High-precision polaroid attaching device with pre-alignment calibration system at feeding end and method

Abstract

The application relates to the technical field of polaroid attaching devices, in particular to a high-precision polaroid attaching device and method with a pre-alignment calibration system at the feeding end, which comprises a substrate seat installed on a processing table, a conveying mechanism installed outside the feeding end of the processing table, a calibration mechanism arranged in the conveying path of the conveying mechanism, a stop mechanism arranged at the discharging end of the substrate seat and an attaching mechanism arranged on the processing table. The pre-alignment calibration mechanism in the form of a jacking rotary mechanism is arranged in the interval area of the conveying belt, and the real-time angle deviation detection and feedback control of the visual detection system are matched, so that the angle deviation is corrected before the polaroid enters the substrate area, the long side of the polaroid is ensured to be parallel to the long side of the substrate, and the influence of the incoming deviation and the conveying deviation on the attaching precision is effectively eliminated.

Description

Technical Field

[0001] This invention relates to the field of polarizer attachment technology, specifically to a high-precision polarizer attachment device and method with a pre-alignment calibration system at the feed end. Background Technology

[0002] Polarizing films are one of the core optical components of liquid crystal display panels, and their bonding accuracy directly affects the display quality and yield rate of the display panel. In existing technologies, polarizing film bonding equipment typically uses an adsorption and conveying method to transfer the polarizing film above the substrate for bonding, followed by rolling after bonding.

[0003] Patent application CN202011605759.4 discloses a polarizer mounting machine and a polarizer mounting method. The method involves using an adsorption device to adsorb polarizers and vertically mount them onto a substrate surface, followed by rolling the substrate with the polarizer mounted on it using a pressure roller during transport. This technical solution has the following shortcomings: First, it lacks a calibration step to ensure the polarizer is parallel to both sides of the substrate before adsorption and transport. Deviations in the polarizer's incoming position or during transport can directly lead to deviations in the mounting angle. Second, using a single roller to roll the polarizer from above can cause the polarizer to slip relative to the substrate during rolling, resulting in secondary misalignment of the already aligned polarizer and affecting mounting accuracy.

[0004] Therefore, there is an urgent need for a polarizer attachment device and method that can perform high-precision angle pre-alignment before attachment and effectively prevent polarizer slippage during the rolling process. Summary of the Invention

[0005] In order to overcome the defects in the prior art, the purpose of this invention is to provide a high-precision polarizer attachment device and method with a pre-alignment calibration system at the feed end, so as to solve the problems mentioned in the background art.

[0006] To achieve the above objectives, on the one hand, the present invention provides a high-precision polarizer attachment device with a pre-alignment calibration system at the feed end, including a substrate holder, which is lifted and mounted on a processing table for placing the substrate; The conveying mechanism consists of two parallel and spaced conveyor belts, used to convey polarizing film along the feeding direction; The calibration mechanism is located between two conveyor belts and consists of a turntable, a lifting drive, and a rotating drive. The turntable is coaxially fixed to the output top of the lifting drive. The turntable rises to support the polarizer and the horizontal angle of the polarizer is adjusted by the rotating drive. The visual inspection system consists of at least two sets of visual sensors, which are respectively set above the long sides of the substrate and above the calibration mechanism. They are used to acquire images of the long edge of the polarizer and the long edge of the substrate, and calculate the angular deviation between them. The control unit is electrically connected to the vision inspection system, the lifting drive and the rotating drive respectively. The control unit receives the angle deviation value and controls the rotating drive to drive the turntable to rotate by the corresponding angle to complete the angle pre-alignment calibration of the polarizer. The stop mechanism consists of a pair of rollers that protrude and rotate at one end of the substrate holder in the material discharge direction. The rollers switch between a stop state and a yield state. In the stop state, the rollers are vertical and protrude from the substrate surface to align and stop the front end of the polarizer conveyed to the substrate. In the yield state, the rollers deflect outward away from the front end face of the substrate. The bonding mechanism consists of an upper pressure roller and a pair of lower clamping rollers arranged vertically at intervals, located on the outer side of the front end of the substrate holder. The two ends of the upper pressure roller and the outer ends of the pair of lower clamping rollers are elastically connected by an elastic pre-tightening assembly. The upper pressure roller and the pair of lower clamping rollers are driven to move horizontally along the length of the substrate by a motor screw thread pair structure to clamp and roll the substrate and the polarizer above it. When the bonding mechanism moves horizontally to the outside of the substrate holder's discharge end, a trigger element triggers the pair of rollers to switch from a stop state to a yield state.

[0007] As a further improvement to this technical solution, the visual inspection system includes an image processing module. The image processing module performs edge extraction and line fitting on the acquired long edge image of the polarizer and the long edge image of the substrate, respectively, and calculates the angle between the two fitted lines as the angle deviation value.

[0008] As a further improvement to this technical solution, the control unit is configured to: when the angle deviation value is greater than the preset threshold, control the rotary drive to drive the turntable to rotate by an angle deviation value, the vision detection system to collect the image again and calculate the deviation, and if it is still greater than the preset threshold, repeat the angle adjustment until the deviation value is less than or equal to the preset threshold.

[0009] As a further improvement to this technical solution, the stop mechanism also includes a pair of rotating drums rotatably connected to the end of the substrate seat in the discharge direction. The rollers are embedded in the side wall of one end of the rotating drum. The upper half of the side wall of the rotating drum is provided with an inclined linkage groove. The two ends of the linkage groove pass through the front and rear end faces of the rotating drum along the axial direction of the rotating drum. The triggering element is a pair of levers installed below the lower clamping roller. The levers engage with the linkage groove and move horizontally to drive the rotating drum to deflect, thereby switching the rollers to the yielding state.

[0010] As a further improvement to this technical solution, the outer wall of the rotating drum is provided with a clearance groove that communicates with both ends of the linkage groove. A guide plate is provided at the intersection of the linkage groove and the clearance groove. The guide plate extends along the inclined side of the linkage groove. The normally closed state of the guide plate is to close the clearance groove.

[0011] As a further improvement to this technical solution, the spacing between a pair of levers is at least equal to the axial length of the rotating drum. The pair of levers are symmetrically arranged on both sides of the lower clamping roller. When rolling polarizers, the first lever moves the linkage groove to drive the rotating drum to rotate downwards, and the second lever slides out from the upper clearance groove. When the bonding mechanism returns to its original position, the second lever moves the linkage groove to drive the rotating drum to rotate upwards and reset, and the first lever slides out from the lower clearance groove.

[0012] As a further improvement to this technical solution, the motor lead screw threaded pair structure is composed of a servo motor and a lead screw coaxially connected. A slider is threadedly connected to the lead screw, and linear guide rails are fixedly arranged on both sides of the base plate. The slider is slidably engaged with the linear guide rails.

[0013] As a further improvement to this technical solution, the elastic preload assembly is composed of an inner and outer sleeve and a movable seat, and a compression spring is fixedly installed between the sleeve and the movable seat to provide an elastic preload force for the lower clamping roller to move upward.

[0014] On the other hand, the present invention provides a high-precision polarizer attachment method with a pre-alignment calibration system at the feed end. Using the aforementioned high-precision polarizer attachment device with a pre-alignment calibration system at the feed end, the method includes the following steps: S1. Place the polarizer on the conveying mechanism and convey it to the substrate holder along the feeding direction; S2. When the polarizer is transported to the top of the calibration mechanism, the vision inspection system acquires images of the long edges of both sides of the substrate and the long edges of both sides of the polarizer, respectively. The system extracts the edge lines through the image processing algorithm, calculates the angle deviation value θ between the long edge of the polarizer and the long edge of the substrate, and sends θ to the control unit. S3. The control unit controls the lifting drive to drive the turntable to rise and lift the polarizer. The control unit controls the rotation drive to drive the turntable to rotate by an angle θ to complete the angle pre-alignment calibration of the polarizer. After calibration, the polarizer is reset and transported. S4. The polarizer is conveyed to the top of the substrate, and its front end abuts against the outer peripheral surface of a pair of rollers in a stop state, so as to align the front and rear ends of the polarizer with the substrate. S5. Drive the upper pressure roller and the lower clamping roller to move towards the front end of the substrate by the servo motor. Trigger the pair of rollers to switch from the stop state to the yield state by the trigger. Thus, the upper pressure roller and the lower clamping roller move along the length of the substrate under the drive of the servo motor, and perform full-process clamping and rolling attachment of the substrate and polarizer to complete the attachment operation.

[0015] As a further improvement to this technical solution, the image processing algorithm in step S2 includes the following sub-steps: S21. Perform grayscale processing and binarization segmentation on the acquired long side image of the substrate and the long side image of the polarizer respectively, and extract the target edge region; S22. The Canny edge detection operator is used to extract edges from the binarized image to obtain a set of edge pixels. S23. The Hough transform line detection algorithm is used to fit the edge pixel point set with a straight line to obtain the long side fitting line L1 of the substrate and the long side fitting line L2 of the polarizer, respectively. S24. Calculate the angle θ between the fitted lines L1 and L2, which is taken as the angle deviation value. The calculation formula is as follows: Where k1 is the slope of the fitted line L1; k2 is the slope of the fitted line L2; The slope difference reflects the difference in the degree of inclination between the two straight lines; This is a correction factor to correct the deviation when simply calculating the included angle using the slope difference; The angle value is obtained by inversely calculating the arctangent function. Since the absolute value is taken in the formula, the actual output θ ranges from 0° to 90°, and the acute angle between the two lines is always output.

[0016] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. The high-precision polarizer attachment device and method with a pre-alignment calibration system at the feeding end, by setting a lifting and rotating pre-alignment calibration mechanism in the interval area of ​​the conveyor belt, and in conjunction with the real-time angle deviation detection and feedback control of the vision inspection system, the angle correction is completed before the polarizer enters the substrate area, ensuring that the long side of the polarizer is parallel to the long side of the substrate, effectively eliminating the influence of incoming material deviation and conveying offset on the attachment accuracy.

[0017] 2. The high-precision polarizer attachment device and method with a pre-alignment calibration system at the feeding end, by setting a clamping rolling anti-slip structure, mainly uses a pair of pressure rollers arranged opposite each other to clamp and roll attach the substrate and polarizer. There is no relative slippage tendency between the pressure rollers and the polarizer, which fundamentally avoids the polarizer offset problem caused by traditional single-roll rolling.

[0018] 3. The high-precision polarizer attachment device and method with a pre-alignment calibration system at the feeding end, by setting a deflectable roller stop mechanism at the front end of the substrate and designing a linkage trigger mechanism to automatically give way when the pressure roller arrives, not only ensures the accurate positioning of the polarizer and the front end of the substrate, but also does not affect the continuity of subsequent rolling operations. The structure is compact and the operation is stable and efficient. Attached Figure Description

[0019] The accompanying drawings described herein are for illustrative purposes only. The shapes and proportions of the components in the drawings are merely schematic and intended to aid in understanding the invention. They are not intended to specifically limit the shapes and proportions of the components of the invention.

[0020] Figure 1 This is one of the overall structural schematic diagrams of the present invention; Figure 2 This is the second schematic diagram of the overall structure of the present invention; Figure 3 For the present invention Figure 2 Side view; Figure 4 This is a schematic diagram of the assembly structure of the calibration mechanism of the present invention; Figure 5 For the present invention Figure 4 Side view; Figure 6 This is a schematic diagram of the overall assembly structure of the attachment mechanism of the present invention; Figure 7 This is a schematic diagram of the assembly structure of the stop mechanism of the present invention; Figure 8 This is a schematic diagram of a partial assembly structure of the attachment mechanism of the present invention; The meanings of the labels in the diagram are as follows: 100, substrate holder; 110, conveying mechanism; 120, guide frame; 121, baffle; 130, vision sensor; 200. Calibration mechanism; 210. Turntable; 211. Transmission gear; 220. Lifting drive component; 230. Rotation drive component; 231. Bushing; 232. Drive gear; 300. Stopping mechanism; 310. Roller; 320. Rotary drum; 321. Linkage groove; 322. Clearance groove; 323. Guide plate; 400, Attachment mechanism; 410, Upper pressure roller; 411, Sleeve base; 420, Lower clamping roller; 421, Moving seat; 422, Slider; 430, Servo motor; 431, Lead screw; 440, Trigger; 450, Linear guide rail. Detailed Implementation

[0021] Under the guidance of this invention, any possible variations of this invention by those skilled in the art should be considered within its scope. The directional terms used herein are based on the orientations shown in the accompanying drawings and are for ease of description and simplification; therefore, they should not be construed as limiting the invention. Furthermore, in the description of this invention, "a number" means two or more, unless otherwise explicitly specified.

[0022] Please see Figures 1-5As shown, the present invention provides a high-precision polarizer attachment device with a pre-alignment calibration system at the feeding end, including a substrate holder 100 mounted on a processing table, a conveying mechanism 110 mounted outside the feeding end of the processing table, a calibration mechanism 200 disposed in the conveying path of the conveying mechanism 110, a stop mechanism 300 disposed at the discharge end of the substrate holder 100, and an attachment mechanism 400 disposed on the processing table.

[0023] Furthermore, the substrate holder 100 is used to place the substrate; the conveying mechanism 110 consists of two parallel and spaced conveyor belts for conveying the polarizer along the feeding direction; an inclined guide frame 120 is fixedly installed on the processing table between the conveyor belt and the substrate holder 100, and several rollers are rotatably connected inside the guide frame 120 by pins for guiding the polarizer to slide onto the substrate holder 100 for alignment; baffles 121 are rotatably connected to both sides of the inclined surface of the guide frame 120 by pins to maintain the correction function during the sliding process of the polarizer.

[0024] Furthermore, the calibration mechanism 200 is located between the two conveyor belts and consists of a turntable 210, a lifting drive 220, and a rotation drive 230. The turntable 210 is coaxially fixedly connected to the output top of the lifting drive 220. The turntable 210 rises to support the polarizer and the horizontal angle of the polarizer is adjusted by the rotation drive 230. The upper surface of the turntable 210 is made of anti-static silicone material, which provides good friction and prevents static damage to the polarizer.

[0025] Furthermore, the lifting drive 220 uses an electric push rod, and the rotary drive 230 uses a servo motor equipped with an encoder; both are fixedly mounted on the frame beam below the interval area of ​​the two conveyor belts; a bushing 231 is coaxially connected to the output shaft of the rotary drive 230, and a drive gear 232 is connected to the central shaft of the bushing 231 via a spline, so that the drive gear 232 can rotate and rise and fall simultaneously; a bearing is sleeved on the top of the telescopic rod of the lifting drive 220, and a transmission gear is coaxially connected to the top surface of the outer ring of the bearing. 211, which enables the transmission gear 211 to rotate and rise simultaneously. The drive gear 232 meshes with the transmission gear 211. The drive gear 232 and the transmission gear 211 are of the same specification, so that the turntable 210 can synchronously obtain the torque force of the rotation drive component 230. In addition, the drive gear 232 is connected to the bearing through a connecting rod. The two ends of the connecting rod are fixed with collars, which are respectively sleeved with the drive shaft of the drive gear 232 and the bearing with a clearance, and are limited by pins, so that the drive gear 232 and the transmission gear 211 can synchronously rise and fall.

[0026] The attachment device also includes a vision inspection system consisting of at least two sets of vision sensors 130, preferably a CCD industrial camera equipped with a coaxial light source to ensure image acquisition quality; the two sets of vision sensors 130 are respectively located above the long sides of the substrate 100 and above the calibration mechanism 200, for acquiring the long edge image of the polarizer and the long edge image of the substrate respectively, and calculating the angular deviation value between the two.

[0027] The control unit is electrically connected to the vision inspection system, the lifting drive 220 and the rotation drive 230 respectively. The control unit receives the angle deviation value and controls the rotation drive 230 to drive the turntable 210 to rotate by the corresponding angle to complete the angle pre-alignment calibration of the polarizer.

[0028] Furthermore, the vision inspection system includes an image processing module embedded in the industrial computer of the control unit. The image processing module performs edge extraction and line fitting on the acquired long edge image of the polarizer and the long edge image of the substrate, respectively, and calculates the angle between the two fitted lines as the angle deviation value.

[0029] The control unit is configured such that when the angle deviation value is greater than the preset threshold, the rotary drive 230 drives the turntable 210 to rotate by an angle deviation value, the vision detection system acquires the image again and calculates the deviation. If it is still greater than the preset threshold, the angle adjustment is repeated until the deviation value is less than or equal to the preset threshold.

[0030] The image processing algorithm includes the following steps: A1. Perform grayscale processing and binarization segmentation on the acquired long side image of the substrate and the long side image of the polarizer respectively to extract the target edge region; use the OTSU method to perform binarization segmentation on the grayscale image to separate the target edge region from the background region; A2. The Canny edge detection operator is used to extract edges from the binarized image to obtain the edge pixel set. The specific parameters of the Canny operator are: low threshold 50, high threshold 150, and Sobel operator kernel size 3×3. After processing by the Canny operator, the pixel set of the target long side edge is obtained. A3. The Hough transform line detection algorithm is used to fit the edge pixel set with a straight line to obtain the long side fitting line L1 of the substrate and the long side fitting line L2 of the polarizer respectively; the Hough transform parameters are set as follows: distance resolution ρ=1 pixel, angle resolution θ=1°, voting threshold=100. A4. Calculate the angle θ between the fitted lines L1 and L2 as the angle deviation value. The calculation formula is as follows: Where k1 is the slope of the fitted straight line L1, representing the placement angle of the substrate; k2 is the slope of the fitted straight line L2, representing the current angular attitude of the polarizer; In a Cartesian coordinate system, the slope k of a straight line is defined as the ratio of the difference between the ordinates of any two points on the line to the difference between their abscissas. The slope difference reflects the difference in the inclination of the two lines; if the two lines are perfectly parallel, then k1 = k2. =0, the calculated angle deviation value is 0°, indicating no angle deviation; if the two lines are not parallel, then k1≠k2, and the larger the absolute value of the difference, the greater the difference in inclination between the two lines. This is a correction factor to correct the deviation when simply calculating the included angle using the slope difference; The angle value is calculated by inversely using the arctangent function. Because the formula uses absolute values, the actual output θ ranges from 0° to 90°, always outputting the acute angle between the two lines. When the two lines are perpendicular... =-1, at which point the denominator is 0. Mathematically, tan(90°) approaches infinity, arctan(infinity) = 90°, and the formula still correctly describes the perpendicular relationship.

[0031] Example 1: The polarizer is parallel to the substrate (no deviation). Assuming the substrate is placed horizontally, and L1 is a horizontal line: =0; The polarizer is also horizontal, and L2 is a horizontal line: =0; Substituting into the formula: θ = arctan(|(0-0) / (1+0×0)|) = arctan(0) = 0°; Conclusion: No angular deviation; Example 2: The polarizer has a slight deflection. Substrate horizontal: =0; the polarizer deflects approximately 5.7°, corresponding to a slope of tan5.7°≈0.1, i.e. =0.1; Substituting into the formula: θ = arctan(|(0-0.1) / (1+0×0.1)|) = arctan(0.1) ≈ 5.7°; Conclusion: A deviation of 5.7° was detected, and the servo motor needs to be rotated 5.7° in the opposite direction to correct the deviation.

[0032] In addition, to improve calibration accuracy, the control unit is configured in a closed-loop calibration mode: when the absolute value of the initially calculated angle deviation value θ is greater than a preset threshold (e.g., the preset threshold is 0.1°), the rotary drive 230 drives the turntable 210 to rotate in the opposite direction by an angle θ; after the rotation is completed, the vision inspection system acquires the image again and recalculates the angle deviation value; if the deviation value is still greater than the preset threshold, the above adjustment steps are repeated until the deviation value is less than or equal to the preset threshold; through this closed-loop iterative calibration method, the angle deviation can be controlled within a very small range to ensure the adhesion accuracy.

[0033] In addition, such as Figures 6-8 As shown, the stop mechanism 300 consists of a pair of rollers 310, which protrude and rotatably set at one end of the substrate holder 100 in the material discharge direction. The rollers 310 switch between a stop state and a clearance state. In the stop state, the rollers 310 are vertical and protrude from the substrate surface, used to align and stop the front end of the polarizer conveyed to the substrate. In the clearance state, the rollers 310 deflect outward away from the front end face of the substrate, making room for subsequent rolling operations. Furthermore, the pair of rollers 310 roll and deflect along the end face of the substrate holder 100, which also helps to recalibrate the alignment between the polarizer and the end of the substrate.

[0034] The bonding mechanism 400 consists of an upper pressure roller 410 and a pair of lower clamping rollers 420 arranged vertically at intervals, and is located on the outer front end of the substrate base 100. The two ends of the upper pressure roller 410 and the outer ends of the pair of lower clamping rollers 420 are elastically connected by an elastic pre-tightening component. The upper pressure roller 410 and the pair of lower clamping rollers 420 are driven to move horizontally along the length of the substrate by a motor screw thread pair structure to clamp and roll the substrate and the polarizer on it to avoid slippage when rolling on the polarizer. When the bonding mechanism 400 moves horizontally to the outside of the material outlet of the substrate base 100, the trigger 440 triggers the pair of rollers 310 to switch from the stop state to the yield state to make room for subsequent rolling operations.

[0035] Furthermore, the outer circumferential surfaces of the roller 310 and the upper pressure roller 410 are provided with an anti-stick coating, which is a polytetrafluoroethylene (PTFE) coating or a ceramic coating. Since the front edge of the polarizer has an exposed pressure-sensitive adhesive layer, the anti-stick coating can effectively prevent the polarizer from sticking to the roller 310 during positioning, ensuring positioning accuracy and product yield.

[0036] Specifically, the stop mechanism 300 also includes a pair of rotating cylinders 320 rotatably connected to the end of the substrate base 100 in the discharge direction. The rotating cylinders 320 are horizontally mounted on the end face of the substrate base 100 by pins or bolts and can rotate. The rollers 310 are embedded in one side wall of the rotating cylinders 320. The upper half side wall of the rotating cylinders 320 is provided with an inclined linkage groove 321. The two ends of the linkage groove 321 penetrate the front and rear end faces of the rotating cylinders 320 along the axial direction of the rotating cylinders 320. That is, the linkage groove 321 is composed of an inclined groove section and straight groove ends at both ends.

[0037] The trigger element 440 consists of a pair of levers installed below the lower clamping roller 420. The levers engage with the linkage groove 321 and move horizontally to drive the rotating drum 320 to deflect, thereby switching the roller 310 to the yielding state. The centerline area of ​​the substrate base 100 and the processing table are lifted and fixedly installed by pads, so that the lower clamping roller 420 passes through the bottom surfaces of both sides of the long side of the substrate base 100 and cooperates with the upper pressure roller 410 to roll and attach the polarizer and substrate.

[0038] Furthermore, the outer wall of the rotating drum 320 is provided with a clearance groove 322 that communicates with both ends of the linkage groove 321. A guide plate 323 is provided at the intersection of the linkage groove 321 and the clearance groove 322. The guide plate 323 extends from the inclined side of the linkage groove 321. The normally closed state of the guide plate 323 is to close the clearance groove 322, so that the first lever moves laterally through the linkage groove 321 and drives the rotating drum 320 to deflect. The second lever enters from the clearance groove 322 and pushes open the guide plate 323 to turn to the turning point of the linkage groove 321, thus passing smoothly and avoiding interference.

[0039] It is worth noting that the spacing between the pair of levers is at least equal to the axial length of the rotating drum 320. The pair of levers are symmetrically arranged on both sides of the lower clamping roller 420. When rolling the polarizer, the first lever moves the linkage groove 321 to drive the rotating drum 320 to rotate downwards, and the second lever slides out from the upper clearance groove 322. When the attachment mechanism 400 returns to its original position, the second lever moves the linkage groove 321 to drive the rotating drum to rotate upwards to reset, and the first lever slides out from the lower clearance groove 322. This allows the pair of rollers 310 to automatically switch between the stop state and the clearance state.

[0040] The further motor lead screw threaded pair structure consists of a servo motor 430 and a lead screw 431 coaxially connected. A slider 422 is threadedly connected to the lead screw 431. Linear guide rails 450 are fixedly arranged on both sides of the base plate 100. The slider 422 is slidably engaged with the linear guide rails 450. The elastic pre-tightening assembly consists of an inner and outer sleeve 411 and a movable seat 421. A compression spring is fixed between the sleeve 411 and the movable seat 421 to provide an upward elastic pre-tightening force for the lower clamping roller 420. In the natural state of the compression spring, the upper pressure roller 410 is almost flush with the top surface of the substrate, leaving only the thickness of the polarizer. The top of the lower clamping roller 420 is higher than the bottom surface of the substrate seat 100. By providing a chamfer at the end edge of the bottom surface of the substrate seat 100, the lower clamping roller 420 can smoothly slide to the bottom surface of the substrate seat 100 and roll. At this time, the compression spring is stretched to form a pre-tightening force, so that the upper pressure roller 410 and the lower clamping roller 420 together clamp the polarizer and the substrate for rolling and attachment, avoiding the polarizer from slipping or shifting.

[0041] The high-precision polarizer attachment method of the present invention, using the above-mentioned high-precision polarizer attachment device with a pre-alignment calibration system at the feed end, includes the following steps: S1. Place the polarizer on the conveying mechanism 110 and convey it to the substrate holder 100 along the feeding direction; S2. When the polarizer is transported to the calibration mechanism 200, the vision inspection system acquires the long edge images of both sides of the substrate and the long edge images of both sides of the polarizer, respectively. The system extracts the edge straight lines through the image processing algorithm, calculates the angle deviation value θ between the long side of the polarizer and the long side of the substrate, and sends θ to the control unit. S3. The control unit controls the lifting drive to drive the turntable to rise and lift the polarizer. The control unit controls the rotation drive to drive the turntable to rotate by an angle θ to complete the angle pre-alignment calibration of the polarizer. After calibration, the polarizer is reset and transported. S4. The polarizer is conveyed to the top of the substrate, and its front end abuts against the outer peripheral surface of a pair of rollers 310 in a stop state, so as to align the front and rear ends of the polarizer with the substrate. S5. The upper pressure roller 410 and the lower clamping roller 420 are driven by the servo motor 430 to move towards the front end of the substrate. The trigger element triggers a pair of rollers 310 to switch from the stop state to the yield state. Thus, the upper pressure roller 410 and the lower clamping roller 420 move along the length of the substrate under the drive of the servo motor 430, and perform full-process clamping and rolling attachment of the substrate and polarizer, thus completing the attachment operation.

[0042] The device of this invention has a compact structure and a high degree of automation. It can be widely used in the polarizer bonding process of flat panel displays such as liquid crystal display panels and organic light-emitting diode display panels. It can also be extended to the field of precision bonding of other thin film materials and substrates, and has high industrial application value.

[0043] It should be noted that the fixed connection and fixing method of the present invention are achieved by conventional fixing means such as bolt connection, welding, or bonding that are compatible with each other. These are existing technologies and will not be described in detail here. The above embodiments are only for illustrating the technical concept and features of the present invention, and their purpose is to enable those skilled in the art to understand the content of the present invention and implement it accordingly. They should not be used to limit the scope of protection of the present invention. All equivalent changes or modifications made according to the spirit and essence of the present invention should be covered within the scope of protection of the present invention.

Claims

1. A high-precision polarizer attachment device with a pre-alignment calibration system at the feed end, characterized in that: Includes a substrate holder, which is lifted and mounted on a processing table for placing substrates; The conveying mechanism consists of two parallel and spaced conveyor belts, used to convey polarizing film along the feeding direction; The calibration mechanism is located between two conveyor belts and consists of a turntable, a lifting drive, and a rotating drive. The turntable is coaxially fixed to the output top of the lifting drive. The turntable rises to support the polarizer and the horizontal angle of the polarizer is adjusted by the rotating drive. The visual inspection system consists of at least two sets of visual sensors, which are respectively set above the long sides of the substrate and above the calibration mechanism. They are used to acquire images of the long edge of the polarizer and the long edge of the substrate, and calculate the angular deviation between them. The control unit is electrically connected to the vision inspection system, the lifting drive and the rotating drive respectively. The control unit receives the angle deviation value and controls the rotating drive to drive the turntable to rotate by the corresponding angle to complete the angle pre-alignment calibration of the polarizer. The stop mechanism consists of a pair of rollers that protrude and rotate at one end of the substrate holder in the material discharge direction. The rollers switch between a stop state and a yield state. In the stop state, the rollers are vertical and protrude from the substrate surface to align and stop the front end of the polarizer conveyed to the substrate. In the yield state, the rollers deflect outward away from the front end face of the substrate. The bonding mechanism consists of an upper pressure roller and a pair of lower clamping rollers arranged vertically at intervals, located on the outer side of the front end of the substrate holder. The two ends of the upper pressure roller and the outer ends of the pair of lower clamping rollers are elastically connected by an elastic pre-tightening assembly. The upper pressure roller and the pair of lower clamping rollers are driven to move horizontally along the length of the substrate by a motor screw thread pair structure to clamp and roll the substrate and the polarizer above it. When the bonding mechanism moves horizontally to the outside of the substrate holder's discharge end, a trigger element triggers the pair of rollers to switch from a stop state to a yield state.

2. The high-precision polarizer attachment device with a pre-alignment calibration system at the feed end according to claim 1, characterized in that: The visual inspection system includes an image processing module, which performs edge extraction and line fitting on the acquired long edge image of the polarizer and the long edge image of the substrate, respectively, and calculates the angle between the two fitted lines as the angle deviation value.

3. The high-precision polarizer attachment device with a pre-alignment calibration system at the feed end according to claim 2, characterized in that: The control unit is configured to: when the angle deviation value is greater than a preset threshold, control the rotary drive to drive the turntable to rotate by an angle deviation value, the vision detection system to collect the image again and calculate the deviation, and if it is still greater than the preset threshold, repeat the angle adjustment until the deviation value is less than or equal to the preset threshold.

4. The high-precision polarizer attachment device with a pre-alignment calibration system at the feed end according to claim 3, characterized in that: The stop mechanism also includes a pair of rotating drums rotatably connected to the end of the substrate seat in the discharge direction. The rollers are embedded in the side wall of one end of the rotating drum. The upper half of the side wall of the rotating drum is provided with an inclined linkage groove. The two ends of the linkage groove pass through the front and rear end faces of the rotating drum along the axial direction. The trigger is a pair of levers installed below the lower clamping roller. The levers engage with the linkage groove and move horizontally to drive the rotating drum to deflect, thereby switching the rollers to the yielding state.

5. The high-precision polarizer attachment device with a pre-alignment calibration system at the feed end according to claim 4, characterized in that: The outer wall of the rotating drum is provided with a clearance groove that communicates with both ends of the linkage groove. A guide plate is provided at the intersection of the linkage groove and the clearance groove. The guide plate extends along the inclined side of the linkage groove. The normally closed state of the guide plate is to close the clearance groove.

6. The high-precision polarizer attachment device with a pre-alignment calibration system at the feed end according to claim 5, characterized in that: The spacing between a pair of levers is at least equal to the axial length of the rotating drum. The pair of levers are symmetrically arranged on both sides of the lower clamping roller. When rolling polarizers, the first lever moves the linkage groove to drive the rotating drum to rotate downwards, and the second lever slides out from the upper clearance groove. When the bonding mechanism returns to its original position, the second lever moves the linkage groove to drive the rotating drum to rotate upwards to reset, and the first lever slides out from the lower clearance groove.

7. The high-precision polarizer attachment device with a pre-alignment calibration system at the feed end according to claim 6, characterized in that: The motor lead screw threaded pair structure consists of a servo motor and a lead screw coaxially connected. A slider is threadedly connected to the lead screw. Linear guide rails are fixedly installed on both sides of the base plate. The slider is slidably engaged with the linear guide rails.

8. The high-precision polarizer attachment device with a pre-alignment calibration system at the feed end according to claim 7, characterized in that: The elastic preload assembly consists of an inner and outer sleeve and a movable seat, with a compression spring fixedly installed between the sleeve and the movable seat to provide an elastic preload force for the lower clamping roller to move upward.

9. A method for attaching a high-precision polarizer with a pre-alignment calibration system at the feed end, using the high-precision polarizer attaching device with a pre-alignment calibration system at the feed end as described in claim 8, characterized in that: Includes the following steps: S1. Place the polarizer on the conveying mechanism and convey it to the substrate holder along the feeding direction; S2. When the polarizer is transported to the top of the calibration mechanism, the vision inspection system acquires images of the long edges of both sides of the substrate and the long edges of both sides of the polarizer, respectively. The system extracts the edge lines through the image processing algorithm, calculates the angle deviation value θ between the long edge of the polarizer and the long edge of the substrate, and sends θ to the control unit. S3. The control unit controls the lifting drive to drive the turntable to rise and lift the polarizer. The control unit controls the rotation drive to drive the turntable to rotate by an angle θ to complete the angle pre-alignment calibration of the polarizer. After calibration, the polarizer is reset and transported. S4. The polarizer is conveyed to the top of the substrate, and its front end abuts against the outer peripheral surface of a pair of rollers in a stop state, so as to align the front and rear ends of the polarizer with the substrate. S5. Drive the upper pressure roller and the lower clamping roller to move towards the front end of the substrate by the servo motor. Trigger the pair of rollers to switch from the stop state to the yield state by the trigger. Thus, the upper pressure roller and the lower clamping roller move along the length of the substrate under the drive of the servo motor, and perform full-process clamping and rolling attachment of the substrate and polarizer to complete the attachment operation.

10. The high-precision polarizer attachment method with a pre-alignment calibration system at the feed end according to claim 9, characterized in that, The image processing algorithm described in step S2 includes the following sub-steps: S21. Perform grayscale processing and binarization segmentation on the acquired long side image of the substrate and the long side image of the polarizer respectively, and extract the target edge region; S22. The Canny edge detection operator is used to extract the edges of the binarized image to obtain the edge pixel set. S23. The Hough transform line detection algorithm is used to fit the edge pixel point set with a straight line to obtain the long side fitting line L1 of the substrate and the long side fitting line L2 of the polarizer, respectively. S24. Calculate the angle θ between the fitted lines L1 and L2, which is taken as the angle deviation value. The calculation formula is as follows: Where k1 is the slope of the fitted line L1; k2 is the slope of the fitted line L2; The slope difference reflects the difference in the degree of inclination between the two straight lines; This is a correction factor to correct the deviation when simply calculating the included angle using the slope difference; The angle value is obtained by inversely calculating the arctangent function. Since the absolute value is taken in the formula, the actual output θ ranges from 0° to 90°, and the acute angle between the two lines is always output.

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