Defect detection equipment

Abstract

The present application relates to a defect detection device, comprising: a light processing device comprising a first light processing unit and a second light processing unit, the first light processing unit being arranged between a line light source device and a film to be detected, the second light processing unit being arranged between the film to be detected and a camera device; and the shifting device is connected with the light processing device and is used for enabling the light processing device to be in the first position state. Wherein the linear light source device is used for emitting light, the first light processing unit is used for changing part of transmission light emitted from the linear light source device into first linearly polarized light, and the to-be-detected film is used for changing the first linearly polarized light into circularly polarized light. The second light processing unit is used for compensating the full wavelength of the visible light region of the circularly polarized light passing through the second light processing unit, and the camera device is used for receiving the circularly polarized light passing through the second light processing unit. The defect detection equipment provided by the utility model realizes the detection of the original film of the liquid crystal compensation film.

Description

Technical Field

[0001] This application relates to the technical field of liquid crystal compensation films, and particularly to a defect detection device. Background Art

[0002] The liquid crystal compensation film, also known as the phase compensation film, is one of the main film materials for producing polarizers for OLEDs. Its main function is to compensate for the phase difference of the liquid crystal material inside the liquid crystal display, significantly improving the performance of the liquid crystal display.

[0003] During preparation, the liquid crystal composition can be coated on the alignment layer of the liquid crystal compensation film by means of liquid crystal coating. Due to the use of coating technology, conditions such as coating thickness and uniformity will affect the phase difference value of the obtained liquid crystal compensation film, resulting in imaging problems after the finished polarizer for OLED is attached to the panel. Moreover, the coated liquid crystal solution is colorless and transparent, and defects on the liquid crystal layer cannot be observed by existing penetration detection methods.

[0004] Therefore, it is necessary to develop a defect detection device and a defect detection method for single-layer film defect detection of liquid crystal compensation films. Summary of the Invention

[0005] This application mainly solves the technical problem that existing penetration detection methods cannot observe defects on the liquid crystal layer and realizes single-layer film defect detection of liquid crystal compensation films.

[0006] To achieve the above object, this application provides a defect detection device, including a line light source device and a camera device. The line light source device and the camera device are respectively arranged on two opposite sides of the film to be detected. It further includes:

[0007] An optical processing device, including a first optical processing unit and a second optical processing unit. The first optical processing unit is arranged between the line light source device and the film to be detected, and the second optical processing unit is arranged between the film to be detected and the camera device;

[0008] A shifting device, connected to the optical processing device, for placing the optical processing device in a first position state;

[0009] Wherein: the line light source device is used to emit light, the first optical processing unit is used to change part of the transmitted light emitted from the line light source device into first linearly polarized light, the film to be detected is used to change the first linearly polarized light into circularly polarized light, the second optical processing unit is used to compensate for the full wavelength in the visible light region of the circularly polarized light passing through, and the camera device is used to receive the circularly polarized light after passing through the second optical processing unit;

[0010] When the optical processing device is in the first position state, the film to be inspected is the original film of the liquid crystal compensation film. The light emitted by the linear light source device becomes the first linearly polarized light after being partially transmitted through the first optical processing unit. The first linearly polarized light becomes circularly polarized light after passing through the film to be inspected, and the circularly polarized light enters the camera device after passing through the second optical processing unit. The second optical processing unit is used to compensate for the full wavelength in the visible light region that passes through.

[0011] As a further improvement of the present application, the camera device includes a camera lens and a crossed polarizer. The crossed polarizer is disposed between the linear light source device and the camera lens, and is used to filter the light perpendicular to the absorption axis direction of the crossed polarizer and reduce the amount of incident light entering the camera lens.

[0012] As a further improvement of the present application, the optical processing device further includes a third optical processing unit. The third optical processing unit is disposed between the linear light source device and the film to be inspected and is on the same horizontal line as the first optical processing unit. Wherein: the third optical processing unit is used to reduce the amount of light of the partially transmitted light emitted from the linear light source device;

[0013] The shifting device is further used to switch the optical processing device between the first position state and the second position state. The film to be inspected is the original film of the liquid crystal compensation film or the TAC transparent film material. When the film to be inspected is the original film of the liquid crystal compensation film, the shifting device is used to switch the optical processing device to the first position state. When the film to be inspected is the TAC transparent film material, the shifting device is used to switch the optical processing device to the second position state;

[0014] When switched to the second position state, the light emitted by the linear light source device passes through the third optical processing unit, then enters the camera device through the film to be inspected, and the third optical processing unit is used to reduce the amount of incident light entering the camera device.

[0015] As a further improvement of the present application, the first optical processing unit includes a polarizing film, the third optical processing unit includes a filter, and the second optical processing unit includes a liquid crystal compensation film.

[0016] As a further improvement of the present application, the acquisition method of the second optical processing unit includes: coating a liquid crystal composition on an alignment layer and then curing it with UV light to obtain a single-film wide-waveband 1 / 4λ phase difference film as the second optical processing unit.

[0017] As a further improvement of the present application, the shifting device includes a glass stage and a power unit. The glass stage is used to carry the first light processing unit, the third light processing unit, and the second light processing unit. The power unit is used to push the glass stage to move in the first direction and realize the switching of the light processing device between the first position state and the second position state. The first direction intersects with the direction of the light emitted by the line light source device.

[0018] As a further improvement of the present application, the glass stage includes a first glass stage and a second glass stage. The polarizing film and the filter are successively mounted on the first glass stage along the first direction, and the liquid crystal compensating film is mounted on the second glass stage.

[0019] As a further improvement of the present application, the power unit includes a first air cylinder, a second air cylinder, an air valve connected to the first air cylinder and the second air cylinder by an air pipe, and a switch for controlling the opening and closing of the air valve. The first air cylinder is used to push the first glass stage, and the second air cylinder is used to push the second glass stage.

[0020] As a further improvement of the present application, when the film to be inspected is the original film of the liquid crystal compensating film, the liquid crystal compensating film and the film to be inspected are of the same type, and the orientations of the liquid crystal layers of the film to be inspected and the liquid crystal compensating film are arranged oppositely.

[0021] The present application also provides a defect detection method, which is applied to the defect detection device described in any one of the above. The defect detection method includes:

[0022] When the film to be inspected is the original film of the liquid crystal compensating film, use the shifting device to switch the light processing device to the first position state; the light processing device includes a first light processing unit and a second light processing unit;

[0023] When switched to the first position state, the light emitted by the line light source device becomes the first linearly polarized light after being partially transmitted through the first light processing unit. The first linearly polarized light becomes circularly polarized light after passing through the film to be inspected, and the circularly polarized light enters the camera device after passing through the second light processing unit; the second light processing unit is used to compensate for the entire visible light wavelength range.

[0024] As a further improvement of the present application, the light processing device further includes a third light processing unit;

[0025] The defect detection method further includes:

[0026] When the film to be inspected is a TAC transparent film material, use the shifting device to switch the light processing device to the second position state;

[0027] When switched to the second position state, the light emitted by the line light source device passes through the third light processing unit and then enters the camera device through the film to be inspected. The third light processing unit is used to reduce the amount of incident light entering the camera device.

[0028] The beneficial effects of the present application are as follows: A defect detection device and a defect detection method are provided. Through the shifting device, the defect detection device can flexibly switch between two detection modes to adapt to different detection requirements. In one state, the second light processing unit can compensate for the full wavelength in the visible light region, enabling it to process light of different wavelengths, thereby improving the accuracy and reliability of detection. In another state, by reducing the amount of incident light through the third light processing unit, background noise can be reduced, making defects more obvious and facilitating identification. The above device is ingeniously designed considering the detection requirements of different types of film materials. By simplifying the position switching steps, it can adapt to different types of detection objects and reduce the time and complexity of device adjustment. In summary, through ingenious light processing and flexible device design, efficient and precise detection of single-layer film defects of liquid crystal compensation films is achieved. Description of the Drawings

[0029] Figure 1 A defect detection device in the first position state of a light processing device is provided;

[0030] Figure 2 A defect detection device in the second position state of a light processing device is provided;

[0031] Figure 3 It is a schematic diagram of the detection principle of a defect detection device for liquid crystal compensation films.

[0032] In the figure: 100, camera device; 101, camera lens; 102, crossed polarizer; 201, first light processing unit; 202, second light processing unit; 203, third light processing unit; 300, line light source device; 400, film to be inspected; 501, first air cylinder; 502, second air cylinder; 503, air pipe; 504, air valve; 505, switch; 506, first glass stage; 507, second glass stage. Detailed Embodiments

[0033] To make the objectives, technical solutions, and advantages of the present application clearer, the technical solutions of the present application will be clearly and completely described below in conjunction with specific embodiments and the accompanying drawings of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments, and are not used to limit the scope of the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the scope of protection of the present application.

[0034] When a liquid crystal compensation film is used in a liquid crystal display, it can improve its contrast, viewing angle, and correct the displayed color. Specifically, the liquid crystal compensation film reduces color distortion and viewing angle limitations of the liquid crystal display by adjusting the arrangement of liquid crystal molecules, thereby improving image quality and viewing experience. Different types of liquid crystal compensation films, such as A-plate, C-plate, and O-plate, are used to compensate for liquid crystal molecules with different alignment modes according to the relationship between their optical axes and the film surface, in order to achieve the best display effect.

[0035] In the related art, the detection equipment and methods for liquid crystal compensation films mainly perform defect detection on the multi-layer film materials after roll-to-roll lamination of the liquid crystal compensation film. It does not consider that factors such as liquid crystal shedding and uneven coating will affect the imaging quality of the polarizer for finished OLEDs, and does not perform defect detection on the single-layer film of the liquid crystal compensation film. During production, it is impossible to observe whether the influence is caused by the original film of the liquid crystal compensation film or the manufacturing process, and it is impossible to better monitor the quality of the original film. At the same time, the existing penetration detection method cannot observe the defects on the liquid crystal layer.

[0036] Based on this, the present application provides a defect detection device and a defect detection method. The light emitted by the line light source device 300 first passes through the first light processing unit 201, and after partial transmission, it becomes the first linearly polarized light. The linearly polarized light then passes through the film to be inspected 400. Due to the characteristics of the liquid crystal compensation film, the linearly polarized light is converted into circularly polarized light. The circularly polarized light is then compensated for the full wavelength in the visible light region by the second light processing unit 202, and finally enters the camera device 100 to form an image, realizing the detection of the original film of the liquid crystal compensation film, so that technicians can observe whether the defect is caused by the original film of the liquid crystal compensation film or the manufacturing process, solving the above technical problems. The equipment will be described first below, and then the method and others will be described.

[0037] Embodiment 1

[0038] See Figure 1 , Figure 1 which is a schematic structural diagram of a defect detection device provided by an embodiment of the present application.

[0039] The present embodiment provides a defect detection device for detecting defects in a single-layer film of a liquid crystal compensation film. The defect detection device includes a line light source device 300 and a camera device 100, and the line light source device 300 and the camera device 100 are respectively arranged on two opposite sides of the film to be inspected 400; it further includes:

[0040] A light processing device, including a first light processing unit 201 and a second light processing unit 202. The first light processing unit 201 is arranged between the line light source device 300 and the film to be inspected 400, and the second light processing unit 202 is arranged between the film to be inspected 400 and the camera device 100;

[0041] A displacement device, connected to the optical processing device, is configured to place the optical processing device in a first position state;

[0042] Wherein: the line light source device 300 is configured to emit light; the first optical processing unit 201 is configured to convert a part of the transmitted light emitted from the line light source device 300 into first linearly polarized light; the film to be inspected 400 is configured to convert the first linearly polarized light into circularly polarized light; the second optical processing unit 202 is configured to compensate for the full wavelength in the visible light region of the circularly polarized light passing therethrough; the camera device 100 is configured to receive the circularly polarized light after passing through the second optical processing unit 202;

[0043] When the optical processing device is in the first position state, the film to be inspected 400 is the original film of the liquid crystal compensation film. The light emitted from the line light source device 300 is partially transmitted through the first optical processing unit 201 and then converted into first linearly polarized light. The first linearly polarized light is converted into circularly polarized light after passing through the film to be inspected 400. The circularly polarized light enters the camera device 100 after passing through the second optical processing unit 202. The second optical processing unit 202 is configured to compensate for the full wavelength in the visible light region of the light passing therethrough.

[0044] Wherein, the line light source device 300 is located on one side of the film to be inspected 400, and is configured to emit light and provide light to irradiate the object to be detected, and may be an LED lamp or a combination of multiple LED lamps, or other types of lighting devices.

[0045] The camera device 100 is located on the other side of the film to be inspected 400, and is configured to capture an image formed by the processed light. The camera device 100 may include an image sensor, and the image sensor is used to convert visible light into an image of an electronic signal, and defects on the film to be inspected 400 can be accurately captured during high-speed operation.

[0046] The optical processing device includes two units, namely the first optical processing unit 201 and the second optical processing unit 202, which play different roles in processing light between the line light source device 300 and the film to be inspected 400, and between the film to be inspected 400 and the camera device 100.

[0047] The displacement device is configured to control the optical processing device to switch between different position states. The displacement device may be a pneumatic displacement device, an electric displacement device, etc.

[0048] In the defect detection device provided in this embodiment, during the detection of the first position state, the light emitted by the linear light source device 300 first passes through the first light processing unit 201, and after partial transmission, it becomes the first linearly polarized light. The linearly polarized light then passes through the film to be detected 400. Due to the characteristics of the liquid crystal compensating film, the linearly polarized light is converted into circularly polarized light. The circularly polarized light is then compensated for the full wavelength in the visible light region by the second light processing unit 202, and finally enters the camera device 100 to form an image.

[0049] Compared with the penetration detection method in the related art, in this application, the shift device can be used to detect the original film of the liquid crystal compensating film in the first position state of the defect detection device, so that technicians can observe whether the defect is caused by the original film of the liquid crystal compensating film or the manufacturing process.

[0050] In an exemplary embodiment, the camera device 100 includes a camera lens 101 and a cross polarizer 102. The cross polarizer 102 is disposed between the linear light source device 300 and the camera lens 101, and is used to filter the light perpendicular to the absorption axis direction of the cross polarizer 102 and reduce the amount of light entering the camera lens 101.

[0051] The camera device 100 is composed of a camera lens 101 and a cross polarizer 102. In a specific application, the camera lens 101 is used to focus light and capture images, and is usually composed of multiple lenses to improve the image quality; the cross polarizer 102 is installed in front of the camera lens 101 of the camera device 100, which can reduce the amount of light entering the camera lens 101. At the same time, it has a filtering effect on the light perpendicular to the absorption axis direction of the polarizer, presenting a dark state. This is because it only allows the light waves parallel to its polarization axis to pass through, while blocking the light waves in other directions, and is used to control the polarization direction of the passing light, which can improve the image quality and detection accuracy. The above design of the camera device 100 can improve the accuracy and efficiency of liquid crystal compensating film defect detection.

[0052] It can be understood that when the light processing device is in the first position state, the light processed by the first light processing unit 201 and the second light processing unit 202 enters the camera lens 101 through the cross polarizer 102. Due to the function of the cross polarizer 102, only the light with a specific polarization direction can pass through, which helps to reduce the stray light in the image and improve the image quality.

[0053] The advantages of this embodiment are as follows. By filtering out unnecessary light with the cross-polarizing lens 102, noise and interference in the image can be reduced, making the defects on the liquid crystal compensation film more obvious and facilitating detection. The use of the cross-polarizing lens 102 ensures that only light with a specific polarization direction is captured by the camera, thus making the detection result more reliable and improving the accuracy of the defect detection device. By reducing unnecessary light interference, the camera device 100 can capture clear images faster, thereby accelerating the speed of defect detection and improving efficiency. Compared with using multiple complex optical elements, the use of the cross-polarizing lens 102 in this embodiment simplifies the structural design, reduces the cost and maintenance difficulty of the device, and is convenient for popularization in industrial production.

[0054] In summary, this technical solution effectively improves the accuracy and efficiency of liquid crystal compensation film defect detection and simplifies the structural design by introducing the cross-polarizing lens 102 into the camera device 100.

[0055] In specific applications, it is allowed to adjust the angle of the cross-polarizing lens 102 to adapt to different detection requirements, further increasing the flexibility of the defect detection device. The cross-polarizing lens 102 can be adjusted according to different detection conditions (such as different film materials or different defect types) to obtain the best detection effect.

[0056] In specific applications, the camera device 100 consists of multiple cameras as a group, and each camera includes a camera lens 101 and a cross-polarizing lens 102. It can be considered that the more the number of cameras, the higher the detection accuracy, and the smaller the defects that can be detected. The preferred type of camera is a line scan camera, which can capture high-resolution images.

[0057] In specific applications, the cross-polarizing lens 102 is a circular lens, which can be installed on the camera lens 101 of the camera and has the function of rotating the lens to approach or move away from the camera lens 101, facilitating the adjustment of the orthogonality state of the optical system.

[0058] In an exemplary embodiment, the light processing device further includes a third light processing unit 203, which is disposed between the line light source device 300 and the film to be inspected 400 and is on the same horizontal line as the first light processing unit 201; wherein: the third light processing unit 203 is used to reduce the light amount of part of the transmitted light emitted from the line light source device 300; the shifting device is further used to switch the light processing device between a first position state and a second position state; the film to be inspected 400 is an original liquid crystal compensation film or a TAC transparent film material. When the film to be inspected 400 is an original liquid crystal compensation film, the shifting device is used to switch the light processing device to the first position state; when the film to be inspected 400 is a TAC transparent film material, the shifting device is used to switch the light processing device to the second position state;

[0059] When switched to the second position state, the light emitted by the linear light source device 300 passes through the third light processing unit 203, then enters the camera device 100 through the film to be inspected 400. The third light processing unit 203 is used to reduce the amount of incident light entering the camera device 100.

[0060] That is to say, during the detection process in its second position state, the light emitted by the linear light source device 300 only passes through the third light processing unit 203. The function of the third light processing unit 203 is to reduce the amount of incident light entering the camera device 100, and the light directly enters the camera device 100 after passing through the film to be inspected 400.

[0061] The defect detection device provided in this embodiment can flexibly switch between two detection modes to adapt to different detection requirements. In one state, the second light processing unit 202 can compensate for the full wavelength in the visible light region, enabling it to process light of different wavelengths, thereby improving the accuracy and reliability of detection. In another state, the amount of incident light is reduced by the third light processing unit 203, which can reduce background noise, making the defects more obvious and facilitating identification.

[0062] That is to say, the shifting device is used to adjust the position of the light processing device to adapt to different types of films to be inspected 400. When the film to be inspected 400 is the original film of the liquid crystal compensation film, the shifting device switches the light processing device to the first position state, and the light processing device is configured to optimize the detection of the defects of the original film of the liquid crystal compensation film. When the film to be inspected 400 is a TAC transparent film material, the shifting device switches the light processing device to the second position state, and the light processing device is configured to optimize the detection of the characteristics of the TAC transparent film material. The above device design cleverly considers the detection requirements of different types of film materials, adapts to different types of detection objects by simplifying the position switching steps, and reduces the time and complexity of device adjustment.

[0063] The advantages of this embodiment are that through the shifting device, without replacing or reconfiguring a complex optical system, the defect detection device can adapt to the detection of different types of film materials. Quickly switching the state of the light processing device can reduce the downtime during the detection process and improve the efficiency of the production line. Optimizing the configuration of the light processing device for different types of film materials can improve the accuracy and reliability of defect detection.

[0064] In summary, through the ingenious light processing and flexible device design, this technical solution realizes the efficient and accurate detection of different films to be inspected 400.

[0065] Among them, the original film of the liquid crystal compensation film is a film material used for liquid crystal displays, which improves the display performance by compensating for the phase difference of the liquid crystal material. The TAC transparent film is a transparent film made of cellulose triacetate, which has good transparency and mechanical properties and is commonly used to support and protect sensitive materials.

[0066] In a specific application, when the light processing device is in the second position state, after the light passes through the third light processing unit 203 and the film to be inspected 400, it can also pass through the crossed polarizer 102. At this time, the function of the crossed polarizer 102 is to further reduce the additional light entering the camera due to film defects, ensuring that the image captured by the camera mainly reflects the true state of the film to be inspected 400.

[0067] In an exemplary embodiment, the first light processing unit 201 includes a polarizing film, the second light processing unit 202 includes a liquid crystal compensation film, and the third light processing unit 203 includes a filter.

[0068] The function of the first light processing unit 201 (polarizing film) is to allow only light waves in a specific direction to pass through, that is, it can turn the incident light into polarized light. In the detection of the original film of the liquid crystal compensation film, the polarizing film is used to control the polarization state of light so that the subsequent detection process can accurately analyze the characteristics or defects of the liquid crystal compensation film. The second light processing unit 202 (liquid crystal compensation film) is used to perform phase compensation on the passing light waves. For example, when using a 1 / 4λ retardation film, it can convert linearly polarized light into circularly polarized light, or vice versa, which helps to form a high-contrast image in the camera, making it easier to detect defects. The third light processing unit 203 (filter) is used to adjust the intensity and / or wavelength of the passing light. When detecting the TAC transparent film, the filter can reduce the amount of light entering the camera device 100 to meet the detection requirements of the transparent film and avoid overexposure.

[0069] The advantage of this embodiment is that by using a polarizing film and a liquid crystal compensation film, the polarization and phase of light can be precisely controlled, thereby improving the detection accuracy of the defects of the liquid crystal compensation film. Through the adjustable third light processing unit 203 (filter), it can adapt to different types of film materials, such as the TAC transparent film, providing flexibility.

[0070] In an exemplary embodiment, the acquisition method of the second light processing unit 202 includes: coating a liquid crystal composition on an alignment layer and then curing it with UV light to obtain a single-film wide-waveband 1 / 4λ retardation film as the second light processing unit 202.

[0071] A liquid crystal composition refers to a mixture containing liquid crystal materials and other additives (such as polymers, dyes, etc.). During the preparation of the second light processing unit 202, first, this liquid crystal composition is evenly coated on the alignment layer. The alignment layer is a special coating used to control the alignment direction of liquid crystal molecules. After coating, the liquid crystal composition is irradiated with ultraviolet (UV) light to cause a polymerization reaction, thereby curing into a film. UV curing is a fast and efficient curing method that can form a uniform and stable thin film. The single-film wide-waveband 1 / 4λ retardation film is a liquid crystal compensating film designed to provide a 1 / 4-wavelength retardation within a wide wavelength range. In the detection device, the second light processing unit 202 (i.e., the 1 / 4λ retardation film) is used to adjust the phase of the passing light, which helps to improve the polarization characteristics of the light, thereby enhancing the contrast and clarity of the image during subsequent detection processes.

[0072] The advantages of this embodiment are that by precisely controlling the phase of light, the detection accuracy of defects in the liquid crystal compensating film can be improved, enabling even tiny defects to be accurately identified. Since the 1 / 4λ retardation film is designed for a wide wavelength range, this allows the detection device to adapt to light sources of more wavelengths, increasing its applicability. UV curing is a fast curing method that can shorten the production cycle and improve production efficiency.

[0073] In specific applications, the angle of the alignment layer can be defined according to requirements. After coating the liquid crystal solution by a general coating method (such as wire bar coating, extrusion coating, direct gravure coating, reverse gravure coating, and die coating), it is then cured with UV light. The finished product is a single-film wide-waveband 1 / 4λ retardation film, which is the liquid crystal compensating film described in the application, and the optical axis angle of the retardation film can be adjusted according to the requirements of the polarizer, which is beneficial for the roll-to-roll lamination process.

[0074] In an exemplary embodiment, the shifting device includes a glass stage and a power unit. The glass stage is used to carry the first light processing unit 201, the third light processing unit 203, and the second light processing unit 202. The power unit is used to push the glass stage to move in a first direction and achieve the switching of the light processing device between a first position state and a second position state. The first direction intersects with the direction of the light emitted by the line light source device 300.

[0075] The glass stage is a planar structure usually made of glass or other transparent materials, used to carry and fix optical elements, such as optical processing units. The power unit is used to provide power to drive mechanical equipment to perform actions, and can be electric, pneumatic or hydraulic. The first direction refers to the direction in which the glass stage moves, intersecting with the direction of the light emitted by the line light source device 300, so as to ensure that the optical processing unit can correctly process the light. When the glass stage moves to different positions, the corresponding optical processing unit processes the light emitted by the line light source device 300 to achieve different detection functions. In a specific application, the first direction can be perpendicular to the direction in which the glass stage moves.

[0076] The advantages of this embodiment are that, through the shifting device, different optical processing units passed by the optical path can be quickly switched according to the detection requirements, improving the flexibility and adaptability of the defect detection equipment. Quickly switching the optical processing unit reduces the downtime during the detection process and improves the detection efficiency of the production line. The power unit can precisely control the movement of the glass stage, improving the detection accuracy. The automated shifting device reduces the need for manual replacement / switching of the optical processing unit, reduces operation errors and improves operation safety.

[0077] In a specific application, the shifting device takes the glass stage as the main body, and the periphery of the glass stage is fixed with aluminum profiles. One end of the long side of the profile is connected with a cylinder, and the cylinder is connected with an air pipe 503 to push the stage to move horizontally in a pneumatic manner. When the air valve 504 switch 505 is opened, the glass stage is pushed directly above the line light source device 300 and directly below the camera lens 101; when the air valve 504 is closed, the glass stage automatically returns to the original un-pushed state. One switch 505 button controls the air valve 504 to achieve the simultaneous forward and backward movement of the two devices, realizing the function of switching back and forth. The switch 505 button can be an electric control switch 505 button.

[0078] In an exemplary embodiment, the glass stage includes a first glass stage 506 and a second glass stage 507. The polarizing film and the filter are sequentially mounted on the first glass stage 506 along the first direction, and the liquid crystal compensation film is mounted on the second glass stage 507.

[0079] The first glass stage 506 is designed to carry specific optical processing units, such as a polarizing film and a filter. The second glass stage 507 is designed to carry another optical processing unit, such as a liquid crystal compensation film. The polarizing film and the filter are sequentially mounted on the first glass stage 506, allowing the light emitted by the light source to selectively pass through the polarizing film or the filter. The liquid crystal compensation film is mounted on the second glass stage 507, and the light can continue to pass through the liquid crystal compensation film on the second glass stage 507 for further optical processing after being processed by the units on the first glass stage 506.

[0080] The advantage of this embodiment is that by separately mounting different types of optical processing units on the glass carrier stage, modular design can be achieved, which is convenient for maintenance and replacement.

[0081] In a specific application, the glass carrier stage is divided into two groups. The first glass carrier stage 506 is used to mount a 1 / 4λ liquid crystal compensating film, and its installation position is in the area between the lower part of the camera lens 101 and the upper part of the film to be inspected 400. The second glass carrier stage 507 is used to mount a common polarizing film, and its installation position is in the area between the lower part of the film to be inspected 400 and the upper part of the linear light source device 300.

[0082] In an exemplary embodiment, when the film to be inspected 400 is the original liquid crystal compensating film, the liquid crystal compensating film and the film to be inspected 400 are of the same type, and the orientations of the liquid crystal layers of the film to be inspected 400 and the liquid crystal compensating film are set opposite to each other.

[0083] When the film to be inspected 400 is the original liquid crystal compensating film, a film of the same type as the film to be inspected 400 is used as the second optical processing unit 202. Films of the same type usually have the same physical and optical properties, such as phase difference, refractive index, etc. The light emitted by the light source first passes through the first optical processing unit 201 (such as a polarizing film), and then passes through the film to be inspected 400. The light passing through the film to be inspected 400 continues to pass through the second optical processing unit 202 (i.e., a liquid crystal compensating film of the same type), where further phase adjustment or compensation is performed.

[0084] The advantage of this embodiment is that a film of the same type as the film to be inspected 400 is used as the second optical processing unit 202. Since their optical properties are similar, the performance of the film to be inspected 400 can be more accurately simulated and detected. Through the phase compensation of the film of the same type, the visibility of potential defects on the film to be inspected 400 can be enhanced, making it easier to identify the defects.

[0085] In a specific application, the 1 / 4λ liquid crystal compensating film mounted on the first glass carrier stage 506 and the film to be inspected 400 in the application are of the same type of film. When attaching along the first direction to the first glass carrier stage 506, only half of it is attached, and the attaching orientation is that the liquid crystal layer faces the linear light source device 300, and the other half is not attached. In the second glass carrier stage 507, the common polarizing film mounted along the first direction is also only attached to half of the second glass carrier stage 507, and the other half is attached with a filter.

[0086] As an example, refer to Figure 1 , a defect detection device in the first position state of an optical processing device is provided.

[0087] The linear light source device 300 is composed of multiple LED modules. The light intensity emitted by each LED lamp bead in the LED module is consistent, and the light-emitting intensity of the lamp beads can be controlled by software / light source controller to ensure the uniformity of the light-emitting surface of the linear light source device 300. When the light emitted by the linear light source device 300 passes through the first glass stage 506, the first glass stage 506 is in the state pushed open by the air cylinder at this time. When the light passes through the first glass stage 506, a layer of ordinary polarizing film (the first light processing unit 201) is attached to the left half of the glass stage. The attaching direction of the polarizing film is that the absorption axis direction is parallel to the physical mechanism direction of the linear light source device 300. According to the characteristics of the polarizing film, when natural light passes through the polarizing film, the light parallel to the absorption axis direction of the polarizing film can pass through, while the light perpendicular to the absorption axis direction of the polarizing film will be filtered. When the light emitted by the linear light source device 300 passes through the first glass stage 506, it becomes the first linearly polarized light. In this example, the film to be inspected 400 is more preferably a 1 / 4λ liquid crystal compensating film. At this time, the absorption axis direction (the polarization direction of light) of the polarizing film attached to the first glass stage 506 forms a 45° angle with the fast axis direction of the film to be inspected 400. When the first linearly polarized light passing through the first glass stage 506 passes through the film to be inspected 400 again, it becomes circularly polarized light. Along the propagation direction of the light, the circularly polarized light formed after passing through the film to be inspected 400 passes through the second glass stage 507. A 1 / 4λ liquid crystal compensating film is attached to the left half of the second glass stage 507. After the circularly polarized light passes through the 1 / 4λ liquid crystal compensating film again, it will become the second linearly polarized light. At this time, the direction of the second linearly polarized light is perpendicular to the absorption axis direction of the crossed polarizer 102 in front of the camera lens 101, so that the light entering the camera becomes less, presenting a crossed dark state. When there are abnormalities or peeling off in the liquid crystal layer of the film to be inspected 400, it will affect the light transmittance, so that the light intensity entering the camera lens 101 will change. The light signal is converted into an electrical signal, so that the presented image has light and dark differences. The appearance of a bright state against a uniform dark background indicates that there are defects in the film to be inspected 400 at the corresponding position.

[0088] It can be understood that the detection principle of the defect detection device for the liquid crystal compensating film utilizes the optical principle of the polarizer for OLED, such as Figure 3As shown in the figure, the combination of a linear polarizer (i.e., a polarizing film) and a 1 / 4λ liquid crystal compensating film is the polarizer for OLEDs. The optical principle of the polarizer for OLEDs is briefly described as follows: When external natural light is incident on the linear polarizer, only the light parallel to the absorption axis direction (the polarization direction of the light) can pass through. At this time, the fast axis of the 1 / 4λ liquid crystal compensating film forms a 45° angle with the polarization direction of the linear polarized light. After passing through the 1 / 4λ liquid crystal compensating film, the linearly polarized light becomes circularly polarized light. The circularly polarized light will be reflected back after passing through the OLED metal electrode, and at the same time, the rotation direction of the circularly polarized light is opposite to the previous one; the circularly polarized light with the opposite rotation direction passes through the 1 / 4λ liquid crystal compensating film again. At this time, the circularly polarized light will be converted into linearly polarized light, and the linear polarization direction is perpendicular to the polarization direction at the initial incidence, and the light cannot exit the linear polarizer, thereby suppressing the reflection interference of the external ambient light.

[0089] In a specific application, the glass stage two 507 and the glass stage one 506 are interlocked. The glass stage two 507 is connected to the second cylinder 502, and the glass stage one 506 is connected to the first cylinder 501. The first cylinder 501 and the second cylinder 502 are connected to the same air valve 504 through an air pipe 503. A switch 505 is used to control the opening and closing of the air valve 504 to control the left and right movement of the first cylinder 501 and the second cylinder 502. When the switch 505 is pressed, the air valve 504 is in the open state, and the first cylinder 501 and the second cylinder 502 respectively push the glass stage one 506 and the glass stage two 507 away at the same time, and the state is as Figure 1 shown; when the switch 505 is closed, the air valve 504 is in the closed state, and the glass stage two 507 and the glass stage one 506 are in the state of not being pushed away, and the state is shown in Figure 2. The fixed position of the switch 505 needs to be defined by the production line personnel themselves to facilitate the change of the detection method when producing different film materials. It should be noted that Figure 1 In Figure 2 the figures, all structures are side views, and there will be no hardware interference during the actual operation process.

[0090] In a specific application, the liquid crystal layer of the film to be detected 400 faces the direction of the camera lens 101, which is upward as shown in Figure 1. It should be noted that the liquid crystal layer of the 1 / 4λ liquid crystal compensating film attached to the glass stage two 507 faces the direction of the linear light source, which is downward as shown in Figure 1. At this time, the liquid crystal layer orientations of the film to be detected 400 and the 1 / 4λ liquid crystal compensating film are opposite. If the liquid crystal layer orientation of any one of the two changes, it will affect the formation of the orthogonal state of the overall detection device.

[0091] In a specific application, the defect detection device utilizes an orthogonal dark-state optical system. The film surface background shown in the imaging is in a dark state. When there are defects or liquid crystal layers peeling off on the liquid crystal compensation film to be tested, it will directly affect the formation of the orthogonal dark state and become a bright-state defect. In order to make the bright-state defect bright enough, the luminous intensity of the linear light source device 300 should be in the strongest state, and at the same time, the aperture of the camera is opened to the maximum, so that the amount of light entering the camera lens 101 reaches the maximum and the imaging effect is the best. In order to facilitate the adjustment of the orthogonal state of the defect detection device, before adding the liquid crystal compensation film, the orthogonal polarizer 102 of the camera device 100 and the ordinary polarizing film attached to the left half of the glass stage 506 are adjusted to a pure orthogonal state, that is, a state where light cannot pass through. Since the fast axis direction of the film 400 to be tested itself forms a 45° angle with the direction of the linear light source device 300, when attaching the ordinary polarizing film to the left half of the glass stage 506, the absorption axis direction (the polarization direction of light) of the polarizing film can be parallel to the direction of the linear light source device 300. After the angles of the orthogonal polarizer 102 and the attached polarizing film are fixed, only the angle of the 1 / 4λ liquid crystal compensation film attached to the glass stage 507 needs to be adjusted when adjusting the entire detection device subsequently.

[0092] As an example, refer to Figure 2 , which provides a defect detection device for a light processing device in the second position state. In a specific application, in order to meet the production of other TAC transparent film materials on the production line and at the same time take into account the defect detection of TAC transparent film materials, as shown in Figure 2, only need to turn off the switch 505, and the air valve 504 will also be closed accordingly. In the absence of air pressure, the glass stage 507 and the glass stage 506 will not be pushed out. At this time, the light emitted by the linear light source device 300 directly penetrates the glass stage 507, the glass stage 506, and the orthogonal polarizer 102 and enters the camera lens 101. It should be noted that when detecting defects in the liquid crystal compensation film, an orthogonal dark-state optical system is used, and the required light intensity is relatively high; when detecting defects in normal TAC transparent film materials, a penetration optical system is required, and the required light intensity is moderate. Without changing the camera aperture, only relying on adjusting the luminous intensity of the linear light source device 300 still cannot reduce the amount of light entering the camera lens 101. Although there is an orthogonal polarizer 102 in front of the camera lens 101 to partially filter the light, the effect still cannot meet the expectation. Therefore, a filter is attached to the right half of the glass stage 506, which can effectively reduce the amount of light entering the camera lens 101 and meet the defect detection requirements of normal TAC transparent film materials. It should be noted that the filter (ND Filter) described in this article only plays a role in weakening the light entering the lens and reducing the sensitivity, has no effect on the color, and has a certain temperature resistance performance.

[0093] The defect detection device provided by this application can flexibly switch between two detection modes through a shifting device to meet different detection requirements. In one state, the second light processing unit 202 can compensate for the full wavelength in the visible light region, enabling it to process light of different wavelengths, thereby improving the accuracy and reliability of detection. In another state, the light input amount is reduced through the third light processing unit 203, which can reduce background noise, making defects more obvious and facilitating identification. The above device design ingeniously considers the detection requirements of different types of film materials. By simplifying the position switching steps, it can adapt to different types of detection objects and reduce the time and complexity of device adjustment. In summary, through ingenious light processing and flexible device design, efficient and precise detection of single-layer film defects of liquid crystal compensation films is achieved.

[0094] In summary, defects in the liquid crystal layer on the liquid crystal compensation film can be detected, which is applicable to full-width roll material detection and can monitor the quality of the original film of the liquid crystal compensation film during the real-time production process. At the same time, by using a cylinder device, switching can be performed when producing different film materials, effectively improving production efficiency.

[0095] Embodiment 2

[0096] This embodiment provides a defect detection method applied to the defect detection device described in any one of Embodiment 1. Its specific implementation manner is consistent with the implementation manner and the achieved technical effects recorded in the above Embodiment 1, and some contents will not be repeated.

[0097] The defect detection method includes:

[0098] When the film to be detected 400 is the original film of the liquid crystal compensation film, the shifting device is used to switch the light processing device to the first position state; the light processing device includes a first light processing unit 201, a third light processing unit 203, and a second light processing unit 202;

[0099] When the film to be detected 400 is a TAC transparent film material, the shifting device is used to switch the light processing device to the second position state;

[0100] Among them, when switched to the first position state, the light emitted by the line light source device 300 becomes the first linearly polarized light after being partially transmitted through the first light processing unit 201. The first linearly polarized light becomes circularly polarized light after passing through the film to be detected 400, and the circularly polarized light enters the camera device 100 after passing through the second light processing unit 202; the second light processing unit 202 is used to compensate for the full wavelength in the visible light region passed through;

[0101] When switched to the second position state, the light emitted by the line light source device 300 passes through the third light processing unit 203, enters the camera device 100 through the film to be inspected 400, and the third light processing unit 203 is used to reduce the amount of incident light entering the camera device 100.

[0102] Although this specification is described according to embodiments, not every embodiment only contains an independent technical solution. This narrative way of the specification is only for clarity. Those skilled in the art should regard the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

[0103] The series of detailed descriptions listed above are only specific descriptions of the feasible embodiments of the present application, and they are not used to limit the protection scope of the present application. Any equivalent embodiments or changes made without departing from the technical spirit of the present application should be included in the protection scope of the present application.

Claims

1. A defect detection device, comprising a linear light source device and a camera device, wherein the linear light source device and the camera device are respectively arranged on two opposite sides of a film to be inspected; characterized in that, Further included are: An optical processing device, including a first optical processing unit and a second optical processing unit. The first optical processing unit is disposed between the line light source device and the film to be inspected, and the second optical processing unit is disposed between the film to be inspected and the camera device; A shifting device, connected to the optical processing device, for placing the optical processing device in a first position state; Wherein: the line light source device is used for emitting light, the first optical processing unit is used for changing part of the transmitted light emitted from the line light source device into first linearly polarized light, the film to be inspected is used for changing the first linearly polarized light into circularly polarized light, the second optical processing unit is used for compensating the full wavelength in the visible light region of the passed circularly polarized light, and the camera device is used for receiving the circularly polarized light after passing through the second optical processing unit.

2. The defect detection device according to claim 1, characterized in that, The camera device includes a camera lens and a crossed polarizer. The crossed polarizer is disposed between the second optical processing unit and the camera lens, and is used for filtering the light perpendicular to the absorption axis direction of the crossed polarizer and reducing the amount of light entering the camera lens.

3. The defect detection device according to claim 1, characterized in that, [[ID=?]]The optical processing device further includes a third optical processing unit, which is disposed between the line light source device and the film to be inspected and is on the same horizontal line as the first optical processing unit; Wherein: the third optical processing unit is used for reducing the amount of light of part of the transmitted light emitted from the line light source device.

4. The defect detection device according to claim 3, characterized in that, The first optical processing unit includes a polarizing film, the second optical processing unit includes a liquid crystal compensating film, and the third optical processing unit includes a filter.

5. The defect detection device according to claim 4, characterized in that, The shifting device includes a glass stage and a power unit. The glass stage is used for carrying the first optical processing unit, the third optical processing unit and the second optical processing unit. The power unit is used for pushing the glass stage to move in a first direction and realizing the switching of the optical processing device between a first position state and a second position state. The first direction intersects with the direction of the light emitted from the line light source device.

6. The defect detection device according to claim 5, wherein, The glass stage includes a first glass stage and a second glass stage. The polarizing film and the filter are sequentially mounted on the first glass stage along the first direction, and the liquid crystal compensating film is mounted on the second glass stage.

7. The defect detection device according to claim 6, wherein, The power unit includes a first air cylinder, a second air cylinder, a pneumatic valve pneumatically connected to the first air cylinder and the second air cylinder, and a switch for controlling the opening and closing of the pneumatic valve. The first air cylinder is used for pushing the first glass stage, and the second air cylinder is used for pushing the second glass stage.

8. The defect detection device according to claim 7, characterized in that, When the film to be inspected is the original film of the liquid crystal compensating film, the liquid crystal compensating film and the film to be inspected are of the same type, and the orientations of the liquid crystal layers of the film to be inspected and the liquid crystal compensating film are opposite to each other.

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