Transparent film surface inspection device and method
By using differential interferometers and alternating lighting devices in transparent film surface inspection devices, the problem that the prior art is difficult to detect surface defects of transparent films quickly and accurately is solved, and efficient detection of peeling and falling defects in UTG production process is achieved.
Patent Information
- Application Number
- CN202411658478.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-20
- Publication Date
- 2025-03-18
AI Technical Summary
Existing inspection methods are difficult to quickly and accurately detect peeling and shedding defects on the surface of transparent films, especially in the production process of UTG, which is difficult to detect by the naked eye or traditional microscope.
A differential interferometer is used to combine the upper/lower lighting device, and the upper and lower lighting light is alternately provided by controlling the working mode of the lighting device and the camera. The video of the transparent film surface is analyzed by a differential interferometer to achieve rapid and accurate detection of the upper/lower surface defects of the transparent film.
It realizes rapid and accurate detection of surface peeling and shedding defects of transparent film, improves the poor detection rate, reduces mechanical judgment errors, and shortens inspection time. It is suitable for high-speed inspection systems for large-scale mass production equipment.
Smart Images
Figure CN119643590A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to a transparent film surface inspection device and method.
[0002] Specifically, it relates to a transparent film surface inspection device and method based on visual inspection, which can quickly and accurately identify defects such as peeling and falling off on the upper / lower surface of the transparent film through a differential interferometer and upper / lower illumination. Background Art
[0003] Recently, foldable phones have attracted much attention as an innovative product with a novel appearance of smartphones. Currently, the foldable phone market has not made much progress due to problems such as high prices, low display yields, and insufficient durability. However, these technical problems are expected to be gradually resolved in the next few years through continuous research and development. It is expected that the foldable phone market will become the fastest growing market in the smartphone field in the next 10 years.
[0004] The first foldable mobile phone to be launched on the market uses PI (Polyimide) film on the liquid crystal. The PI film has good surface strength and curvature, good durability to alkali, can be mass-produced, and is widely used in the electrical and electronic fields and mechanical parts. It is easy to be applied to foldable mobile phones; however, as the number of times the PI film is used for a long time, curved parts will appear, and the picture will be distorted. Therefore, foldable mobile phones that use ultra-thin tempered glass (UTG; ultrathingglass) instead of PI film are currently being developed.
[0005] The display of a foldable screen mobile phone is composed of multiple layers such as a cover window, a polarizing plate, a touch sensor, a film bag layer, an OLED light-emitting layer, a TFT substrate, and a base film. The material of UTG is glass, so it is relatively more fragile than transparent plastic (CPI; colorless polyimide) in terms of external impact. However, it is better than CPI in terms of surface hardness, aesthetics, appearance, transmittance, heat resistance, and recovery. Therefore, it is used in high-end specifications of foldable screen mobile phones.
[0006] UTG uses diamond chain cutting (Diamond Chain Cutter) or laser cutting (Laser Cutter) to cut and temper the glass according to product specifications, and then assemble it on the folding screen mobile phone after acceptance and testing; the current mechanical diamond chain cutting method or laser cutting method will produce various sizes of peeling (chipping) or shedding (scale) in the process of extracting the unit from the original (Mother Glass), that is, the slitting (Breaking) process.
[0007] Peeling or shedding of more than 10um is the cause of defects in subsequent processes (restoration process, tempering process, etc.), and is also a factor that causes a serious decline in the overall yield and generates a lot of costs; in addition, since the folding conditions required for the final evaluation and inspection are not met and are ultimately treated as defects, it is necessary to use inspection equipment in the UTG state to ensure the yield as a method to solve the huge waste of resources and the low final yield. The existing inspection method is to cut and split (Breaking) the original glass unit and extract it. There is no professional tester to evaluate the unit quality. Since the operator inspects the surface quality of the unit with the naked eye, it is difficult to find subtle causes of defects, and only part of the sample unit is inspected, resulting in limitations in defect detection.
[0008] In addition, visual inspection equipment based on optical microscopes has been developed and is used for surface inspection and other aspects. It is feasible to observe opaque materials with ordinary optical microscopes or traditional differential interferometers, but there are certain limitations for thin films of transparent materials such as film glass. Due to the transmittance of light and the inclusion of illumination light in the image, it is difficult to accurately detect peeling and falling off. Summary of the invention
[0009] The object of the present invention is to provide a transparent film surface inspection device and method, which can quickly and accurately identify defects such as peeling and falling off on the upper / lower surface of the transparent film through a differential interferometer and upper / lower illumination.
[0010] A transparent film surface inspection device according to an embodiment of the present invention includes: a differential interferometer, which analyzes a video of the transparent film surface; an illumination device, which provides illumination light to the transparent film surface; the illumination device includes: an upper illumination device, which provides upper illumination light from the upper part of the transparent film to the upper part of the transparent film; and a lower illumination device, which provides lower illumination light from the lower part of the transparent film to the lower part of the transparent film.
[0011] The upper illumination device and the lower illumination device may be arranged on the rear focal plane of the objective lens of the differential interferometer to ensure that the imaging of the upper illumination light and the imaging of the lower illumination light can be combined with each other.
[0012] According to the transparent film surface inspection device of an embodiment of the present invention, it also includes: a control unit, which controls the lighting device and the camera of the differential interferometer; the control unit can control the upper lighting device and the lower lighting device to ensure that the upper lighting light and the lower lighting light can be alternately provided to the transparent film.
[0013] The control unit includes: a first lighting control unit, which turns on / off the upper light source of the upper lighting device according to a set cycle; a second lighting control unit, which turns on / off the lower light source of the lower lighting device according to a set cycle; the second lighting control unit can drive the lower light source to ensure that the lower lighting light can be output from the lower light source at a time that is staggered with the light-emitting time of the upper light source.
[0014] The control unit also includes: a camera control unit, which can control the camera shooting time of the differential interferometer; the camera control unit can control the camera to ensure that odd-numbered inspection videos can be shot during the period when the upper illumination light is provided by the upper illumination device under the control of the first illumination control unit; the camera control unit can control the camera to ensure that even-numbered inspection videos can be shot during the period when the lower illumination light is provided by the lower illumination device under the control of the second illumination control unit.
[0015] The control unit also includes: an inspection unit, which analyzes the peeling and falling off of the transparent film; the inspection unit can extract the odd-numbered inspection video frames among the inspection video frames obtained by the camera as an upper surface defect video that emphasizes the upper surface defect portion of the transparent film, and the inspection unit can extract the even-numbered inspection video frames among the inspection video frames obtained by the camera as a lower surface defect video that emphasizes the lower surface defect portion of the transparent film.
[0016] The differential interferometer comprises: a body; a semi-reflecting mirror arranged in the body; an objective lens arranged at the lower end of the body; a condenser arranged between the semi-reflecting mirror and the objective lens; and a Wollaston filter, a polarizing filter and a camera arranged in sequence at the upper end of the body.
[0017] The differential interferometer further includes: an upper polarizer and an upper Wollaston prism arranged on one side of the upper lighting device; and a lower polarizer and a lower Wollaston prism arranged on one side of the lower lighting device.
[0018] The upper lighting device includes: an upper lighting body; an upper light source arranged in the upper lighting body; an upper heat filter arranged between the upper polarizer and the upper Wollaston prism; an upper aperture arranged between the upper Wollaston prism and the semi-reflecting mirror; an upper field of view aperture arranged between the upper aperture and the semi-reflecting mirror; and an upper condenser arranged between the upper field of view aperture and the semi-reflecting mirror.
[0019] The lower lighting device includes: a lower lighting body; a lower light source arranged in the lower lighting body; a lower heat filter arranged between the lower polarizer and the lower Wollaston prism; a lower aperture arranged between the lower Wollaston prism and the transparent film; a lower field of view aperture arranged between the lower aperture and the transparent film; and a lower condenser arranged between the lower field of view aperture and the transparent film.
[0020] According to an embodiment of the present invention, the transparent film surface inspection method includes: a step of providing illumination light to the transparent film surface by an illumination device; a step of analyzing a video of the transparent film surface by a differential interferometer; the step of providing the illumination light includes: a step of providing upper illumination light from the upper part of the transparent film to the upper part of the transparent film by an upper illumination device; and a step of providing lower illumination light from the lower part of the transparent film to the lower part of the transparent film by a lower illumination device.
[0021] The above summary is for illustrative purposes only and is not intended to be limiting in any way. In addition to the illustrative aspects, embodiments and features described above, further aspects, embodiments and features of the present invention will be readily apparent by reference to the accompanying drawings and the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS
[0022] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.
[0023] Figure 1 is a schematic diagram schematically showing a transparent film surface inspection device according to an embodiment of the present invention;
[0024] Figure 2 and Figure 3 is a cross-sectional view showing a differential interferometer and an illumination device constituting a transparent thin film surface inspection device according to an embodiment of the present invention;
[0025] Figure 4 is a structural diagram of a control unit constituting a transparent film surface inspection device according to an embodiment of the present invention;
[0026] Figure 5 and Figure 6 is a schematic diagram for explaining the effect of the transparent film surface inspection device according to an embodiment of the present invention;
[0027] Figure 7 is an example diagram of obtaining an inspection video for a transparent film according to an embodiment of the present invention.
[0028] Figure numerals: 10: transparent film; 20: lower bracket; 30: upper frame; 100: transparent film surface inspection device; 210: body; 230: objective lens; 240b: lower polarizer; 250b: lower Wollaston prism; 270: Wollaston filter; 290: camera; 310: upper lighting body; 330: upper heat filter; 350: upper field of view aperture; 400: lower lighting device; 420: lower light source; 440: lower aperture aperture; 460: lower condenser; 510: motor control unit; 530: second lighting control unit; 5 50: inspection unit; 700: user interface device; 40: light-transmitting surface; 200: differential interferometer; 220: half-reflecting mirror; 240a: upper polarizer; 250a: upper Wollaston prism; 260: condenser; 280: polarizing filter; 300: upper lighting device; 320: upper light source; 340: upper aperture; 360: upper condenser; 410: lower lighting body; 430: lower heat filter; 450: lower field of view aperture; 500: control unit; 520: first lighting control unit; 540: camera control unit; 600: display device. DETAILED DESCRIPTION
[0029] In the following, only some exemplary embodiments are briefly described. As those skilled in the art will appreciate, the described embodiments may be modified in various ways without departing from the spirit or scope of the present invention. Therefore, the drawings and descriptions are considered to be exemplary and non-restrictive in nature.
[0030] The embodiments of the present invention are described in detail below with reference to the accompanying drawings.
[0031] Figure 1 is a schematic diagram schematically showing a transparent film surface inspection device according to an embodiment of the present invention; Figure 1 It can be seen that the transparent film surface inspection device (100) according to the embodiment of the present invention is provided to ensure that the surface of a transparent film (10) made of a transparent material such as ultra-thin tempered glass (UTG; ultrathingglass) with a thickness of about 30 to 50 microns can be inspected quickly and accurately.
[0032] The transparent film surface inspection device (100) according to an embodiment of the present invention comprises: a differential interferometer (200) for analyzing a video of the surface of the transparent film (10); an illumination device ( Figure 2 and Figure 3300, 400 in the figure), which provides illumination for the surface of the transparent film (10); and a control unit (500), which controls the differential interferometer (200) and the illumination device (300, 400) etc. in order to inspect the surface of the transparent film (10).
[0033] The transparent film (10) can be arranged on the light-transmitting surface (40) on the upper frame (30), and the light-transmitting surface (40) can be made of materials such as glass that can allow the illumination light (lower illumination light) provided from the lower part to pass through. The upper frame (30) can be realized by an XY moving platform that can move horizontally along the X / Y axis on the lower support (20), and the upper frame (30) can be moved along the X / Y axis according to the edge shape of the transparent film (10) by the XY moving platform driving motor (omitted in the figure). Therefore, the inspection video can be continuously generated along the edge of the transparent film (10) by the differential interferometer (200).
[0034] The control unit (500) can drive the driving motor of the XY moving platform according to the edge shape of the transparent film (10), and control the camera of the differential interferometer (200), so as to obtain a video of the edge portion of the transparent film (10); in addition, the control unit (500) can control the lighting device ( Figure 2 and Figure 3 The control unit (500) is controlled to ensure that appropriate lighting is provided for inspecting the surface of the transparent film (10), and the control unit (500) includes at least one processor.
[0035] The inspection video obtained by the camera of the differential interferometer (200) can be displayed by the display device (600). After the user issues an instruction to start the surface inspection operation of the transparent film (10) through the user interface device (700) such as a keyboard, a mouse, a touch pad, etc., various instructions can be input to display the inspection video obtained on the surface of the transparent film (10) through the display device (600) or to store it in a memory.
[0036] Since the differential interferometer (200) uses the interference fringes generated by the difference in optical paths to place great emphasis on the curvature of the surface to be inspected or its interface, it can be used to inspect objects that are difficult to detect easily with ordinary optical systems. In order to use the advantages of this differential interferometer (200) for surface inspection of transparent films (10), the design of the lighting device is very important.
[0037] Figure 2 and Figure 3The invention is a cross-sectional view showing a differential interferometer and an illumination device constituting a transparent film surface inspection device according to an embodiment of the present invention. In the embodiment of the present invention, the illumination device (300) comprises: an upper illumination device (300) which provides upper illumination light from the upper part of the transparent film (10) toward the upper part of the transparent film (10) to the lower part; and a lower illumination device (400) which provides lower illumination light from the lower part of the transparent film (10) toward the lower part of the transparent film (10) to the upper part.
[0038] exist Figure 2 and Figure 3 In the figure, the solid line indicates the path for providing illumination, and the dotted line indicates the imaging path of the differential interferometer (200) camera (290); Figure 2 The figure shows a state where the upper lighting device (300) provides upper lighting light from the upper part of the transparent film (10) toward the upper part of the transparent film (10) and toward the lower part thereof. Figure 3 The figure shows a state where the lower lighting device (400) provides lower lighting light from the lower part of the transparent film (10) toward the upper part below the transparent film (10).
[0039] The upper lighting device (300) can provide upper lighting light to the transparent film (10) for more effectively detecting upper surface defects such as chipping and scaling of the transparent film (10), and the lower lighting device (400) can provide lower lighting light to the transparent film (10) for more effectively detecting lower surface defects of the transparent film (10); the upper lighting light and the lower lighting light can be provided to the transparent film (10) simultaneously, or independently at different times; for example, the upper lighting light and the lower lighting light can be provided to the transparent film (10) repeatedly at high speed and alternately.
[0040] The differential interferometer (200) can detect defects such as peeling and falling off on the surface of a transparent film (10) by using interference fringes generated by differences in optical paths. A portion of the differential interferometer (200) can be combined with an upper lighting device (300), and the remaining portion of the differential interferometer (200) can be combined with a lower lighting device (400). The differential interferometer (200) comprises: a body (210); a half mirror (220) disposed in the body (210); an objective lens (230) disposed at the lower end of the body (210); a condenser lens (260) disposed between the half mirror (220) and the objective lens (230); a Wollaston filter (270) disposed at the upper end of the body (210); a polarizing filter (280); and a camera (290).
[0041] In addition, the differential interferometer (200) includes: an upper polarizer (240a) and an upper Wollaston prism (250a) arranged on one side of the upper lighting device (300); a lower polarizer (240b) and a lower Wollaston prism (250b) arranged on one side of the lower lighting device (400); and a Wollaston filter (270), an upper Wollaston prism (250a) and a lower Wollaston prism (250b) providing a function of using orthogonal polarization to separate light into two linearly polarized light beams.
[0042] The upper Wollaston prism (250a) and the lower Wollaston prism (250b) provide a function of separating polarized light beams and also provide a function of gathering light; the polarizing filter (280), the upper polarizer (240a) and the lower polarizer (240b) provide a polarization function of allowing illumination light to pass in one direction; the upper polarizer (240a) and the lower polarizer (240b) provide a function of gathering illumination light and also provide a function of separating polarized light beams and also provide a function of gathering illumination light.
[0043] The upper polarizer (240a) and the upper Wollaston prism (250a) utilize the upper illumination light provided by the upper illumination device (300) to perform the function of centralized detection of defects on the upper surface of the transparent film (10) through the principle of differential interferometer, and the lower polarizer (240b) and the lower Wollaston prism (250b) utilize the lower illumination light provided by the lower illumination device (400) to perform the function of centralized detection of defects on the lower surface of the transparent film (10) through the principle of differential interferometer.
[0044] The upper lighting device (300) comprises: an upper lighting body (310); an upper light source (320) disposed in the upper lighting body (310); an upper heat filter (330) disposed between an upper polarizer (240a) and an upper Wollaston prism (250a) for filtering heat; an upper aperture stop (340) disposed between the upper Wollaston prism (250a) and a semi-reflecting mirror (220); an upper field stop (350) disposed between the upper aperture stop (340) and the semi-reflecting mirror (220); and an upper condenser (upper convex lens) (360) disposed between the upper field stop (350) and the semi-reflecting mirror (220).
[0045] The lower lighting device (400) comprises: a lower lighting body (410); a lower light source (420) disposed in the lower lighting body (410); a lower heat filter (430) disposed between a lower polarizer (240b) and a lower Wollaston prism (250b) for filtering heat; a lower aperture (440) disposed between the lower Wollaston prism (250b) and a transparent film (10); a lower field of view aperture (450) disposed between the lower aperture (440) and the transparent film (10); and a lower condenser (lower convex lens) (460) disposed between the lower field of view aperture (450) and the transparent film (10).
[0046] The upper lighting device (300) and the lower lighting device (400) can be arranged on the rear focal plane of the objective lens (200) of the differential interferometer (200) to ensure that the images of the illumination light can be combined with each other; therefore, the focus of the light source (320, 420) is concentrated on the aperture (aperture diaphragm) on the front focal plane of the condenser (260), and when the light passes through the condenser (260) and the objective lens (230), the image of the illumination light is located on the rear focal plane of the objective lens (230), so that while providing uniform illumination to the inspection object area (edge portion) of the transparent film (10), it is also possible to prevent the images of the illumination light from being combined with each other in the video obtained by the camera (290).
[0047] Figure 4 is a diagram of the structure of the control unit of the transparent film surface inspection device of the embodiment of the present invention; Figure 4 It can be seen that the control unit (500) includes: a motor control unit (510), a first lighting control unit (520), a second lighting control unit (530), a camera control unit (540) and an inspection unit (550); the motor control unit (510) controls the driving motor of the XY moving platform, thereby moving the transparent film (10) supported on the light-transmitting surface (40) of the upper frame (30).
[0048] The first lighting control unit (520) can control the upper light source (320) of the upper lighting device (300), and the first lighting control unit (520) can turn on / off the upper light source (320) according to a certain cycle; in one embodiment, the first lighting control unit (520) can control the upper light source (320) to ensure that the upper lighting light is output from the upper light source (320) during the shooting of odd-numbered inspection videos, and the upper lighting light is not output from the upper light source (320) during the shooting of even-numbered inspection videos.
[0049] The second lighting control unit (530) can control the lower light source (420) of the lower lighting device (400), and the second lighting control unit (530) can turn on / off the lower light source (420) according to a certain cycle; in this case, the second lighting control unit (530) can drive the lower light source (420) to ensure that the lower lighting light can be output from the lower light source (420) at a time that is staggered with the light-emitting time of the upper light source (320).
[0050] In one embodiment, the second lighting control unit (530) can control the lower light source (420) in a manner opposite to that of the first lighting control unit (520) to ensure that the lower lighting light is output from the lower light source (420) during the shooting of even-numbered inspection videos, and the lower lighting light is not output from the lower light source (420) during the shooting of odd-numbered inspection videos; the on / off pulse period of the upper light source (320) and the lower light source (420) can be set to a shorter time that is difficult for the user to recognize with the naked eye to avoid causing visual discomfort to the user.
[0051] The camera control unit (540) can control the shooting time of the camera (290) of the differential interferometer (200); the camera control unit (540) can control the camera (290) to ensure that odd-numbered inspection videos can be shot during the period when the upper illumination light is provided by the upper illumination device (300) under the control of the first illumination control unit (520); and the camera (290) can be controlled to ensure that even-numbered inspection videos can be shot during the period when the lower illumination light is provided by the lower illumination device (400) under the control of the second illumination control unit (530).
[0052] Figure 5 and Figure 6 This is a schematic diagram for explaining the effect of the transparent film surface inspection device according to an embodiment of the present invention. The odd-numbered inspection video frames among the inspection video frames obtained by the camera (290) can be extracted as an upper surface defect video emphasizing the upper defect portion (12a) such as peeling and falling off of the upper surface (12) of the transparent film (10) during the output of the upper illumination light, and the even-numbered inspection video frames can be extracted as a lower surface defect video emphasizing the lower defect portion (14a) such as peeling and falling off of the lower surface (14) of the transparent film (10) during the output of the lower illumination light.
[0053] Figure 71 is an example diagram of obtaining an inspection video for a transparent film according to an embodiment of the present invention. The inspection unit (550) can analyze the upper surface defect video and the lower surface defect video to analyze the defects formed on the upper surface and the lower surface of the transparent film (10) separately, which helps to understand the causes of the defects of the transparent film (10). According to the embodiment of the present invention, in addition to the upper surface defects of the transparent film (10), the lower surface defects can also be accurately analyzed, thereby improving the defect detection rate.
[0054] According to the embodiments of the present invention, it is possible to prevent the imaging of illumination light from generating spots, thereby enabling accurate inspection of the surface of the transparent film (10); at the same time, it is possible to accurately detect the shedding of ultra-thin tempered glass that is difficult to detect using an ordinary optical microscope, thereby enabling defective products to be processed; and it is also possible to simultaneously inspect the upper and lower surfaces of the transparent film (10) while the transparent film (10) is being moved via an XY moving platform, thereby enabling the surface inspection time (normal / defective determination time) of the transparent film (10) to be shortened to less than 20 seconds.
[0055] As described above, according to the embodiments of the present invention, scattering or diffraction generated by the transparent glass film can be blocked, and the shape of small detachments can be clearly displayed; in addition, according to the embodiments of the present invention, a relatively large FOV (Field of View) can be ensured, thereby ensuring large-area visibility; this effect of the inspection equipment can reduce mechanical judgment errors and shorten the inspection time; therefore, it is suitable for high-speed inspection systems for large-scale mass production equipment.
[0056] According to the embodiment of the present invention, the transparent film surface inspection device can be arranged on the process line for transparent film production, and is used for judging whether the transparent film is defective or good, judging whether the product has any abnormality, and transmitting the visual processing technology; in addition, according to the embodiment of the present invention, if the corresponding transparent film is judged to be defective through the result value judged in the visual processing, the production equipment for producing the corresponding transparent film and the relevant information and the judgment value of the defect can be transmitted, and on this basis, the visual inspection device and the production equipment that need to be replaced and repaired can be remotely operated to operate / stop.
[0057] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art can easily think of various changes or substitutions within the technical scope disclosed by the present invention, which should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.
Claims
1. A transparent film surface inspection device, characterized in that: include: Differential interferometry, which is used to analyze video of transparent film surfaces; An illumination device, which is used to provide illumination light to the surface of the transparent film; The lighting device comprises: an upper lighting device, which provides upper lighting light from the upper part of the transparent film to the upper surface of the transparent film; A lower lighting device provides lower lighting light from the lower part of the transparent film to the bottom of the transparent film.
2. The transparent film surface inspection device according to claim 1, characterized in that: The upper illumination device and the lower illumination device are arranged on the rear focal plane of the objective lens of the differential interferometer to ensure that the imaging of the upper illumination light and the imaging of the lower illumination light can be combined with each other.
3. The transparent film surface inspection device according to claim 1, characterized in that: Also includes: A control unit, which controls the lighting device and the camera of the differential interferometer; The control unit controls the upper lighting device and the lower lighting device to ensure that the upper lighting light and the lower lighting light can be alternately provided to the transparent film.
4. The transparent film surface inspection device according to claim 3, characterized in that: The control unit includes: a first lighting control unit, which turns on / off the upper light source of the upper lighting device according to a set cycle; a second lighting control unit, which turns on / off the lower light source of the lower lighting device according to a set cycle; the second lighting control unit drives the lower light source to ensure that the lower light source outputs lower lighting light at a time that is staggered with the light-emitting time of the upper light source.
5. The transparent film surface inspection device according to claim 4, characterized in that: The control unit further includes: a camera control unit, which controls the camera shooting time of the differential interferometer; The camera control unit controls the camera to ensure that odd-numbered inspection videos can be shot during the period when the upper illumination light is provided by the upper illumination device under the control of the first illumination control unit; and controls the camera to ensure that even-numbered inspection videos can be shot during the period when the lower illumination light is provided by the lower illumination device under the control of the second illumination control unit.
6. The transparent film surface inspection device according to claim 5, characterized in that: The control unit also includes: an inspection unit, which analyzes the peeling and falling off of the transparent film; the inspection unit extracts the odd-numbered inspection video frames from the inspection video frames obtained by the camera as an upper surface defect video that emphasizes the upper surface defect portion of the transparent film, and the inspection unit extracts the even-numbered inspection video frames from the inspection video frames obtained by the camera as a lower surface defect video that emphasizes the lower surface defect portion of the transparent film.
7. The transparent film surface inspection device according to claim 1, characterized in that: The differential interferometer comprises: a body; a semi-reflecting mirror arranged in the body; an objective lens arranged at the lower end of the body; a condenser arranged between the semi-reflecting mirror and the objective lens; and a Wollaston filter, a polarizing filter and a camera arranged in sequence at the upper end of the body.
8. The transparent film surface inspection device according to claim 7, characterized in that: The differential interferometer further includes: an upper polarizer and an upper Wollaston prism arranged on one side of the upper lighting device; and a lower polarizer and a lower Wollaston prism arranged on one side of the lower lighting device.
9. The transparent film surface inspection device according to claim 8, characterized in that: The upper lighting device includes: an upper lighting body; an upper light source arranged in the upper lighting body; an upper heat filter arranged between the upper polarizer and the upper Wollaston prism; an upper aperture arranged between the upper Wollaston prism and the semi-reflecting mirror; an upper field of view aperture arranged between the upper aperture and the semi-reflecting mirror; and an upper condenser arranged between the upper field of view aperture and the semi-reflecting mirror.
10. The transparent film surface inspection device according to claim 8, characterized in that: The lower lighting device includes: a lower lighting body; a lower light source arranged in the lower lighting body; a lower heat filter arranged between the lower polarizer and the lower Wollaston prism; a lower aperture arranged between the lower Wollaston prism and the transparent film; a lower field of view aperture arranged between the lower aperture and the transparent film; and a lower condenser arranged between the lower field of view aperture and the transparent film.