Thin film defect detection system based on differential interference imaging technology

Abstract

The invention relates to the technical field of film defect detection, and discloses a film defect detection system based on differential interference imaging technology, comprising: a frame provided with a transmission module for transmitting a film to be detected; the visual detection module is arranged in the rack and is used for carrying out defect detection on the thin film in the conveying process; the visual detection module comprises a differential interference visual detection unit, a lighting unit and an adjusting unit. According to the thin film defect detection system based on the differential interference imaging technology, the angles of the differential interference visual detection unit and the illumination unit can be synchronously adjusted, illumination treatment can be performed on a thin film in real time, and bending treatment can be performed on the thin film to be detected; further, defects on the surface of the thin film are deformed or displaced under the action of bending stress, and the defect exposure effect is enhanced; and real-time detection of the film in different bending states is carried out in cooperation with the differential interference visual detection unit.

Description

Technical Field

[0001] This invention relates to the field of thin film defect detection technology, specifically a thin film defect detection system based on differential interferometry imaging technology. Background Technology

[0002] In recent years, with the continuous advancement of optical imaging technology, differential interferometry (DI) imaging technology has been increasingly applied to the field of thin film defect detection. DI, utilizing the principle of light interference, can perform high-precision detection of minute defects on thin film surfaces, offering advantages such as high accuracy, high sensitivity, and the provision of rich defect information. However, existing thin film defect detection systems based on DI still have some shortcomings.

[0003] First, most existing inspection systems can only inspect thin films from a single angle, failing to comprehensively detect defects under different bending conditions. In practical applications, thin films are often subjected to various stresses, causing defects to manifest differently under different conditions. Single-angle inspection may miss some potential defects, affecting the comprehensiveness and accuracy of the inspection.

[0004] Secondly, existing detection systems have certain limitations in terms of illumination. The light source position of the illumination unit is fixed and cannot be adaptively adjusted according to changes in the detection angle. This may result in the light source not providing ideal illumination when detecting at different angles, thereby reducing the accuracy of the detection. In addition, prolonged illumination may cause the light source temperature to rise, affecting the lifespan and stability of the light source.

[0005] In summary, existing thin film defect detection technologies still have shortcomings in terms of detection accuracy, comprehensiveness, light source adaptability, and thin film tension control, failing to meet the high requirements of modern industrial production for thin film quality inspection. Therefore, developing a thin film defect detection system based on differential interferometry imaging technology, capable of multi-angle detection, adaptive illumination adjustment, and real-time tension control, is of significant practical importance for improving the accuracy and efficiency of thin film defect detection. Summary of the Invention

[0006] (a) Technical problems to be solved

[0007] To address the shortcomings of existing technologies, this invention provides a thin film defect detection system based on differential interferometry imaging technology, which solves the problem that the system can only detect defects in thin films from a single angle and cannot comprehensively detect defects in thin films under different bending conditions.

[0008] (II) Technical Solution

[0009] To achieve the above objectives, the present invention provides the following technical solution: a thin film defect detection system based on differential interferometry imaging technology, comprising:

[0010] A frame, on which a transmission module is provided for transmitting the film to be tested;

[0011] A visual inspection module is installed inside the frame and is used to detect defects in the film during the transmission process.

[0012] The visual inspection module includes a differential interference visual inspection unit, an illumination unit, and an adjustment unit;

[0013] The differential interferometric visual inspection unit is used to acquire images of the thin film to be inspected through differential interferometric imaging technology, and to analyze the acquired differential interferometric images through an external image processing and analysis system to extract defect information;

[0014] The illumination unit is used to illuminate the thin film under test from both sides, providing a stable plane light wave for the differential interferometry vision inspection unit;

[0015] The adjustment unit is used to adjust the angle of the differential interference vision inspection unit and the illumination unit to enable vision inspection of the thin film at different bending angles.

[0016] Tension control module, which is used to adaptively adjust the tension of the film under test during the transmission process.

[0017] Preferably, the adjustment unit includes two rotatable circular plates;

[0018] The differential interference visual inspection unit consists of two units, both of which are connected between two circular plates. The two differential interference visual inspection units are used to detect defects on both sides of the film under test.

[0019] The number of lighting units is two, and both lighting units are connected between two circular plates.

[0020] Preferably, the inner surfaces of the two circular plates are provided with annular grooves, and the two differential interference vision detection units are slidably connected between the two annular grooves via guide rails in an annular sliding manner. Self-locking bolts are provided on both guide rails.

[0021] Preferably, the lighting unit includes a hollow shaft rotatably connected between two circular plates and a transparent light tube, the transparent light tube being used to enclose the hollow shaft;

[0022] A linear array light source is embedded in the outer surface of the hollow shaft, and the linear array light source is connected to a controller. The controller is used to output pulse drive signals to the linear array light source so that the linear array light source provides pulsed illumination.

[0023] Preferably, the linear array light sources in the two lighting units illuminate upwards and downwards, respectively;

[0024] The hollow shafts in both lighting units are fixedly connected to heat dissipation fins, and the bottom of the frame is fixedly connected to a cooling fan unit for inputting gas into the two hollow shafts.

[0025] Preferably, the tension control module includes a control unit, two leveling rollers, and two guide rollers disposed inside the frame;

[0026] The film is transported to the test area through a control unit, two leveling rollers and two guide rollers, and defects are detected by a vision inspection module.

[0027] Preferably, the control unit includes a directional roller and an adjusting roller rotatably connected inside the frame. Both ends of the adjusting roller are rotatably connected to sliding blocks, and both sliding blocks are slidably installed in a way that allows for vertical adjustment.

[0028] Preferably, it also includes a data comparison and processing module, which is used to collect information before bending deformation and information after bending deformation, and to compare and analyze the collected information before bending deformation and information after bending deformation.

[0029] When the data before and after bending deformation are basically consistent, it means that the film can transmit and detect under this stable bending state.

[0030] When the data before and after bending deformation are inconsistent, it indicates that the bending angle and tension during bending are too large, causing self-damage in the bending test. In this case, it is necessary to reduce the bending angle and tension coefficient of the film.

[0031] (III) Beneficial Effects

[0032] Compared with the prior art, the present invention provides a thin film defect detection system based on differential interferometry imaging technology, which has the following advantages:

[0033] This invention allows for simultaneous angle adjustment of the differential interferometric visual inspection unit and the illumination unit via an adjustment unit. This not only provides real-time illumination for the thin film but also allows for bending of the film under test, causing surface defects to deform or shift under bending stress, thus enhancing defect exposure. Furthermore, it works in conjunction with the differential interferometric visual inspection unit to perform real-time inspection of the film under different bending conditions. Based on the tensile pressure during transmission, the invention automatically adjusts the tension of the film under test to prevent tearing or excessive deformation that could interfere with defect detection data.

[0034] This invention incorporates a center-of-gravity block within the hollow shafts of both illumination units. By using these two center-of-gravity blocks, the center of gravity of the two hollow shafts can be controlled independently. This ensures that when the two circular plates are rotated, the linear array light sources in the two illumination units always maintain upward and downward illumination, providing adaptive adjustment. This prevents the differential interferometry visual inspection unit from having its light source position fixed and inconvenient due to changes in the detection angle, which could easily reduce its detection effectiveness.

[0035] This invention utilizes toothed discs mounted on two circular plates, which mesh with two racks. This allows the circular plates to simultaneously drive the adjusting rollers in the tension control module as the angles of the illumination unit and the differential interference vision inspection unit are adjusted. The adjusting rollers automatically adapt to changes in the tensile pressure of the film according to the angle adjustments of the illumination unit and the differential interference vision inspection unit. This not only prevents film breakage due to increased tensile force but also prevents changes in tensile force caused by raising the detection angle of the vision inspection module, thus avoiding any impact on the accuracy of defect detection. Attached Figure Description

[0036] Figure 1 This is a schematic diagram of the structure of the present invention;

[0037] Figure 2 This is a bottom view of the structure of the present invention;

[0038] Figure 3 This is a rear view of the structure of the present invention;

[0039] Figure 4 This is a cross-sectional schematic diagram of the present invention;

[0040] Figure 5 This is a schematic diagram of the transmission between the adjustment unit and the tension control module of the present invention;

[0041] Figure 6 This is a combined diagram of the differential interferometry visual detection unit, illumination unit, and adjustment unit of the present invention;

[0042] Figure 7 For the present invention Figure 6 The front view of the cross section;

[0043] Figure 8 This is a top view of the frame cross-section of the present invention;

[0044] Figure 9 This is a schematic diagram of the module principle of the present invention;

[0045] Figure 10 This is a schematic diagram of the differential interference imaging principle of the differential interference visual detection unit of the present invention.

[0046] In the picture:

[0047] 100. Rack;

[0048] 200. Visual Inspection Module;

[0049] 210. Differential Interference Visual Inspection Unit;

[0050] 220. Lighting unit; 221. Hollow shaft; 222. Transparent light tube; 223. Linear array light source; 224. Heat sink fins; 225. U-shaped tube; 226. Cooling fan unit; 227. Center of gravity block;

[0051] 230. Adjustment unit; 231. Circular plate; 232. Motor; 233. Gear disc; 234. Sliding frame; 235. Rack frame; 236. Connecting rod; 237. Transmission frame; 238. T-shaped rod; 239. Spring;

[0052] 300. Tension control module; 301. Leveling roller; 302. Guide roller; 303. Orientation roller; 304. Adjusting roller; 305. Sliding block. Detailed Implementation

[0053] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0054] Example 1:

[0055] See attached document Figures 1 to 10 A thin film defect detection system based on differential interferometry imaging technology includes:

[0056] The frame 100 is equipped with a transmission module for transporting the film to be tested; the transmission module is used to transport the film to be tested.

[0057] A vision inspection module 200 is disposed inside the frame 100 and is used to detect defects in the film during the transmission process.

[0058] The visual inspection module 200 includes a differential interferometry visual inspection unit 210, an illumination unit 220, and an adjustment unit 230;

[0059] The differential interference visual inspection unit 210 is used to acquire images of the thin film to be inspected through differential interference imaging technology, and to analyze the acquired differential interference images through an external image processing and analysis system to extract defect information;

[0060] See attached document Figure 9 As shown, the specific principle of the differential interference visual detection unit 210 is as follows: First, light passes through lens 1 and is converted into a plane wave, which covers the transparent film to be detected.

[0061] The plane wave is split into two distinct waves by a differential interference system. These two waves meet on the transparent film and produce interference; they reinforce or weaken each other, forming specific patterns.

[0062] The interfering light rays pass through lens 2 and are focused into an image; the CCD camera captures this image; the computer receives the image from the CCD and analyzes it;

[0063] Finally, by analyzing the interference pattern, the computer can calculate the three-dimensional shape of the transparent film surface. This is like performing a 3D scan on the transparent film, clearly showing whether there are any defects on its surface.

[0064] The illumination unit 220 is used to illuminate the thin film under test from both sides, providing a stable plane light wave for the differential interferometry visual inspection unit 210;

[0065] The adjustment unit 230 is used to adjust the angles of the differential interference visual inspection unit 210 and the illumination unit 220 to form visual inspection work under different bending angles of the thin film.

[0066] By adjusting the angle of the illumination unit 220, not only can the film be illuminated in real time, but the film under test can also be bent, thereby causing the defects on the film surface to deform or shift under bending stress, making them easier to detect by differential interferometry imaging technology. It can also improve the film unfolding effect, reduce wrinkles and non-uniformity, and thus improve the accuracy of detection.

[0067] By adjusting the angle of the differential interference vision detection unit 210, not only can the detection of films under different bending states be achieved, but also the detection at different angles can be realized, further improving the accuracy of film detection.

[0068] By using the differential interference visual inspection unit 210 and the illumination unit 220 for synchronous adjustment, the synchronization of illumination, bending, and inspection debugging is enhanced.

[0069] Tension control module 300 is used to adaptively adjust the tension of the film under test during the transmission process.

[0070] The tension control module 300 is used to automatically adjust the tension of the film under test during the transmission process according to the tensile pressure of the film bending. This prevents the film from tearing due to the increasing tensile pressure during bending, which, while enhancing the exposure of defects, can also cause excessive deformation of defects and interfere with the defect detection data.

[0071] See attached document Figures 4 to 7 The adjustment unit 230 includes two rotatable circular plates 231;

[0072] The two circular plates 231 are rotatably mounted, which facilitates the rotation and adjustment of the differential interference vision detection unit 210 and the illumination unit 220 installed between the two circular plates 231.

[0073] In this embodiment, there are two differential interference visual inspection units 210, and both differential interference visual inspection units 210 are connected between two circular plates 231. The two differential interference visual inspection units 210 are used to detect defects on the front and back sides of the film to be tested, respectively.

[0074] Two differential interference vision inspection units 210 are connected between two circular plates 231, so that when the two circular plates 231 are rotated, the inspection angle and orientation of the two differential interference vision inspection units 210 can be adjusted to meet the inspection work at different positions of the thin film and improve its inspection effect.

[0075] It should be noted that there are two illumination units 220, which facilitates illumination of both sides of the film and improves the comprehensiveness of film detection. Both illumination units 220 are connected between two circular plates 231, which allows the two illumination units 220 to perform circular motion with the rotation of the circular plates 231, thereby adjusting the bending angle of the film.

[0076] See attached document Figure 5 and Figure 6 Both circular plates 231 have annular grooves on their inner sides, and both differential interference vision detection units 210 are slidably connected between the two annular grooves via guide rails in an annular sliding manner. Both guide rails are equipped with self-locking bolts.

[0077] By opening an annular groove on the inner side of the circular plate 231, the two differential interference vision inspection units 210 can be adjusted in an annular shape with the circular plate 231 as the center, thereby meeting the vision inspection work at different positions and angles. Furthermore, the self-locking bolts are used to lock the guide rail frame that slides inside the annular groove, thereby ensuring that the differential interference vision inspection units 210 are locked after adjustment at different positions and angles, and ensuring their stability after adjustment.

[0078] See attached document Figure 7 The lighting unit 220 includes a hollow shaft 221 rotatably connected between two circular plates 231 and a transparent light tube 222, the transparent light tube 222 being used to wrap the hollow shaft 221;

[0079] The transparent light tube 222 is used to wrap the hollow shaft 221, and the two are independently connected to the circular plate 231 to ensure that they do not interfere with each other, thereby improving the smoothness of the transparent light tube 222 in transmitting the film and improving the adaptability of the hollow shaft 221.

[0080] A linear array light source 223 is embedded in the outer surface of the hollow shaft 221, and the linear array light source 223 is connected to a controller. The controller is used to output pulse drive signals to the linear array light source 223, so that the linear array light source 223 can perform pulsed illumination, which can increase the contrast between defects and background. By using a multi-angle light source group and adopting time-division lighting technology, image data of multiple illuminations at different angles are collected on the same spot on the surface of the tested product to increase the contrast between defects and background.

[0081] By setting the strobe control logic parameters of the light source controller to control the lighting sequence of each light source, and setting the logic output external trigger signal of the light source controller to control the camera to perform time-division exposure, the light sources are lit simultaneously, achieving high-quality image output.

[0082] See attached document Figure 7 The linear array light sources 223 in the two lighting units 220 illuminate upwards and downwards, respectively;

[0083] The linear array light source 223 in the illumination unit 220 illuminates upwards and downwards respectively, which facilitates illumination of both sides of the film under test. The two sets of differential interference vision inspection units 210 perform visual inspection of different sides, which can not only capture the defect information of the film more comprehensively and reduce the false detection and missed detection that may occur due to single-sided inspection, but also detect the inner and outer bending of the film, further improving the accuracy of its inspection.

[0084] The hollow shafts 221 in both lighting units 220 are fixedly connected to heat dissipation fins 224, and the inner bottom of the frame 100 is fixedly connected to a heat dissipation fan unit 226 for inputting gas into the two hollow shafts 221.

[0085] The hollow shaft 221 is hollow inside, which facilitates heat dissipation of the linear array light source 223. The heat dissipation effect can be further improved by fixing heat dissipation fins 224 inside the hollow shaft 221. By injecting gas into the interior of the two hollow shafts 221 through the cooling fan unit 226, the high-intensity heat dissipation of the linear array light source 223 under pulsed lighting can be met. It has different levels of heat dissipation function, which solves the problem that the lighting environment temperature of the linear array light source 223 will increase significantly due to long-term pulsed lighting, thus affecting the service life of the linear array light source 223.

[0086] See attached document Figure 4 The tension control module 300 includes a control unit, two leveling rollers 301 and two guide rollers 302, which are disposed inside the frame 100.

[0087] The film is transferred to the test area through the control unit, two leveling rollers 301 and two guide rollers 302, and defect detection is performed by the vision inspection module 200.

[0088] Two leveling rollers 301 are used to level the film during the transmission process; two guide rollers 302 are used to guide the film after inspection and output; the control unit is used to adjust the tightness according to the real-time transmission of the film.

[0089] See attached document Figure 4 The control unit includes a directional roller 303 and an adjusting roller 304 rotatably connected inside the frame 100. Both ends of the adjusting roller 304 are rotatably connected to sliding blocks 305, and both sliding blocks 305 are slidably installed in a way that can be adjusted up and down.

[0090] The orienting roller 303 is used to orient the film during the transport process, and the adjusting roller 304 is used to control the tightness of the film during the transport process. Specifically, the upward movement of the adjusting roller 304 can increase the tightness of the film; conversely, the downward drive of the adjusting roller 304 can decrease the tightness of the film.

[0091] It should be noted that the two sliding blocks 305 in this embodiment can be driven by electric cylinders.

[0092] See attached document Figure 9It also includes a data comparison and processing module, which is used to collect information before and after bending deformation, and to compare and analyze the collected information before and after bending deformation.

[0093] By setting up a data comparison and processing module, information before and after bending deformation is detected in real time, and the two sets of data are compared and analyzed. This prevents the bending deformation intensity from being too large, which could cause the film to self-damage during the test process, thus affecting the detection accuracy of the visual inspection module 200. The self-damage of the film can easily interfere with the defect detection data of the film.

[0094] It should be noted here that the information before and after bending deformation can be collected using an ultrasonic detector or other instruments and equipment with detection functions.

[0095] When the data before and after bending deformation are basically consistent, it means that the film can be transmitted and detected in a stable bending state. This adjustment can avoid the self-damage phenomenon of the film due to bending treatment, which can easily interfere with the defect detection data of the film.

[0096] When the data before and after bending deformation are inconsistent, it indicates that the film bending angle and the tensile force during bending are too large, causing self-damage in the film bending detection. In this case, it is necessary to reduce the film bending angle and tensile force coefficient. This method can promptly determine whether the film bending angle and tensile force during bending exceed the specified threshold, causing self-damage to the film, thus having a self-checking function.

[0097] Example 2: The difference from Example 1 is that;

[0098] See attached document Figures 5 to 7 Two hollow shafts 221 are rotatably connected at one end by two first sealing rotating parts to a U-shaped tube 225. By rotatably connecting the two hollow shafts 221 at one end to the U-shaped tube 225, gas can be injected into the interior of the two hollow shafts 221 through the U-shaped tube 225 for heat dissipation of the lighting unit 220 without affecting the rotation of the hollow shafts 221. The cooling fan unit 226 is connected to the interior of the U-shaped tube 225 through an air outlet pipe, and the air outlet pipe is rotatably connected to the U-shaped tube 225 by a second sealing rotating part. The rotation axis of the second sealing rotating part coincides with the rotation axis of the circular plate 231, ensuring that the cooling fan unit 226 injects gas into the interior of the two hollow shafts 221 in an orderly manner for heat dissipation without affecting the normal rotation adjustment of the circular plate 231.

[0099] Each of the two illumination units 220 has a center of gravity block 227 inside its hollow shaft 221. By setting the two center of gravity blocks 227, the center of gravity of the two hollow shafts 221 can be controlled respectively. When the two circular plates 231 are rotated, the linear array light sources 223 in the two illumination units 220 always keep the illumination facing upward and downward. This has an adaptive adjustment function, which prevents the light source from being in a fixed and inconvenient state due to the change of detection angle when the differential interference vision detection unit 210 is detected at different angles, which would easily reduce its detection effect.

[0100] Example 3: The difference from Example 1 is that;

[0101] See attached document Figures 4 to 6 and Figure 8 Two rotatable circular plates 231 are mounted inside the frame 100 in a rotating manner, and one of the circular plates 231 is driven to rotate by a motor 232 mounted on the frame 100. Gear discs 233 are fixedly connected to the outer surfaces of both circular plates 231. A sliding frame 234 is slidably connected to the inner bottom of the frame 100 through a sliding guide rail. Two rack frames 235 are fixedly connected to the sliding frame 234, and the two rack frames 235 mesh with the outer surfaces of the two gear discs 233 respectively.

[0102] Motor 232 is connected to an external power source and control switch. It is a forward and reverse motor and is set up using existing connection and coding methods. It is used to drive one of the circular plates 231 to rotate. The illumination unit 220 and the differential interference vision detection unit 210 are installed between the two circular plates 231, so that the illumination unit 220 and the differential interference vision detection unit 210 can adjust the detection angle and the illumination angle.

[0103] By installing toothed discs 233 on two circular plates 231 and engaging two rack frames 235, the circular plates 231 can simultaneously drive the adjusting rollers 304 in the tension control module 300 when adjusting the angle of the illumination unit 220 and the differential interference vision inspection unit 210. This allows the adjusting rollers 304 to automatically adapt to the tension of the film according to the angle adjustment of the illumination unit 220 and the differential interference vision inspection unit 210. This not only prevents the film from breaking due to increased tension, but also prevents the tension of the film from changing due to the increase of the detection angle of the vision inspection module 200, thus affecting the accuracy of defect detection.

[0104] By adjusting the film tension synchronously, the detection data detected by the vision inspection module 200 can be obtained intuitively, without the need to use a reverse calculation method to restore the detection data of films with large tension.

[0105] A connecting rod 236 is connected to the sliding frame 234, and both ends of the connecting rod 236 are rotatably connected to inclined transmission frames 237. The two transmission frames 237 are respectively hinged to the two sliding blocks 305.

[0106] The connecting rod 236 moves synchronously with the sliding frame 234, so that when the connecting rod 236 moves laterally, it drives the two transmission frames 237 to move in a fan shape, which in turn drives the two sliding blocks 305 to adjust up and down, thereby forming the height adjustment of the adjusting roller 304; by adjusting the height of the adjusting roller 304, the tightness of the film during the transmission process can be adjusted.

[0107] For example, when the angle of the illumination unit 220 and the differential interference vision detection unit 210 is adjusted by the adjustment unit 230, the tension of the film in that part will change. At this time, the adjustment unit 230 indirectly drives the adjustment roller 304 downward. When the adjustment roller 304 moves downward, it can reduce the tension of the film, making the film loose. The film pressure in the loose area will be spread evenly on the two transparent light tubes 222, so that the tightness of the film wrapped on the two transparent light tubes 222 changes, forming an adaptive adjustment operation.

[0108] It should be noted here that when the two transparent light tubes 222 are adjusting their angle, the pressure of the film tension at that part is equal to the pressure of the adjusting roller 304 when it is loose, and the two are in a state of balance.

[0109] At least two T-shaped rods 238 are fixedly connected to the connecting rod 236. The at least two T-shaped rods 238 are slidably connected to the inside of the sliding frame 234 in a through sliding manner. A spring 239 is fixed between the two T-shaped rods 238 and the sliding frame 234. A pressure sensor for detecting the elastic coefficient of the spring 239 is provided on the two T-shaped rods 238.

[0110] The connecting rod 236 is connected to the sliding frame 234 by two T-shaped rods 238. When the sliding frame 234 moves laterally, the connecting rod 236 can be driven to move synchronously by the spring 239. The spring 239 can be used to adaptively buffer and adjust the tension of the film to be tested, reducing damage to the film during tension adjustment.

[0111] This solves the problem that when the adjustment unit 230 adjusts the angle of the vision inspection module 200 and then adjusts the tension of the film to be tested, the rigid adjustment method can easily cause tearing damage to the film.

[0112] By setting a pressure sensor on the T-shaped rod 238 to detect the elastic coefficient of the spring 239, it is convenient to judge the tensile force of the membrane by detecting the pressure change of the elastic coefficient of the spring 239 in real time, and prevent the membrane from being damaged due to excessive tensile force.

[0113] Furthermore, by detecting the tensile force of the film using a pressure sensor, the tension of the film can be adaptively adjusted in conjunction with the adjustment unit 230, thereby reducing the problem of errors in film defect detection caused by excessive tensile force.

[0114] Finally, it should be noted that the above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A thin film defect detection system based on differential interferometry imaging technology, characterized in that, include: A frame (100) is provided with a transmission module for transmitting the film to be tested; A visual inspection module (200) is disposed inside the frame (100) and is used to detect defects in the film during the transmission process; The visual inspection module (200) includes a differential interference visual inspection unit (210), an illumination unit (220), and an adjustment unit (230); The differential interference visual inspection unit (210) is used to acquire an image of the thin film to be inspected through differential interference imaging technology, and to analyze the acquired differential interference image through the image processing and analysis system of the peripheral device to extract defect information; The illumination unit (220) is used to illuminate the thin film under test from both sides, providing a stable plane light wave for the differential interferometry visual inspection unit (210); The adjustment unit (230) is used to adjust the angle of the differential interference visual inspection unit (210) and the illumination unit (220) to form visual inspection work under different bending angles of the thin film; Tension control module (300), which is used to adaptively adjust the tension of the film under test during the transmission process.

2. The thin film defect detection system based on differential interferometry imaging technology according to claim 1, characterized in that: The adjustment unit (230) includes two rotatable circular plates (231); The number of differential interference visual inspection units (210) is two, and the two differential interference visual inspection units (210) are connected between two circular plates (231). The two differential interference visual inspection units (210) are used to detect defects on the front and back sides of the film to be tested, respectively. The number of lighting units (220) is two, and both lighting units (220) are connected between two circular plates (231).

3. The thin film defect detection system based on differential interferometry imaging technology according to claim 2, characterized in that: The inner surfaces of the two circular plates (231) are provided with annular grooves, and the two differential interference vision detection units (210) are slidably connected between the two annular grooves through the guide rail frame in an annular sliding manner. The two guide rail frames are provided with self-locking bolts.

4. A thin film defect detection system based on differential interferometry imaging technology according to claim 2, characterized in that: The lighting unit (220) includes a hollow shaft (221) rotatably connected between two circular plates (231) and a transparent light tube (222), the transparent light tube (222) being used to wrap the hollow shaft (221); A linear array light source (223) is embedded in the outer surface of the hollow shaft (221), and the linear array light source (223) is connected to a controller. The controller is used to output a pulse drive signal to the linear array light source (223) so that the linear array light source (223) performs pulsed illumination.

5. A thin film defect detection system based on differential interferometry imaging technology according to claim 4, characterized in that: The linear array light sources (223) in the two lighting units (220) illuminate upwards and downwards, respectively; The hollow shafts (221) in the two lighting units (220) are fixedly connected to heat dissipation fins (224), and the inner bottom of the frame (100) is fixedly connected to a heat dissipation fan unit (226) for inputting gas into the two hollow shafts (221).

6. A thin film defect detection system based on differential interferometry imaging technology according to claim 1, characterized in that: The tension control module (300) includes a control unit, two leveling rollers (301) and two guide rollers (302) disposed inside the frame (100); The film is transported to the test area through a control unit, two leveling rollers (301) and two guide rollers (302), and defect detection is performed by a vision inspection module (200).

7. A thin film defect detection system based on differential interferometry imaging technology according to claim 6, characterized in that: The control unit includes a directional roller (303) and an adjusting roller (304) rotatably connected inside the frame (100). Both ends of the adjusting roller (304) are rotatably connected to sliding blocks (305), and both sliding blocks (305) are slidably installed in a way that can be adjusted up and down.

8. A thin film defect detection system based on differential interferometry imaging technology according to claim 1, characterized in that: It also includes a data comparison and processing module, which is used to collect information before bending deformation and information after bending deformation, and to compare and analyze the collected information before bending deformation and information after bending deformation. When the data before and after bending deformation are basically consistent, it means that the film can transmit and detect under this stable bending state. When the data before and after bending deformation are inconsistent, it indicates that the bending angle and tension during bending are too large, causing self-damage in the bending test. In this case, it is necessary to reduce the bending angle and tension coefficient of the film.

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