A method, system and device for detecting defects of a microdisplay

Abstract

The present application discloses a defect detection method, system and device for a micro display device, which is used to improve the defect detection accuracy of the micro display. The present application method includes: obtaining a first initial image and a second initial image of the micro display; obtaining first initial coordinate parameters corresponding to a plurality of lamp beads according to the first initial image, and obtaining second initial coordinate parameters corresponding to a plurality of lamp beads according to the second initial image; obtaining first valid coordinate parameters and abnormal coordinate parameters in the first initial coordinate parameters according to the standard coordinate parameters; obtaining second valid coordinate parameters corresponding to the abnormal coordinate parameters according to the first valid coordinate parameters; obtaining first physical coordinate parameters of any lamp bead according to the first valid coordinate parameters and the second valid coordinate parameters; obtaining second physical coordinate parameters of any lamp bead according to the second initial coordinate parameters and the standard coordinate parameters; and calculating the coordinate offset of any lamp bead according to the first physical coordinate parameters and the second physical coordinate parameters.

Description

Technical Field

[0001] The present application relates to the technical field of display devices, and in particular to a defect detection method, system and device for a microdisplay. Background Art

[0002] A microdisplay is a miniature flat display panel that uses micro-LED (Micro-Light Emitting Diode) display technology or submillimeter light-emitting diode (Mini-LED) display technology. Micro-LED chips and Mini-LED chips have the characteristics of small size and high density, but this also makes their surfaces susceptible to contamination, wear or other physical damage. Since any tiny defect may affect the performance and reliability of Micro-LED chips or Mini-LED chips, it is particularly important to improve the accuracy of defect detection in the production process of microdisplay devices.

[0003] Currently, in order to meet the tight rhythm requirements of defect detection, it is necessary to use high-speed cameras to capture images in a very short time and perform fast and accurate analysis to detect and record any defects or anomalies.

[0004] However, in the actual inspection process, due to the high-speed movement of the inspection platform or the camera, the collected image may cause a large offset, making it impossible to accurately locate the multiple lamp beads in the image, and thus impossible to perform accurate defect analysis based on the collected image, which will lead to a reduction in defect detection accuracy. Summary of the invention

[0005] The present application provides a method, system and device for defect detection of a microdisplay, which can improve the defect detection accuracy of the microdisplay.

[0006] The first aspect of the present application provides a defect detection method for a micro display, comprising:

[0007] Acquire a first initial image and a second initial image of the microdisplay, wherein the first initial image is an image captured by a camera in a flying shooting mode, and the second initial image is an image captured by a positioning component;

[0008] Acquire first initial coordinate parameters corresponding to a plurality of lamp beads according to the first initial image, and acquire second initial coordinate parameters corresponding to the plurality of lamp beads according to the second initial image;

[0009] Acquire the first valid coordinate parameter and the abnormal coordinate parameter in the first initial coordinate parameter according to the standard coordinate parameters corresponding to the plurality of lamp beads in the preset standard image;

[0010] Acquire a second valid coordinate parameter corresponding to the abnormal coordinate parameter according to the first valid coordinate parameter;

[0011] Acquire a first physical coordinate parameter of any of the lamp beads according to the first effective coordinate parameter and the second effective coordinate parameter;

[0012] Acquire a second physical coordinate parameter of any of the lamp beads according to the second initial coordinate parameter and the standard coordinate parameter;

[0013] The coordinate offset of any of the lamp beads is calculated according to the first physical coordinate parameter and the second physical coordinate parameter.

[0014] Optionally, the step of acquiring the first valid coordinate parameter and the abnormal coordinate parameter in the first initial coordinate parameter according to the standard coordinate parameters corresponding to the plurality of lamp beads in the preset standard image includes:

[0015] Acquiring the standard image of the microdisplay;

[0016] Acquire the standard coordinate parameters corresponding to the plurality of lamp beads according to the standard image;

[0017] Obtaining a correlation coefficient between the standard coordinate parameter and the first initial coordinate parameter;

[0018] Determining whether the correlation coefficient is within a preset range;

[0019] If the correlation coefficient is within the preset range, determining whether the first initial coordinate parameter of each lamp bead matches the corresponding standard coordinate parameter;

[0020] If the first initial coordinate parameter of the lamp bead matches the corresponding standard coordinate parameter, the first initial coordinate parameter of the lamp bead is determined to be a first valid coordinate parameter. If the first initial coordinate parameter of the lamp bead does not match the corresponding standard coordinate parameter, the first initial coordinate parameter of the lamp bead is determined to be an abnormal coordinate parameter.

[0021] Optionally, the step of acquiring, according to the first valid coordinate parameter, a second valid coordinate parameter corresponding to the abnormal coordinate parameter comprises:

[0022] Acquire the first valid coordinate parameters corresponding to the two lamp beads adjacent to the lamp bead corresponding to the abnormal coordinate parameters;

[0023] An interpolation method is used to calculate a second valid coordinate parameter corresponding to the abnormal coordinate parameter.

[0024] Optionally, the step of acquiring the first physical coordinate parameter of any of the lamp beads according to the first effective coordinate parameter and the second effective coordinate parameter includes:

[0025] Obtain the minimum circumscribed rectangle corresponding to any of the lamp beads according to the first valid coordinate parameter and the second valid coordinate parameter;

[0026] Acquire a peripheral rectangle located outside the minimum circumscribed rectangle according to a preset spacing;

[0027] Determine a transition area where the boundary of the lamp bead is located in the direction from the outer rectangle to the minimum circumscribed rectangle;

[0028] Performing threshold segmentation on the transition area and screening boundary pixel points that meet preset conditions;

[0029] Fitting a target rectangle corresponding to any of the lamp beads according to the acquired multiple boundary pixel points;

[0030] Obtain the coordinate value of the center pixel point within the target rectangle;

[0031] The first physical coordinate parameter of any of the lamp beads is obtained according to the coordinate value of the central pixel point and a preset calibration coefficient.

[0032] Optionally, the step of acquiring the second physical coordinate parameter of any of the lamp beads according to the second initial coordinate parameter and the standard coordinate parameter includes:

[0033] Calculate the difference between the standard coordinate parameter of any of the lamp beads and the corresponding second initial coordinate parameter;

[0034] The second physical coordinate parameter of any of the lamp beads is calculated according to the second initial coordinate parameter, the difference and the frame value corresponding to the acquired second initial image.

[0035] Optionally, the defect detection method further includes:

[0036] Divide each of the lamp beads on the first initial image into a sub-area according to the first effective coordinate parameter and the second effective coordinate parameter;

[0037] Acquire characteristic information of the lamp beads in any of the sub-areas;

[0038] Calculate the restored coordinate parameters of the lamp bead according to the characteristic information;

[0039] A restored image is obtained according to the restored coordinate parameters.

[0040] Optionally, after the step of acquiring the restored image according to the restored coordinate parameters, the defect detection method further includes:

[0041] Difference is performed between the restored image and the standard image to obtain a differential image;

[0042] Performing image preprocessing on the differential image;

[0043] Binarization is performed on the difference image after image preprocessing;

[0044] Mark the connected regions of the binary difference image;

[0045] Acquire feature information of each of the connected regions;

[0046] It is determined whether the lamp bead located in any of the connected areas has defects according to the characteristic information.

[0047] A second aspect of the present application provides a defect detection system for a micro display, comprising:

[0048] an acquisition unit, used to acquire a first initial image and a second initial image of the microdisplay, wherein the first initial image is an image acquired by the camera in a flying shooting mode, and the second initial image is an image acquired by the positioning component, and used to acquire first initial coordinate parameters corresponding to a plurality of lamp beads according to the first initial image, and to acquire second initial coordinate parameters corresponding to a plurality of the lamp beads according to the second initial image;

[0049] A calculation unit is used to obtain the first valid coordinate parameter and the abnormal coordinate parameter in the first initial coordinate parameter according to the standard coordinate parameters corresponding to the multiple lamp beads in the preset standard image, and to obtain the second valid coordinate parameter corresponding to the abnormal coordinate parameter according to the first valid coordinate parameter. The calculation unit is also used to obtain the first physical coordinate parameter of any lamp bead according to the first valid coordinate parameter and the second valid coordinate parameter, and to obtain the second physical coordinate parameter of any lamp bead according to the second initial coordinate parameter and the standard coordinate parameter, and to calculate the coordinate offset of any lamp bead according to the first physical coordinate parameter and the second physical coordinate parameter.

[0050] Optionally, the defect detection system further includes a matching module, and the matching module is used to divide each of the lamp beads on the first initial image into a sub-area according to the first effective coordinate parameter and the second effective coordinate parameter;

[0051] The matching module is also used to obtain characteristic information of the lamp beads in any of the sub-areas;

[0052] The matching module is also used to calculate the restored coordinate parameters of the lamp bead according to the characteristic information;

[0053] The matching module is also used to obtain a restored image according to the restored coordinate parameters.

[0054] Optionally, the defect detection system further includes a detection module, and the detection module is used to perform a difference between the restored image and the standard image to obtain a differential image;

[0055] The detection module is also used to perform image preprocessing on the differential image;

[0056] The detection module is also used to perform binarization processing on the difference image after image preprocessing;

[0057] The detection module is also used to mark the connected areas of the difference image after the binary processing;

[0058] The detection module is also used to obtain feature information of each of the connected areas;

[0059] The detection module is also used to determine whether the lamp bead located in any of the connected areas has defects based on the characteristic information.

[0060] A third aspect of the present application provides a microdisplay defect detection device, comprising the microdisplay defect detection system as described in the second aspect above and a workbench for placing the microdisplay to be tested.

[0061] It can be seen from the above technical solutions that this application has the following effects:

[0062] First, a first initial image and a second initial image of the microdisplay are acquired, wherein the first initial image is an image captured by the camera in the flying shooting mode, and the second initial image is an image captured by the positioning component; then, first initial coordinate parameters corresponding to a plurality of lamp beads are acquired according to the first initial image, wherein the first initial coordinate parameters include first valid coordinate parameters and abnormal coordinate parameters, and second initial coordinate parameters corresponding to a plurality of lamp beads are acquired according to the second initial image; then, first valid coordinate parameters and abnormal coordinate parameters in the first initial coordinate parameters are acquired according to standard coordinate parameters corresponding to a plurality of lamp beads in a preset standard image; second valid coordinate parameters corresponding to the abnormal coordinate parameters are acquired according to the first valid coordinate parameters; first physical coordinate parameters of any lamp bead are further acquired according to the first valid coordinate parameters and the second valid coordinate parameters; second physical coordinate parameters of any lamp bead are further acquired according to the second initial coordinate parameters and the standard coordinate parameters; finally, the coordinate offset of any lamp bead is calculated according to the first physical coordinate parameters and the second physical coordinate parameters. Through the above steps, the first initial image collected by the microdisplay in the flying mode can be preliminarily positioned, and the first initial coordinate parameters corresponding to the multiple lamp beads can be obtained according to the preliminary positioning results. Then, the first valid coordinate parameters in the first initial coordinate parameters and the second valid coordinate parameters corresponding to the abnormal coordinate parameters can be determined by using the preset standard image. Then, the first initial image can be further positioned according to the first valid coordinate parameters and the second valid coordinate parameters in the first initial coordinate parameters to obtain the first physical coordinate parameters for accurate positioning of the multiple lamp beads. Then, the reference points of the multiple lamp beads can be positioned according to the second initial coordinate parameters corresponding to the second initial image collected by the positioning component and the standard coordinate parameters corresponding to the standard image to obtain the second physical coordinate parameters corresponding to the multiple lamp beads. Finally, the coordinate offsets corresponding to the multiple lamp beads can be determined according to the first physical coordinate parameters and the second physical coordinate parameters. Thus, the situation of inaccurate positioning of the lamp beads due to image offset can be reduced through multiple positioning, thereby improving the defect detection accuracy of the microdisplay. BRIEF DESCRIPTION OF THE DRAWINGS

[0063] Figure 1 A schematic diagram of an embodiment of a defect detection method for a micro display in the present application;

[0064] Figure 2-1 , Figure 2-2 , Figure 2-3 and Figure 2-4 A schematic diagram of another embodiment of a defect detection method for a micro display in the present application;

[0065] Figure 3 A schematic diagram of an embodiment of a defect detection system for a micro display in the present application;

[0066] Figure 4A schematic diagram of another embodiment of a defect detection system for a micro display in the present application;

[0067] Figure 5 A schematic diagram of an embodiment of a defect detection device for a micro display in the present application. DETAILED DESCRIPTION

[0068] The present application provides a method, system and device for defect detection of a microdisplay, which are used to improve the defect detection accuracy of the microdisplay.

[0069] The microdisplay defect detection method described in this application is applied to a server, system, terminal or other device with logic processing capability for execution and implementation, and this application does not limit this. The embodiment of this application is described by taking a system with image analysis and processing capability as an example, please refer to Figure 1 As shown, an embodiment of the defect detection method of the micro display in the present application includes:

[0070] 101. The system acquires a first initial image and a second initial image of a micro display, wherein the first initial image is an image captured by a camera in a flying shooting mode, and the second initial image is an image captured by a positioning component.

[0071] In this embodiment, the aperture focal length of the camera lens is first fixed under the condition of satisfying the high-speed flying mode, and then the positional relationship between the detection platform and the camera is adjusted, the point light source is fixed on one side of the camera lens, and the camera parameters are saved to complete the preliminary preparations. When the high-speed flying mode is started, the camera's photo-taking action is triggered, and the image acquisition of the microdisplay is completed to generate the first initial image of the microdisplay, and the first initial image is transmitted to the system. Before using the flying mode to obtain the first initial image, it is necessary to first use the positioning component to acquire the image of the microdisplay in a static state to obtain the second initial image.

[0072] It should be noted that when the camera completes shooting in the flying shooting mode, the first initial image is usually interfered and affected by various noises during the acquisition, transmission and storage process, which degrades the quality. Therefore, in order to improve the image quality of the first initial image, a mean filter algorithm or a Gaussian filter algorithm can be used to perform noise reduction processing on it first. When using the mean filter algorithm, a 3×3 mean filter window can be used to filter the first initial image. When using the Gaussian filter algorithm, a Gaussian function can be used as a filter to perform weighted averaging on the signal to smooth the signal and reduce noise, and the first initial image can be filtered.

[0073] 102. The system obtains first initial coordinate parameters corresponding to the plurality of lamp beads according to the first initial image, and obtains second initial coordinate parameters corresponding to the plurality of lamp beads according to the second initial image.

[0074] In this embodiment, the system extracts the features of all the lamp beads on the first initial image, and determines the first initial coordinate parameters corresponding to each lamp bead on the first initial image based on the extracted lamp bead feature information. Similarly, the system extracts the features of all the lamp beads on the second initial image, and determines the second initial coordinate parameters corresponding to each lamp bead on the second initial image based on the extracted lamp bead feature information.

[0075] In this embodiment, the first initial coordinate parameter includes the coordinate value of the geometric center of the lamp bead and the distance from the geometric center of the lamp bead to the border of the lamp bead. For example, in the row direction, the distance from the geometric center of the lamp bead to the border of the lamp bead is L1, and in the column direction, the distance from the geometric center of the lamp bead to the border of the lamp bead is L2. Among them, L1 and L2 can be equal or unequal.

[0076] 103. The system obtains the first valid coordinate parameter and the abnormal coordinate parameter in the first initial coordinate parameter according to the standard coordinate parameters corresponding to the multiple lamp beads in the preset standard image.

[0077] In this embodiment, since the first initial image acquired by the system in the flying mode may be offset, deformed, blurred, etc., the first initial coordinate parameters acquired by the system based on the first initial image are rough coordinate parameters, and the first initial coordinate parameters include first valid coordinate parameters with higher positioning accuracy and abnormal coordinate parameters with lower positioning accuracy. At this time, the system can select an image with intact lamp beads, obvious features and clear background from several finished micro-display images as a standard image, and compare the standard image with the first initial image to determine the first valid coordinate parameters and abnormal coordinate parameters in the first initial coordinate parameters.

[0078] 104. The system obtains a second valid coordinate parameter corresponding to the abnormal coordinate parameter according to the first valid coordinate parameter.

[0079] In this embodiment, after the system determines the first valid coordinate parameter and the abnormal coordinate parameter in the first initial coordinate parameter, it needs to determine the second valid coordinate parameter corresponding to the abnormal coordinate parameter. Specifically, the interpolation method can be used to fit the second valid coordinate parameter corresponding to the abnormal coordinate parameter based on the known first valid coordinate parameter.

[0080] 105. The system obtains the first physical coordinate parameter of any lamp bead according to the first valid coordinate parameter and the second valid coordinate parameter.

[0081] In this embodiment, the system obtains the first effective coordinate parameter and the second effective coordinate parameter as the effective coordinates of each lamp bead on the first initial image in the image coordinate system. The system needs to use the preset calibration coefficient to convert the effective coordinates into the first physical coordinate parameter. The first physical coordinate parameter is the real physical coordinate of each lamp bead on the first initial image relative to the flying point. It can be understood that when converting the first effective coordinate parameter and the second effective coordinate parameter to the first physical coordinate parameter, each lamp bead can be further positioned, that is, the more accurate coordinates of each lamp bead are determined by finding the edge area using the minimum circumscribed rectangle, and then the preset calibration coefficient is used to convert the coordinates into the first material coordinate parameter. The specific implementation process will be described in the subsequent embodiments.

[0082] 106. The system obtains the second physical coordinate parameter of any lamp bead according to the second initial coordinate parameter and the standard coordinate parameter.

[0083] In this embodiment, the system first subtracts the first initial coordinate parameter from the standard coordinate parameter, and then obtains the second physical coordinate parameter of each lamp bead based on the obtained difference. The second physical coordinate parameter is the real physical coordinate of the calibration point corresponding to each lamp bead relative to the flying point.

[0084] 107. The system calculates the coordinate offset of any lamp bead according to the first physical coordinate parameter and the second physical coordinate parameter.

[0085] The system can obtain the coordinate offset corresponding to each lamp bead by subtracting the calculated first physical coordinate parameter from the second physical coordinate parameter. The coordinate offset is the real physical offset of the lamp bead.

[0086] In this embodiment, the first initial image and the second initial image of the microdisplay are first acquired, the first initial image is an image captured by the camera in the flying shooting mode, and the second initial image is an image captured by the positioning component. Then, the first initial coordinate parameters corresponding to the plurality of lamp beads are acquired according to the first initial image, the first initial coordinate parameters include the first valid coordinate parameters and the abnormal coordinate parameters, and the second initial coordinate parameters corresponding to the plurality of lamp beads are acquired according to the second initial image. Then, the first valid coordinate parameters and the abnormal coordinate parameters in the first initial coordinate parameters are acquired according to the standard coordinate parameters corresponding to the plurality of lamp beads in the preset standard image. The second valid coordinate parameters corresponding to the abnormal coordinate parameters are acquired according to the first valid coordinate parameters. Further, the first physical coordinate parameters of any lamp bead are acquired according to the first valid coordinate parameters and the second valid coordinate parameters. Further, the second physical coordinate parameters of any lamp bead are acquired according to the second initial coordinate parameters and the standard coordinate parameters. Finally, the coordinate offset of any lamp bead is calculated according to the first physical coordinate parameters and the second physical coordinate parameters. In this way, the first initial image collected by the microdisplay in the flying mode can be preliminarily positioned, and the first initial coordinate parameters corresponding to the multiple lamp beads can be obtained according to the preliminary positioning results. Then, the first valid coordinate parameters in the first initial coordinate parameters and the second valid coordinate parameters corresponding to the abnormal coordinate parameters can be determined by using the preset standard image. Then, the first initial image can be further positioned according to the first valid coordinate parameters and the second valid coordinate parameters in the first initial coordinate parameters to obtain the first physical coordinate parameters for accurate positioning of the multiple lamp beads. Then, the reference points of the multiple lamp beads can be positioned according to the second initial coordinate parameters corresponding to the second initial image collected by the positioning component and the standard coordinate parameters corresponding to the standard image to obtain the second physical coordinate parameters corresponding to the multiple lamp beads. Finally, the coordinate offsets corresponding to the multiple lamp beads can be determined according to the first physical coordinate parameters and the second physical coordinate parameters. In this way, the situation of inaccurate positioning of the lamp beads due to image offset can be reduced through multiple positioning, thereby improving the defect detection accuracy of the microdisplay.

[0087] See also Figure 2-1 , Figure 2-2 , Figure 2-3 and Figure 2-4 As shown, another embodiment of the defect detection method of the micro display in the present application includes:

[0088] 201. The system takes a first initial image and a second initial image of the microdisplay, wherein the first initial image is an image captured by the camera in a flying shooting mode, and the second initial image is an image captured by the positioning component.

[0089] 202. The system obtains first initial coordinate parameters corresponding to the plurality of lamp beads according to the first initial image, and obtains second initial coordinate parameters corresponding to the plurality of lamp beads according to the second initial image.

[0090] Steps 201 to 202 in this embodiment are similar to those in the previous Figure 1 Steps 101 to 102 in the illustrated embodiment are similar and will not be described in detail herein.

[0091] 203. The system obtains a standard image of the microdisplay.

[0092] 204. The system obtains standard coordinate parameters corresponding to a plurality of lamp beads according to the standard image.

[0093] 205. The system obtains a correlation coefficient between the standard coordinate parameter and the first initial coordinate parameter.

[0094] 206 . The system determines whether the correlation coefficient is within a preset range. If so, execute step 207 .

[0095] 207. The system determines whether the first initial coordinate parameter of each lamp bead matches the corresponding standard coordinate parameter. If so, execute step 208; if not, execute step 209.

[0096] 208. The system determines the first initial coordinate parameter of the lamp bead as the first valid coordinate parameter.

[0097] 209. The system determines that the first initial coordinate parameter of the lamp bead is an abnormal coordinate parameter.

[0098] Optionally, in this embodiment, after acquiring the standard image, the system extracts the image features of each lamp bead on the standard image, and determines the standard coordinate coefficient corresponding to each lamp bead based on the extracted image feature information. The standard image is slid along the possible position area of ​​each lamp bead on the first initial image one by one, and the correlation coefficient between the standard coordinate parameter and the first initial coordinate parameter of the current lamp bead is calculated during each sliding process. When calculating the correlation coefficient, it is necessary to zero-mean the standard coordinate parameter and the first initial coordinate parameter, and then calculate the normalized cross-correlation between them. Specifically, the following formula can be used for calculation:

[0099]

[0100] Wherein, (x', y') represents the standard coordinate parameter of any lamp bead on the standard image, (x, y) represents the first initial coordinate parameter of any lamp bead on the first initial image, T(x+x', y+y') represents the current pixel value of the standard image, and I(x', y') represents the current pixel value of the first initial image. represents the average pixel value of the standard image, Represents the average pixel value of the first initial image, and NCC(x,y) represents the correlation coefficient between the standard coordinate parameter and the first initial coordinate parameter. The numerator of the formula is the covariance of the two signals, and the denominator is the product of their respective standard deviations, which is used to standardize the cross-correlation value result to the range of [-1,1]. If NCC(x,y) is close to 1, it means that the current lamp bead possible position area in the first initial image is highly similar to the standard image. If NCC(x,y) is close to -1, it means that the current lamp bead possible position area in the first initial image is highly opposite to the standard image. If NCC(x,y) is close to 0, it means that the current lamp bead possible position area in the first initial image has no obvious correlation with the standard image. Therefore, the correlation coefficient can be calculated one by one between the standard image and all the lamp bead possible position areas near a certain lamp bead A, and it can be determined whether the correlation coefficient is within the preset range. If the correlation coefficient is within the preset range, it is continued to determine whether the first initial coordinate parameter of the lamp bead A matches the corresponding standard coordinate parameter. If the first initial coordinate parameter of the lamp bead A matches the corresponding standard coordinate parameter, it means that the first initial coordinate parameter of the lamp bead A is a first valid coordinate parameter. If the first initial coordinate parameter of the lamp bead A does not match the corresponding standard coordinate parameter, it means that the first initial coordinate parameter of the lamp bead A is an abnormal coordinate parameter.

[0101] 210. The system obtains first valid coordinate parameters corresponding to two lamp beads adjacent to the lamp bead corresponding to the abnormal coordinate parameters.

[0102] 211. The system uses interpolation method to calculate the second valid coordinate parameters corresponding to the abnormal coordinate parameters.

[0103] Optionally, in this embodiment, the system may first arrange all first initial coordinate parameters according to the distribution of lamp beads, and then select all first initial coordinate parameters in the same row as the abnormal coordinate parameter or all first initial coordinate parameters in the same column as the abnormal coordinate parameter. Then, two first valid coordinate parameters adjacent to the abnormal coordinate parameter are selected from all the selected first initial coordinate parameters, and finally, the interpolation method is used to perform coordinate fitting on the two first valid coordinate parameters to fit the second valid coordinate parameter corresponding to the abnormal coordinate parameter.

[0104] 212. The system obtains the minimum circumscribed rectangle corresponding to any lamp bead according to the first valid coordinate parameter and the second valid coordinate parameter.

[0105] 213. The system obtains an outer rectangle located outside the minimum circumscribed rectangle according to a preset spacing.

[0106] 214. The system determines the transition area where the boundary of the lamp bead is located from the outer rectangle to the minimum circumscribed rectangle.

[0107] 215. The system performs threshold segmentation on the transition area and selects boundary pixels that meet the preset conditions.

[0108] 216. The system fits a target rectangle corresponding to any lamp bead according to the obtained multiple boundary pixel points.

[0109] 217. The system obtains the coordinate value of the center pixel point within the target rectangle.

[0110] 218. The system obtains the first physical coordinate parameter of any lamp bead according to the coordinate value of the central pixel point and the preset calibration coefficient.

[0111] Optionally, in this embodiment, the minimum enclosing rectangle of a lamp bead refers to the minimum area rectangle that can contain the target lamp bead. After the system obtains the first effective coordinate parameters and the second effective coordinate parameters of all the lamp beads, it can solve the minimum enclosing rectangle of the corresponding lamp bead according to the first effective coordinate parameters or the second effective coordinate parameters corresponding to each lamp bead. This can be achieved by using the rotating caliper method, that is, first find the convex shell of the target lamp bead area, and then solve the minimum enclosing rectangle of the convex shell. The specific minimum enclosing rectangle solution algorithm is not limited here. The sides of the minimum enclosing rectangle are vertical or parallel directions. The vertical direction is a direction perpendicular to a coordinate axis in the image coordinate system of the first initial image, and the parallel direction is a direction parallel to the coordinate axis.

[0112] Expand the minimum circumscribed rectangle by a preset spacing to obtain the outer rectangle outside it, for example: expand by 30 pixels. The specific expansion parameters are determined according to actual needs and are not limited here. Then, take the rectangular side of the outer rectangle as the base point, and perform edge detection in the direction of the minimum circumscribed rectangle to determine the transition area where the boundary of the lamp bead is located. Then perform threshold segmentation on the transition area to filter out the boundary pixels that meet the preset conditions, and fit the target rectangle corresponding to the lamp bead based on this part of the boundary pixels. The target rectangle is the minimum circumscribed rectangle corresponding to the true outline of the lamp bead. Finally, obtain the coordinate value of the center pixel point in the target rectangle. The coordinate value of the center pixel point is the true coordinate value of the image coordinate system of any lamp bead on the first initial image. Suppose the coordinate value of the center pixel point of any lamp bead is The calibration coefficient is β, then the first physical coordinate parameter of the corresponding lamp bead is in

[0113] 219. The system calculates the difference between the standard coordinate parameter of any lamp bead and the corresponding second initial coordinate parameter.

[0114] 220. The system calculates the second physical coordinate parameter of any lamp bead according to the second initial coordinate parameter, the difference value and the frame value corresponding to the acquired second initial image.

[0115] Optionally, in this embodiment, the second initial coordinate parameter of any lamp bead is The difference between the standard coordinate parameter of the corresponding lamp bead and the second initial coordinate parameter is The second physical coordinate parameter corresponding to the lamp bead is The calculation formula of the second physical coordinate parameter is as follows:

[0116]

[0117]

[0118] Where n is the frame value corresponding to the current second initial image, and are the differences between the standard coordinate parameters and the second initial coordinate parameters in the x direction and y direction respectively.

[0119] 221. The system calculates the coordinate offset of any lamp bead according to the first physical coordinate parameter and the second physical coordinate parameter.

[0120] In this embodiment, after the first physical coordinate parameter and the second physical coordinate parameter are obtained, the first physical coordinate parameter can be subtracted from the second physical coordinate parameter, and the corresponding difference can be determined as the coordinate offset of the lamp bead. x ,offset y ), the corresponding calculation formula is:

[0121]

[0122]

[0123] in, is the x-axis coordinate value of the first physical coordinate parameter, is the y-axis coordinate value of the first physical coordinate parameter, is the x-axis coordinate value of the second physical coordinate parameter, is the y-axis coordinate value of the second physical coordinate parameter.

[0124] 222. The system divides each lamp bead on the first initial image into a sub-area according to the first effective coordinate parameter and the second effective coordinate parameter.

[0125] 223. The system obtains characteristic information of the lamp beads in any sub-area.

[0126] 224. The system calculates the restored coordinate parameters of the lamp beads based on the characteristic information.

[0127] 225. The system obtains a restored image according to the restored coordinate parameters.

[0128] Optionally, in this embodiment, in the high-speed flying mode, due to the high-speed movement of the detection platform or industrial camera, the target image may be blurred, slightly deformed, and distorted, so that the real defects on the surface of the lamp beads cannot be extracted. Therefore, the Lucas-Kanade algorithm can be used to correct the slight deformation of the lamp beads, and then detect the real surface defects. The Lucas-Kanade algorithm is a method that uses the changes in pixels in the time domain in an image sequence and the correlation between adjacent frames to find the corresponding relationship between the previous frame and the current frame, thereby calculating the motion information of objects between adjacent frames. Its basic idea is based on the following three assumptions:

[0129] 1. Constant brightness: The brightness of the same point will not change over time.

[0130] 2. Motion: The change of time will not cause drastic changes in position. Only in the case of small motion can the grayscale change caused by the unit position change between the previous and next frames be used to approximate the partial derivative of grayscale with respect to position.

[0131] 3. Spatial consistency: adjacent points on a scene are also adjacent points when projected onto the image, and the speed of adjacent points is consistent. Because the basic equation constraint of the optical flow method is only one, and the speed in the x and y directions has two unknown variables, it is necessary to solve multiple equations simultaneously.

[0132] The basic constraint equation is:

[0133] Suppose a pixel I(x,y,t) has a light intensity in the first frame (where t represents the time dimension). It moves a distance (dx,dy) to the next frame, which takes dt time. Because it is the same pixel, it is assumed that the light intensity of the pixel before and after the movement is unchanged, that is:

[0134] I(x,y,t)=I(x+dx,y+dy,t+dt)

[0135] After expanding the right side of the above formula using Taylor's formula, we can get:

[0136]

[0137] Assume u and v are the velocity vectors of the x-axis and y-axis respectively, that is:

[0138]

[0139]

[0140] set up Then we have:

[0141] I xdx+I y dy+I t dt = 0

[0142] I x u+I y v=-I t

[0143]

[0144] It is expressed in matrix form as:

[0145]

[0146] Finally, the least squares method can be used to obtain:

[0147]

[0148]

[0149] in, is the final solved optical flow.

[0150] The system first cuts each lamp bead on the first initial image according to the first effective coordinate parameters or the second effective coordinate parameters corresponding to the multiple lamp beads to divide each lamp bead into a sub-area. Then, the system extracts features of the lamp beads in each sub-area to obtain their corresponding feature information. Then, the feature information is input into the basic constraint equation of the above-mentioned Lucas-Kanade algorithm, and the restored coordinate parameters of the corresponding lamp beads are determined according to the solved optical flow. Finally, the restored coordinate parameters of all lamp beads are mapped to the first initial image to obtain the restored image of the micro display.

[0151] 226. The system performs a differential operation on the restored image and the standard image to obtain a differential image.

[0152] 227. The system performs image preprocessing on the differential image.

[0153] 228. The system performs binarization on the differential image after image preprocessing.

[0154] 229. The system marks the connected areas of the binary differential image.

[0155] 230. The system obtains feature information of each connected region.

[0156] 231. The system determines whether there are defects in the lamp beads located in any connected area based on the characteristic information.

[0157] Optionally, in this embodiment, the restored image is firstly differentiated from the standard image to obtain a differential image of the two. Then, the obtained differential image is subjected to image preprocessing, and the image preprocessing process may include grayscale processing and denoising processing. Among them, grayscale processing is: converting a color image into a grayscale image to simplify the subsequent processing process. Denoising processing is: using a filter (such as a Gaussian filter) to remove noise in the image. After the image preprocessing is completed, binarization processing is performed to convert the differential image into a black and white image so that the defect and the background can be clearly distinguished. The binarization processing can be completed by using methods such as threshold segmentation or adaptive threshold segmentation, which are not specifically limited here. Then, the differential image after the binarization processing is connected to mark the connected areas, and each connected area in the image is identified. The connected component marking algorithm can be used to complete the connected area marking. Then extract the feature information of each marked connected area, such as area, perimeter, shape and other feature information, and this part of the feature information can be used to distinguish the normal part and the defect part in the image. Finally, based on the extracted feature information, appropriate rules or models are designed to determine whether there are defects in the lamp beads in each connected area. For example, it can be determined based on features such as area size and perimeter, and then the judgment results are analyzed and recorded to generate the surface defect detection results of the lamp beads of the micro display. It is worth mentioning that after completing the surface defect detection of the lamp beads, the performance of the defect detection process can be evaluated, including indicators such as accuracy, recall rate, and false detection rate, to verify its effectiveness and reliability.

[0158] See also Figure 3 As shown, an embodiment of a defect detection system for a micro display in the present application includes:

[0159] The acquisition unit 301 is used to acquire a first initial image and a second initial image of the microdisplay, wherein the first initial image is an image captured by the camera in a flying shooting mode, and the second initial image is an image captured by the positioning component, and is used to acquire first initial coordinate parameters corresponding to a plurality of lamp beads according to the first initial image, and to acquire second initial coordinate parameters corresponding to a plurality of lamp beads according to the second initial image.

[0160] The calculation unit 302 is used to obtain the first valid coordinate parameter and the abnormal coordinate parameter in the first initial coordinate parameter according to the standard coordinate parameter corresponding to multiple lamp beads in the preset standard image, and to obtain the second valid coordinate parameter corresponding to the abnormal coordinate parameter according to the first valid coordinate parameter. The calculation unit is also used to obtain the first physical coordinate parameter of any lamp bead according to the first valid coordinate parameter and the second valid coordinate parameter, and to obtain the second physical coordinate parameter of any lamp bead according to the second initial coordinate parameter and the standard coordinate parameter, and to calculate the coordinate offset of any lamp bead according to the first physical coordinate parameter and the second physical coordinate parameter.

[0161] In this embodiment, the acquisition unit 301 acquires a first initial image and a second initial image of the microdisplay, the first initial image is an image captured by the camera in the flying mode, and the second initial image is an image captured by the positioning component, and is used to acquire first initial coordinate parameters corresponding to multiple lamp beads according to the first initial image, and to acquire second initial coordinate parameters corresponding to multiple lamp beads according to the second initial image; the calculation unit 302 acquires first valid coordinate parameters and abnormal coordinate parameters in the first initial coordinate parameters according to standard coordinate parameters corresponding to multiple lamp beads in a preset standard image, and acquires second valid coordinate parameters corresponding to the abnormal coordinate parameters according to the first valid coordinate parameters, and the calculation unit is also used to acquire first physical coordinate parameters of any lamp bead according to the first valid coordinate parameters and the second valid coordinate parameters, and to acquire second physical coordinate parameters of any lamp bead according to the second initial coordinate parameters and the standard coordinate parameters, and to calculate the coordinate offset of any lamp bead according to the first physical coordinate parameters and the second physical coordinate parameters. In this way, the first initial image collected by the microdisplay in the flying mode can be preliminarily positioned, and the first initial coordinate parameters corresponding to the multiple lamp beads can be obtained according to the preliminary positioning results. Then, the first valid coordinate parameters in the first initial coordinate parameters and the second valid coordinate parameters corresponding to the abnormal coordinate parameters can be determined by using the preset standard image. Then, the first initial image can be further positioned according to the first valid coordinate parameters and the second valid coordinate parameters in the first initial coordinate parameters to obtain the first physical coordinate parameters for accurate positioning of the multiple lamp beads. Then, the reference points of the multiple lamp beads can be positioned according to the second initial coordinate parameters corresponding to the second initial image collected by the positioning component and the standard coordinate parameters corresponding to the standard image to obtain the second physical coordinate parameters corresponding to the multiple lamp beads. Finally, the coordinate offsets corresponding to the multiple lamp beads can be determined according to the first physical coordinate parameters and the second physical coordinate parameters. In this way, the situation of inaccurate positioning of the lamp beads due to image offset can be reduced through multiple positioning, thereby improving the defect detection accuracy of the microdisplay.

[0162] See also Figure 4 As shown, another embodiment of the defect detection system of the micro display in the present application includes:

[0163] The acquisition unit 401 is used to acquire a first initial image and a second initial image of the microdisplay, wherein the first initial image is an image captured by the camera in a flying shooting mode, and the second initial image is an image captured by the positioning component, and is used to acquire first initial coordinate parameters corresponding to a plurality of lamp beads according to the first initial image, and to acquire second initial coordinate parameters corresponding to a plurality of lamp beads according to the second initial image.

[0164] The calculation unit 402 is specifically used to obtain a standard image of the micro display. According to the standard image, standard coordinate parameters corresponding to a plurality of lamp beads are obtained. The correlation coefficient between the standard coordinate parameter and the first initial coordinate parameter is obtained. It is determined whether the correlation coefficient is within a preset range. If the correlation coefficient is within the preset range, it is determined whether the first initial coordinate parameter of each lamp bead matches the corresponding standard coordinate parameter. If the first initial coordinate parameter of the lamp bead matches the corresponding standard coordinate parameter, the first initial coordinate parameter of the lamp bead is determined to be a first valid coordinate parameter. If the first initial coordinate parameter of the lamp bead does not match the corresponding standard coordinate parameter, the first initial coordinate parameter of the lamp bead is determined to be an abnormal coordinate parameter. And according to the first valid coordinate parameter, the second valid coordinate parameter corresponding to the abnormal coordinate parameter is obtained. The first valid coordinate parameter corresponding to the two adjacent lamp beads corresponding to the lamp bead corresponding to the abnormal coordinate parameter is obtained. The second valid coordinate parameter corresponding to the abnormal coordinate parameter is calculated by interpolation. The calculation unit is also specifically used to obtain the minimum circumscribed rectangle corresponding to any lamp bead according to the first valid coordinate parameter and the second valid coordinate parameter. The outer rectangle located outside the minimum circumscribed rectangle is obtained according to the preset spacing. The transition area where the boundary of the lamp bead is located is determined from the outer rectangle to the direction of the minimum circumscribed rectangle. Perform threshold segmentation on the transition area and filter the boundary pixels that meet the preset conditions. Fit the target rectangle corresponding to any lamp bead based on the multiple boundary pixels obtained. Obtain the coordinate value of the center pixel point located in the target rectangle. Obtain the first physical coordinate parameter of any lamp bead based on the coordinate value of the center pixel point and the preset calibration coefficient. And specifically used to calculate the difference between the standard coordinate parameter of any lamp bead and the corresponding second initial coordinate parameter. Calculate the second physical coordinate parameter of any lamp bead based on the second initial coordinate parameter, the difference and the frame value corresponding to the obtained second initial image. And used to calculate the coordinate offset of any lamp bead based on the first physical coordinate parameter and the second physical coordinate parameter.

[0165] The matching module 403 is used to divide each lamp bead on the first initial image into a sub-region according to the first effective coordinate parameter and the second effective coordinate parameter. The matching module is also used to obtain the characteristic information of the lamp bead in any sub-region. The matching module is also used to calculate the restored coordinate parameters of the lamp bead according to the characteristic information. The matching module is also used to obtain the restored image according to the restored coordinate parameters.

[0166] The detection module 404 is used to perform a difference between the restored image and the standard image to obtain a difference image. The detection module is also used to perform image preprocessing on the difference image. The detection module is also used to perform a binarization process on the difference image after image preprocessing. The detection module is also used to mark the connected areas of the difference image after the binarization process. The detection module is also used to obtain feature information of each connected area. The detection module is also used to determine whether the lamp beads located in any connected area are defective based on the feature information.

[0167] In this embodiment, the functions of each unit and module are the same as those described above. Figure 2-1 , Figure 2-2 , Figure 2-3 and Figure 2-4 The functions of steps 201 to 231 in the illustrated embodiment are similar and will not be described in detail here.

[0168] See also Figure 5 As shown, an embodiment of the defect detection device of the micro display in the present application includes: Figure 3 or Figure 4 The defect detection system for a microdisplay and the workbench for placing the microdisplay to be tested in the illustrated embodiment specifically include: a central processing unit 502 , a memory 501 , an input / output interface 503 , a wired or wireless network interface 504 and a power supply 505 .

[0169] The memory 501 is a temporary storage memory or a permanent storage memory.

[0170] The CPU 502 is configured to communicate with the memory 501 and execute the instructions in the memory 501 to perform the aforementioned Figure 1 to Figure 2-1 , Figure 2-2 , Figure 2-3 and Figure 2-4 Steps in the illustrated embodiment.

[0171] The defect detection device of the micro display also provides a computer-readable storage medium, including instructions, which, when executed on a computer, enable the computer to execute the aforementioned Figure 1 to Figure 2-1 , Figure 2-2 , Figure 2-3 and Figure 2-4 Steps in the illustrated embodiment.

[0172] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working processes of the systems, devices and units described above can refer to the corresponding processes in the aforementioned method embodiments and will not be repeated here.

[0173] In the several embodiments provided in the present application, it should be understood that the disclosed systems, devices and methods can be implemented in other ways. For example, the device embodiments described above are only schematic. For example, the division of units is only a logical function division. There may be other division methods in actual implementation. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be an indirect coupling or communication connection through some interfaces, devices or units, which can be electrical, mechanical or other forms.

[0174] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0175] In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above-mentioned integrated unit may be implemented in the form of hardware or in the form of software functional units.

[0176] If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application, or the part that contributes to the prior art, or all or part of the technical solution can be embodied in the form of a software product, which is stored in a storage medium and includes several instructions for a computer device (which can be a personal computer, server, or network device, etc.) to perform all or part of the steps of the various embodiments of the present application. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, read-only memory), random access memory (RAM, random access memory), disk or optical disk, etc. Various media that can store program codes.

Claims

1. A defect detection method for a micro display, characterized in that: include: Acquire a first initial image and a second initial image of the microdisplay, wherein the first initial image is an image captured by a camera in a flying mode, and the second initial image is an image captured by a positioning component, wherein the positioning component is used to capture an image of the microdisplay in a static state; Acquire first initial coordinate parameters corresponding to a plurality of lamp beads according to the first initial image, and acquire second initial coordinate parameters corresponding to the plurality of lamp beads according to the second initial image; Acquire the first valid coordinate parameter and the abnormal coordinate parameter in the first initial coordinate parameter according to the standard coordinate parameters corresponding to the plurality of lamp beads in the preset standard image; Acquire a second valid coordinate parameter corresponding to the abnormal coordinate parameter according to the first valid coordinate parameter; Acquire a first physical coordinate parameter of any of the lamp beads according to the first effective coordinate parameter and the second effective coordinate parameter; Acquire a second physical coordinate parameter of any of the lamp beads according to the second initial coordinate parameter and the standard coordinate parameter; Calculate the coordinate offset of any of the lamp beads according to the first physical coordinate parameter and the second physical coordinate parameter; The defect detection method further comprises: Divide each of the lamp beads on the first initial image into a sub-region according to the first effective coordinate parameter and the second effective coordinate parameter; obtain feature information of the lamp beads in any of the sub-regions; calculate the restored coordinate parameters of the lamp beads according to the feature information; Acquire a restored image according to the restored coordinate parameters; The restored image is differentiated from the standard image to obtain a differential image; the differential image is preprocessed; the differential image after image preprocessing is binarized; the connected area of ​​the differential image after binarization is marked; characteristic information of each connected area is obtained; and whether the lamp bead located in any of the connected areas is defective is determined based on the characteristic information.

2. The defect detection method according to claim 1, characterized in that: The step of acquiring the first valid coordinate parameter and the abnormal coordinate parameter in the first initial coordinate parameter according to the standard coordinate parameters corresponding to the plurality of lamp beads in the preset standard image comprises: Acquiring the standard image of the microdisplay; Acquire the standard coordinate parameters corresponding to the plurality of lamp beads according to the standard image; Obtaining a correlation coefficient between the standard coordinate parameter and the first initial coordinate parameter; Determining whether the correlation coefficient is within a preset range; If the correlation coefficient is within the preset range, determining whether the first initial coordinate parameter of each lamp bead matches the corresponding standard coordinate parameter; If the first initial coordinate parameter of the lamp bead matches the corresponding standard coordinate parameter, the first initial coordinate parameter of the lamp bead is determined to be a first valid coordinate parameter. If the first initial coordinate parameter of the lamp bead does not match the corresponding standard coordinate parameter, the first initial coordinate parameter of the lamp bead is determined to be an abnormal coordinate parameter.

3. The defect detection method according to claim 1, characterized in that: The step of acquiring the second valid coordinate parameter corresponding to the abnormal coordinate parameter according to the first valid coordinate parameter comprises: Acquire the first valid coordinate parameters corresponding to the two lamp beads adjacent to the lamp bead corresponding to the abnormal coordinate parameters; An interpolation method is used to calculate a second valid coordinate parameter corresponding to the abnormal coordinate parameter.

4. The defect detection method according to claim 1, characterized in that: The step of acquiring the first physical coordinate parameter of any of the lamp beads according to the first effective coordinate parameter and the second effective coordinate parameter comprises: Obtain the minimum circumscribed rectangle corresponding to any of the lamp beads according to the first valid coordinate parameter and the second valid coordinate parameter; Acquire a peripheral rectangle located outside the minimum circumscribed rectangle according to a preset spacing; Determine a transition area where the boundary of the lamp bead is located in the direction from the outer rectangle to the minimum circumscribed rectangle; Performing threshold segmentation on the transition area and screening boundary pixel points that meet preset conditions; Fitting a target rectangle corresponding to any of the lamp beads according to the acquired multiple boundary pixel points; Obtain the coordinate value of the center pixel point within the target rectangle; The first physical coordinate parameter of any of the lamp beads is obtained according to the coordinate value of the central pixel point and a preset calibration coefficient.

5. The defect detection method according to claim 1, characterized in that: The step of acquiring the second physical coordinate parameter of any of the lamp beads according to the second initial coordinate parameter and the standard coordinate parameter comprises: Calculate the difference between the standard coordinate parameter of any of the lamp beads and the corresponding second initial coordinate parameter; The second physical coordinate parameter of any of the lamp beads is calculated according to the second initial coordinate parameter, the difference and the frame value corresponding to the acquired second initial image.

6. A defect detection system for a microdisplay, characterized in that: include: an acquisition unit, used to acquire a first initial image and a second initial image of the microdisplay, wherein the first initial image is an image acquired by the camera in a flying shooting mode, and the second initial image is an image acquired by the positioning component, and used to acquire first initial coordinate parameters corresponding to a plurality of lamp beads according to the first initial image, and to acquire second initial coordinate parameters corresponding to a plurality of the lamp beads according to the second initial image, wherein the positioning component is used to perform image acquisition on the microdisplay in a static state; A calculation unit, used for obtaining a first valid coordinate parameter and an abnormal coordinate parameter in the first initial coordinate parameter according to standard coordinate parameters corresponding to a plurality of the lamp beads in a preset standard image, and obtaining a second valid coordinate parameter corresponding to the abnormal coordinate parameter according to the first valid coordinate parameter, the calculation unit is further used for obtaining a first physical coordinate parameter of any of the lamp beads according to the first valid coordinate parameter and the second valid coordinate parameter, and for obtaining a second physical coordinate parameter of any of the lamp beads according to the second initial coordinate parameter and the standard coordinate parameter, and for calculating a coordinate offset of any of the lamp beads according to the first physical coordinate parameter and the second physical coordinate parameter; The defect detection system further includes a matching module, which is used to divide each of the lamp beads on the first initial image into a sub-area according to the first effective coordinate parameter and the second effective coordinate parameter; The matching module is also used to obtain characteristic information of the lamp beads in any of the sub-areas; The matching module is also used to calculate the restored coordinate parameters of the lamp bead according to the characteristic information; The matching module is also used to obtain a restored image according to the restored coordinate parameters; The defect detection system further includes a detection module, which is used to perform a difference between the restored image and the standard image to obtain a differential image; The detection module is also used to perform image preprocessing on the differential image; The detection module is also used to perform binarization processing on the difference image after image preprocessing; The detection module is also used to mark the connected areas of the difference image after the binary processing; The detection module is also used to obtain feature information of each of the connected areas; The detection module is also used to determine whether the lamp bead located in any of the connected areas has defects based on the characteristic information.

7. A defect detection device for a micro display, characterized in that: It comprises a defect detection system for a micro display as claimed in claim 6 and a workbench for placing the micro display to be tested.

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