Light guide plate defect detection and sorting device

Abstract

The application provides a light guide plate defect detection and sorting device, which comprises a rack, a conveying unit, a cleaning unit, a pose correction unit, an image acquisition unit, a sorting unit and a control unit arranged on the rack; the control unit is used for lighting the first line-scan light source, the second line-scan light source and the third line-scan light source in a stroboscopic mode, and detecting the light guide plate defects 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 comprises alternately performing 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. The application improves the defect detection efficiency and detection accuracy of the light guide plate, and reduces the probability of defect omission and misjudgment caused by human factors or light interference.

Description

Technical Field

[0001] This invention relates to a defect detection device, specifically a light guide plate defect detection and sorting device, belonging to the field of product defect visual inspection technology. Background Technology

[0002] Light guide plates are core optical components in optoelectronic products such as LCD displays, backlight modules, and VR glasses. Their quality directly affects the brightness uniformity, contrast, and overall display effect of the display device. During the production process of light guide plates, various processing defects or flaws inevitably appear on their surface due to factors such as raw materials, equipment usage, processing techniques, and manual operation. These defects include bright spots, black spots, scratches, dents, and contamination. Traditional light guide plate defect detection mainly relies on manual refraction. Manual refraction requires professionally trained optometrists to work in strong light environments, which not only easily causes visual fatigue, leading to missed or false detections and affecting the quality of detection, but also has a certain impact on the physical and mental health of optometrists over a long period. Existing technologies also include automated detection systems that use image acquisition equipment to detect defects in light guide plates. These systems typically use a combination of a fixed-angle light source and a camera, using image processing algorithms to identify defects. However, the single light source and fixed lighting method result in insufficient sensitivity of the image imaging for certain types of defects, easily leading to false or missed detections. To improve the comprehensiveness of inspection, some inspection systems employ multiple inspection stations, each responsible for detecting a specific type of defect. While this approach increases the detection rate, it also increases equipment investment and floor space, reducing the overall efficiency of the production line. Furthermore, many production lines separate the inspection and sorting systems, increasing product turnover time and intermediate inventory, which is detrimental to the implementation of lean manufacturing. Summary of the Invention

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

[0004] To achieve the above-mentioned objectives, the present invention provides the following technical solution:

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

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

[0007] The cleaning unit is used to clean the top and bottom surfaces of the light guide plate by adhesive method, 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 scan light source, a second line scan light source, a third line scan light source, and a line scan camera module. The second line scan light source and the line scan camera module are respectively located above and below the conveying unit, and are arranged opposite to each other. The intersection of the optical paths of the second line scan light source and the line scan camera module on the surface of the conveying unit is configured as a detection position. The optical path of the second line scan light source is perpendicular to the detection position. The first line scan light source and the third line scan light source are respectively located on both sides of the second line scan light source, and the optical paths of the first line scan light source and the third line scan light source are respectively inclined towards the detection position.

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

[0010] The control unit is electrically connected to the conveying unit, the pose correction unit, the image acquisition unit, and the sorting unit, respectively. The control unit is used to illuminate the first line scan light source, the second line scan light source, and the third line scan light source in a strobe mode, and to detect defects in the light guide plate based on the white field image and dark field image of the light guide plate obtained by the line scan camera module. The strobe mode includes alternating periods of a first illumination state for a first set time and a second illumination state for a second set time. The first illumination state is when the first line scan light source and the third line scan light source are illuminated, and the second illumination state is when the first line scan light source, the second line scan light source, and the third line scan light source are illuminated.

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

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

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

[0014] Edge detection is performed on the image to detect the horizontal and vertical edges of the light guide plate in the image, respectively;

[0015] Extract straight line segments representing the boundaries of the light guide plate from the horizontal and vertical edge detection results;

[0016] The extracted line segments were fitted using the least squares method to obtain the accurate equation of the light guide plate boundary line.

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

[0018] Based on the coordinates of the four corner points, calculate the perspective transformation matrix and perform perspective transformation on the image;

[0019] By using perspective transformation, tilted or distorted images are corrected into rectangles, resulting in the corrected image.

[0020] Preferably, the control unit is also used to perform corner detection based on the white field image to detect black spot defects in 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 in the light guide plate.

[0021] Preferably, the cleaning unit includes multiple silicone rollers, multiple elastic connectors, multiple pressing modules, and multiple adhesive rollers. The silicone rollers are arranged in pairs and hinged to the frame. Each pair of silicone rollers is used to abut against and clean the top and bottom surfaces of the light guide plate. Each adhesive roller can abut against at least one silicone roller. Each adhesive roller is connected to the frame through an elastic connector. The adhesive roller is used to remove dust from the surface of the silicone roller. Each pressing module is fixed to the frame and corresponds to one adhesive roller. The pressing module can apply pressure to the adhesive roller to displace it so that the adhesive roller abuts against the silicone roller.

[0022] Preferably, the cleaning unit further includes the plurality of ion air bars, which are arranged in pairs and at least two pairs are configured. The at least two pairs of ion air bars are respectively located at one end of the cleaning unit adjacent to the posture correction unit and the other end away from the posture correction unit. Each pair of ion air bars is used to blow ion air onto the top surface and bottom surface of the light guide plate.

[0023] Preferably, the pose 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 projected position of the light guide plate relative to the conveying unit. The centering module is used to push the light guide plate from two opposite sides to correct the displacement posture of the light guide plate in the conveying unit.

[0024] Preferably, the centering module includes two oppositely arranged push rod modules. Each push rod module includes a pneumatic push rod, a cylinder connecting plate, a centering plate, and multiple rollers. The pneumatic push rod is fixedly connected to the frame, and the moving end of the pneumatic push rod is fixedly connected to the centering plate through the cylinder connecting plate. Multiple rollers are hinged to the end of the centering plate.

[0025] Preferably, the sorting unit includes a linear displacement module, a material picking module, and two laminating modules. The material picking module is mounted on the slider of the linear displacement module and is used to pick up and place the light guide plate. The linear displacement module is used to move the material picking module in a straight line. The two laminating modules are located at both ends of the linear displacement module and are used to laminate the light guide plate.

[0026] Preferably, the frame is equipped 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 located outside the sealing cover and communicates with its interior. 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] This invention discloses a light guide plate defect detection and sorting device. After the cleaning unit removes dirt from the surface of the light guide plate and the posture correction unit corrects the displacement posture and relative position of the light guide plate on the conveying unit, the surface of the light guide plate is illuminated in a strobe mode by a multi-angle line scan light source. The different combinations of backlight and side light enable clear imaging of various defects of the light guide plate, reducing the interference of conventional lighting methods on the detection of specific types of defects. Only one detection position is needed to achieve accurate detection of various defects of the light guide plate. Based on the detection results, the light guide plate is sorted by a sorting unit. This light guide plate defect detection and sorting device improves the defect detection efficiency and accuracy of the light guide plate and reduces the probability of missed and false detections of defects caused by human factors or lighting factors. Attached Figure Description

[0029] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

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

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

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

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

[0034] Figure 5 This is a three-dimensional structural diagram of the conveying unit and the pose correction unit in this invention;

[0035] Figure 6 This is a three-dimensional structural diagram of the conveying unit and the image acquisition unit in this invention;

[0036] Figure 7 This is a three-dimensional structural diagram of the conveying unit and the sorting unit in this invention;

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

[0038] Figure 9 This is a schematic diagram of the process by which the control unit performs defect detection based on the white field image in this invention;

[0039] Figure 10 This is a schematic diagram of the process by which the control unit performs defect detection based on dark field images in this invention;

[0040] In the diagram: 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. Drive module; 202. Belt conveyor module; 301. Silicone roller; 302. Elastic connector; 303. Pressing module; 304. Adhesive roller; 305. Ionizing air bar; 401. Rotating module; 402. Centering module; 4021. Pneumatic push rod; 4022. Cylinder connecting plate; 4023. Centering plate; 4024. Roller; 501. First line scan light source; 502. Second line scan light source; 503. Third line scan light source; 504. Line scan camera module; 601. Linear displacement module; 602. Material handling module; 603. Coating machine module. Detailed Implementation

[0041] The technical solution of the present invention will be 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 modifications and / or alterations made to the present invention will fall within the protection scope of the present invention.

[0042] In this invention, unless otherwise specified, all parts and percentages are by weight, and the equipment and raw materials used are commercially available or commonly used in the art. Unless otherwise specified, the methods in the following embodiments are conventional methods in the art. Unless otherwise specified, the components or equipment in the following embodiments are general standard parts or components known to those skilled in the art, and their structures and principles can be learned by those skilled in the art through technical manuals or conventional experimental methods.

[0043] The embodiments of the present invention will now be described in detail with reference to the accompanying drawings. In this detailed description, numerous specific details are set forth to facilitate explanation and provide a thorough understanding of the embodiments of the present invention. However, one or more embodiments may be practiced 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 pose correction unit 4, an image acquisition unit 5, a sorting unit 6 and a control unit 7 disposed on the frame 1.

[0045] The conveying unit 2 is used to convey the light guide plate in a straight line 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 and bottom surfaces of the light guide plate by adhesive method, 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 linear scanning light source 501, a second linear scanning light source 502, a third linear scanning light source 503, and a linear scanning camera module 504. The second linear scanning light source 502 and the linear scanning camera module 504 are respectively located above and below the transport unit 2, and are arranged opposite to each other. The intersection of the optical paths of the second linear scanning light source 502 and the linear scanning camera module 504 on the surface of the transport unit 2 is configured as a detection position. The optical path of the second linear scanning light source 502 is perpendicular to the detection position. The first linear scanning light source 501 and the third linear scanning light source 503 are respectively located on both sides of the second linear scanning light source 502, and the optical paths of the first linear scanning light source 501 and the third linear scanning light source 503 are inclined towards the detection position.

[0048] Sorting unit 6 is used to sort the light guide plates to the set positions according to the detection results.

[0049] The control unit 7 is electrically connected to the conveying unit 2, the pose correction unit 4, the image acquisition unit 5, and the sorting unit 6, respectively. The control unit 7 is used to illuminate the first line scan light source 501, the second line scan light source 502, and the third line scan light source 503 in a strobe mode, and to detect defects in the light guide plate based on the white field image and dark field image of the light guide plate obtained by the line scan camera module 504. The strobe mode includes alternating periods of a first illumination state for a first set time and a second illumination state for a second set time. The first illumination state is when the first line scan light source 501 and the third line scan light source 503 are illuminated, and the second illumination state is when the first line scan light source 501, the second line scan light source 502, and the third line scan light source 503 are illuminated.

[0050] Each unit will be described in detail below.

[0051] The frame 1 is equipped 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 located outside the sealing cover 101 and communicates with its interior. The dust removal fan 102 is used to remove dust from the inside of the sealing cover 101 by suction. By removing dust from the inside of the sealing cover 101 through the dust removal fan 102, a good detection environment for the device is ensured, and interference from dust on the detection is reduced.

[0052] like Figure 4 As shown, the conveying unit 2 includes a drive module 201 and multiple belt conveyor modules 202. The drive module 201 drives the belt conveyor modules 202 through belt drive, and the belt conveyor modules 202 transmit power to each other 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 against and clean the top and bottom surfaces 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, thereby causing the light guide plate to move forward under friction. Each adhesive roller 304 can abut against at least one silicone roller 301; in this embodiment, one adhesive roller 304 can abut against two silicone rollers 301. Each adhesive roller 304 is connected to the frame 1 via an elastic connector 302 and 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, causing the adhesive roller 304 to abut against the silicone roller 301. After the pressure module 303 removes the pressure on the adhesive roller 304, the adhesive roller 304 returns to its original position under the rebound action of the elastic connector 302, and a certain gap is generated between its surface and the surface of the silicone roller 301.

[0054] The cleaning unit 3 also includes four ion air blowers 305, which are arranged in pairs. Two pairs of ion air blowers 305 are respectively located at one end of the cleaning unit 3 adjacent to the pose correction unit 4 and the other end away from the pose correction unit 4. Each pair of ion air blowers 305 is used to blow ion air onto the top and bottom surfaces of the light guide plate. Thus, before and after the silicone roller 301 cleans the light guide plate, ion air further removes dust from the light guide plate, improving the dust removal effect.

[0055] like Figure 5 As shown, the pose 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 projected 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 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 located at the bottom of the pneumatic rotating mechanism. After the light guide plate is picked up by the suction cup mechanism and leaves the conveying unit 2, 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 opposing push rod modules. 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. The four rollers 4024 are hinged to the end of the centering plate 4023. During the centering operation, the two push rod modules move synchronously. The rollers 4024 at the end of the centering plate 4023 protect the side of the light guide plate and apply a flexible thrust to the side of the light guide plate.

[0058] like Figure 6 As shown, the first line scan light source 501, the second line scan light source 502, the third line scan light source 503, and the line scan camera module 504 are all fixed on the frame 1 by an adjustment device. The orientation of the first line scan light source 501, the second line scan light source 502, the third line scan light source 503, and the line scan camera module 504 can be finely adjusted by the adjustment device to better adapt them 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 modules 603. The material picking module 602 is mounted on the slider of the linear displacement module 601 and is used to pick up and release the light guide plate. The linear displacement module 601 is used to move the material picking module 602 in a straight line. The two laminating modules 603 are located at both ends of the linear displacement module 601 and are used to laminate the light guide plate. The material picking module 602 also includes a pneumatic rotating mechanism and a suction cup mechanism located at the bottom of the pneumatic rotating mechanism. After the light guide plate is picked up by the suction cup mechanism and leaves the conveying unit 2, the pneumatic rotating mechanism rotates the light guide plate, causing it to rotate back to its original position. The linear displacement module 601 moves the light guide plate to the corresponding laminating module 603 according to the detection result. Then, the suction cup mechanism releases the light guide plate, and the laminating module 603 laminates the light guide plate.

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

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

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

[0063] Edge detection is performed on the image to detect the horizontal and vertical edges of the light guide plate in the image, respectively;

[0064] Extract straight line segments representing the boundaries of the light guide plate from the horizontal and vertical edge detection results;

[0065] The extracted line segments were fitted using the least squares method to obtain the accurate equation of the light guide plate boundary line.

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

[0067] Based on the coordinates of the four corner points, calculate the perspective transformation matrix and perform perspective transformation on the image;

[0068] By using perspective transformation, tilted or distorted images are corrected into rectangles, resulting in the corrected image.

[0069] The control unit 7 is also used to perform corner detection based on the white field image to detect black spot defects in 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 in the light guide plate.

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

[0071] Dark-field images are fed into a deep learning object detection network for defect detection in the light guide plate, such as... Figure 10 As shown, deep features of the image are extracted and information is exchanged through a convolutional neural network to achieve real-time detection of surface defects of the light guide plate.

[0072] This light guide plate defect detection and sorting device, after cleaning the surface of the light guide plate by the cleaning unit 3 and correcting the displacement posture and relative position of the light guide plate on the conveying unit 2 by the posture correction unit 4, illuminates the surface of the light guide plate in a strobe mode using a multi-angle line scan light source. The combination of backlight and sidelight clearly images various defects of the light guide plate, reducing the interference of conventional lighting methods on the detection of specific types of defects. Only one detection position is needed to achieve accurate detection of various defects in the light guide plate. Based on the detection results, the light guide plates are sorted by the sorting unit 6. This light guide plate defect detection and sorting device improves the efficiency and accuracy of defect detection, and reduces the probability of missed or false detections caused by human factors or lighting interference.

[0073] This article uses specific examples to illustrate the principles and implementation methods of the present invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of the present invention. It should be noted that those skilled in the art can make several improvements and modifications to the present invention without departing from the principles of the present invention, and these improvements and modifications also fall within the protection scope of the claims of the present invention.

Claims

1. A light guide plate defect detection and sorting apparatus, characterized by: The light guide plate defect detection and sorting device comprises a rack (1), a conveying unit (2), a cleaning unit (3), a pose correction unit (4), an image acquisition unit (5), a sorting unit (6) and a control unit (7) arranged on the rack (1); The conveying unit (2) is used for conveying the light guide plate to sequentially pass through the cleaning unit (3), the pose correction unit (4), the image acquisition unit (5) and the sorting unit (6) in a straight line direction; The cleaning unit (3) is used for cleaning the top surface and the bottom surface of the light guide plate in an adhesive manner, and the pose correction unit (4) is used for correcting 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 arranged above and below the conveying unit (2) respectively, and the second line scanning light source (502) and the line scanning camera module (504) are oppositely arranged, the intersection of the light path of the second line scanning light source (502) and the light path of the line scanning camera module (504) on the surface of the conveying unit (2) is configured as a detection position, the light 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 arranged on the two sides of the second line scanning light source (502) respectively, and the light path of the first line scanning light source (501) and the light path of the third line scanning light source (503) are respectively inclined towards the detection position; The sorting unit (6) is used for sorting the light guide plate to a set position according to the detection result; The control unit (7) is electrically connected with the conveying unit (2), the pose correction unit (4), the image acquisition unit (5) and the sorting unit (6) respectively, and is used for lighting 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 detecting the 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 comprises alternately performing 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 detecting and sorting apparatus according to claim 1, wherein: The first set time is 15 microseconds, and the second set time is 12 microseconds.

3. The light guide plate defect detecting and sorting apparatus according to claim 1, wherein: The control unit (7) is also used for image preprocessing of the white field image and the dark field image, and the image preprocessing comprises the following steps: Performing gray scale enhancement processing on the acquired image; Performing edge detection on the image to detect the transverse edge and the longitudinal edge of the light guide plate in the image respectively; Extracting straight line segments representing the light guide plate boundary from the transverse edge and longitudinal edge detection results; Using the least square method to perform straight line fitting on the extracted straight line segments to obtain accurate light guide plate boundary straight line equations; Calculating the intersection coordinates of the four boundary straight lines obtained by fitting, and the four intersection points respectively represent the four corner points of the light guide plate; According to the coordinates of the four corner points, a perspective transformation matrix is calculated, and the image is subjected to perspective transformation; Through perspective transformation, the inclined or deformed image is corrected to a rectangle to obtain a corrected image.

4. The light guide plate defect detecting and sorting apparatus according to claim 1, wherein: The control unit (7) is also used for angle point detection according to the white field image to detect black point defects of the light guide plate, and extraction of image deep features through a convolutional neural network according to 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 detecting and sorting apparatus according to claim 1, wherein: The cleaning unit (3) comprises a plurality of silica gel rollers (301), a plurality of elastic connecting members (302), a plurality of pressing modules (303) and a plurality of adhesive rollers (304). The silica gel rollers (301) are arranged in pairs and are hinged to the rack (1). Each pair of silica gel rollers (301) is used to abut to clean the top surface and the bottom surface of the light guide plate respectively. Each adhesive roller (304) can abut to at least one silica gel roller (301). Each adhesive roller (304) is connected to the rack (1) through an elastic connecting member (302). The adhesive roller (304) is used to remove dust on the surface of the silica gel roller (301). Each pressing module (303) is fixed to the rack (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 to the silica gel roller (301).

6. The LGP defect detection and sorting apparatus according to claim 5, wherein: The cleaning unit (3) further comprises a plurality of ion wind rods (305). The ion wind rods (305) are arranged in pairs and at least two pairs are provided. At least two pairs of ion wind rods (305) are respectively arranged at one end of the cleaning unit (3) adjacent to the pose correction unit (4) and at one end of the cleaning unit (3) away from the pose correction unit (4). 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 respectively.

7. The light guide plate defect detecting and sorting apparatus according to claim 1, wherein: The pose correction unit (4) comprises a rotating module (401) and a centering module (402). The rotating 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).

8. The LGP defect detection and sorting apparatus according to claim 7, wherein: The centering module (402) comprises two oppositely arranged push rod modules. 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 with the rack (1). The moving end of the pneumatic push rod (4021) is fixedly connected with the centering plate (4023) through the cylinder connecting plate (4022). The end of the centering plate (4023) is hinged with a plurality of rollers (4024).

9. The light guide plate defect detecting and sorting apparatus according to claim 1, wherein: The sorting unit (6) comprises a linear displacement module (601), a material taking module (602) and two film laminating machine modules (603), the material taking module (602) is arranged on the slider of the linear displacement module (601), the material taking module (602) is used for taking and placing the light guide plate, the linear displacement module (601) is used for moving the material taking module (602) in a straight line, and the two film laminating machine modules (603) are respectively located at the two ends of the linear displacement module (601), and the film laminating machine module (603) is used for laminating the light guide plate.

10. The light guide plate defect detecting and sorting apparatus according to claim 1, wherein: The rack (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 pose correction unit (4) and the image acquisition unit (5), the dust removal fan (102) is arranged outside the sealing cover (101) and communicates with the inside of the sealing cover (101), and the dust removal fan (102) is used for sucking dust in the inside of the sealing cover (101).

Images