Detection system for optical film

Abstract

The utility model relates to a detection system for an optical film. The system comprises a first detection device and a second detection device, the first detection device comprises a mark detection part, the mark detection part detects whether a mark exists on the optical film or not, and for the optical film where the mark is detected, a to-be-detected area of the optical film is determined based on the position and the size of the mark on the optical film; the second detection device comprises a bright spot detection component which detects the to-be-detected area of the optical film so as to obtain a characteristic value related to a bright spot. According to the system, automation of feeding, conveying, detection and storage of the optical film is achieved, the detection accuracy is improved, meanwhile, the detection efficiency is improved, and manpower is greatly saved.

Description

Technical Field

[0001] The utility model relates to a detection system for optical films. Background Art

[0002] In the front-end process of manufacturing optical films, defects of the optical films may be marked. Then, in the back-end process of cutting the optical films, for the cut optical films, it is necessary to identify the mark again and perform further defect detection. The traditional method is to use manual inspection, but the process is complex, very time-consuming, inefficient, and has low accuracy. Summary of the Utility Model

[0003] The purpose of the utility model is to provide a detection system for automatically detecting optical films, realizing the automation of loading, conveying, detecting, and storing optical films, improving the accuracy of detection, and at the same time improving the detection efficiency, greatly saving manpower.

[0004] The utility model discloses a detection system for optical films, and the system includes a first detection device and a second detection device;

[0005] The first detection device includes a mark detection component, and the mark detection component detects whether there is a mark on the optical film, and for the optical film with the detected mark, determines the area to be detected of the optical film based on the position and size of the mark on the optical film;

[0006] The second detection device includes a bright point detection component, and the bright point detection component detects the area to be detected of the optical film to obtain characteristic values related to bright points.

[0007] Optionally, the mark detection component divides the area to be detected to determine multiple detection areas and a detection sequence;

[0008] The bright point detection component detects the multiple detection areas in the area to be detected according to the detection sequence, wherein the bright point detection component includes a camera, and the size of the detection area is associated with the single effective field of view of the camera.

[0009] Optionally, the second detection device further includes a mark re-inspection component, and the mark re-inspection component determines whether the area to be detected is at a specified position, and when the area to be detected is not at the specified position, the optical film is re-placed.

[0010] Optionally, the second detection device further includes a 3D detection component, and the 3D detection component determines the warping degree of the area to be detected at the specified position, and the depth of field of the camera of the bright point detection component is adjusted based on the warping degree.

[0011] Optionally, the system further includes a third detection device;

[0012] The third detection device includes a reverse film detection component. The reverse film detection component uses a filter set to detect whether the optical film has the release film layer facing up, and for the optical film detected with the release film layer facing up, determines the filter in the filter set that matches the optical film;

[0013] The bright spot detection component selects the matching filter to detect the area to be inspected of the optical film.

[0014] Optionally, the system further includes one or more carrier devices;

[0015] The one or more carrier devices carry the optical film to move it to the corresponding detection device; each carrier device includes a platform having air suction holes and through holes. The air suction holes adsorb the optical film, and the through holes serve as the designated positions through which light can pass and enter the camera of the bright spot detection component.

[0016] Optionally, the platform can be translated in the X direction and the Y direction and rotated about the Z axis to adjust the adsorbed optical film and move the optical film in accordance with the detection sequence.

[0017] Optionally, the system further includes a feeding device;

[0018] The feeding device includes an adsorption component and a multi-piece detection component. The adsorption component adsorbs the optical film from the feeding bin. The multi-piece detection component detects whether the adsorbed optical film is a single piece, and for the optical film detected as a single piece, the adsorption component places the optical film on the carrier device.

[0019] Optionally, the system further includes a transfer device;

[0020] The transfer device transfers the optical film carried on one carrier device to another carrier device.

[0021] Optionally, the inspected optical film is collected in the corresponding receiving bin.

[0022] Compared with the prior art, the main differences and effects of the present utility model are as follows:

[0023] The present utility model realizes the automation of the feeding, conveying, detection, and storage of the optical film, improves the accuracy of detection, and at the same time improves the detection efficiency, greatly saving manpower. Description of the Drawings

[0024] Figure 1 is an overall schematic diagram of the detection system according to an embodiment of the present utility model;

[0025] Figure 2 is a schematic diagram of a detection area according to an embodiment of the present invention;

[0026] Figure 3 is a schematic diagram of a detection sequence for detecting a detection area according to an embodiment of the present invention;

[0027] Figure 4 is a schematic diagram of a bright spot detection component according to an embodiment of the present invention. Detailed implementation manners

[0028] To make the objectives and technical solutions of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the described embodiments of the present invention without creative efforts shall fall within the scope of protection of the present invention.

[0029] The embodiments of the present invention relate to a detection system for detecting an optical film.

[0030] Figure 1 is a schematic diagram of a detection system according to an embodiment of the present invention. As Figure 1 shown, the detection system includes a loading device 101, a first detection device, a second detection device, and one or more carrier devices. The first detection device includes a mark detection component 102, the second detection device includes a bright spot detection component 103, and the one or more carrier devices may include a first carrier device 104, a second carrier device 105, and a third carrier device 106.

[0031] The loading device 101 includes an adsorption component. In one embodiment, a suction cup is provided on the adsorption component, and a plurality of suction nozzles are provided on the suction cup. When loading, the loading device 101 sucks the optical film from a loading bin (not shown) through the suction cup of the adsorption component and places the sucked optical film on the carrier device 104. In one embodiment, a grid-shaped material rod is further provided on the loading bin to clamp the stacked optical films to be sucked. Corresponding to different sizes of optical films, the position of the material rod can be synchronously adjusted to clamp the optical film stack.

[0032] In addition, the loading device 101 further includes multiple detection components. When sucking the optical film, the multiple detection components detect the number of optical films sucked by the adsorption component at one time through, for example, photoelectric induction. When it is detected that there are multiple optical films adsorbed on the suction nozzle, the suction nozzle can drop the excess optical films or all the multiple optical films by, for example, moving up and down, and place them into the corresponding first material collection bin 107 to prevent the multiple stacking from affecting the detection during the subsequent detection process. In one embodiment, the number of times of multiple suction can be displayed in real time, and the cumulative occurrence times are saved within a set time. If multiple suction occurs continuously for a set number of times, the alarm shutdown function of the system will be triggered. Additionally, if the dropped optical film is caught on the above-mentioned material rod, the alarm shutdown function of the system will be triggered. Further, when the suction nozzle performs adsorption, if it is detected that the suction nozzle does not adsorb the optical film, the alarm shutdown function of the system will also be triggered.

[0033] The detection system includes one or more carrier devices. Specifically, it includes a first carrier device 104, a second carrier device 105, and a third carrier device 106. Refer to Figure 1 , where the first carrier device 104 carries the optical film from the loading device 101 to the second carrier device 105, the second carrier device 105 carries the optical film to the first detection device, and the third carrier device 106 carries the optical film to the second detection device.

[0034] In this embodiment, the optical film detection system further includes a transfer device 108, and the transfer device 108 transfers the optical film carried on the second carrier device 105 that has been detected by the first detection device to the third carrier device 106.

[0035] As an example, the transfer device 108 is a robotic arm. Further, the robotic arm can have two grippers. When one gripper is performing grasping and placing, the other gripper is in a standby state, and the two grippers work alternately in a cycle to improve the work efficiency. In addition, each type of optical film has its own fixed axis angle, and the detection system writes different axis angles and the corresponding rotation angle values corresponding to each axis angle into the system. Thus, before the robotic arm transports the optical film to the bright point detection carrier device, the optical film will be rotated by the corresponding angle based on the rotation angle corresponding to the current optical film saved in the system.

[0036] One or more carrier devices include a platform for carrying the optical film. Suction holes are provided on the platform, and the adsorption capacity can be visually operated and managed by controlling the air chamber pressure value to achieve stable adsorption of various optical films. Additionally, through holes are provided on the platform, and the optical film can be imaged through the through holes, where the light source and the camera are respectively arranged on both sides of the through hole.

[0037] One or more carrier devices can be translated in the X direction and the Y direction, and rotated about the Z direction axis, where the X direction and the Y direction respectively refer to the axial angular direction and the vertical axial angular direction of the optical film, and the Z direction refers to the height direction of the optical film. When transporting the optical film via the carrier device, the position of the optical film can be adjusted by the rotation function of the carrier device, and the adjustment method is as follows: First, determine the deflection angle θ of the long side of the optical film relative to the forward direction, and then make a judgment. If θ < α (α is a predetermined deflection angle threshold, which is associated with the upper limit of the rotation function of the third carrier device 106), then correct the deflection angle θ by rotating the carrier device about the Z direction axis; if θ > α, it means that the deflection angle θ cannot be completely corrected by the rotation of the carrier device, so the alarm shutdown function of the system is triggered.

[0038] After the loading process is completed, the first carrier device 104 transports the adsorbed optical film to the first detection device. The first detection device includes a mark detection component 102, and the mark detection component 102 operates on the optical film to be detected, including detecting whether there is a mark on the optical film.

[0039] The mark comes from the defect detection link in the previous process of manufacturing the optical film, and it indicates the defects detected on the uncut optical film (such as bright spots that are leakage light points of the liquid crystal layer in the optical film). After the optical film is cut, the mark may be located on one or more cut optical films, and some cut optical films may not have marks either. Whether there is a mark on the cut optical film can be detected by means of, for example, image recognition.

[0040] The operations performed by the mark detection component 102 also include, for the optical film on which a mark is detected, determining the area to be detected of the optical film based on the position and size of the mark on the optical film.

[0041] Locate the optical film to be detected and the mark thereon, calculate the center point coordinates of the optical film and the center point coordinates of the mark respectively, so as to determine the position of the mark on the optical film; calculate the size of the mark; determine the area to be detected of the optical film based on the position and size of the mark on the optical film. It can be understood that the area to be detected refers to a rectangular or non-rectangular area surrounding the mark. In one embodiment, when two or more areas to be detected are detected on the optical film or no mark is detected on the optical film, no subsequent detection is performed and the transfer device 108 is used to transport the optical film to the corresponding second receiving bin 109. The second receiving bin 109 is used to receive other optical films except for the multiple sucked optical films received by the first receiving bin 107 described above, and classify them.

[0042] The operations performed by the logo detection component 102 also include dividing the area to be inspected, determining multiple detection areas and a detection sequence, so that the bright point detection component to be mentioned later can detect the multiple detection areas in accordance with the detection sequence to obtain characteristic values related to bright points.

[0043] It can be understood that the detection area refers to a smaller rectangular or non-rectangular area than the area to be inspected. The multiple divided detection areas constitute the area to be inspected, and the size of each detection area is associated with the single effective field of view of the camera included in the bright point detection component. For example, the overall field of view of the camera is 21mm * 16mm, and the single effective field of view is 7mm * 6mm. Therefore, the size of the detection area can also be 7mm * 6mm, or slightly larger or slightly smaller than 7mm * 6mm.

[0044] In one embodiment, there may also be overlapping parts between the divided detection areas, so as to avoid missed detection. For example, referring to Figure 2 the example shown in Figure 2 depicts 6 detection areas 202 divided in the area to be inspected 201 1-6 , where the detection area 2021 has overlapping parts with the detection areas 2022 and 2024 respectively, the detection area 2022 has overlapping parts with the detection areas 2021, 2023 and 2025 respectively, the detection area 2023 has overlapping parts with the detection areas 2022 and 2026 respectively, the detection area 2024 has overlapping parts with the detection areas 2021 and 2025 respectively, the detection area 2025 has overlapping parts with the detection areas 2022, 2024 and 2026 respectively, and the detection area 2026 has overlapping parts with the detection areas 2023 and 2025 respectively. For example, the overlapping part is 1mm to 1.5mm.

[0045] The detection sequence refers to the sequence of detecting each detection area in the subsequent bright point detection operation, that is, by keeping the camera included in the bright point detection component stationary and moving the second carrier device 105 at the second detection device, thereby driving the detection areas on the optical film carried thereon to move to the imaging position of the camera in sequence according to the detection sequence, and then performing the bright point detection operation on the optical film. For example, referring to Figure 3 the example shown in Figure 3 depicts 6 detection areas 202 divided in the area to be inspected 201 1-6 moving to the imaging position of the camera in sequence in the direction indicated by the arrow, that is, the detection areas 2021, 2022, 2023, 2026, 2025 and 2024 are moved to the imaging position of the camera in sequence.

[0046] After the completion of the mark detection, the optical film is conveyed to the second detection device via the second vehicle device 105. The second detection device includes a bright spot detection component 103. For example, referring to Figure 4 the example shown in Figure 4 FIG. 4 depicts the specific configuration of the bright spot detection component 103. The bright spot detection component 103 includes a camera 401, a filter set 402, a field of view compensation sheet 403, a band-pass filter 405, and a light source 406. The optical film 404 to be detected is placed between the field of view compensation sheet 403 and the band-pass filter 405 for detection. As an example, the optical film to be detected is a polarizing film, which includes at least three layers, namely a protective layer, a polarizing layer, and a release layer arranged in sequence. The bright spot detection component 103 detects a plurality of detection areas in the area to be detected on the optical film according to the above-mentioned detection sequence to obtain eigenvalue related to bright spots. The eigenvalues include, for example, in-plane average gray level, bright spot area, maximum gray level value of bright spots, etc.

[0047] The filter set 402 includes multiple filters. Different filters have different light-receiving amounts. When performing bright spot detection, a filter matching the optical film is selected so that the gray level value of the filter is the lowest (for example, select the filter with a gray level value of 3 as the matching filter from multiple filters with gray level values of 3, 5, 8, 11, 7, 6, 5, 4 respectively), so that the bright spots are more obvious, that is, the detection result is more accurate.

[0048] The field of view compensation sheet 403 is used to improve the uniformity of the effective field of view of the camera, that is, to keep the brightness difference in the effective field of view area of the camera small, and the brightness at each position in the field of view is relatively close, which is beneficial to improving the accuracy of the detection result.

[0049] Since the marks existing on the optical film may affect the detection of bright spots, a band-pass filter 405 is introduced in the bright spot detection component 103 to remove the interference of the marks on the bright spot detection.

[0050] Since it is necessary to exclude the interference of uncontrollable factors as much as possible during the detection process, the bright spot detection process can be carried out in a dark box, and at the same time, a light source 406 is used to provide the light required for the detection process.

[0051] The optical film 404 to be detected is placed on the third carrier device 106 at the bright point detection component 103. This third carrier device 106 can also be referred to as the bright point detection carrier device, which may be a device with the same structure or a device with a different structure as the first carrier device 104 at the first detection device. The bright point detection carrier device includes a platform for carrying the optical film. Suction holes are provided on the platform, and the adsorption capacity can be visually operated and managed by controlling the air chamber pressure value to achieve stable adsorption of various optical films. Additionally, through holes are provided on the platform, and the optical film can be imaged through the through holes. Among them, the band-pass filter 405 and the light source 406 are arranged on one side of the through hole, and the camera 401, the filter set 402, the field of view compensation sheet 403, and the optical film 404 are arranged on the other side of the through hole. For example, the size of the through hole is 50mm * 50mm. In another embodiment, two through holes are provided on the platform, and the configurations of the two through holes can adapt to different sizes of optical films and different detection angles. For example, the sizes of the two through holes are 25mm * 20mm and 50mm * 50mm respectively, and the center distance between the two through holes is 100mm. It can be understood that, according to the actual detection requirements, those skilled in the art can adjust the size of each through hole and the center distance between the two through holes, which is not limited herein.

[0052] Similar to the second carrier device 105 at the first detection device, the platform included in the bright point detection carrier device can also be translated in the X direction and the Y direction, and rotated about the Z axis, so that when the optical film moves to the imaging position of the camera, the jog displacement of the optical film adsorbed on its surface can be driven by the jog displacement of the platform in space to sequentially detect multiple detection regions in the detection order, and the deflection angle of the optical film can be corrected by the rotation of the platform in space.

[0053] The number of the second material collection bins 109 can be multiple, and the categories of the optical films collected by each second material collection bin 109 can be set by itself, so that the optical films passing through different detection processes can be transported to the corresponding second material collection bins 109. Specifically, the optical films detected at the first detection device with two or more regions to be detected or without detected marks can be transported to the corresponding second material collection bins 109, and the optical films that have completed the bright point detection at the second detection device can be transported to the corresponding second material collection bins 109.

[0054] In one embodiment, the detection system further includes a third detection device. After the first carrier device 104 transports the optical film to the second carrier device 105, the second carrier device 105 first transports the optical film to the third detection device, and then to the mark detection component 102. The third detection device includes a reverse film detection component 110. Considering that the bright point detection should be performed on the optical film with the same side facing up, there is no comparison significance between the bright point characteristic values of the optical films with different sides facing up. Therefore, the reverse film detection component 110 is provided here to detect whether the optical film has the release film layer facing up. In this embodiment, when the protective layer of the optical film faces up (i.e., the release layer faces down), it is a reverse film.

[0055] Due to the structural characteristics of the optical film, the polarization of light by the release film layer and the protective film layer of the optical film is different. Therefore, the light source can be arranged on one side of the through hole of the platform included in the first carrier device 104, and the camera, the filter set, and the optical film are arranged on the other side of the through hole of the platform. The reverse film detection component 110 detects whether the optical film has the release film layer facing up by determining the gray value of the filter. Among them, when the release film layer faces up, the gray value of the filter is within the first range (such as 3 - 220), and when the release film layer faces down, the gray value of the filter is within the second range (such as 50 - 80). Based on this, when the gray values of a group of filters are all within the second range (for example, the gray values of this group of filters are 58, 60, 66, 69, 74, 71, 68, 62 respectively), it indicates that the current optical film has the release film layer facing down, and subsequent detection is not performed, and the optical film is transported to the corresponding second receiving bin 109. If reverse films are detected continuously for multiple times, the alarm and shutdown function of the system is triggered.

[0056] In one embodiment, the reverse film detection component 110 has multiple filter groups, and each filter group includes multiple filters with different light receiving amounts. For different types of optical films, the corresponding filter group can be automatically switched according to the setting. If it is determined that the optical film has the release film layer facing up, but the gray values of the corresponding filter group are all greater than the set threshold (for example, the gray values of this group of filters are 15, 16, 17, 18, 19, 20, 17, 16 respectively), it indicates that the optical film is a mixed material, that is, the actual type of the optical film is different from its marked type, and subsequent detection is not performed, and the optical film is transported to the corresponding second receiving bin 109. If the situation of mixed materials occurs a predetermined number of times continuously, the alarm and shutdown function of the system is triggered.

[0057] In addition, the anti-film detection component 110 can also be used to select a matching filter for subsequent bright point detection for the second detection device 103. That is, when the anti-film detection component 110 determines that the optical film has the release film layer facing up and is not a mixed material, it can further determine the filter that matches the optical film, such that the gray value of the filter is the lowest (for example, select the filter with a gray value of 3 from multiple filters with gray values of 3, 5, 8, 11, 7, 6, 5, 4 respectively). This matching filter information is sent to the second detection device 103 to select the corresponding filter from the filter group 402.

[0058] Therefore, the anti-film detection component 110 can simultaneously implement the functions of anti-film detection and selecting the best filter, which can save workstations.

[0059] In one embodiment, the second detection device may further include a mark re-inspection component 111. Before bright point detection, the bright point detection carrier device first transports the optical film to the mark re-inspection component 111. The mark re-inspection component 111 can determine whether the area to be inspected of the optical film is placed at the center of the through hole of the platform included in the bright point detection carrier device according to the center coordinates of the area to be inspected. When it is detected that the area to be inspected is not in the specified position, the optical film can be re-placed. In addition, the mark re-inspection component 111 can also determine the deflection angle of the optical film to perform correction through the rotation function of the platform. In addition, when the rotation function of the platform cannot correct the deflection of the optical film, the transfer device 108 is used to transport the optical film to the corresponding second receiving bin 109.

[0060] In one embodiment, the second detection device may further include a 3D detection component 112. After mark re-inspection, the bright point detection carrier device then transports the optical film to the 3D detection component 112. The 3D detection component 112 measures the optical film using, for example, a 3D line scan measuring instrument, and thereby obtains the contour point cloud map of the optical film. Through this contour point cloud map, the extreme value or average value of the 3D measurement values of each detection area located at the center of the through hole can be calculated, and this extreme value or average value can indicate the warpage degree of the detection area. This warpage degree is sent to the bright point detection component 103, such that the bright point detection component 103 can adjust the depth of field of the camera (for example, ±0.5 mm) according to this warpage degree to correct the warpage degree of the corresponding detection area, and then detect each detection area in sequence within the normal depth of field range. Additionally, if the warpage degree of the optical film exceeds the set value, that is, when it cannot be corrected by adjusting the depth of field of the camera, subsequent bright point detection is not performed, but the optical film is transported to the corresponding second receiving bin 109. In addition, if the warpage degrees of multiple consecutive optical films all exceed the set value, the alarm shutdown function of the system is triggered.

[0061] It should be noted that in the claims and the specification of the present utility model, relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the term "comprising", "including" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method, article or device comprising a series of elements not only includes those elements, but also includes other elements not expressly listed, or further includes elements inherent to such process, method, article or device. Without further limitation, an element defined by the statement "comprising one" does not exclude the presence of additional identical elements in the process, method, article or device comprising said element.

[0062] Although the present utility model has been illustrated and described by reference to certain preferred embodiments thereof, those of ordinary skill in the art should understand that various changes may be made in form and detail without departing from the spirit and scope of the present utility model.

Claims

1. An inspection system for an optical film, characterized in that, The system includes a first detection device and a second detection device; The first detection device includes a mark detection component, which detects whether there is a mark on the optical film, and for the optical film with the mark detected, determines the area to be inspected of the optical film based on the position and size of the mark on the optical film; The second detection device includes a bright point detection component, which detects the area to be inspected of the optical film to obtain characteristic values related to the bright points.

2. The system according to claim 1, wherein The mark detection component divides the area to be inspected to determine a plurality of detection areas and a detection sequence; The bright point detection component detects the plurality of detection areas in the area to be inspected according to the detection sequence. Among them, the bright point detection component includes a camera, and the size of the detection area is associated with the single effective field of view of the camera.

3. The system according to claim 2, wherein The second detection device further includes a mark re-inspection component, which determines whether the area to be inspected is at a specified position, and when the area to be inspected is not at the specified position, the optical film is re-placed.

4. The system according to claim 3, wherein The second detection device further includes a 3D detection component, which determines the warping degree of the area to be inspected at the specified position, and the depth of field of the camera of the bright point detection component is adjusted based on the warping degree.

5. The system according to claim 4, wherein The system further includes a third detection device; The third detection device includes a reverse film detection component, which uses a filter set to detect whether the optical film has the release film layer facing up, and for the optical film detected with the release film layer facing up, determines the filter in the filter set that matches the optical film; The bright point detection component selects the matching filter to detect the area to be inspected of the optical film.

6. The system according to claim 5, characterized in that, The system further includes one or more carrier devices; The optical film is carried by the one or more carrier devices to move to the corresponding detection device; each carrier device includes a platform having air suction holes and through holes. The air suction holes adsorb the optical film, and the through holes serve as the specified position so that light can pass through them and enter the camera of the bright point detection component.

7. The system according to claim 6, characterized in that, The platform can be translated in the X direction and the Y direction and rotated about the Z axis to adjust the adsorbed optical film and move the optical film according to the detection sequence.

8. The system according to claim 7, characterized in that The system further includes a loading device; The loading device includes an adsorption component and a multi-piece detection component. The adsorption component adsorbs the optical film from the loading bin, the multi-piece detection component detects whether the adsorbed optical film is a single piece, and for the optical film detected as a single piece, the adsorption component places the optical film on the carrier device.

9. The system according to claim 8, wherein The system further includes a transfer device; The transfer device transfers the optical film carried on one carrier device to another carrier device.

10. The system according to claim 9, wherein, The inspected optical film is collected in the corresponding receiving bin.

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