PETG film uniformity detection device based on optical interference

Abstract

The invention relates to the technical field of film uniformity detection, in particular to a PETG film uniformity detection device based on optical interference, which is used for film uniformity detection and comprises a workbench, and the workbench is provided with a micrometer, a light emitting module, an acquisition module, a processing module, a storage module and a control module. By means of the film interference phenomenon that light beams can be reflected after passing through the upper surface and the lower surface of a film, an imaging plate and an area-array camera are adopted to record graphic data of an upper light reflecting area, a lower light reflecting area and a highlight area, and comparison data are formed by combining manual and mechanical detection thickness values of a ten-thousand-minute ruler. A plurality of contrast data meeting the uniformity requirement are selected for pattern contour integration to form a highlight range region, when the thin film is continuously detected, the detection part of the thin film meets the uniformity requirement as long as the highlight region formed by irradiating the thin film is in the highlight range region, and rapid and continuous detection can be realized.

Description

Technical Field

[0001] The present invention relates to the technical field of thin film uniformity detection, and particularly relates to a PETG thin film uniformity detection device based on optical interference. Background Art

[0002] Thin films are widely used in fields such as liquid crystal TVs, tablet computers, smart phones, vehicle-mounted displays, etc. Due to limitations in production processes or production environments, etc., thin films are prone to quality defects during production, mainly manifested as uneven thickness, scratches on the surface, bubbles inside, or impurities and dust incorporated inside the thin film. Therefore, thin film uniformity detection has become an important part of the production quality control of thin film materials.

[0003] Traditional detection generally uses a micrometer to perform manual mechanical detection on thin films. This is generally suitable for detecting small-sized samples and requires operators to perform random multi-point detection. There may be situations where parts that do not meet the uniformity standard are not detected, but the detected parts are qualified; in order to improve accuracy, the Derpson thin film thickness gauge for thin sheets uses a continuous equidistant detection method. Although it saves manpower through automation and can detect longer-sized thin films, and at the same time uses the equidistant detection method to increase the samples at the detection positions, there is still a situation in the detection on a straight line, that is, positions with non-conforming thickness uniformity between two detection points are not detected;

[0004] To solve this problem, such thickness gauges can only shorten the distance between two detection points and increase the detection frequency to improve the detection accuracy, which greatly reduces the detection efficiency.

[0005] The above information disclosed in the background art section is only used to strengthen the understanding of the background of the present disclosure, and therefore it may include information that does not constitute the prior art known to those of ordinary skill in the art. Summary of the Invention

[0006] The object of the present invention is to design a device that can continuously and quickly detect the thickness uniformity of a thin film by using the thin film interference phenomenon to solve the above deficiencies in the technology.

[0007] To achieve the above object, the present invention provides the following technical solution: A PETG thin film uniformity detection device based on optical interference, used for the uniformity detection of thin films, includes a workbench, on which a micrometer, a light emitting module, a collection module, a processing module, a storage module, and a control module are installed;

[0008] The acquisition module includes an imaging plate and an area array camera. The light beam emitted by the light-emitting module is reflected by the upper and lower surfaces of the film, forming an upper reflective area and a lower reflective area on the imaging plate. The overlapping part of the upper and lower reflective areas forms a highlight area. The upper reflective area, the lower reflective area, and the highlight area are recorded as graphic data by the area array camera. The ten-thousand-meter measures and records the film thickness value in the area of ​​the film illuminated by the light-emitting module. The thickness value and graphic data are saved as a set of reference data by the storage module.

[0009] The processing module calls multiple sets of reference data to form a highlight range area. When continuously detecting the film, it determines whether the variation of the formed highlight area within the highlight range area exceeds the range. If it exceeds the range, the control module stops driving the film to move. The micrometer measures and records the thickness value of the area exceeding the range to determine whether to modify the highlight range area to match the uniformity detection of the film.

[0010] Preferably, the light beam generated by the light-emitting module is a columnar light beam with oblique illumination, and the shape of the columnar light beam when it contacts the upper surface of the film is elliptical. Both the upper reflective area and the lower reflective area are elliptical in size.

[0011] Preferably, the light beam generated by the light-emitting module is a conical light beam with oblique illumination. When the conical light beam contacts the upper surface of the thin film, its shape is elliptical. The upper reflective area and the lower reflective area are both elliptical in shape, and the size of the lower reflective area is larger than that of the upper reflective area.

[0012] Preferably, the worktable has a groove, and a slider fixedly connected to the micrometer is slidably installed in the groove. When the slider is located at the end of the groove, the measuring end of the micrometer is located on the upper surface of the film irradiated by the light emitted by the light-emitting module.

[0013] Preferably, the acquisition module is configured in two groups. One group of acquisition modules is located at the top of the worktable to record the graphic data of the upper reflective area, the lower reflective area, and the highlight area. The other group of acquisition modules is located at the bottom of the worktable. The light emitted by the light-emitting module is refracted on the thin film and passes through the groove to illuminate the imaging plate in the lower acquisition module to form a refracted light area.

[0014] Preferably, the image data recorded by the area array camera for the upper reflective area, lower reflective area, and highlight area also includes the image data of the refracted light area.

[0015] Preferably, the control module includes bottom rollers rotatably mounted on both sides of the worktable, and a top roller rotatably mounted on the worktable above the bottom rollers. The top roller cooperates with the bottom rollers to drive the film to move in tension, and an input shaft is fixedly mounted at the end of one of the bottom rollers.

[0016] Preferably, the control module further includes a power component for driving the input shaft to rotate, and a display showing the film's movement speed, the comparison data, the beam angle of the light-emitting module, and the uniformity of the film.

[0017] The technical effects and advantages provided by the present invention in the above technical solution are as follows:

[0018] 1. This invention utilizes the thin-film interference phenomenon, where light beams are reflected from both the upper and lower surfaces of a thin film. An imaging plate and an area array camera are used to record the graphic data of the upper reflective area, lower reflective area, and highlight area. The thickness values ​​are then combined with the manual mechanical thickness measurement using a ten-thousand-meter to form reference data. Multiple reference data that meet the uniformity requirements are selected and the graphic contours are integrated to form the highlight area. When continuously inspecting the thin film, as long as the highlight area formed by the illumination of the thin film is within the highlight area, it means that the inspection area of ​​the thin film meets the uniformity requirements, enabling rapid and continuous inspection.

[0019] 2. When the highlight area formed by the irradiation of the film is outside the highlight range area, the control module will stop feeding the film, and the micrometer will manually and mechanically detect the thickness of the irradiated area of ​​the film. When the thickness meets the uniformity requirements, the thickness value and graphic data are saved as a set of reference data, and the position and area of ​​the high-gloss range area are updated and expanded. When the thickness does not meet the uniformity requirements, the conclusion that the film uniformity does not meet the requirements is drawn, thereby adjusting and expanding the high-gloss range area in real time to meet the uniformity standard, which facilitates rapid and continuous detection.

[0020] 3. Compared with the prior art which uses a ten-thousand-meter to randomly detect points on the film, this invention is suitable for films with shorter lengths but is insufficient for detecting long films. This product only requires the initial thickness detection of multiple points on the film and the establishment of reference data, and can then perform continuous automatic detection of the film. First, the film is detected along a straight line, making the detection more thorough. Second, it can achieve automated detection while the film is moving at a constant speed.

[0021] 4. Compared with the prior art of using interference fringes to detect film thickness, the present invention only needs to determine whether the highlight area generated when the film is irradiated is within the range. It only needs to deal with the position and size of the ellipse. Compared with the multiple formulas and the need to know the refractive index of the film material in the thickness detection using interference fringes, the amount of calculation is reduced, and at the same time, it is not necessary to know the refractive index of the film material.

[0022] 5. This invention designs a slide for the micrometer to move, allowing the light beam transmitted through the thin film to pass through the slide and be received by the imaging plate below. By utilizing the different paths of the light beam refraction in the thin film, there will be a lateral offset on the imaging plate below, thereby forming reference data to re-inspect the uniformity of the thin film judged by the imaging plate above. Furthermore, this light beam will not be reflected back through the surface of the worktable, affecting the imaging of the highlight area of ​​the thin film. Attached Figure Description

[0023] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this invention. For those skilled in the art, other drawings can be obtained based on these drawings.

[0024] Figure 1 This is a simplified schematic diagram of the overall structure of the present invention;

[0025] Figure 2 This is a simplified front view of the present invention;

[0026] Figure 3 This is a simplified schematic diagram illustrating the reflection and refraction of a thin film by a light beam irradiation according to the present invention.

[0027] Figure 4 This is a simplified schematic diagram illustrating the motion of the thin film irradiated by the light beam according to the present invention.

[0028] Figure 5 This is a simplified schematic diagram of the highlight region of the thin film irradiated by the columnar beam of the present invention;

[0029] Figure 6 This is a simplified schematic diagram of the highlight region of the thin film irradiated by the conical beam of the present invention;

[0030] Figure 7 This is a simplified schematic diagram of the highlight area formed by the columnar beam illumination of the present invention.

[0031] Figure 8 This is a simplified schematic diagram of the highlight area formed by the conical beam illumination of the present invention.

[0032] Figure 9 This is a simplified schematic diagram of the detection process of the present invention.

[0033] Explanation of reference numerals in the attached figures:

[0034] 1. Thin film; 2. Worktable; 3. Micrometer; 4. Light output module; 5. Acquisition module; 51. Imaging plate; 52. Area scan camera; 6. Processing module; 7. Storage module; 8. Control module; 801. Bottom roller; 802. Top roller; 803. Input shaft; 9. Upper reflective area; 10. Lower reflective area; 11. Highlight area; 12. Highlight range area; 13. Slide groove; 14. Slider; 15. Refraction area; 16. Display. Detailed Implementation

[0035] To enable those skilled in the art to better understand the technical solutions in this application, the technical solutions in the embodiments of this application will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0036] To better understand the above technical solutions, the following will provide a detailed explanation of the technical solutions in conjunction with the accompanying drawings and specific implementation methods.

[0037] This invention provides, for example Figure 1-9 The illustrated device is a PETG thin film uniformity detection device based on optical interference, such as... Figures 1-2 As shown, the system includes a worktable 2, on which a slide groove 13 is provided. A slider 14 is slidably installed in the slide groove 13. A micrometer 3 is fixedly installed on the slider 14. The micrometer 3 can manually and mechanically measure the thickness of the film 1. A light-emitting module 4 is fixedly installed on the worktable 2 for emitting an inclined light beam toward the film 1. At the same time, an acquisition module 5, a processing module 6, a storage module 7, and a control module 8 are fixedly installed on the worktable 2. The acquisition module 5 consists of an imaging plate 51 and an area array camera 52. There are two acquisition modules 5, located above and below the worktable 2, respectively.

[0038] like Figures 3-4 As shown, due to the interference phenomenon of thin film 1, when the beam is obliquely incident on thin film 1, part of the beam will be reflected on the upper surface of thin film 1, part of the beam will be transmitted into thin film 1 and reflected on the lower surface and then transmitted out again, and a part of the beam will be transmitted out of thin film 1.

[0039] like Figure 3 and Figure 5As shown, after being reflected on the upper surface of the thin film 1, part of the light beam will form an upper reflective area 9 on the upper imaging plate 51. After being reflected on the lower surface of the thin film 1, part of the light beam will form a lower reflective area 10 on the upper imaging plate 51. The upper reflective area 9 and the lower reflective area 10 will overlap. The brightness of the overlapping area is higher than that of the upper reflective area 9 and the lower reflective area 10, forming a highlight area 11. If the thickness of the thin film 1 decreases, the highlight area 11 will increase. If the thickness of the thin film 1 increases, the highlight area 11 will decrease. The light beam projected from the thin film 1 will illuminate the lower imaging plate 51, forming a refracted light area 15.

[0040] like Figure 5 As shown, when the light beam emitted by the light-emitting module 4 is a parallel columnar light beam that is irradiated at an angle, the refracted light area 15, the upper reflective area 9 and the lower reflective area 10 will form an ellipse of the same size. The horizontal distance between the two ellipses changes depending on the thickness of the thin film 1.

[0041] like Figure 6 As shown, when the light beam emitted by the light-emitting module 4 is a parallel conical light beam that is irradiated at an angle, the refracted light area 15, the upper reflective area 9 and the lower reflective area 10 will still form an elliptical bright spot. However, the size of the lower reflective area 10 will be larger than the size of the upper reflective area 9, and the size ratio and horizontal spacing will change with the thickness of the thin film 1.

[0042] like Figures 7-9 As shown, when the light beam emitted by the light-emitting module 4 is projected onto the thin film 1, forming an upper reflective area 9, a lower reflective area 10, a highlight area 11, and a refracted light area 15 on the imaging plate 51, the area array camera 52 records the horizontal position and size of these four light areas on the plane to form graphic data. Then, the micrometer 3 is operated to detect the part of the thin film 1 irradiated by the light beam emitted by the light-emitting module 4. When the thickness value is detected, a set of reference data is formed by combining the graphic data. Then, the processing module 6 calls up multiple sets of reference data to form the highlight range area 12. The control module 8 includes a bottom roller 801 and a top roller 802 rotatably mounted on both sides of the worktable 2. The top roller 802 cooperates above the bottom roller 801 to drive the thin film 1 to move in a taut and wrinkle-free state. An input shaft 803 is installed on one of the bottom rollers 801. The control module 8 also includes a power component for controlling the rotation speed of the input shaft 803 and a display 16. The display 16 displays the movement speed of the thin film 1, the reference data, the beam angle, and the current uniformity of the thin film 1.

[0043] like Figures 1-3As shown, the external power component drives the bottom roller 801 to rotate at a constant speed via the drive input shaft 803, causing the bottom roller 801 and top roller 802 to drive the film 1 to move at a constant speed. This causes the light beam emitted by the light-emitting module 4 to illuminate different positions of the film 1, resulting in changes in the thickness of the film 1. Consequently, the resulting highlight area 11 also changes dynamically. When the highlight area 11 continuously changes within the highlight range 12 and does not exceed the highlight range 12, it indicates that the uniformity of the film 1 meets the requirements. When the highlight area 11 exceeds the highlight range 12, the control module 8 stops driving the film 1. At this time, the micrometer 3 is used to manually detect the thickness of the film 1 at the position illuminated by the light beam emitted by the light-emitting module 4. Figure 8 Figure 9 As shown, if this thickness is within the allowable thickness error, that is, within the allowable uniformity variation, then the highlight area 11 is used as the new boundary to define the highlight range area 12. The micrometer 3 is removed and the film 1 is driven to move at a constant speed to detect uniformity. When this thickness is not within the allowable thickness error, that is, within the allowable uniformity variation, the detection result that the film 1 does not conform to the uniformity variation is obtained.

[0044] like Figure 9 As shown, the entire process of using the device is as follows: First, a micrometer 3 is used to randomly perform manual mechanical thickness detection at various points on the film 1, and the graphic data of the detected thickness is recorded to form reference data. This ensures that the thickness of the film 1 in the reference data is within the allowable thickness error, i.e., the allowable uniformity variation range. Then, the processing module 6 calls the data in the storage module 7 to form the highlight range area 12. The control module 8 drives the film 1 to move linearly at a uniform speed and monitors in real time whether the highlight area 11 formed by the part of the film irradiated by the beam is within the highlight range area 12. When the highlight area 11 exceeds the highlight range area 12, the micrometer 3 is used again to detect the thickness of the corresponding part of the film 1, and the highlight range area 12 is detected and updated until the uniformity of the entire film 1 is continuously detected until it meets or does not meet the requirements.

[0045] It is important to note that the constructions and arrangements of this application shown in several different exemplary embodiments are merely illustrative. Although only a few embodiments are described in detail in this disclosure, those who consult this disclosure will readily understand that many modifications are possible (e.g., changes in the size, dimensions, structure, shape and proportion of various elements, as well as parameter values ​​(e.g., temperature, pressure, etc.), installation arrangements, use of materials, color, orientation, etc.) without substantially departing from the novel teachings and advantages of the subject matter described in this application.

Claims

1. A PETG thin film uniformity detection device based on optical interference, used for uniformity detection of thin film (1), characterized in that: It includes a workbench (2), on which a micrometer (3), a light output module (4), a data acquisition module (5), a processing module (6), a storage module (7), and a control module (8) are installed; The acquisition module (5) includes an imaging plate (51) and an area array camera (52). The light beam emitted by the light-emitting module (4) is reflected by the upper and lower surfaces of the thin film (1) and forms an upper reflective area (9) and a lower reflective area (10) on the imaging plate (51). The overlapping part of the upper reflective area (9) and the lower reflective area (10) forms a highlight area (11). The upper reflective area (9), the lower reflective area (10) and the highlight area (11) are recorded as graphic data by the area array camera (52). The ten-thousand-meter (3) measures and records the thickness value of the thin film (1) in the area of ​​the thin film (1) illuminated by the light-emitting module (4). The thickness value and graphic data are saved as a set of reference data by the storage module (7). The processing module (6) calls multiple sets of reference data to form a highlight range area (12). When continuously detecting the film (1), it determines whether the change of the formed highlight area (11) within the highlight range area (12) exceeds the range. If it exceeds the range, the control module (8) stops driving the film (1) to move. The micrometer (3) measures and records the thickness value of the area exceeding the range to determine whether to modify the highlight range area (12) to match the uniformity detection of the film (1).

2. The PETG thin film uniformity detection device based on optical interference according to claim 1, characterized in that: The light beam generated by the light-emitting module (4) is a columnar light beam that is irradiated at an angle. When the columnar light comes into contact with the upper surface of the thin film (1), it is elliptical. The upper reflective area (9) and the lower reflective area (10) are both elliptical in size.

3. The PETG thin film uniformity detection device based on optical interference according to claim 1, characterized in that: The light beam generated by the light-emitting module (4) is a conical light beam that is irradiated at an angle. When the conical light beam comes into contact with the upper surface of the thin film (1), the shape is elliptical. The upper reflective area (9) and the lower reflective area (10) are both elliptical in shape, and the size of the lower reflective area (10) is larger than the size of the upper reflective area (9).

4. The PETG thin film uniformity detection device based on optical interference according to claim 1, characterized in that: The workbench (2) has a slide groove (13), and a slider (14) fixedly connected to the micrometer (3) is slidably installed in the slide groove (13). When the slider (14) is located at the end of the slide groove (13), the measuring end of the micrometer (3) is located on the upper surface of the light irradiated by the light emitted by the light-emitting module (4).

5. The PETG thin film uniformity detection device based on optical interference according to claim 4, characterized in that: The acquisition module (5) is set in two groups. One group of acquisition modules (5) is located on the top of the worktable (2) to record the graphic data of the upper reflective area (9), the lower reflective area (10) and the highlight area (11). The other group of acquisition modules (5) is located at the bottom of the worktable (2). The light emitted by the light-emitting module (4) is refracted on the thin film (1) and passes through the slide (13) to irradiate the imaging plate (51) in the acquisition module (5) below to form a refracted light area (15).

6. The PETG thin film uniformity detection device based on optical interference according to claim 5, characterized in that: The image data recorded by the area array camera (52) for the upper reflective area (9), lower reflective area (10) and highlight area (11) also includes the image data of the refracted light area (15).

7. The PETG thin film uniformity detection device based on optical interference according to claim 1, characterized in that: The control module (8) includes bottom rollers (801) rotatably mounted on both sides of the worktable (2) and top rollers (802) rotatably mounted on the worktable (2) above the bottom rollers (801). The top rollers (802) cooperate with the bottom rollers (801) to drive the film (1) to move and tension. An input shaft (803) is fixedly mounted at the end of one of the bottom rollers (801).

8. The PETG thin film uniformity detection device based on optical interference according to claim 7, characterized in that: The control module (8) also includes a power component that drives the input shaft (803) to rotate, and a display (16) that displays the movement speed of the thin film (1), the reference data, the beam angle of the light-emitting module (4), and the uniformity of the thin film (1).

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