel points in the bright spots other than the dust points as bad pixels.

[0059] In a possible implementation, the industrial computer is further used for:

[0060] For each pixel of the dark state image, execute:

[0061] Determine a grayscale value of the pixel in the dark state image, and a plurality of grayscale values ​​corresponding to a plurality of pixels within a third preset neighborhood of the pixel;

[0062] removing the maximum value among the plurality of grayscale values ​​and taking the average value of the other grayscale values ​​as the second reference value;

[0063] taking the sum of the second reference value and the second preset grayscale difference as a second grayscale threshold;

[0064] The grayscale value of the pixel is compared with the second grayscale threshold, and if the grayscale value of the pixel is greater than the second grayscale threshold, the pixel is regarded as a bright spot.

[0065] In a possible implementation, the industrial computer is further used for:

[0066] Determine the grayscale value of the bright spot in the dark state image, the connected domain where the adjacent bright spots are located, and the maximum grayscale value in the connected domain;

[0067] Acquiring a reference image when the display panel displays a reference picture;

[0068] Determine, from the reference image, a cumulative histogram of the pixel points corresponding to the bright spot within a fourth preset neighborhood;

[0069] Determining the boundary grayscale of the pixel points corresponding to the bright spot according to the cumulative histogram;

[0070] The maximum grayscale value is compared with the boundary grayscale to determine the brightness level of the bright spot.

[0071] In a possible implementation, the industrial computer is further used for:

[0072] Inverting the bright state image to obtain an inverted image;

[0073] For each pixel in the inverted image, execute:

[0074] Determine the grayscale value of the pixel point, and multiple grayscale values ​​corresponding to multiple pixels within a fifth preset neighborhood of the pixel point;

[0075] removing the maximum value among the plurality of grayscale values, and taking the average value of the other grayscale values ​​as the third reference value;

[0076] taking the sum of the third reference value and the third preset grayscale difference as a third grayscale threshold;

[0077] The grayscale value of the pixel is compared with the third grayscale threshold. If the grayscale value of the pixel is greater than the third grayscale threshold, the pixel is regarded as a dark point.

[0078] In a possible implementation, the industrial computer is further used for:

[0079] The pixel points in the dark spots except the dust points are regarded as bad pixels;

[0080] Determine the grayscale value of the bad pixel in the inverted image and the connected domain where the adjacent bad pixels are located;

[0081] If the contrast, area and center of gravity grayscale value of each pixel point in the connected domain meet the preset conditions, the connected domain is determined to be a scratch;

[0082] The pixel points corresponding to the scratches in the bad pixels are removed.

[0083] In a possible implementation, the industrial computer is further used for:

[0084] Acquire a bright screen image of the display panel when the screen is bright;

[0085] Determining a plurality of detection areas of the display panel according to the bright screen image;

[0086] Bright spot and dark spot detection are performed for each of the detection areas.

[0087] The beneficial effects of the present invention are as follows:

[0088] The embodiment of the present invention provides a detection method and detection system for a display panel, which detects the bright spots of the display panel by acquiring a dark-state image when the display panel displays a dark-state picture, and detects the dark spots of the display panel by acquiring a bright-state image when the display panel displays a bright-state picture. In other words, the bright spots and dark spots of the display panel can be automatically detected directly based on the dark-state image and the bright-state image, thereby improving the detection efficiency of the bright and dark spots of the display panel. BRIEF DESCRIPTION OF THE DRAWINGS

[0089] Figure 1 A method flow chart of a display panel detection method provided by an embodiment of the present invention;

[0090] Figure 2 A method flow chart after step S102 in a display panel detection method provided by an embodiment of the present invention;

[0091] Figure 3 A method flow chart of step S202 in a display panel detection method provided by an embodiment of the present invention;

[0092] Figure 4 A schematic diagram of a first preset neighborhood in a display panel detection method provided by an embodiment of the present invention;

[0093] Figure 5 A method flow chart of step S102 in a display panel detection method provided by an embodiment of the present invention;

[0094] Figure 6 A schematic diagram of a third preset field in a display panel detection method provided by an embodiment of the present invention;

[0095] Figure 7 A method flow chart after step S102 in a display panel detection method provided by an embodiment of the present invention;

[0096] Figure 8 A method flow chart of step S104 in a display panel detection method provided by an embodiment of the present invention;

[0097] Fig. 9 A method flow chart after step S104 in a display panel detection method provided by an embodiment of the present invention;

[0098] Fig.10 In a display panel detection method provided by an embodiment of the present invention, Figure 8 A schematic diagram of the detection results obtained by performing dark spot detection according to the steps shown;

[0099] Fig.11 In a display panel detection method provided by an embodiment of the present invention, Fig. 9 The steps shown are Fig.10 Schematic diagram of dark spot display after filtering the scratches in the dark spots shown;

[0100] Fig.12 A schematic diagram of the distribution of bright spots and dark spots detected according to bright spot and dark spot standards set by a customer in a display panel detection method provided by an embodiment of the present invention;

[0101] Fig.13 A schematic diagram of a method for detecting a display panel provided in an embodiment of the present invention when the display panel is a panel corresponding to a VR device;

[0102] Fig.14 A schematic diagram of a bright screen image in a display panel detection method provided by an embodiment of the present invention;

[0103] Fig.15 A schematic structural diagram of a display panel detection system provided by an embodiment of the present invention;

[0104] Fig.16 A schematic diagram of a structure of a display panel detection system provided by an embodiment of the present invention;

[0105] Fig.17 A schematic diagram of one of the operation interfaces for automatic detection of bright and dark points in a detection system for a display panel provided by an embodiment of the present invention;

[0106] Fig.18 A schematic diagram of one of the operation interfaces for automatic detection of bright and dark spots in a detection system for a display panel provided by an embodiment of the present invention.

[0107] Explanation of reference numerals: 10 - industrial computer; 20 - image acquisition unit; 30 - side light source; 100 - display panel; 40 - lighting machine; 50 - display. DETAILED DESCRIPTION

[0108] In order to make the purpose, technical solution and advantages of the embodiment of the present invention clearer, the technical solution of the embodiment of the present invention will be clearly and completely described below in conjunction with the drawings of the embodiment of the present invention. Obviously, the described embodiment is a part of the embodiment of the present invention, not all of the embodiments. And in the absence of conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other. Based on the described embodiments of the present invention, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present invention.

[0109] Unless otherwise defined, the technical terms or scientific terms used in the present invention shall have the common meanings understood by people with ordinary skills in the field to which the present invention belongs. The words "include" or "comprise" and the like used in the present invention mean that the elements or objects appearing before the word include the elements or objects listed after the word and their equivalents, but do not exclude other elements or objects.

[0110] It should be noted that the sizes and shapes of the figures in the accompanying drawings do not reflect the actual proportions, but are only intended to illustrate the content of the present invention. The same or similar reference numerals throughout represent the same or similar elements or elements with the same or similar functions.

[0111] In the prior art, the bright and dark spots of the display panel are mainly detected by the human eye. The entire detection process is prone to missed detections and has low detection efficiency.

[0112] In view of this, an embodiment of the present invention provides a detection method and a detection system for a display panel, which are used to improve the detection efficiency of bright and dark points of a display panel.

[0113] like Figure 1 The method flow chart of a method for detecting a display panel provided by an embodiment of the present invention includes:

[0114] S101: Acquire a dark state image when the display panel displays a dark state picture;

[0115] In a specific implementation process, the dark state picture is a completely black picture with all grayscales being "0", and a dark state image of the display panel when displaying the dark state picture can be acquired by collecting and obtaining the dark state image through a high-resolution black and white industrial camera.

[0116] S102: Detecting bright spots of the display panel according to the dark state image;

[0117] In a specific implementation process, the bright spot refers to a pixel point that still has relatively high brightness when the display panel is on and displays a dark image.

[0118] S103: Acquire a bright state image of the display panel when displaying a bright state picture;

[0119] In a specific implementation process, the bright state image is a full white image with all grayscales being "255", which can be acquired by a high-resolution black and white industrial camera to obtain a dark state image of the display panel when displaying the bright state image.

[0120] S104: Detecting dark spots of the display panel according to the bright state image.

[0121] In the specific implementation process, the dark spot is specifically a "black spot" where the display panel cannot display content when the screen is on and the bright state image is displayed. The "black spot" is a pixel with lower brightness. In this way, the bright spot and dark spot of the display panel can be automatically detected directly based on the dark state image and the bright state image of the display panel, thereby improving the detection efficiency of the bright and dark spots of the display panel.

[0122] In the embodiment of the present invention, Figure 2 As shown, before step S102: detecting the bright spot of the display panel according to the dark state image, the method further includes:

[0123] S201: When at least one side light source located around the display panel is turned on, acquiring a black screen image of the display panel when the display panel is in a black screen state;

[0124] S202: Detect dust spots on the display panel according to the black screen image.

[0125] In the specific implementation process, the specific implementation process of step S201 to step S202 is as follows:

[0126] First, when at least one side light source located around the display panel is turned on, a black screen image of the display panel when the screen is black is obtained, which can be acquired by a black and white industrial camera when the screen is not lit, that is, the black screen image of the display panel is black. Among them, at least one side light source can be one or more, and each side light source can be a linear light source. By turning on at least one side light source located around the display panel, the uniformity of the light on the surface of the display panel can be ensured, and the image effect of the collected black screen image can be improved. Then, based on the black screen image, the dust spots of the display panel are detected. Since the dust spots on the display panel often affect the detection accuracy of the bright and dark spots of the display panel, the dust spots of the display panel are detected in advance before the bright spots of the display panel are detected, so as to avoid the influence of the dust spots on the bright spot detection, thereby improving the accuracy of the bright spot detection of the display panel.

[0127] In the embodiment of the present invention, Figure 3 As shown, step S202: detecting dust spots on the display panel according to the black screen image, including:

[0128] For each pixel of the black screen image, execute:

[0129] S301: Determine the grayscale value of the pixel point, and multiple grayscale values ​​corresponding to multiple pixels within a first preset neighborhood of the pixel point;

[0130] S302: removing the maximum value among the plurality of grayscale values, and taking the average value of other grayscale values ​​among the plurality of grayscale values ​​as a first reference value;

[0131] S303: taking the sum of the first reference value and the first preset grayscale difference as the first grayscale threshold of the pixel;

[0132] S304: Compare the grayscale value of the pixel with the first grayscale threshold; if the grayscale value of the pixel is greater than the first grayscale threshold, treat the pixel and the pixels within a second preset neighborhood of the pixel as dust points, wherein the first preset neighborhood surrounds the second preset neighborhood.

[0133] In the specific implementation process, the specific implementation process of step S301 to step S304 is as follows:

[0134] First, the black screen image is traversed, and for each pixel in the black screen image, the grayscale value of the pixel and the grayscale values ​​corresponding to the multiple pixels in the first preset neighborhood of the pixel are determined, wherein the size of the first preset neighborhood is N×M, N and M are integers greater than 1, for example, it can be as follows Figure 4The neighborhood is formed by eight pixels that are 1 / 2 period away from the pixel point shown in the figure. These eight pixels are located in eight different directions of the pixel point to be detected. In the specific implementation process, the size of the neighborhood can be set according to the relationship between the resolution of the photosensitive element of the camera used to collect the black screen image and the resolution of the display panel, and the pixels in the neighborhood of the pixel point to be detected are selected accordingly. Then, the maximum value among the multiple grayscale values ​​is removed, and the average value of the other grayscale values ​​among the multiple grayscale values ​​is used as the first reference value. Figure 4 For example, remove the maximum value among the eight grayscale values, and take the average value X of the remaining eight grayscale values ​​as the first reference value. Then, take the sum of the first reference value and the first preset grayscale difference as the first grayscale threshold of the pixel. The first preset grayscale difference is a grayscale difference set according to actual application needs, which can be a positive value or a negative value. Still taking the above example, if the first preset grayscale difference is △X, the first grayscale threshold is X+△X.

[0135] In the specific implementation process, two grayscale differences can be set according to the area and contrast. Accordingly, there can be two first grayscale thresholds. For example, one grayscale threshold is a threshold for a large area but a small contrast, and the other grayscale threshold is a threshold for a small area but a large contrast. Technical personnel in this field can set the corresponding thresholds according to actual application needs, and no limitation is made here.

[0136] Then, the grayscale value of the pixel is compared with the first grayscale threshold. If the grayscale value of the pixel is greater than the first grayscale threshold, the pixel and the pixels located in the second preset neighborhood of the pixel are regarded as dust points, wherein the first preset neighborhood surrounds the second preset neighborhood. Based on the same dust point detection process, the same detection process is performed on all corresponding pixels in the dark state image, thereby realizing the dust point detection of the display panel. In the specific implementation process, the surrounding neighborhood is expanded for all pixels that meet the grayscale value greater than the first grayscale threshold as the final dust point. For example, all pixels within two pixels of the pixel that meets the grayscale value greater than the first grayscale threshold can be regarded as the final dust point, thereby preventing the detected dust points from being incompletely covered, thereby improving the detection accuracy of the dust points.

[0137] In the embodiment of the present invention, after detecting the bright spots of the display panel according to the dark state image in step S102, the method further comprises: treating the pixels of the bright spots other than the dust spots as bad spots. In the specific implementation process, by removing all the dust spots in the bright spots and then treating the pixels corresponding to the other bright spots as bad spots, the accuracy of bad spot detection is improved.

[0138] In the embodiment of the present invention, Figure 5As shown, step S102: detecting the bright spot of the display panel according to the dark state image, including:

[0139] For each pixel of the dark state image, execute:

[0140] S501: Determine a grayscale value of the pixel in the dark state image, and a plurality of grayscale values ​​corresponding to a plurality of pixels within a third preset neighborhood of the pixel;

[0141] S502: removing the maximum value among the plurality of grayscale values, and taking the average value of the other grayscale values ​​as a second reference value;

[0142] S503: taking the sum of the second reference value and the second preset grayscale difference as a second grayscale threshold;

[0143] S504: Compare the grayscale value of the pixel with the second grayscale threshold, and if the grayscale value of the pixel is greater than the second grayscale threshold, treat the pixel as a bright spot.

[0144] In the specific implementation process, the specific implementation process of step S501 to step S504 is as follows:

[0145] First, the dark state image is traversed, and for each pixel in the dark state image, the grayscale value of the pixel in the dark state image and the grayscale values ​​corresponding to the multiple pixels in the third preset neighborhood of the pixel are determined, wherein the third preset neighborhood can be as follows: Figure 4 The neighborhood is composed of eight pixels that are 1 / 2 period away from the pixel point, and these eight pixels are located in eight different directions of the detected pixel point. The third preset neighborhood can be as follows Figure 6 The neighborhood shown is composed of four pixels that are 1 / 2 period away from the pixel point. The four pixels are respectively located in four different directions of the detected pixel point.

[0146] Then, the maximum value among the plurality of grayscale values ​​is removed, and the average value of the other grayscale values ​​among the plurality of grayscale values ​​is used as the second reference value. Figure 4 For example, remove the maximum value among the eight grayscale values, and take the average value Y of the remaining eight grayscale values ​​as the second reference value. Then, take the sum of the second reference value and the second preset grayscale difference as the second grayscale threshold of the pixel. Among them, the second preset grayscale difference is a grayscale difference set according to actual application needs, which can be a positive value or a negative value. Still taking the above example, if the second preset grayscale difference is △Y, the second grayscale threshold is Y+△Y.

[0147] In the specific implementation process, two grayscale differences can be set according to the area and contrast. Accordingly, there can be two second grayscale thresholds. For example, one grayscale threshold is a threshold for a large area but a small contrast, and the other grayscale threshold is a threshold for a small area but a large contrast. Technical personnel in this field can set the corresponding thresholds according to actual application needs, and no limitation is made here.

[0148] Then, the grayscale value of the pixel is compared with the second grayscale threshold. If the grayscale value of the pixel is greater than the second grayscale threshold, the pixel and the pixels within the second preset neighborhood of the pixel are regarded as bright spots. Based on the same bright spot detection process, the same detection process is performed on all corresponding pixels in the dark state image, thereby realizing bright spot detection of the display panel.

[0149] In the embodiment of the present invention, Figure 7 As shown, in step S102: after detecting the bright spot of the display panel according to the dark state image, the following steps are included:

[0150] S701: Determine the grayscale value of the bright spot in the dark state image, the connected domain where the adjacent bright spots are located, and the maximum grayscale value in the connected domain;

[0151] S702: Acquire a reference image when the display panel displays a reference picture;

[0152] S703: Determine, from the reference image, a cumulative histogram of the pixel points corresponding to the bright spot within a fourth preset neighborhood;

[0153] S704: Determine the boundary grayscale of the pixel point corresponding to the bright spot according to the cumulative histogram;

[0154] S705: Compare the maximum grayscale value with the boundary grayscale to determine the brightness level of the bright spot.

[0155] In the specific implementation process, the specific implementation process of step S701 to step S705 is as follows:

[0156] First, determine the grayscale value of the bright spot in the dark state image, as well as the connected domain where the adjacent bright spots are located, and the maximum grayscale value in the connected domain. That is to say, determine the pixels located in the same area from the determined bright spots, and the area is the corresponding connected domain. In addition, the number of pixels, area, maximum grayscale value, minimum grayscale value, contrast, brightness, etc. in the connected domain can also be counted. Of course, those skilled in the art can count the relevant information in the connected domain according to the actual application needs, which is not limited here. Then, obtain a reference image when the display panel displays the reference picture. The reference picture can be a full green picture G28 with a grayscale value of "28", or a full green picture G48 with a grayscale value of "48", which is not limited here. The reference image of the display panel when displaying the reference picture can be obtained by an industrial camera. Then, determine the cumulative histogram of the pixel points corresponding to the bright spot in the fourth preset neighborhood from the reference image, where the fourth preset neighborhood can be as follows Figure 4 The neighborhood formed by eight pixels that are 1 / 2 cycle away from the pixel point shown, these eight pixels are respectively located in eight different directions of the detected pixel point. Of course, the fourth preset neighborhood can also be set according to the actual application, which is not limited here. Then, according to the cumulative histogram, the boundary grayscale of the pixel point corresponding to the bright spot is determined. For example, the grayscale value corresponding to 90% in the cumulative histogram can be calculated as the boundary grayscale. Then, the maximum grayscale value in the connected domain is compared with the boundary grayscale to determine the brightness level of the bright spot. For example, the bright spot level is between G28 and G48.

[0157] In the embodiment of the present invention, Figure 8 As shown, step S104: detecting dark spots of the display panel according to the bright state image, including:

[0158] S801: inverting the bright state image to obtain an inverted image;

[0159] S802: For each pixel in the inverted image, execute:

[0160] Determine the grayscale value of the pixel point, and multiple grayscale values ​​corresponding to multiple pixels within a fifth preset neighborhood of the pixel point;

[0161] removing the maximum value among the plurality of grayscale values, and taking the average value of the other grayscale values ​​as the third reference value;

[0162] taking the sum of the third reference value and the third preset grayscale difference as a third grayscale threshold;

[0163] The grayscale value of the pixel is compared with the third grayscale threshold. If the grayscale value of the pixel is greater than the third grayscale threshold, the pixel is regarded as a dark point.

[0164] In the specific implementation process, the specific implementation process of step S801 to step S802 is as follows:

[0165] The bright image is inverted to obtain an inverted image. For example, the grayscale value of a pixel in the bright image is "255". After inversion, the grayscale value of the pixel in the inverted image is "0". Then, the inverted image is traversed and a detection method related to the bright spot detection method is used to perform dark spot detection on the inverted image. Specifically, the grayscale value of the pixel and the grayscale values ​​corresponding to multiple pixels in the fifth preset neighborhood of the pixel are determined; wherein the fifth preset neighborhood can be Figure 4 The neighborhood shown. Remove the maximum value among the multiple grayscale values, and use the average value of the other grayscale values ​​as the third reference value; use the sum of the third reference value and the third preset grayscale difference as the third grayscale threshold; compare the grayscale value of the pixel with the third grayscale threshold, and if the grayscale value of the pixel is greater than the third grayscale threshold, then the pixel is regarded as a dark spot. Since the specific method of dark spot detection is the same as that of bright spot, it will not be described in detail here.

[0166] In the embodiment of the present invention, Fig. 9 As shown, in step S104: after detecting the dark spot of the display panel according to the bright state image, the method further includes:

[0167] S901: Counting the pixel points in the dark spots except the dust points as bad pixels;

[0168] S902: Determine the grayscale value of the bad pixel in the inverted image and the connected domain where the adjacent bad pixels are located;

[0169] S903: If the contrast, area and centroid grayscale value of each pixel point in the connected domain meet preset conditions, the connected domain is determined to be a scratch;

[0170] S904: removing the pixel points corresponding to the scratches in the bad pixels.

[0171] In the specific implementation process, the specific implementation process of step S901 to step S904 is as follows:

[0172] First, the pixels in the dark spots except the dust spots are regarded as bad spots, thereby improving the accuracy of dark spot detection. Then, the grayscale value of the bad spots in the inverted image and the connected domain where the adjacent bad spots are located are determined, and then the contrast, area and grayscale value of the center of gravity of each pixel in each connected domain are determined. If the contrast, area and grayscale value of the center of gravity of each pixel in the connected domain meet the preset conditions, the connected domain is determined as a scratch. For example, if the contrast of each pixel in the connected domain is greater than 127, and the area of ​​the connected domain is greater than 15 and less than 42, and the grayscale value of the center of gravity of the connected domain is less than 80, it indicates that the connected domain meets the preset conditions, and accordingly, the connected domain is determined as a scratch. Then, the pixel points corresponding to the scratches in the bad spots are removed. In the specific implementation process, since the dark spot detection is performed under a bright screen with high brightness, once there is a scratch on the display panel, the brightness at the scratch position will decay, which may easily interfere with the dark spot detection. During the dark spot detection process, the pixel points at the scratch position are filtered accordingly to ensure the accuracy of the dark spot detection.

[0173] like Fig.10 Shown by Figure 8 Schematic diagram of the detection results obtained by performing dark spot detection according to the steps shown in FIG. 1 , wherein the small dots in the figure are dark spots, such as Fig.11 To pass Fig. 9 The steps shown are Fig.10 The dark spots shown are shown in the schematic diagram after the scratches in the dark spots are filtered. Fig.12 This is one of the schematic diagrams of the distribution of bright spots and dark spots detected according to the bright spot and dark spot standards set by the customer. Of course, in actual applications, due to different bright spot and dark spot standards set by the customer, the distribution of bright spots and dark spots detected from the display panel will also be different, which is not limited here.

[0174] In the embodiment of the present invention, Fig.13 As shown, if the display panel is a panel corresponding to a VR device, the method further includes:

[0175] S1011: Acquire a bright screen image of the display panel when the screen is bright;

[0176] S1012: determining a plurality of detection areas of the display panel according to the bright screen image;

[0177] S1013: Perform bright spot and dark spot detection on each detection area.

[0178] In the specific implementation process, the specific implementation process of step S1011 to step S1013 is as follows:

[0179] First, obtain a bright screen image when the display panel is on; for example, obtain a bright screen image when the display panel is displaying a full white screen, and then determine multiple detection areas of the display panel based on the bright screen image. In the specific implementation process, since the pixels on the display panel are distributed periodically, the acquired image has strict periodicity. Before determining the detection area of ​​the display panel, Gaussian filtering can be used to blur the periodic structure, thereby improving the accuracy of regional detection. In the actual detection process, Harris corner detection and Canny edge detection can be used to locate each area in the display panel. For example, Fig.14 FIG. 1 is a schematic diagram of a bright screen image. Accordingly, the distribution of each detection area of ​​the display panel is determined as follows: Fig.14 As shown, specifically, the detection areas corresponding to the display panel include panel area A, field of view area B and core area C. After determining the various detection areas of the display panel, bright spot and dark spot detection is performed for each detection area. In the specific implementation process, it can be adopted Figure 5 , Figure 7-9 The bright spot detection and dark spot detection methods corresponding to the above are used to detect each detection area in the display panel corresponding to the VR device, which will not be described in detail here. Fig.11 Taking the detection area shown as an example, the probability of human eyes gazing at the core area C is usually greater than the probability of gazing at the visual field area B, and the probability of human eyes gazing at the visual field area B is greater than the probability of human eyes gazing at the panel area. In this way, corresponding bright spot detection standards and dark spot detection standards can be set for each detection area, and accordingly, different grayscale thresholds are set to perform bright and dark spot detection, thereby ensuring targeted detection of different detection areas and further ensuring the display quality of the display panel.

[0180] Based on the same inventive concept, Fig.15 As shown, an embodiment of the present invention further provides a display panel detection system, including:

[0181] An industrial computer 10, and an image acquisition unit 20 electrically connected to the industrial computer 10; wherein:

[0182] The image acquisition unit 20 is used to acquire a dark state image when the display panel 100 displays a dark state image, and to acquire a bright state image when the display panel 100 displays a bright state image;

[0183] The industrial computer 10 is used to detect the bright spots of the display panel 100 according to the dark state image, and to detect the dark spots of the display panel 100 according to the bright state image.

[0184] In a specific implementation process, the image acquisition unit 20 may be a high-precision industrial black-and-white camera, or other black-and-white cameras, which is not limited here.

[0185] In the embodiment of the present invention, Fig.16 The detection system shown also includes at least one side light source 30 located around the display panel 100. The industrial computer 10 is electrically connected to the at least one side light source 30 and controls whether the at least one side light source 30 is turned on or not. The industrial computer 10 is used to obtain a black screen image of the display panel 100 when the at least one side light source 30 located around the display panel 100 is turned on; and detect dust spots on the display panel 100 based on the black screen image. Fig.16 Specifically illustrated is the case when there are two at least one side light sources 30. In the specific implementation process, the detection system also includes a lighting machine 40 electrically connected to the industrial computer 10, and the lighting machine 40 is electrically connected to the display panel. Among them, the industrial computer 10 can send the picture to be displayed on the display panel 100 to the lighting machine 40, and then the lighting machine 40 sends the picture to be displayed to the display panel 100, thereby realizing the display panel to display the picture to be displayed. In addition, at least one side light source 30 can be a white light LED light source. By irradiating the display panel 100 with the at least one side light source 30, the dust points on the display panel can be detected. In actual applications, the distance between the lens of the image acquisition unit 20 and the display panel 100 can be set according to the actual scene requirements. For example, the distance can be between 300mm and 720mm.

[0186] In the specific implementation process, in order to further realize the automatic detection of bright and dark spots, the detection system also includes a display 50, which is used to display an operation interface for bright spot detection and dark spot detection of the display panel 100. On this operation interface, the user can input relevant parameters for bright spot detection and dark spot detection according to actual application needs, and the relevant detection results are presented to the user, thereby realizing the automatic detection of bright spots and dark spots while improving the detection efficiency of bright spot detection and dark spot detection, thereby improving the user experience.

[0187] like Fig.17 and Fig.18 FIG. 1 is a schematic diagram of two operation interfaces for automatic detection of bright and dark spots provided by an embodiment of the present invention, wherein Fig.17In the figure, the parameters marked in area D are mainly used for image type and shooting time settings, such as image type: sequence diagram, absence details, acquisition delay 50ms, exposure time 20ms. The parameters marked in area E are image processing related parameters. For example, in the process of locating the detection area of ​​the display panel, the detection parameters include the preprocessing algorithm as mean filtering, the area type double hole and inner area, the area mode as a regular rectangle, the boundary shrinkage of two pixels on the top, bottom, left and right, the panel pixel is 2500×1400, the number of sub-pixels is 1×1, the upper left corner of the image corresponds to the upper left corner of the panel, the upper right corner of the figure corresponds to the upper right corner of the panel, the lower right corner of the image corresponds to the lower right corner of the panel, and the lower left corner of the image corresponds to the lower left corner of the panel. Area F marks the status of related devices, such as camera status, lighting machine status, industrial computer status, etc. It can be marked with different colors, for example, red indicates that the device is not turned on, green indicates that the device is turned on and working normally, and yellow indicates that the device status is abnormal. Area G marks the input signal status indication, for example, the input signal status indication can be bright and dark point detection, detection result, reset, lighting machine on, etc. Area H is marked with output signal indication, for example, the output signal indication can be the bad pixel detection failure state "NG", or the bad pixel detection passing state "OK", for example, the number of bright spots does not exceed the preset number, and the brightness level of the bright spots is within a reasonable range. It can also be the backlight, side light, green light, yellow light, red light and other on states. Fig.18 The area I in the middle is marked with a list of detection images, for example, it may be an upper surface dust map, a positioning map for determining the detection area of ​​the display panel, a completely black image L0, a reference image G28, and a reference image G48. Fig.18 The area J in the middle is marked with historical detection records, and the area K is marked with detection result statistics. For example, the total number of detection display panels is 19, the number of good products is 18, the number of defective products is 0, the system failure (timeout) is 0, and the system failure (check) is 1. Of course, those skilled in the art can set the specific display of the operation interface according to actual application needs, which will not be described in detail here.

[0188] In addition, during the specific implementation process, the display panel 100 can also be transported to the detection system by automatic loading, and the detection system performs light and dark point detection on the display panel 100, thereby improving the automated detection efficiency of light and dark point detection.

[0189] In the embodiment of the present invention, the industrial computer 10 is used to execute, for each pixel point of the black screen image:

[0190] Determine the grayscale value of the pixel point, and multiple grayscale values ​​corresponding to multiple pixels within a first preset neighborhood of the pixel point;

[0191] removing a maximum value among the plurality of grayscale values, and taking an average value of other grayscale values ​​among the plurality of grayscale values ​​as a first reference value;

[0192] The sum of the first reference value and the first preset grayscale difference is used as the first grayscale threshold of the pixel;

[0193] The grayscale value of the pixel is compared with the first grayscale threshold. If the grayscale value of the pixel is greater than the first grayscale threshold, the pixel and the pixels within a second preset neighborhood of the pixel are regarded as dust points, wherein the first preset neighborhood surrounds the second preset neighborhood.

[0194] In the embodiment of the present invention, the industrial computer 10 is further configured to regard the pixel points in the bright spots except the dust points as bad pixels.

[0195] In the embodiment of the present invention, the industrial computer 10 is also used for:

[0196] For each pixel of the dark state image, execute:

[0197] Determine a grayscale value of the pixel in the dark state image, and a plurality of grayscale values ​​corresponding to a plurality of pixels within a third preset neighborhood of the pixel;

[0198] removing the maximum value among the plurality of grayscale values ​​and taking the average value of the other grayscale values ​​as the second reference value;

[0199] taking the sum of the second reference value and the second preset grayscale difference as a second grayscale threshold;

[0200] The grayscale value of the pixel is compared with the second grayscale threshold, and if the grayscale value of the pixel is greater than the second grayscale threshold, the pixel is regarded as a bright spot.

[0201] In the embodiment of the present invention, the industrial computer 10 is also used for:

[0202] Determine the grayscale value of the bright spot in the dark state image, the connected domain where the adjacent bright spots are located, and the maximum grayscale value in the connected domain;

[0203] Acquiring a reference image when the display panel displays a reference picture;

[0204] Determine, from the reference image, a cumulative histogram of the pixel points corresponding to the bright spot within a fourth preset neighborhood;

[0205] Determining the boundary grayscale of the pixel points corresponding to the bright spot according to the cumulative histogram;

[0206] The maximum grayscale value is compared with the boundary grayscale to determine the brightness level of the bright spot.

[0207] In the embodiment of the present invention, the industrial computer 10 is also used for:

[0208] Inverting the bright state image to obtain an inverted image;

[0209] For each pixel in the inverted image, execute:

[0210] Determine the grayscale value of the pixel point, and multiple grayscale values ​​corresponding to multiple pixels within a fifth preset neighborhood of the pixel point;

[0211] removing the maximum value among the plurality of grayscale values, and taking the average value of the other grayscale values ​​as the third reference value;

[0212] taking the sum of the third reference value and the third preset grayscale difference as a third grayscale threshold;

[0213] The grayscale value of the pixel is compared with the third grayscale threshold. If the grayscale value of the pixel is greater than the third grayscale threshold, the pixel is regarded as a dark point.

[0214] In the embodiment of the present invention, the industrial computer 10 is also used for:

[0215] The pixel points in the dark spots except the dust points are regarded as bad pixels;

[0216] Determine the grayscale value of the bad pixel in the inverted image and the connected domain where the adjacent bad pixels are located;

[0217] If the contrast, area and center of gravity grayscale value of each pixel point in the connected domain meet the preset conditions, the connected domain is determined to be a scratch;

[0218] The pixel points corresponding to the scratches in the bad pixels are removed.

[0219] In the embodiment of the present invention, the industrial computer 10 is also used for:

[0220] Acquire a bright screen image of the display panel when the screen is bright;

[0221] Determining a plurality of detection areas of the display panel according to the bright screen image;

[0222] Bright spot and dark spot detection are performed for each of the detection areas.

[0223] The beneficial effects of the present invention are as follows:

[0224] The embodiment of the present invention provides a detection method and detection system for a display panel, which detects the bright spots of the display panel by acquiring a dark-state image when the display panel displays a dark-state picture, and detects the dark spots of the display panel by acquiring a bright-state image when the display panel displays a bright-state picture. In other words, the bright spots and dark spots of the display panel can be automatically detected directly based on the dark-state image and the bright-state image, thereby improving the detection efficiency of the bright and dark spots of the display panel.

[0225] Although the preferred embodiments of the present invention have been described, other changes and modifications may be made to these embodiments once the basic creative concept is known to those skilled in the art. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications falling within the scope of the present invention.

[0226] Obviously, those skilled in the art can make various changes and modifications to the present application without departing from the spirit and scope of the present application. Thus, if these modifications and variations of the present application fall within the scope of the claims of the present application and their equivalents, the present application is also intended to include these modifications and variations.

Claims

1. A method for detecting a display panel, characterized in that: include: Acquire a dark state image when the display panel displays a dark state picture; Detecting a bright spot of the display panel according to the dark state image; Acquire a bright state image of the display panel when displaying a bright state picture; Detecting dark spots of the display panel according to the bright state image; Before detecting the bright spot of the display panel, the method further includes: When at least one side light source located around the display panel is turned on, acquiring a black screen image of the display panel when the display panel is in a black screen state; Detecting dust spots on the display panel according to the black screen image; Wherein, detecting dust spots on the display panel according to the black screen image includes: For each pixel of the black screen image, execute: Determine the grayscale value of the pixel point, and multiple grayscale values ​​corresponding to multiple pixels within a first preset neighborhood of the pixel point; removing a maximum value among the plurality of grayscale values, and taking an average value of other grayscale values ​​among the plurality of grayscale values ​​as a first reference value; The sum of the first reference value and the first preset grayscale difference is used as the first grayscale threshold of the pixel; The grayscale value of the pixel point is compared with the first grayscale threshold. If the grayscale value of the pixel point is greater than the first grayscale threshold, the pixel point and the pixels located in a second preset neighborhood of the pixel point are regarded as dust points, wherein the first preset neighborhood surrounds the second preset neighborhood.

2. The detection method according to claim 1, characterized in that After detecting the bright spot of the display panel according to the dark state image, the method further includes: Pixels in the bright spots except the dust spots are regarded as bad spots.

3. The detection method according to claim 1, characterized in that The step of detecting the bright spot of the display panel according to the dark state image comprises: For each pixel of the dark state image, execute: Determine a grayscale value of the pixel in the dark state image, and a plurality of grayscale values ​​corresponding to a plurality of pixels within a third preset neighborhood of the pixel; removing the maximum value among the plurality of grayscale values ​​and taking the average value of the other grayscale values ​​as the second reference value; taking the sum of the second reference value and the second preset grayscale difference as a second grayscale threshold; The grayscale value of the pixel is compared with the second grayscale threshold, and if the grayscale value of the pixel is greater than the second grayscale threshold, the pixel is regarded as a bright spot.

4. The detection method according to claim 1, characterized in that After detecting the bright spot of the display panel according to the dark state image, the method further includes: Determine the grayscale value of the bright spot in the dark state image, the connected domain where the adjacent bright spots are located, and the maximum grayscale value in the connected domain; Acquiring a reference image when the display panel displays a reference picture; Determine, from the reference image, a cumulative histogram of the pixel points corresponding to the bright spot within a fourth preset neighborhood; Determining the boundary grayscale of the pixel points corresponding to the bright spot according to the cumulative histogram; The maximum grayscale value is compared with the boundary grayscale to determine the brightness level of the bright spot.

5. The detection method according to claim 1, characterized in that The step of detecting a dark spot of the display panel according to the bright state image includes: Inverting the bright state image to obtain an inverted image; For each pixel in the inverted image, execute: Determine the grayscale value of the pixel point, and multiple grayscale values ​​corresponding to multiple pixels within a fifth preset neighborhood of the pixel point; removing the maximum value among the plurality of grayscale values, and taking the average value of the other grayscale values ​​as the third reference value; taking the sum of the third reference value and the third preset grayscale difference as a third grayscale threshold; The grayscale value of the pixel is compared with the third grayscale threshold. If the grayscale value of the pixel is greater than the third grayscale threshold, the pixel is regarded as a dark point.

6. The detection method according to claim 5, characterized in that After detecting the dark spot of the display panel according to the bright state image, the method further includes: The pixel points in the dark spots except the dust points are regarded as bad pixels; Determine the grayscale value of the bad pixel in the inverted image and the connected domain where the bad pixel is adjacent; If the contrast, area and center of gravity grayscale value of each pixel point in the connected domain meet the preset conditions, the connected domain is determined to be a scratch; The pixel points corresponding to the scratches in the bad pixels are removed.

7. The detection method according to claim 1, characterized in that If the display panel is a panel corresponding to a VR device, the method further includes: Acquire a bright screen image of the display panel when the screen is bright; Determining a plurality of detection areas of the display panel according to the bright screen image; Bright spot and dark spot detection are performed for each of the detection areas.

8. A detection system based on the display panel detection method according to any one of claims 1 to 7, characterized in that: include: An industrial computer, and an image acquisition unit electrically connected to the industrial computer; wherein: The image acquisition unit is used to acquire a dark state image when the display panel displays a dark state image, and to acquire a bright state image when the display panel displays a bright state image; The industrial computer is used to detect the bright spots of the display panel according to the dark state image, and to detect the dark spots of the display panel according to the bright state image.

Images