Light guide plate defect detecting and sorting device

Abstract

The invention provides a light guide plate defect detecting and sorting device. The light guide plate defect detecting and sorting device comprises a rack, and a conveying unit, a cleaning unit, a pose correction unit, an image acquisition unit, a sorting unit and a control unit which are arranged on the rack, the control unit is used for lightening the first line scanning light source, the second line scanning light source and the third line scanning light source in a stroboscopic mode, and detecting the defects of the light guide plate according to a white field image and a dark field image of the light guide plate obtained by the line scanning camera module; the stroboscopic mode comprises that the first lighting state lasts for a first set time, the second lighting state lasts for a second set time, the first lighting state is that the first line scanning light source and the third line scanning light source are lighted, and the second lighting state is that the first line scanning light source, the second line scanning light source and the third line scanning light source are lighted. According to the invention, the defect detection efficiency and detection precision of the light guide plate are improved, and the probability of missing detection and false detection of defects caused by human factor interference or lighting factor interference is reduced.

Description

Technical Field

[0001] The present invention relates to a defect detection device, in particular to a light guide plate defect detection and sorting device, belonging to the technical field of product defect visual detection. Background Art

[0002] The light guide plate is the core optical component in optoelectronic products such as liquid crystal displays, backlight modules, and VR glasses. Its quality directly affects the brightness uniformity, contrast, and overall display effect of the display device. In the production process of the light guide plate, due to factors such as raw materials, equipment usage, processing technology, and manual operation, various processing defects or flaws will inevitably appear on its surface, such as bright spots, black spots, line scratches, crushing, pollution, etc. Traditional light guide plate defect detection mainly relies on manual optometry. Manual optometry requires professionally trained optometrists to work in a strong light environment, which not only easily causes visual fatigue, missed detection, and false detection, affecting the detection quality, but also has a certain impact on the physical and mental health of optometrists over a long period of time. There are also automated detection systems in the prior art that use image acquisition equipment to detect defects on light guide plates. Such systems usually use a fixed-angle light source and camera combination to identify defects through image processing algorithms, but the light source is single and the lighting method is fixed, which makes the image imaging insensitive to certain specific types of defects, which easily leads to false detection and missed detection. In order to improve the comprehensiveness of detection, some detection systems use multiple detection stations, each of which is responsible for a specific type of defect detection. Although this method improves the detection rate, it also increases equipment investment and floor space, reducing the overall efficiency of the production line. In addition, many production lines set up the detection system and sorting system separately, which increases the product flow time and intermediate inventory on the production line, which is not conducive to the implementation of lean production. Summary of the invention

[0003] Based on the above background, the object of the present invention is to provide a light guide plate defect detection and sorting device to solve the problems described in the background technology.

[0004] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0005] A light guide plate defect detection and sorting device comprises a frame, and a conveying unit, a cleaning unit, a posture correction unit, an image acquisition unit, a sorting unit and a control unit arranged on the frame;

[0006] The conveying unit is used to convey the light guide plate in a straight line direction to sequentially pass through the cleaning unit, the posture correction unit, the image acquisition unit and the sorting unit;

[0007] The cleaning unit is used to clean the top surface and the bottom surface of the light guide plate in an adhesive manner, and the posture correction unit is used to correct the displacement posture and relative position of the light guide plate on the conveying unit;

[0008] The image acquisition unit includes a first line scanning light source, a second line scanning light source, a third line scanning light source and a line scanning camera module, the second line scanning light source and the line scanning camera module are respectively arranged above the conveying unit and below the conveying unit, and the second line scanning light source and the line scanning camera module are arranged opposite to each other, the intersection of the optical path of the second line scanning light source and the optical path of the line scanning camera module at the surface of the conveying unit is configured as a detection position, the optical path of the second line scanning light source is perpendicular to the detection position, the first line scanning light source and the third line scanning light source are respectively arranged on both sides of the second line scanning light source, and the optical path of the first line scanning light source and the optical path of the third line scanning light source are respectively inclined toward the detection position;

[0009] The sorting unit is used to sort the light guide plates to a set position according to the detection result;

[0010] The control unit is electrically connected to the conveying unit, the posture correction unit, the image acquisition unit and the sorting unit, respectively. The control unit is used to light up the first line-scan light source, the second line-scan light source and the third line-scan light source in a stroboscopic mode, and detect defects of the light guide plate according to the white field image and the dark field image of the light guide plate obtained by the line-scan camera module. The stroboscopic mode includes alternating a first lighting state for a first set time and a second lighting state for a second set time. The first lighting state is that the first line-scan light source and the third line-scan light source are lit, and the second lighting state is that the first line-scan light source, the second line-scan light source and the third line-scan light source are lit.

[0011] Preferably, the first set time is 15 microseconds, and the second set time is 12 microseconds.

[0012] Preferably, the control unit is further used to perform image preprocessing on the white field image and the dark field image, and the image preprocessing comprises the following steps:

[0013] Perform grayscale enhancement processing on the collected images;

[0014] Performing edge detection on the image, respectively detecting the horizontal edge and the vertical edge of the light guide plate in the image;

[0015] Extracting a straight line segment representing a boundary of the light guide plate from the horizontal edge and the vertical edge detection results;

[0016] The least square method is used to perform straight line fitting on the extracted straight line segments to obtain the accurate boundary straight line equation of the light guide plate;

[0017] Calculate the coordinates of the intersections of the four boundary lines obtained by fitting, where the four intersections represent the four corner points of the light guide plate;

[0018] According to the coordinates of the four corner points obtained, the perspective transformation matrix is ​​calculated and the image is perspective transformed;

[0019] Through perspective transformation, the tilted or deformed image is corrected to a rectangle to obtain a corrected image.

[0020] Preferably, the control unit is also used to perform corner point detection based on the white field image to detect black spot defects of the light guide plate, and to extract deep image features through a convolutional neural network based on the dark field image to detect scratch defects, white stain defects and surface defects of the light guide plate.

[0021] Preferably, the cleaning unit comprises a plurality of silicone rollers, a plurality of elastic connecting members, a plurality of pressing modules and a plurality of adhesive rollers, the silicone rollers being arranged in pairs and hinged to the frame, each pair of silicone rollers being respectively used for abutting to clean the top surface and the bottom surface of the light guide plate, each adhesive roller being able to abut at least one silicone roller, each adhesive roller being connected to the frame via an elastic connecting member, the adhesive roller being used to remove dust from the surface of the silicone roller, each pressing module being fixed to the frame and corresponding to an adhesive roller, the pressing module being able to apply pressure to the adhesive roller to displace it so that the adhesive roller abuts against the silicone roller.

[0022] Preferably, the cleaning unit also includes the plurality of ion wind rods, which are arranged in pairs and at least two pairs are configured, and the at least two pairs of ion wind rods are respectively arranged at one end of the cleaning unit adjacent to the posture correction unit and at an end away from the posture correction unit, and each pair of ion wind rods is respectively used to blow ion wind toward the top surface and the bottom surface of the light guide plate.

[0023] Preferably, the posture correction unit includes a rotation module and a centering module, the rotation module is used to rotate the light guide plate in the XY coordinate system to change the projection position of the light guide plate relative to the conveying unit, and the centering module is used to push the light guide plate from two opposite sides of the light guide plate to correct the displacement posture of the light guide plate in the conveying unit.

[0024] Preferably, the centering module includes two relatively arranged push rod modules, each push rod module includes a pneumatic push rod, a cylinder connecting plate, a centering plate and a plurality of rollers, the pneumatic push rod is fixedly connected to the frame, the moving end of the pneumatic push rod is fixedly connected to the centering plate through the cylinder connecting plate, and the end of the centering plate is hinged to a plurality of rollers.

[0025] Preferably, the sorting unit includes a linear displacement module, a material picking module and two laminating machine modules. The material picking module is arranged on a slider of the linear displacement module. The material picking module is used to pick up and discharge the light guide plate. The linear displacement module is used to move the material picking module along a straight line. The two laminating machine modules are respectively located at two ends of the linear displacement module. The laminating machine module is used to coat the light guide plate.

[0026] Preferably, the frame is provided with a sealing cover and a dust removal fan, the sealing cover covers the outside of the cleaning unit, the posture correction unit and the image acquisition unit, the dust removal fan is arranged outside the sealing cover and connected with the inside thereof, and the dust removal fan is used to remove dust from the inside of the sealing cover by suction.

[0027] Compared with the prior art, the present invention has the following advantages:

[0028] A light guide plate defect detection and sorting device of the present invention, after removing dirt from the surface of the light guide plate by a cleaning unit and correcting the displacement posture and relative position of the light guide plate on a conveying unit by a posture correction unit, illuminates the surface of the light guide plate in a stroboscopic mode by a multi-angle line scanning light source, and different combinations of backlight and side light enable various defects of the light guide plate to be clearly imaged, reducing the interference of conventional lighting methods on the detection of specific types of defects, and only requires one detection position to achieve accurate detection of various defects of the light guide plate, and sorts the light guide plates according to the detection results by a sorting unit. The light guide plate defect detection and sorting device improves the defect detection efficiency and detection accuracy of the light guide plate, and reduces the probability of defect omission and false detection caused by human interference or lighting interference. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0030] Figure 1 It is a three-dimensional structural schematic diagram of a light guide plate defect detection and sorting device of the present invention;

[0031] Figure 2 It is a schematic diagram of the top view of the structure of a light guide plate defect detection and sorting device of the present invention;

[0032] Figure 3 yes Figure 2 Schematic diagram of the middle AA section;

[0033] Figure 4 It is a three-dimensional structural schematic diagram of the conveying unit and the cleaning unit in the present invention;

[0034] Figure 5 It is a schematic diagram of the three-dimensional structure of the conveying unit and the posture correction unit in the present invention;

[0035] Figure 6 It is a schematic diagram of the three-dimensional structure of the conveying unit and the image acquisition unit in the present invention;

[0036] Figure 7 It is a schematic diagram of the three-dimensional structure of the conveying unit and the sorting unit in the present invention;

[0037] Figure 8 It is a schematic diagram of the process of image preprocessing performed by the control unit in the present invention;

[0038] Fig. 9 It is a schematic diagram of the process of the control unit in the present invention performing defect detection according to the white field image;

[0039] Fig.10 It is a schematic diagram of the process of the control unit in the present invention performing defect detection based on the dark field image;

[0040] In the figure: 1. frame; 2. conveying unit; 3. cleaning unit; 4. posture correction unit; 5. image acquisition unit; 6. sorting unit; 7. control unit; 101. sealing cover; 102. dust removal fan; 201. driving module; 202. belt conveying module; 301. silicone roller; 302. elastic connector; 303. pressing module; 304. adhesive roller; 305. ion wind rod; 401. rotating module; 402. centering module; 4021. pneumatic push rod; 4022. cylinder connecting plate; 4023. centering plate; 4024. roller; 501. first line scanning light source; 502. second line scanning light source; 503. third line scanning light source; 504. line scanning camera module; 601. linear displacement module; 602. material taking module; 603. laminating machine module. DETAILED DESCRIPTION

[0041] The technical solution of the present invention is further described in detail below through specific embodiments and in conjunction with the accompanying drawings. It should be understood that the implementation of the present invention is not limited to the following embodiments, and any form of modification and / or change made to the present invention will fall within the protection scope of the present invention.

[0042] In the present invention, unless otherwise specified, all parts and percentages are weight units, and the equipment and raw materials used can be purchased from the market or are commonly used in the art. The methods in the following embodiments, unless otherwise specified, are conventional methods in the art. The components or equipment in the following embodiments, unless otherwise specified, are universal standard parts or components known to those skilled in the art, and their structures and principles are known to those skilled in the art through technical manuals or conventional experimental methods.

[0043] The embodiments of the present invention are described in detail below in conjunction with the accompanying drawings. In the following detailed description, for ease of explanation, many specific details are set forth to provide a comprehensive understanding of the embodiments of the present invention. However, one or more embodiments may also be implemented by those skilled in the art without these specific details.

[0044] like Figure 1-3 As shown, an embodiment of the present invention discloses a light guide plate defect detection and sorting device, including a frame 1, and a conveying unit 2, a cleaning unit 3, a posture correction unit 4, an image acquisition unit 5, a sorting unit 6 and a control unit 7 arranged on the frame 1.

[0045] The conveying unit 2 is used to convey the light guide plate in a straight line direction to pass through the cleaning unit 3, the posture correction unit 4, the image acquisition unit 5 and the sorting unit 6 in sequence.

[0046] The cleaning unit 3 is used to clean the top surface and the bottom surface of the light guide plate by gluing, and the posture correction unit 4 is used to correct the displacement posture and relative position of the light guide plate on the conveying unit 2 .

[0047] The image acquisition unit 5 includes a first line scanning light source 501, a second line scanning light source 502, a third line scanning light source 503 and a line scanning camera module 504. The second line scanning light source 502 and the line scanning camera module 504 are respectively arranged above the conveying unit 2 and below the conveying unit 2, and the second line scanning light source 502 and the line scanning camera module 504 are arranged opposite to each other. The intersection of the optical path of the second line scanning light source 502 and the optical path of the line scanning camera module 504 on the surface of the conveying unit 2 is configured as a detection position. The optical path of the second line scanning light source 502 is perpendicular to the detection position. The first line scanning light source 501 and the third line scanning light source 503 are respectively arranged on both sides of the second line scanning light source 502, and the optical path of the first line scanning light source 501 and the optical path of the third line scanning light source 503 are respectively inclined toward the detection position.

[0048] The sorting unit 6 is used to sort the light guide plates to a set position according to the detection result.

[0049] The control unit 7 is electrically connected to the conveying unit 2, the posture correction unit 4, the image acquisition unit 5 and the sorting unit 6, respectively. The control unit 7 is used to light up the first line scanning light source 501, the second line scanning light source 502 and the third line scanning light source 503 in a stroboscopic mode, and detect defects of the light guide plate according to the white field image and the dark field image of the light guide plate obtained by the line scanning camera module 504. The stroboscopic mode includes alternatingly continuing a first lighting state for a first set time and continuing a second lighting state for a second set time. The first lighting state is that the first line scanning light source 501 and the third line scanning light source 503 are lit, and the second lighting state is that the first line scanning light source 501, the second line scanning light source 502 and the third line scanning light source 503 are lit.

[0050] Each unit is described in detail below.

[0051] The frame 1 is provided with a sealing cover 101 and a dust removal fan 102. The sealing cover 101 is covered on the outside of the cleaning unit 3, the posture correction unit 4 and the image acquisition unit 5. The dust removal fan 102 is arranged on the outside of the sealing cover 101 and is connected with the inside thereof. The dust removal fan 102 is used to remove dust from the inside of the sealing cover 101 by suction. The dust removal fan 102 removes dust from the inside of the sealing cover 101 to ensure a good detection environment of the device and reduce the interference of dust on the detection.

[0052] like Figure 4 As shown, the conveying unit 2 includes a driving module 201 and a plurality of belt conveying modules 202 . The driving module 201 drives the belt conveying modules 202 by belt transmission, and the belt conveying modules 202 transmit power through belts.

[0053] The cleaning unit 3 includes eight silicone rollers 301, four elastic connectors 302, four pressing modules 303 and four adhesive rollers 304. The silicone rollers 301 are arranged in pairs and hinged to the frame 1. Each pair of silicone rollers 301 is used to abut to clean the top surface and the bottom surface of the light guide plate. A power module is provided on the side of the cleaning unit 3 to drive the silicone rollers 301 to rotate relative to the frame 1, so that the light guide plate moves forward under the action of friction. Each adhesive roller 304 can abut at least one silicone roller 301. In this embodiment, one adhesive roller 304 can abut two silicone rollers 301. Each adhesive roller 304 is connected to the frame 1 through an elastic connector 302, and the adhesive roller 304 is used to remove dust on the surface of the silicone roller 301. Each pressing module 303 is fixed to the frame 1 and corresponds to one adhesive roller 304. The pressing module 303 can apply pressure to the adhesive roller 304 to displace it, so that the adhesive roller 304 abuts against the silicone roller 301. After the pressing module 303 removes the pressure on the adhesive roller 304 , the adhesive roller 304 returns to its original position due to the rebound effect of the elastic connecting member 302 , and a certain distance is generated between its surface and the surface of the silicone roller 301 .

[0054] The cleaning unit 3 also includes four ion wind rods 305, which are arranged in pairs. Two pairs of ion wind rods 305 are respectively arranged at one end of the cleaning unit 3 adjacent to the posture correction unit 4 and at one end away from the posture correction unit 4, and each pair of ion wind rods 305 is used to blow ion wind to the top surface and the bottom surface of the light guide plate. In this way, before and after the silicone roller 301 cleans the light guide plate, the ion wind further removes dust from the light guide plate, thereby improving the dust removal effect.

[0055] like Figure 5 As shown, the posture correction unit 4 includes a rotation module 401 and a centering module 402. The rotation module 401 is used to rotate the light guide plate in the XY coordinate system to change the projection position of the light guide plate relative to the conveying unit 2. The centering module 402 is used to push the light guide plate from two opposite sides of the light guide plate to correct the displacement posture of the light guide plate in the conveying unit 2.

[0056] The rotating module 401 includes a pneumatic rotating mechanism and a suction cup mechanism disposed at the bottom of the pneumatic rotating mechanism. After the light guide plate is sucked away from the conveying unit 2 by the suction cup mechanism, the pneumatic rotating mechanism rotates the light guide plate, thereby changing the projection position of the light guide plate relative to the conveying unit 2.

[0057] The centering module 402 includes two push rod modules arranged opposite to each other, each push rod module includes a pneumatic push rod 4021, a cylinder connecting plate 4022, a centering plate 4023 and four rollers 4024, the pneumatic push rod 4021 is fixedly connected to the frame 1, the moving end of the pneumatic push rod 4021 is fixedly connected to the centering plate 4023 through the cylinder connecting plate 4022, and the end of the centering plate 4023 is hinged to the four rollers 4024. During the centering operation, the two push rod modules move synchronously, and the rollers 4024 at the ends of the centering plate 4023 protect the side of the light guide plate and apply a thrust to the side of the light guide plate with a flexible thrust.

[0058] like Figure 6 As shown, the first line scanning light source 501, the second line scanning light source 502, the third line scanning light source 503 and the line scanning camera module 504 are all fixed on the frame 1 through the adjustment device. The orientation of the first line scanning light source 501, the second line scanning light source 502, the third line scanning light source 503 and the line scanning camera module 504 can be fine-tuned through the adjustment device to make them better adapt to the detection of light guide plates of different specifications.

[0059] like Figure 7As shown, the sorting unit 6 includes a linear displacement module 601, a material picking module 602 and two laminating machine modules 603. The material picking module 602 is arranged on the slider of the linear displacement module 601, and the material picking module 602 is used to pick up and discharge the light guide plate. The linear displacement module 601 is used to move the material picking module 602 along a straight line. The two laminating machine modules 603 are respectively located at the two ends of the linear displacement module 601, and the laminating machine modules 603 are used to coat the light guide plate. The material picking module 602 also includes a pneumatic rotating mechanism and a suction cup mechanism arranged at the bottom of the pneumatic rotating mechanism. After the light guide plate is sucked away from the conveying unit 2 by the suction cup mechanism, the pneumatic rotating mechanism rotates the light guide plate so that the light guide plate rotates back to the original posture. After the linear displacement module 601 displaces the light guide plate to the corresponding laminating machine module 603 according to the detection result, the suction cup mechanism releases the light guide plate, and the laminating machine module 603 coats the light guide plate.

[0060] In the stroboscopic mode of the control unit 7, the first setting time is 15 microseconds and the second setting time is 12 microseconds.

[0061] The control unit 7 is also used to perform image preprocessing on the white field image and the dark field image, such as Figure 8 As shown, image preprocessing includes the following steps:

[0062] Perform grayscale enhancement processing on the collected images;

[0063] Performing edge detection on the image, respectively detecting the horizontal edge and the vertical edge of the light guide plate in the image;

[0064] Extracting a straight line segment representing a boundary of the light guide plate from the horizontal edge and the vertical edge detection results;

[0065] The least square method is used to perform straight line fitting on the extracted straight line segments to obtain the accurate boundary straight line equation of the light guide plate;

[0066] Calculate the coordinates of the intersections of the four boundary lines obtained by fitting, where the four intersections represent the four corner points of the light guide plate;

[0067] According to the coordinates of the four corner points obtained, the perspective transformation matrix is ​​calculated and the image is perspective transformed;

[0068] Through perspective transformation, the tilted or deformed image is corrected to a rectangle to obtain a corrected image.

[0069] The control unit 7 is also used to perform corner point detection based on the white field image to detect black dot defects of the light guide plate, and to extract deep image features through a convolutional neural network based on the dark field image to detect scratch defects, white stain defects and surface defects of the light guide plate.

[0070] White field images are mainly used for black spot defect detection, such as Fig. 9As shown in Figure 1, the general process can be divided into image preprocessing, corner point detection, and corner point secondary confirmation. Image preprocessing can remove image noise, enhance image contrast, and simplify the design of subsequent algorithms. Corner point secondary confirmation can improve the detection accuracy.

[0071] The dark field image is fed into the deep learning object detection network for light guide plate defect detection, such as Fig.10 As shown, the convolutional neural network is used to extract deep features of the image and perform information interaction to achieve real-time detection of surface defects of the light guide plate.

[0072] The light guide plate defect detection and sorting device, after the cleaning unit 3 removes dirt on the light guide plate surface and the posture correction unit 4 corrects the displacement posture and relative position of the light guide plate on the conveying unit 2, illuminates the light guide plate surface in a stroboscopic mode through a multi-angle line scanning light source, and the different combinations of backlight and sidelight make various defects of the light guide plate clearly imaged, reducing the interference of conventional lighting methods on the detection of specific types of defects, and only one detection position is required to achieve accurate detection of various defects of the light guide plate, and the light guide plate is sorted by the sorting unit 6 according to the detection results. The light guide plate defect detection and sorting device improves the defect detection efficiency and detection accuracy of the light guide plate, and reduces the probability of defect omission and false detection caused by human interference or lighting interference.

[0073] The principles and implementation methods of the present invention are described in this article using specific examples. The description of the above embodiments is only used to help understand the method and core ideas of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made to the present invention without departing from the principles of the present invention, and these improvements and modifications also fall within the scope of protection of the claims of the present invention.

Claims

1. A light guide plate defect detection and sorting device, characterized in that: The light guide plate defect detection and sorting device comprises a frame (1), and a conveying unit (2), a cleaning unit (3), a posture correction unit (4), an image acquisition unit (5), a sorting unit (6) and a control unit (7) arranged on the frame (1); The conveying unit (2) is used to convey the light guide plate in a straight line direction to sequentially pass through the cleaning unit (3), the posture correction unit (4), the image acquisition unit (5) and the sorting unit (6); The cleaning unit (3) is used to clean the top surface and the bottom surface of the light guide plate in an adhesive manner, and the posture correction unit (4) is used to correct the displacement posture and relative position of the light guide plate on the conveying unit (2); The image acquisition unit (5) comprises a first line scanning light source (501), a second line scanning light source (502), a third line scanning light source (503) and a line scanning camera module (504); the second line scanning light source (502) and the line scanning camera module (504) are respectively arranged above the conveying unit (2) and below the conveying unit (2); the second line scanning light source (502) and the line scanning camera module (504) are arranged opposite to each other; the intersection of the optical path of the second line scanning light source (502) and the optical path of the line scanning camera module (504) on the surface of the conveying unit (2) is configured as a detection position; the optical path of the second line scanning light source (502) is perpendicular to the detection position; the first line scanning light source (501) and the third line scanning light source (503) are respectively arranged on both sides of the second line scanning light source (502); and the optical path of the first line scanning light source (501) and the optical path of the third line scanning light source (503) are respectively oriented towards the detection position in an inclined direction; The sorting unit (6) is used to sort the light guide plates to a set position according to the detection result; The control unit (7) is electrically connected to the conveying unit (2), the posture correction unit (4), the image acquisition unit (5) and the sorting unit (6) respectively. The control unit (7) is used to light up the first line scanning light source (501), the second line scanning light source (502) and the third line scanning light source (503) in a stroboscopic mode, and detect defects of the light guide plate according to the white field image and the dark field image of the light guide plate obtained by the line scanning camera module (504). The stroboscopic mode includes alternating a first lighting state for a first set time and a second lighting state for a second set time. The first lighting state is that the first line scanning light source (501) and the third line scanning light source (503) are lit, and the second lighting state is that the first line scanning light source (501), the second line scanning light source (502) and the third line scanning light source (503) are lit.

2. The light guide plate defect detection and sorting device according to claim 1, characterized in that: The first setting time is 15 microseconds, and the second setting time is 12 microseconds.

3. The light guide plate defect detection and sorting device according to claim 1, characterized in that: The control unit (7) is further used to perform image preprocessing on the white field image and the dark field image, wherein the image preprocessing comprises the following steps: Perform grayscale enhancement processing on the collected images; Performing edge detection on the image, respectively detecting the horizontal edge and the vertical edge of the light guide plate in the image; Extracting a straight line segment representing a boundary of the light guide plate from the horizontal edge and the vertical edge detection results; The least square method is used to perform straight line fitting on the extracted straight line segments to obtain the accurate boundary straight line equation of the light guide plate; Calculate the coordinates of the intersections of the four boundary lines obtained by fitting, where the four intersections represent the four corner points of the light guide plate; According to the coordinates of the four corner points obtained, the perspective transformation matrix is ​​calculated and the image is perspective transformed; Through perspective transformation, the tilted or deformed image is corrected to a rectangle to obtain a corrected image.

4. The light guide plate defect detection and sorting device according to claim 1, characterized in that: The control unit (7) is also used to perform corner point detection based on the white field image to detect black spot defects of the light guide plate, and to extract image deep features through a convolutional neural network based on the dark field image to detect scratch defects, white stain defects and surface defects of the light guide plate.

5. The light guide plate defect detection and sorting device according to claim 1, characterized in that: The cleaning unit (3) comprises a plurality of silicone rollers (301), a plurality of elastic connecting members (302), a plurality of pressing modules (303) and a plurality of adhesive rollers (304); the silicone rollers (301) are arranged in pairs and are hinged to the frame (1); each pair of silicone rollers (301) is respectively used to abut against and clean the top surface and the bottom surface of the light guide plate; each adhesive roller (304) can abut against at least one silicone roller (301); each adhesive roller (304) is connected to the frame (1) via an elastic connecting member (302); the adhesive roller (304) is used to remove dust from the surface of the silicone roller (301); each pressing module (303) is fixed to the frame (1) and corresponds to one adhesive roller (304); the pressing module (303) can apply pressure to the adhesive roller (304) to displace it, so that the adhesive roller (304) abuts against the silicone roller (301).

6. The light guide plate defect detection and sorting device according to claim 5, characterized in that: The cleaning unit (3) further comprises the plurality of ion wind rods (305), wherein the ion wind rods (305) are arranged in pairs and at least two pairs are configured, and the at least two pairs of ion wind rods (305) are respectively arranged at one end of the cleaning unit (3) adjacent to the posture correction unit (4) and at one end away from the posture correction unit (4), and each pair of ion wind rods (305) is respectively used to blow ion wind toward the top surface and the bottom surface of the light guide plate.

7. The light guide plate defect detection and sorting device according to claim 1, characterized in that: The posture correction unit (4) comprises a rotation module (401) and a centering module (402), wherein the rotation module (401) is used to rotate the light guide plate in an XY coordinate system to change the projection position of the light guide plate relative to the conveying unit (2), and the centering module (402) is used to push the light guide plate against two opposite sides of the light guide plate to correct the displacement posture of the light guide plate in the conveying unit (2).

8. The light guide plate defect detection and sorting device according to claim 7, characterized in that: The centering module (402) comprises two push rod modules arranged opposite to each other, each push rod module comprises a pneumatic push rod (4021), a cylinder connecting plate (4022), a centering plate (4023) and a plurality of rollers (4024), the pneumatic push rod (4021) is fixedly connected to the frame (1), the movable end of the pneumatic push rod (4021) is fixedly connected to the centering plate (4023) via the cylinder connecting plate (4022), and the end of the centering plate (4023) is hinged to the plurality of rollers (4024).

9. The light guide plate defect detection and sorting device according to claim 1, characterized in that: The sorting unit (6) comprises a linear displacement module (601), a material taking module (602) and two laminating machine modules (603); the material taking module (602) is arranged on a slider of the linear displacement module (601); the material taking module (602) is used to take and discharge the light guide plate; the linear displacement module (601) is used to move the material taking module (602) along a straight line; the two laminating machine modules (603) are respectively located at two ends of the linear displacement module (601); and the laminating machine module (603) is used to laminar the light guide plate.

10. The light guide plate defect detection and sorting device according to claim 1, characterized in that: The frame (1) is provided with a sealing cover (101) and a dust removal fan (102); the sealing cover (101) covers the outside of the cleaning unit (3), the posture correction unit (4) and the image acquisition unit (5); the dust removal fan (102) is arranged outside the sealing cover (101) and is connected to the inside thereof; the dust removal fan (102) is used to remove dust from the inside of the sealing cover (101) by suction.

Images