Thin film defect detection system and thin film production apparatus

Abstract

This utility model discloses a thin film defect detection system and thin film production equipment, relating to the technical field of thin film production equipment. The thin film defect detection system includes a first detection module, a second detection module, and a controller. The first detection module includes a first mounting bracket and a first camera. The first mounting bracket is fixedly mounted relative to the frame, and the first camera is mounted on the first mounting bracket and used to photograph the thin film located in a first region for initial inspection. The second mounting bracket is movably mounted on the frame. A light source unit is used to illuminate a local area of ​​the thin film located in a second region, and the second camera is used to photograph at least the thin film within the area illuminated by the light source unit for re-inspection. The second region is located downstream of the first region. The controller is electrically connected to the second mounting bracket and a work roller, and the controller is used to control the moving speed of the second mounting bracket to achieve synchronous movement between the second mounting bracket and the thin film. The technical solution provided by this utility model improves the reliability of thin film defect detection.

Description

Technical Field

[0001] This utility model relates to the field of thin film production equipment technology, and in particular to a thin film defect detection system and thin film production equipment. Background Technology

[0002] MDO (Mixed Fiber Oxide) production lines are key equipment in plastic film manufacturing. They alter the physical properties of the film through longitudinal stretching, improving its mechanical properties and transparency. After the MDO process, film defects (such as scratches, bubbles, and crystal points) directly affect product quality and end-application performance; therefore, efficient and reliable testing technology is crucial.

[0003] The typical inspection process includes initial inspection and re-inspection. The initial inspection is performed by an automated vision inspection system, while the re-inspection is performed by manual observation. The vision inspection system used in the initial inspection usually consists of multiple cameras distributed laterally for automated visual inspection. Because the thin film moves at high speeds during operation, defects such as bubbles and crystal points captured by the cameras often appear as shadows, making it difficult to accurately distinguish between different types of defects. Therefore, manual visual inspection is necessary for supplementary re-inspection.

[0004] However, manual re-inspection is limited by factors such as subjective experience differences, low detection efficiency, insufficient consistency, and fatigue from long hours of work, which can easily lead to fluctuations in the accuracy of judgment and low efficiency, thus affecting the reliability of thin film defect detection. Utility Model Content

[0005] The main objective of this invention is to propose a thin film defect detection system, which aims to improve the reliability of thin film defect detection.

[0006] To achieve the above objectives, the present invention proposes a film defect detection system applied to film production equipment. The film production equipment includes a frame and multiple work rollers spaced apart on the frame. The frame has an inlet end and an outlet end. The work rollers act on the film, enabling the film to move from the inlet end to the outlet end. The film defect detection system includes:

[0007] The first detection module includes a first mounting bracket and a first camera. The first mounting bracket is fixedly disposed relative to the frame. The first camera is mounted on the first mounting bracket and is used to photograph the film located in the first area to achieve initial inspection.

[0008] The second detection module is electrically connected to the first detection module. The second detection module includes a second mounting bracket, a second camera and a light source unit mounted on the second mounting bracket. The second mounting bracket is movably mounted on the frame. The light source unit is used to irradiate a local area of ​​the film located in the second region. The second camera is used to photograph at least the film within the area irradiated by the light source unit to achieve re-inspection. The second region is located downstream of the first region.

[0009] The controller is electrically connected to the second mounting bracket and the working roller. The controller is used to control the moving speed of the second mounting bracket so as to realize the synchronous movement of the second mounting bracket and the film.

[0010] In one embodiment, the thin film defect detection system includes a first driving member and a second driving member. The second mounting bracket includes a first frame and a second frame. The first frame is disposed on the frame, and the first driving member drives and connects to the first frame so that the first frame can move relative to the frame along a first direction. The second frame is disposed on the first frame, and the second driving member drives and connects to the second frame so that the second frame can move relative to the first frame along a second direction. The first direction and the second direction are intersecting.

[0011] In one embodiment, the thin film defect detection system further includes a third driving member, and the second mounting bracket further includes a third frame disposed on the second frame. The third driving member drives the third frame to move relative to the second frame along a third direction, wherein the first direction, the second direction, and the third direction are arranged to intersect each other.

[0012] In one embodiment, the thin film defect detection system further includes an arc-shaped drive component, an arc-shaped grating ruler, and a rotary bearing mounted on the third frame. The second mounting bracket also includes a fourth frame, which is sleeved on the rotary bearing. The second camera and the light source unit are mounted on the fourth frame.

[0013] In one embodiment, the light source unit includes a mounting box, a beam splitter, and a coaxial light source. The mounting box has an opening corresponding to the second camera for the optical axis of the second camera to pass through. The beam splitter is disposed inside the mounting box corresponding to the opening and is inclined. The coaxial light source is disposed inside the mounting box and is disposed on the side of the beam splitter near the frame.

[0014] In one embodiment, the light source unit further includes a side light source, which is located on the side of the mounting box near the frame, and the connecting line between the side light source and the second camera forms an angle with the optical axis of the second camera.

[0015] In one embodiment, there are multiple side light sources, which are spaced apart along the optical axis of the second camera. The angle between the connecting line between at least one side light source and the second camera and the optical axis of the second camera is greater than the angle between the connecting line between another side light source and the second camera and the optical axis of the second camera.

[0016] In one embodiment, the side light source is configured as a red light source and / or a blue light source.

[0017] This utility model also proposes a thin film production equipment, including the aforementioned thin film defect detection system.

[0018] In one embodiment, the frame includes an inlet section, a working section, and an outlet section that are sequentially distributed along the direction from the inlet end to the outlet end, and each of the inlet section, the working section, and the outlet section is provided with at least the second detection module.

[0019] This invention's technical solution, by setting a first detection module fixed relative to the frame and a second detection module movable relative to the frame, enables a first camera to perform initial inspection of the film and monitor its overall condition in real time. The second camera then performs a re-inspection based on the target areas of defects detected by the first camera. Driven by a second mounting bracket, the second camera moves synchronously with the film and images, effectively avoiding image blurring or shadow interference, further improving the accuracy of defect type identification, and thus providing a more comprehensive and accurate assessment of film quality. This solution not only balances detection speed and accuracy to meet the online inspection needs of production lines but also ensures the accuracy of defect identification, thereby reducing reliance on manual re-inspection, minimizing misjudgments and accuracy fluctuations caused by human factors, improving the consistency, stability, and reliability of inspection results, and increasing inspection efficiency. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of this utility model 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 some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0021] Figure 1 A schematic diagram of the structure of an embodiment of the film production equipment provided by this utility model;

[0022] Figure 2 for Figure 1 Cross-sectional view of the thin film production equipment in the diagram;

[0023] Figure 3 forFigure 1 A schematic diagram of the structure of the second detection module in one embodiment;

[0024] Figure 4 for Figure 1 A cross-sectional view of an embodiment of the second camera and light source unit;

[0025] Figure 5 A schematic diagram of the fourth frame of this utility model being fitted onto the rotary bearing.

[0026] Explanation of icon numbers:

[0027] 10. Frame; 20. Work roller; 30. Film; 100. First detection module; 200. Second detection module; 101. Inlet end; 102. Outlet end; 110. First mounting bracket; 120. First camera; 210. Second mounting bracket; 211. First frame; 212. Second frame; 213. Third frame; 214. Fourth frame; 220. Second camera; 230. Light source unit; 231. Mounting box; 2311. Port; 232. Beam splitter; 233. Coaxial light source; 234. Side light source; 2341. Red light source; 2342. Blue light source; 310. First drive component; 320. Second drive component; 330. Third drive component; 340. Arc-shaped drive component; 350. Arc-shaped grating ruler; 360. Rotary bearing.

[0028] The realization of the purpose, functional features and advantages of this utility model will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0029] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present utility model.

[0030] It should be noted that if the embodiments of this utility model involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of the components in a specific posture. If the specific posture changes, the directional indicators will also change accordingly.

[0031] Furthermore, if the embodiments of this utility model involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the use of "and / or" or "and / or" throughout the text includes three parallel solutions. For example, "A and / or B" includes solution A, solution B, or a solution where both A and B are satisfied simultaneously. Furthermore, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this utility model.

[0032] This invention proposes a thin film defect detection system.

[0033] Please see Figure 1 and Figure 2 In one embodiment of this utility model, a film defect detection system is applied to a film production equipment. The film production equipment includes a frame 10 and a plurality of work rollers 20 spaced apart on the frame 10. The frame 10 has an inlet end 101 and an outlet end 102. The work rollers 20 act on the film 30, enabling the film 30 to move from the inlet end 101 to the outlet end 102. The film defect detection system includes a first detection module 100, a second detection module 200, and a controller. The first detection module 100 includes a first mounting bracket 110 and a first camera 120. The first mounting bracket 110 is fixedly disposed relative to the frame 10. The first camera 120 is mounted on the first mounting bracket 110 and is used to photograph the film 30 located in a first region to detect defects. Initial inspection is performed; the second inspection module 200 is electrically connected to the first inspection module 100. The second inspection module 200 includes a second mounting bracket 210, a second camera 220 mounted on the second mounting bracket 210, and a light source unit 230. The second mounting bracket 210 is movably mounted on the frame 10. The light source unit 230 is used to irradiate a local area of ​​the film 30 located in the second region. The second camera 220 is used to photograph at least the film 30 within the area irradiated by the light source unit 230 to achieve re-inspection. The second region is located downstream of the first region. The controller is electrically connected to the second mounting bracket 210 and the work roller 20. The controller is used to control the moving speed of the second mounting bracket 210 to achieve synchronous movement of the second mounting bracket 210 and the film 30.

[0034] In the production process of film 30, the MDO (Machine Direction Orientation) is one of the key pieces of equipment. It is responsible for shaping the molecular orientation of film 30 in the direction from the inlet end 101 to the outlet end 102 through heating and stretching, thereby improving the mechanical strength, transparency, and barrier properties of film 30. The film production equipment includes a frame 10 and multiple spaced work rolls 20. The frame 10 serves as a support carrier, providing a mounting base for components such as the work rolls 20 and the film defect detection system. The work rolls 20 continuously transport film 30 from the inlet end 101 to the outlet end 102 through mechanical transmission (such as motor drive), completing processes such as preheating, stretching, cooling, and winding.

[0035] The thin film defect detection system is a key piece of equipment for quality monitoring during the production process of thin film 30. It is mainly used for real-time detection of surface and internal defects of thin film 30 (such as scratches, bubbles, crystal points, uneven thickness, color deviation, etc.) to ensure that the thin film 30 product meets quality standards. The thin film defect detection system includes a first detection module 100 and a second detection module 200, which work together to cover the defect detection needs of different areas and types of defects in thin film 30.

[0036] Specifically, the first detection module 100 is fixed relative to the frame 10. The first detection module 100 includes a first mounting bracket 110 fixedly disposed relative to the frame 10, and a first camera 120 is mounted on the first mounting bracket 110, that is, the position of the first camera 120 relative to the frame 10 is fixed. The first camera 120 can be installed at the entrance end 101, the exit end 102, or the middle area of ​​the frame 10 for preliminary inspection of the film 30, and can achieve full coverage of the detection area of ​​the film 30 in the width direction.

[0037] However, the film 30 operates at a relatively high speed, and the defects such as bubbles and crystal points captured by the first camera 120 often appear as shadows, making it difficult to accurately distinguish between at least these two types of defects. The information on the defect type received by the upstream production process is inaccurate, which is not conducive to timely adjustment of parameters according to the defect type.

[0038] The second detection module 200 includes a second mounting bracket 210 movable along the frame 10, a second camera 220 mounted on the second mounting bracket 210, and a light source unit 230. The controller can acquire the rotational speed of the work roller 20 and calculate the running speed of the film 30 accordingly. Simultaneously, the controller can adjust the moving speed of the second mounting bracket 210 so that the moving speed of the second detection module 200 in the first direction is synchronized or nearly synchronized with the moving speed of the film 30. In this way, the second camera 220 can stably acquire clearer images during the running of the film 30, avoiding the appearance of bubbles, crystal points, and other defects as blurry shadows in the image due to speed differences, thereby improving the accuracy of defect identification. Through accurate identification of defect types, the detection system can feed back the detection results to the upstream production process, facilitating the adjustment of relevant process parameters according to the specific defect type, ultimately optimizing product quality.

[0039] Understandably, the first camera 120 captures real-time images of the thin film 30 located in the first region, completing a preliminary inspection, identifying target areas that may contain defects, and recording and transmitting the relevant location information to the control system. As the thin film 30 continues to operate, when the defective area moves to the second region, the control system controls the second camera 220 to perform a precise re-inspection of the target area based on the preliminary inspection results. At this time, the second camera 220, combined with the local illumination of the light source unit, moves synchronously with the thin film 30 and images under the drive of the second mounting bracket, thereby effectively avoiding image blurring or shadow interference. Through the secondary inspection by the second camera 220, not only can the existence of defects be verified, but their specific types can also be further identified, thereby improving the accuracy and reliability of defect identification.

[0040] The light source unit 230 can utilize different types of light sources. For example, a side-light source creates shadows on the surface of the thin film 30 through oblique incident light, amplifying the contrast of minute scratches and bumps. A coaxial light source 233, with perpendicular incident light, enters the camera after reflection from the thin film 30, suitable for detecting the thickness uniformity (interference fringes) or minute surface protrusions of transparent / semi-transparent thin films 30. Light sources of different wavelengths can also be selected. For instance, an ultraviolet light source can enhance the fluorescence properties of certain contaminants or crystal points, facilitating identification; an infrared light source can penetrate part of the thin film 30 material (such as amorphous polymers) to detect internally embedded bubbles, impurities, or delamination defects. This multi-light source synergy significantly improves the ability to identify low-contrast, small-sized, and texture-superimposed defects, compensating for the shortcomings of traditional single natural light source detection, thereby reducing the false negative rate and improving the detection accuracy of complex defects.

[0041] In addition, the controller of the thin film defect detection system can further realize functions such as defect classification, alarm prompts, and data recording based on the image information collected by the first camera 120 and the second camera 220 and subsequent image processing algorithms. It can also feed back to the upstream process (such as adjusting the stretching temperature and cooling rate) according to the defect type, size and distribution to achieve closed-loop quality control and improve production efficiency and product yield.

[0042] It is worth mentioning that the second detection module 200 also has a sampling inspection function. When the system is idle or under low load, the second detection module 200 can randomly sample areas that the first camera 120 has determined to be non-defective, thereby effectively verifying and supplementing the initial inspection results. This helps to discover minor defects that may have been missed in the initial inspection, reducing the risk of missed detections and further improving the reliability and accuracy of the inspection results. It should be noted that the idle state refers to the period during which the first detection module 100 does not detect any defects and the second detection module 200 does not need to perform the re-inspection function.

[0043] The technical solution of this utility model, by setting a first detection module 100 fixed relative to the frame 10 and a second detection module 200 movable relative to the frame 10, enables the first camera 120 to perform initial inspection of the film 30 and monitor the overall state of the film 30 in real time; the second camera 220 performs re-inspection based on the target area of ​​defects detected by the first camera 120. Driven by the second mounting bracket, the second camera 220 moves synchronously with the film 30 and images, which can effectively avoid image blurring or shadow interference, further improve the accuracy of defect type identification, and more comprehensively and accurately assess the quality of the film 30. This solution not only balances detection speed and accuracy to meet the online detection needs of the production line, but also ensures the accuracy of defect identification, thereby reducing reliance on manual re-inspection, reducing misjudgments and accuracy fluctuations caused by human factors, improving the consistency, stability and reliability of detection results, and increasing detection efficiency.

[0044] In one implementation, please refer to Figure 1 and Figure 3 The thin film defect detection system includes a first driving component 310 and a second driving component 320. The second mounting bracket 210 includes a first frame 211 and a second frame 212. The first frame 211 is disposed on the frame 10. The first driving component 310 drives and connects to the first frame 211 so that the first frame 211 can move relative to the frame 10 along a first direction. The second frame 212 is disposed on the first frame 211. The second driving component 320 drives and connects to the second frame 212 so that the second frame 212 can move relative to the first frame 211 along a second direction. The first direction and the second direction are intersecting.

[0045] Referring to the general operating state of the film production equipment, the first direction corresponds to the film conveying direction, and the second direction corresponds to the film width direction. When the film production equipment is used in other states, the first and second directions can also be other directions. As the film 30 moves from the inlet end 101 to the outlet end 102, the first detection module 100 quickly captures the overall state of the film 30 located in the first area using a fixed first camera 120 for initial detection. When the first camera 120 does not find any defective areas, the second detection module 200 can perform random checks at any position. When the first camera 120 finds a defective target area, the first drive component 310 drives the first frame 211 to move synchronously with the film 30, while the second drive component 320 drives the second frame 212 to move along the second direction, so that the second camera 220 and the light source unit 230 are precisely aligned with the target area. The second camera 220 acquires images and combines them with image processing algorithms to complete defect identification. The detection results are fed back to the control system for quality judgment or parameter adjustment.

[0046] The first drive unit 310 can drive the first frame 211 to move relative to the frame 10 along a first direction. Under the control of the controller, the second camera 220 can move synchronously with the film 30 to obtain clear images and improve the accuracy of defect type identification. The second drive unit 320 can drive the second frame 212 to move relative to the first frame 211 along a second direction, so that the second detection module 200 can be arbitrarily positioned on the two-dimensional plane and accurately aligned with the target area of ​​the film 30 for re-inspection. The first drive unit 310 and the second drive unit 320 can be cylinders, servo motors, etc.

[0047] In one implementation, please refer to Figure 1 and Figure 3 The thin film defect detection system also includes a third drive component 330, and the second mounting bracket 210 also includes a third frame 213 disposed on the second frame 212. The third drive component 330 drives and connects to the third frame 213 so that the third frame 213 can move relative to the second frame 212 along a third direction. The first direction, the second direction and the third direction are arranged to intersect each other.

[0048] With reference to the general operating state of the film production equipment, the third direction is the height direction of the frame 10. When the film production equipment is used in other states, the third direction can also be other directions. The third drive unit 330 can drive the third frame 213 to move relative to the second frame 212 along the third direction, realizing the adjustment of the second camera 220 and the light source unit 230 in the third direction, so as to adjust the distance between the second camera 220 and the work roller 20. The multiple work rollers 30 have a certain height difference in the third direction to realize functions such as tensioning and stretching of the film 20. The distance between the work roller 20 and the second camera 220 is different at different positions, and the distance between the film 30 and the second camera is also different at the corresponding positions. By enabling the third frame 213 to move along the third direction, the distance between the second camera 220 and the film 30 can be adjusted, thereby ensuring that the second camera 220 is always in the optimal focal length position at different positions, effectively improving the image clarity and defect recognition rate. The third drive unit 330 can be a cylinder, servo motor, etc.

[0049] In other embodiments, the second mounting bracket 210 may also be configured as a SCARA robot arm, enabling the second camera 220 and the light source unit 230 to move in the first, second, and third directions through multi-joint linkage.

[0050] In one implementation, please refer to Figure 1 , Figure 3 and Figure 5 The thin film defect detection system also includes an arc-shaped drive unit 340, an arc-shaped grating ruler 350 and a rotary bearing 360 installed on the third frame 213. The second mounting bracket 210 also includes a fourth frame 214, which is fitted onto the rotary bearing 360. The second camera 220 and the light source unit 230 are installed on the fourth frame 214.

[0051] The third frame 213 has a mounting protrusion passing through the inner ring of the rotary bearing 360, allowing the rotary bearing 360 to be mounted on the third frame 213. The arc-shaped drive member 340 drives the fourth frame 214 to rotate around the rotary bearing 360, thereby enabling the second detection module 200 to rotate around the rotation axis. When the second camera 220 captures images of the thin film 30 in the tilted area, the optical axis of the second camera 220 can be made perpendicular to the surface of the thin film 30 by rotating the fourth frame 214, thus allowing the second camera 220 to acquire more realistic and clearer images. In addition, the rotation angle of the fourth frame 214 can be linked to the movement distance of the first frame 211 in the first direction, ensuring that the optical axis of the second camera 220 is perpendicular to the surface of the thin film 30 during the movement of the first frame 211 in the first direction. For thin films 30 with slight undulations, wavy deformations, or uneven thickness, the rotation angle can be matched to their surface morphology to maintain the optimal shooting posture between the second camera 220 and the thin film 30, avoiding defocusing or misjudgment due to deformation. The 350 arc-shaped grating ruler is used to accurately feedback the rotation angle, realizing high-precision closed-loop feedback of the rotation angle. Combined with a PLC or vision controller, it can realize functions such as automatic angle compensation and adaptive adjustment, significantly improving system stability and intelligent control level.

[0052] In other embodiments, a stepper motor or servo motor can be used to drive a drive gear, which meshes with a driven gear fixed on the fourth frame 214, thereby causing the fourth frame 214 to rotate. A magnetic encoder is installed on the fourth frame 214 to provide real-time feedback on the rotation angle, and precise control is achieved through a motor or other drive device.

[0053] In one implementation, please refer to 3 and Figure 4 The light source unit 230 includes a mounting box 231, a beam splitter 232, and a coaxial light source 233. The mounting box 231 has an opening 2311 for the optical axis of the second camera 220 to pass through. The beam splitter 232 is located inside the mounting box 231 corresponding to the opening 2311 and is inclined. The coaxial light source 233 is located inside the mounting box 231 and is located on the side of the beam splitter 232 near the frame 10.

[0054] Mounting housing 231 is used to carry and protect internal optical components (such as beam splitter 232 and coaxial light source 233) from environmental dust interference, while also fixing the optical path structure. Beam splitter 232 is mounted at a 45° angle inside mounting housing 231 and is positioned corresponding to the port 2311 of second camera 220. It is used to reflect the light emitted by coaxial light source 233 onto the surface of thin film 30 and to directionally transmit the reflected light from thin film 30 to the lens of second camera 220. Optionally, beam splitter 232 can be a prism beam splitter 232, thin film 30 beam splitter 232, etc.

[0055] Please refer to Figure 4. The dotted lines and arrows in the figure represent the illumination path of the coaxial light source 233. The second camera 220 is aligned with the area of ​​the film 30 to be inspected through the port 2311. The coaxial light source 233 is located on the side of the beam splitter 232 near the frame 10, directly illuminating the beam splitter 232. The coaxial light source 233 is a high-density LED array. After being homogenized by a diffuser plate, the light is reflected by the beam splitter 232. The reflected light is perpendicular to the optical axis of the second camera 220 and illuminates the surface of the film 30. The light reflected from defects or textures on the surface of the film 30 passes through the beam splitter 232 again and enters the lens of the second camera 220. The second camera 220 acquires images and extracts high-quality image information by combining the characteristics of the light source. The coaxial light source 233, in conjunction with the beam splitter 232, ensures that the illumination direction coincides with the optical axis of the second camera 220, thereby ensuring that the illumination optical path coincides with the imaging optical path. This effectively reduces shadow and reflection interference, avoids specular glare from highly reflective surfaces and uneven illumination caused by optical path offset in traditional side lighting or backlighting, and ensures clear imaging of defect details (scratches, bubbles, crystal points, etc.). It is especially suitable for detecting micro-defects on the surface of transparent or semi-transparent thin films 30.

[0056] In one implementation, please refer to Figure 3 and Figure 4 The light source unit 230 also includes a side light source 234, which is located on the side of the mounting box 231 near the frame 10. The connecting line between the side light source 234 and the second camera 220 forms an angle with the optical axis of the second camera 220.

[0057] The connecting line between the side-light source 234 and the second camera 220 forms an angle with the optical axis of the second camera 220. This means the side-light source 234 illuminates the surface of the thin film 30 at a certain angle. By utilizing the differences in reflection, refraction, scattering, or transmission of light on the surface of the thin film 30, defects in the thin film 30 are presented with high contrast in the image, facilitating capture and analysis by the second camera 220. Since the side-light source 234 illuminates from the side, it creates shadows on defects such as scratches, bubbles, and crystal points on the thin film 30, making them more prominent and easier to identify. The side-light source 234 is particularly suitable for detecting low-contrast defects, improving reflection interference and enhancing image stability. The LEDs of the side-light source 234 can be located on one side of the outer periphery of the mounting box 231, on opposite sides of the outer periphery of the mounting box 231, or distributed circumferentially along the mounting box 231. When the side-light source 234 is working, depending on the illumination requirements, only one side of the LEDs can be used for illumination, or multiple sides can be used simultaneously.

[0058] Depending on the shooting environment, the side-light source 234 and the coaxial light source 233 can operate independently or in conjunction. When they operate in conjunction, the side-light source 234 and the coaxial light source 233 illuminate the film sequentially according to a set time sequence, while the second camera 220 captures images at different times to obtain images with different imaging effects. By fusing these image information, comprehensive and accurate detection of surface defects on the thin film 30 can be achieved. Specifically, the second camera 220 is aligned with the area of ​​the thin film 30 to be inspected through the port 2311; the coaxial light source 233 in the light source unit 230 provides front illumination to identify minute defects in flat areas; the side-light source 234 illuminates the surface of the thin film 30 at a certain angle to enhance edges, textures, or height differences, or to suppress reflections and enhance contrast, so that the light reflected from the surface defects or textures of the thin film 30 enters the lens of the second camera 220 to form a clear image, thereby improving the recognition accuracy and achieving comprehensive, high-quality imaging and stable detection of surface defects on the thin film 30.

[0059] In other embodiments, the light source unit 230 may also include a backlight source, with the thin film 30 located between the backlight source and the second camera 220. Light is incident perpendicularly from the back of the thin film 30, and after passing through the thin film 30, the transmitted light is received by the second camera 220. Defects such as bubbles, crystal points, and uneven thickness will cause changes in the intensity of transmitted light due to light scattering or absorption, thus presenting differences in brightness in the image and realizing the function of defect detection. Furthermore, polarizers or multispectral technology can be combined to infer the thickness of the thin film 30 from the transmitted light intensity distribution, realizing online measurement of the thickness of the thin film 30.

[0060] In one implementation, please refer to Figure 3 and Figure 4 Multiple side light sources 234 are provided, and the multiple side light sources 234 are distributed at intervals along the optical axis of the second camera 220. The angle formed by the connecting line between at least one side light source 234 and the second camera 220 and the optical axis of the second camera 220 is greater than the angle formed by the connecting line between another side light source 234 and the second camera 220 and the optical axis of the second camera 220.

[0061] Multiple side-light sources 234 are arranged in a stepped pattern along the optical axis of the second camera 220. The side-light sources 234 closer to the second camera 220 are closer to the optical axis and form an angle α with it; the side-light sources 234 farther from the second camera 220 are farther from the optical axis and form an angle β with it, where β is greater than α. This allows the side-light sources 234 at different positions along the optical axis to illuminate the surface of the thin film 30 at different angles, enabling multi-dimensional feature extraction of the thin film 30 surface. Specifically, low-angle light sources enhance the detail of surface smoothness and texture, while medium- and high-angle light sources strengthen the contrast of minute scratches and edge protrusions. Addressing the glare or localized overexposure issues common in high-reflectivity thin film 30 materials, the multi-angle light sources effectively eliminate illumination blind spots through combined illumination, resulting in a more uniform and stable image output. Multiple side light sources 234 together form a multi-angle lighting system, which can specifically highlight different types of defects (such as scratches, bumps, texture abnormalities, etc.) and realize flexible switching between low-angle and high-angle composite lighting modes, thereby adapting to various material properties and defect types.

[0062] In other embodiments, only one side light source 234 may be provided.

[0063] In one implementation, please refer to Figure 4 The side light source 234 is configured as a red light source 2341 and / or a blue light source 2342.

[0064] The red light source 2341 is configured as a red light-emitting LED, and the blue light source 2342 is configured as a blue light-emitting LED. The red light source 2341 and the blue light source 2342 can be positioned at different tilt angles, and can operate independently or in conjunction. When operating in conjunction, the red light source 2341 and the blue light source 2342 illuminate sequentially according to a set time sequence, while the second camera 220 captures images at different times, obtaining images with different imaging effects. Therefore, the combination of the red light source 2341 and the blue light source 2342 can cover the detection needs of both surface and internal defects.

[0065] The red light emitted by the red light source 2341 has a longer wavelength and stronger light penetration, making it sensitive to minute undulations (such as scratches and pits) on the surface of the film 30. Furthermore, it exhibits less attenuation in transparent / semi-transparent films 30 (such as PET and CPP), making it suitable for detecting surface scratches, color unevenness, crystal points, and other defects. For example, red light has a high reflectivity on the surface of the transparent film 30. Scratches, due to surface deformation, experience enhanced diffuse reflection, resulting in a significant difference in grayscale compared to normal areas, creating a high-contrast feature.

[0066] The blue light emitted by the blue light source 2342 has a short wavelength and strong light scattering properties, making it easily scattered by tiny particles (such as bubbles and impurities) inside the thin film 30. This makes it suitable for detecting internal defects such as bubbles, delamination, and inclusions. For example, when blue light propagates inside the thin film 30, it will be strongly scattered when it encounters bubbles (whose refractive index differs greatly from that of the thin film 30). The brightness of the bubble area in the transmitted light captured by the camera is significantly lower than that of the normal area, forming a clear defect image.

[0067] In a thin film defect detection system, the wavelength selection of the side-light source 234 can be comprehensively designed based on the material properties of the thin film 30, the defect type, and the detection requirements. In other embodiments, the side-light source 234 can also be configured as a light source capable of emitting ultraviolet, infrared, or green light.

[0068] This utility model also proposes a film production equipment, which includes a frame 10, a work roller 20 disposed on the frame 10, and a film defect detection system. The specific structure of the film defect detection system is as described in the above embodiments. Since this film production equipment adopts all the technical solutions of all the above embodiments, it has at least all the beneficial effects brought about by the technical solutions of the above embodiments, which will not be described in detail here.

[0069] In one embodiment, the frame 10 includes an inlet section, a working section and an outlet section that are sequentially distributed along the direction from the inlet end 101 to the outlet end 102, and each of the inlet section, the working section and the outlet section is provided with at least a second detection module 200.

[0070] The inlet section is located near the feeding end of the film 30, the outlet section is located near the discharging end of the film 30, and the working section is located between the inlet and outlet sections. The inlet, working, and outlet sections are distributed sequentially along the running direction of the film 30. Each section is equipped with at least a second detection module 200. Alternatively, each section may have both a first detection module 100 and a second detection module 200; or the first detection module 100 may be located in the inlet section and / or the working section, and the second detection module 200 may be located in each section. The detection modules in each section work together to achieve quality monitoring of the film 30 at different process stages.

[0071] The second detection module 200 located at the inlet section is used for initial state detection of the film 30 to obtain its original defects, thus characterizing the quality of the incoming material from the previous process. The second detection module 200 located in the working section is used for process detection of the film 30 to obtain cracks, stress deformation, and local thickness changes generated during the stretching process. The detection module located at the outlet section is used for final inspection of the finished film 30 to obtain its final defects, conduct an overall quality assessment, and confirm whether it meets the finished product standards. By installing at least one second detection module 200 at the inlet, working, and outlet sections of the frame 10, the system achieves full-process defect tracking and quality assessment of the film 30 during the longitudinal stretching process, from raw material input and stretching to finished product output. Multi-segment collaborative detection can also be used for defect tracing, determining whether the defect is in the raw material or a new defect generated during processing, providing a basis for subsequent process adjustments. If an abnormal defect increase trend is detected in the working section, the system can immediately issue an early warning and coordinate with the control system to adjust parameters such as stretching speed and temperature to prevent the generation of batch defective products. By comparing the initial image of the inlet section with the final image of the outlet section, new defects generated during processing can be identified. Subsequently, the second detection module 200 of the working section can be used for further investigation to accurately locate the position of the new defect and analyze and deal with its cause.

[0072] In other embodiments, a film defect detection system may also be provided in the working section and / or the exit section. Alternatively, only one film defect detection system may be provided, wherein a first detection module 100 is located in the inlet section, a second detection module 200 is located downstream of the first detection module 100, and the second detection module 200 can move freely between the inlet section, the working section, and the exit section.

[0073] The above description is merely an exemplary embodiment of the present utility model and does not limit the scope of protection of the present utility model. Any equivalent structural transformations made based on the technical concept of the present utility model and the contents of the present utility model specification and drawings, or direct / indirect applications in other related technical fields, are included within the scope of protection of the present utility model.

Claims

1. A thin film defect detection system, applied to a thin film production equipment, the thin film production equipment comprising a frame and a plurality of work rollers spaced apart on the frame, the frame having an inlet end and an outlet end, the work rollers acting on the thin film, the thin film being movable from the inlet end to the outlet end, characterized in that, The thin film defect detection system includes: The first detection module includes a first mounting bracket and a first camera. The first mounting bracket is fixedly disposed relative to the frame. The first camera is mounted on the first mounting bracket and is used to photograph the film located in the first area to achieve initial inspection. The second detection module is electrically connected to the first detection module. The second detection module includes a second mounting bracket, a second camera and a light source unit mounted on the second mounting bracket. The second mounting bracket is movably mounted on the frame. The light source unit is used to irradiate a local area of ​​the film located in the second region. The second camera is used to photograph at least the film within the area irradiated by the light source unit to achieve re-inspection. The second region is located downstream of the first region. The controller is electrically connected to the second mounting bracket and the working roller. The controller is used to control the moving speed of the second mounting bracket so as to realize the synchronous movement of the second mounting bracket and the film.

2. The thin film defect detection system as described in claim 1, characterized in that, The thin film defect detection system includes a first driving component and a second driving component. The second mounting bracket includes a first frame and a second frame. The first frame is disposed on the frame. The first driving component drives and connects to the first frame so that the first frame can move relative to the frame in a first direction. The second frame is disposed on the first frame, and the second drive unit drives the second frame to move relative to the first frame in a second direction, wherein the first direction and the second direction are intersecting.

3. The thin film defect detection system as described in claim 2, characterized in that, The thin film defect detection system further includes a third driving component, and the second mounting bracket further includes a third frame disposed on the second frame. The third driving component drives and connects to the third frame so that the third frame can move relative to the second frame along a third direction. The first direction, the second direction, and the third direction are arranged to intersect each other.

4. The thin film defect detection system as described in claim 3, characterized in that, The thin film defect detection system also includes an arc-shaped drive component, an arc-shaped grating ruler, and a rotary bearing installed on the third frame. The second mounting bracket also includes a fourth frame, which is sleeved on the rotary bearing. The second camera and the light source unit are installed on the fourth frame.

5. The thin film defect detection system as described in claim 1, characterized in that, The light source unit includes a mounting box, a beam splitter, and a coaxial light source. The mounting box has an opening corresponding to the second camera for the optical axis of the second camera to pass through. The beam splitter is located inside the mounting box corresponding to the opening and is inclined. The coaxial light source is located inside the mounting box and is located on the side of the beam splitter close to the frame.

6. The thin film defect detection system as described in claim 5, characterized in that, The light source unit also includes a side light source, which is located on the side of the mounting box near the frame. The connection line between the side light source and the second camera forms an angle with the optical axis of the second camera.

7. The thin film defect detection system as described in claim 6, characterized in that, The side light source is provided in multiple ways, and the multiple side light sources are distributed at intervals along the optical axis of the second camera. The angle formed by the connecting line between at least one side light source and the second camera and the optical axis of the second camera is greater than the angle formed by the connecting line between another side light source and the second camera and the optical axis of the second camera.

8. The thin film defect detection system as described in claim 6, characterized in that, The side light source is configured as a red light source and / or a blue light source.

9. A thin film production equipment, characterized in that, Including the thin film defect detection system as described in any one of claims 1 to 8.

10. The thin film production equipment as described in claim 9, characterized in that, The frame includes an inlet section, a working section, and an outlet section distributed sequentially along the direction from the inlet end to the outlet end, and each of the inlet section, the working section, and the outlet section is provided with at least the second detection module.

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