Method for detecting optical axis angle of optical film and film bonding process

Abstract

This invention provides a method for detecting the optical axis angle of an optical film and a film bonding process. The detection method includes the following steps: clamping the optical film between a clamp and a rotating device using a fixture, covering the light-transmitting aperture of the rotating device; controlling a light source unit to emit light; controlling a detector to detect the transmitted light intensity; and obtaining the optical axis angle based on the rotation angle data of the rotating device and the transmitted light intensity data measured by the detector through data fitting. This invention's detection method can improve detection efficiency while ensuring detection accuracy. The film bonding process includes the following steps: performing online optical axis angle detection on multiple optical films to be bonded to obtain the optical axis angles of the multiple optical films; acquiring the size information of the multiple optical films; and bonding the multiple optical films based on the optical axis angle and the size information. This invention's film bonding process improves the alignment accuracy of various functional optical films.

Description

Technical Field

[0001] This invention relates to the fields of optical films and virtual reality / augmented reality / mixed reality technologies, specifically to a method for detecting the optical axis angle of an optical film and a film bonding process. Background Technology

[0002] Currently, in the field of Virtual Reality (VR), the methods for detecting the optical axis used in bonding optical films such as absorptive polarizers, reflective polarizers, and phase films can be broadly divided into two categories. One is visual alignment, which utilizes the physical properties of the optical film for bonding. This method generally relies on the factory characteristics of the optical film, with a bonding accuracy of ±1-2°. Currently, in the VR field, the ultra-short focal length optical folding path (pancake) solution better meets market demands due to its miniaturization and lightweight design. However, the pancake VR solution requires even higher bonding accuracy for the optical films, making this method no longer sufficient for market needs. Another type is to use the polarization characteristics of optical films for secondary detection of the optical axis. This method can improve the bonding accuracy of optical films. However, the current secondary detection of the optical axis is greatly affected by the detection light source and detector. This detection often requires rotating the optical film 360° to detect the point of maximum light intensity and then determine it as the optical axis. The point of maximum light intensity is greatly affected by the fluctuation of light intensity, making it difficult to guarantee the detection accuracy. In addition, it has the disadvantages of being time-consuming, not being able to be integrated into the production line process, and only being able to be used for scientific research and experimental purposes.

[0003] Meanwhile, the production process of the pancake solution's corresponding modules involves the lamination of multiple optical films. Currently, the lamination of multiple optical films usually uses optical lenses to identify physical edges for alignment, which results in low lamination accuracy, excessive stray light, significant light leakage, and poor display quality.

[0004] Therefore, there is a need to provide improved methods for detecting the optical axis angle of optical films for VR, Augmented Reality (AR), or Mixed Reality (MR) fields, as well as film bonding processes, to overcome or reduce at least some of the shortcomings of the prior art. Summary of the Invention

[0005] The first aspect of the present invention provides a method for detecting the optical axis angle of an optical film, the method comprising the following steps:

[0006] An optical film is clamped between the clamp and the rotating device using a fixture and covers the light-transmitting hole of the rotating device so that the optical film rotates with the rotation of the rotating device;

[0007] Control the light source unit to emit light toward the optical film;

[0008] The detector located downstream of the rotating device controls the intensity of light transmitted through the light-transmitting hole and optical film after the light emitted by the light source unit passes through the light-transmitting hole.

[0009] The optical axis angle is obtained by data fitting based on the rotation angle data of the rotating device and the transmitted light intensity data measured by the detector.

[0010] Optionally, in the detection method, the rotating device is controlled to rotate intermittently, and the detector is controlled to detect the transmitted light intensity during the stop gap of the intermittent rotation of the rotating device.

[0011] Optionally, the step of controlling the intermittent rotation of the rotating device includes: controlling the rotating device to rotate a preset single rotation angle, stopping for a preset time period, and repeating the aforementioned steps until the angle rotated by the rotating device reaches a preset total rotation angle threshold.

[0012] Optionally, the detector includes: a main detector and at least one auxiliary detector, wherein the main detector and at least one auxiliary detector are used to detect the transmitted light intensity, respectively;

[0013] The steps for obtaining the optical axis angle based on the rotation angle data of the rotating device and the transmitted light intensity data measured by the detector through data fitting include:

[0014] Each transmitted light intensity data obtained by the main detector is compared with the corresponding transmitted light intensity data obtained by the auxiliary detector.

[0015] The optical axis angle is obtained by data fitting based on the ratio data and the rotation angle data of the rotating device.

[0016] Optionally, the step of obtaining the optical axis angle based on the rotation angle data of the rotating device and the transmitted light intensity data measured by the detector through data fitting includes:

[0017] The rotation angle corresponding to the theoretical minimum transmitted light intensity is calculated using the first built-in function; this is the optical axis angle, where the optical axis angle is the angle between the optical axis of the optical film and the polarization axis of the polarized light source.

[0018] The first built-in function is:

[0019] y = Asin(Bx + C) + D,

[0020] In the formula, x is the rotation angle, y is the transmitted light intensity, and A, B, C, and D are constants.

[0021] Optionally, the light source unit includes a polarizing light source and a correction element, wherein the correction element is a polarizer whose optical axis direction has been calibrated as T and is located downstream of the polarizing light source;

[0022] In the detection method, the rotating device is controlled to rotate starting from direction T;

[0023] The steps for obtaining the optical axis angle based on the rotation angle data of the rotating device and the transmitted light intensity data measured by the detector through data fitting include:

[0024] The angle of rotation of the rotating device relative to direction T when the transmitted light intensity is 0 is calculated using the second built-in function; this angle is the optical axis angle, where the optical axis angle is the angle between the optical axis of the optical film and direction T.

[0025] The second built-in function is:

[0026] I = I0cos 2 (θ+t),

[0027] In the formula, I is the transmitted light intensity, I0 and t are constant parameters, and θ is the angle of rotation of the rotating device relative to the direction T.

[0028] Optionally, after fixing the optical film and the rotating device, the detection method further includes the step of controlling a CCD image sensor located downstream of the rotating device and upstream of the detector to start recording the size information of the optical film.

[0029] Optionally, after obtaining the optical axis angle, the detection method further includes the step of calibrating the optical film based on the optical axis angle and size information.

[0030] A second aspect of the present invention provides a diaphragm bonding process, the diaphragm bonding process comprising the following steps:

[0031] Online axial angle detection is performed on multiple optical films to be bonded to obtain the optical axis angles of multiple optical films;

[0032] Obtain the size information of multiple optical films;

[0033] Multiple optical films are bonded based on optical axis angle and size information.

[0034] Optionally, the online axis angle detection can be performed using the aforementioned detection method.

[0035] Optionally, the step of bonding multiple optical films based on optical axis angle and size information includes:

[0036] The optical axis direction of each optical film and the angle between the optical axis direction and the physical edge of the optical film are determined based on the optical axis angle and size information.

[0037] Using the optical axis direction of one of the multiple optical films as the reference side, and based on the difference in the included angles of the multiple optical films, each optical film is positioned according to the required angular relationship.

[0038] Multiple optical films are bonded together.

[0039] Optionally, before the step of performing online axial angle detection on the multiple optical films to be bonded, the film bonding process further includes the following step: cleaning the optical films.

[0040] Optionally, prior to the step of bonding multiple optical films based on optical axis angle and size information, the film bonding process further includes the step of: peeling off the upper and / or lower protective film of the optical film based on the position of the optical film in the optical module.

[0041] Optionally, in the film bonding process, multiple optical films are prepared, cleaned, and subjected to online axial angle detection at the same time. The protective film is also removed at the same time, and finally bonded sequentially along the vertical direction of the stacking according to the stacking order of the multiple optical films in the optical module.

[0042] Optionally, in the film bonding process, according to the stacking order of multiple optical films in the optical module, along the stacking vertical direction, the optical films located at the top are controlled to sequentially undergo the processing steps of preparation, cleaning, online axial angle detection, and removal of protective film, while the optical films located at the bottom are controlled to undergo the processing steps of preparation, cleaning, online axial angle detection, and removal of protective film in a delayed manner.

[0043] The optical axis angle detection method of the present invention involves simply and securely clamping the optical film between the clamp and the rotating device using a fixture, and covering the light-transmitting hole of the rotating device. The optical film rotates with the rotating device, and the detector controls the detection of the light intensity transmitted through the light-transmitting hole and the optical film by the light emitted by the light source unit. Then, based on the rotation angle data of the rotating device and the transmitted light intensity data measured by the detector, the optical axis angle of the optical film is obtained by data fitting. This method can improve detection efficiency while ensuring detection accuracy. At the same time, the detection time is further compressed, so the detection method can be applied to production line equipment to meet the production cycle requirements. In addition, the repeatability accuracy is also effectively improved.

[0044] The film bonding process of this invention performs online optical axis angle detection on multiple optical films to be bonded and obtains the size information of multiple optical films. Then, based on the optical axis angle and size information, multiple optical films are bonded. This allows for online optical axis angle detection before the optical films are bonded, improving the overall bonding efficiency. Compared with the existing process that relies solely on physical edge alignment, this film bonding process improves the alignment accuracy of each functional optical film, improves the stray light problem caused by large optical axis angle deviation in the optical module, reduces stray light, and optimizes the user viewing experience.

[0045] The above and other objects, advantages and features of the present invention will become more apparent to those skilled in the art from the following detailed description of specific embodiments of the invention in conjunction with the accompanying drawings. Attached Figure Description

[0046] The features, advantages, and exemplary embodiments of the present invention will now be described with reference to the accompanying drawings, in which the same reference numerals indicate the same elements, and wherein:

[0047] Figure 1 This is a schematic diagram of the application of a detection device for an optical film used in a method for detecting the optical axis angle of an optical film according to an embodiment of the present invention.

[0048] Figure 2 This is a schematic diagram of the application of a detection device for an optical film used in a method for detecting the optical axis angle of an optical film according to another embodiment of the present invention.

[0049] Figure 3 yes Figure 1 The diagram shows a partial block diagram of the detection device.

[0050] Figure 4 This is a schematic flowchart of a method for detecting the optical axis angle of an optical film according to an embodiment of the present invention.

[0051] Figure 5 It shows the detection results and fitting curves for power and rotation angle.

[0052] Figure 6 This is a block diagram of the components of a film bonding device used in a film bonding process according to an embodiment of the present invention.

[0053] Figure 7 This is a schematic flowchart of a film bonding process according to an embodiment of the present invention.

[0054] Figure 8 This is a schematic diagram showing the angle between the optical axis of the optical film and its short side.

[0055] Figure 9 It is to utilize Figure 7 A schematic diagram of the structure of the optical module obtained by the film bonding process.

[0056] Figure 10 It is to utilize Figure 7 A schematic diagram of the production process for the film lamination technology.

[0057] Figure 11 It is to utilize Figure 7 Another production process diagram of the film lamination process.

[0058] Figure 12This is a schematic diagram of stray light intensity of an optical module with physical edge alignment using existing technology.

[0059] Figure 13 Is adopted Figure 7 A schematic diagram of stray light intensity in an optical module using a film bonding process. Detailed Implementation

[0060] The exemplary embodiments of the present invention will now be described in detail with reference to the accompanying drawings. The description of the exemplary embodiments is merely exemplary and is by no means a limitation of the present invention or its application or use. Furthermore, the dimensions and proportions of the components in the drawings are merely schematic and do not strictly correspond to actual products. Identical or similar devices and components are referred to by the same reference numerals. In the following text, "upstream" and "downstream" refer to the direction of light emitted from the light source, with the light emanating from the light source from "upstream" towards "downstream".

[0061] This invention provides a method for detecting the optical axis angle of an optical film 200. Figure 1 This is a schematic diagram of the application of a detection device 100 for an optical film 200 used in a method for detecting the optical axis angle of an optical film 200 according to an embodiment of the present invention. Figure 2 This is an application diagram of a detection device 100 for an optical film 200 used in a method for detecting the optical axis angle of an optical film 200 according to another embodiment of the present invention. Figure 3 yes Figure 1 The diagram shows a partial component configuration of the detection device 100. Figure 4 This is a schematic flowchart of a method for detecting the optical axis angle of an optical film 200 according to an embodiment of the present invention. Figure 5 The results and fitting curves for detecting power and rotation angle are provided. This invention also provides a diaphragm bonding process. Figure 6 This is a block diagram of the components of a film bonding apparatus 300 used in a film bonding process according to an embodiment of the present invention. Figure 7 This is a schematic flowchart of a film bonding process according to an embodiment of the present invention. Figure 8 This is a schematic diagram of the angle between the optical axis direction and the short side of the optical film 200. Figure 9 It is to utilize Figure 7 A schematic diagram of the structure of the optical module 204 obtained by the film bonding process. Figure 10 It is to utilize Figure 7 A schematic diagram of the production process for the film lamination technology. Figure 11 It is to utilize Figure 7 Another production process diagram of the film lamination process.

[0062] like Figure 1As shown, the detection device 100 for an optical film 200 according to an embodiment of the present invention includes: a rotating device 103, a clamp 130, a light source unit, a detector 104, and a controller 105. The rotating device 103 is a device for rotating the optical film 200 and has a light-transmitting hole (not shown in the figure). The rotating device 103 can be a rotatable platform. The clamp 130 is fixed to the rotating device 103. The clamp 130 can also be part of the rotating device 103. The optical film 200 is clamped between the clamp 130 and the rotating device 103 and covers the light-transmitting hole; the optical film 200 rotates with the rotation of the rotating device 103. The light source unit is located upstream of the rotating device 103 and is used to emit light. The detector 104 is located downstream of the rotating device 103 and is used to detect the intensity of light transmitted through the light-transmitting hole and the optical film 200 after the light emitted by the light source unit passes through the light-transmitting hole. The controller 105 is connected to the rotating device 103 and the detector 104. It is used to control the rotation of the rotating device 103 and obtain the optical axis angle of the optical film 200 by data fitting based on the rotation angle data of the rotating device 103 and the transmitted light intensity data measured by the detector 104.

[0063] The detection device 100 for the optical film 200 in this embodiment of the invention is configured to include a rotating device 103, a clamp 130, a light source unit, a detector 104, and a controller 105. A light-transmitting hole is provided on the rotating device 103. The clamp 130 can be used to simply and securely fix the optical film 200 on the rotating device 103. The optical film 200 rotates with the rotating device 103. The detector 104 detects the transmitted light intensity after the light emitted by the light source unit passes through the light-transmitting hole and the optical film 200. The controller 105 is used to obtain the optical axis angle of the optical film 200 by data fitting based on the rotation angle data of the rotating device 103 and the transmitted light intensity data measured by the detector 104. This allows for improved detection efficiency while ensuring detection accuracy. Furthermore, due to the further compression of detection time, the detection device 100 can be integrated into the production line equipment to meet the production cycle requirements. In addition, the repeatability accuracy is also effectively improved. The detection device 100 of this embodiment only needs to control the rotation device 103 to rotate, so that the detection device 100 of this embodiment only needs one rotation mechanism, with fewer components, lower cost, and easier control. It is understood that the rotation mechanism that drives the rotation device 103 to rotate can be any mechanism in the prior art that can drive the component to rotate, and is not limited here. The light-transmitting hole of the rotation device 103 can be elongated, circular, elliptical, etc.

[0064] The following is combined Figures 1 to 5The present invention describes in detail a detection device 100 for an optical film 200 according to a preferred embodiment of the present invention, and describes in detail a method for detecting the optical axis angle of the optical film 200 using the detection device 100.

[0065] In the detection device 100 of this embodiment, the optical film 200 to be tested can be any optical film that requires optical axis angle detection, preferably an optical film 200 with polarization absorption characteristics. For example, an absorptive polarizer 201, a reflective polarizer 202, a phase retardation film 203, etc. The clamp 130 can include a set of Y-shaped pressure plates, fixed to the rotating device 103 with screws. By setting the clamp 130, the optical film 200 can be easily and securely fixed on the rotating device 103. The detector 104 is an existing instrument capable of detecting transmitted light intensity or optical power, such as an optical power meter. The response speed of the optical power meter can be ≤0.2ms. The controller 105 can control the rotation of the rotating device 103 and the detection of the optical axis through a communication protocol. The controller 105 can be a PLC, a data acquisition card, a computer, or other devices.

[0066] In the detection device 100 of this embodiment, the light source unit may include a polarizing light source 101 and a correction element 102. The polarizing light source 101 is used to emit light. The correction element 102 is disposed downstream of the polarizing light source 101 and is used to improve the polarization degree of the light emitted by the polarizing light source 101. The light emitted by the polarizing light source 101 passes through the correction element 102, and then at the optical film 200, part of the polarized light is absorbed, and the rest passes through. The transmitted polarized light finally enters the detector 104. By setting the correction element 102, the polarization degree of the polarizing light source 101 can be further improved, thereby improving the detection accuracy. The correction element 102 may be a polarizer. The light source unit of this embodiment may also include a collimating lens or the like that matched with the polarizing light source 101. Depending on the beam quality output by the polarizing light source 101, if the polarization degree is high and the beam divergence angle is small, the aforementioned correction element 102, collimating lens, etc., may not be required. The polarizing light source 101 of this embodiment may include a laser light source or an LED light source. The extinction ratio of the polarization light source 101 can be 500-10000:1, and the power stability RMS ≤ 2%. The extinction ratio of the correction element 102 can be 1000-10000:1.

[0067] like Figure 1 As shown, the rotating device 103 and the polarizing light source 101 are configured such that the optical diaphragm 200 rotates in a direction perpendicular to the beam centerline of the polarizing light source 101. The beam centerline Z of the polarizing light source 101 is in a vertical direction, while the rotating device 103 is arranged in a horizontal direction and rotates in the horizontal plane.

[0068] like Figure 2As shown, in some embodiments, the detector 104 in the detection device 100 of this invention includes a main detector 141 and at least one auxiliary detector 142. The main detector 141 and at least one auxiliary detector 142 are used to detect transmitted light intensity. The controller 105 is used to obtain the optical axis angle based on the rotation angle data of the rotating device 103, the transmitted light intensity data measured by the main detector 141, and / or the transmitted light intensity data measured by at least one auxiliary detector 142 through data fitting. Here, "main detector" refers to the detector 104 that must be set, and "auxiliary detector" refers to the one or more detectors 104 that can be set or not. The actual function of the main detector 141 and the auxiliary detector 142 is the same, both of which are to detect transmitted light intensity. By setting the main detector 141 and at least one auxiliary detector 142, the accuracy of the detection results can be further improved compared with setting a single detector 104.

[0069] The transmitted light intensity data of the main detector 141 and the auxiliary detector 142 can be combined in various ways to improve the accuracy of the detection results. For example, the final transmitted light intensity data can be obtained by averaging the transmitted light intensity data measured by the main detector 141 and the transmitted light intensity data measured by the auxiliary detector 142, and then the optical axis angle can be obtained based on the rotation angle data and the final transmitted light intensity data.

[0070] In a preferred embodiment, the controller 105 of the detection device 100 of this invention is configured to obtain the optical axis angle by data fitting based on the ratio of the transmitted light intensity data detected by the main detector 141 to the transmitted light intensity data detected by the auxiliary detector 142 and the rotation angle data of the rotating device 103. Specifically, each transmitted light intensity data detected by the main detector 141 is compared with the corresponding transmitted light intensity data detected by the auxiliary detector 142, and the optical axis angle is obtained by data fitting based on the obtained ratio data and the rotation angle data of the rotating device 103. The inventors have found that the ratio of the transmitted light intensity data detected by the main detector 141 to the transmitted light intensity data detected by the auxiliary detector 142 can also reflect the change of transmitted light intensity with the rotation angle. Therefore, the optical axis angle can be obtained by fitting a built-in function with respect to the rotation angle data and the ratio data. Traditional optical axis detection methods often rely on the change in optical power at its extreme points. However, the power change at these extreme points is not only affected by the change in the optical axis angle but also by the power fluctuations of the detection light source itself. When the required detection angle accuracy is below 1°, the impact of the power fluctuations of the detection light source on the detection results becomes increasingly significant. By introducing an auxiliary detector 142, the power change of the current detection light source can be directly reflected. Through appropriate data processing, the power fluctuation factor of the detection light source can be eliminated from the detection results of the main detector 141, thereby further improving the accuracy of the detection results.

[0071] like Figure 2 As shown, the detection device 100 of this embodiment may further include a beam splitter 107. The beam splitter 107 is disposed between the polarization light source 101 and the correction element 102, and / or between the rotation device 103 and the detector 104. The beam splitter 107, used in conjunction with the auxiliary detector 142, can reduce the influence of the intensity fluctuation of the transmitted light from the polarization light source 101 on the detection results. The beam splitter 107 disposed between the polarization light source 101 and the correction element 102 can be a flat beam splitter. By setting the flat beam splitter to an angle of 45° with the beam centerline of the polarization light source 101, a portion of the light is emitted along the original optical path, while the other portion of the light is reflected.

[0072] In some embodiments, the detection device 100 of this invention may further include a polarizing element (not shown in the figure), which is disposed downstream of the rotating device 103 and upstream of the detector 104. The polarizing element is an optical device with an optical axis; natural light / non-linearly polarized light becomes polarized light after passing through the polarizing element. The advantage of setting a polarizing element is that the polarizing element can form an orthogonal relationship with the polarized light of the polarized light source 101, thus detecting the optical film 200 with phase difference.

[0073] like Figure 1As shown, the detection device 100 of this embodiment may further include a CCD image sensor 106, which is disposed downstream of the rotating device 103 and upstream of the detector 104, and is used to record the size information of the optical film 200. The size information of the optical film 200 typically includes the physical edge information of the optical film 200, which is typically the short side information and / or long side information of the rectangular optical film 200. The resolution of the CCD image sensor 106 can be ≤0.04mm.

[0074] The controller 105 of the detection device 100 in this embodiment can also be connected to the CCD image sensor 106 for calibrating the optical film 200 based on the optical axis angle and size information. Specifically, the optical axis angle can be calibrated with respect to the short side and / or long side of the optical film 200. After the optical axis detection is completed, due to limitations of the inkjet printing and scribing methods, it is difficult to mark specific optical axis data on the optical film 200. However, the size information of the optical film 200 can be used to calibrate the optical axis effectively, thereby facilitating subsequent bonding of the optical film 200 and enabling convenient offline querying.

[0075] In some embodiments, in the detection device 100 of this invention, the controller 105 is configured to cause the rotating device 103 to rotate intermittently, and the detector 104 detects the transmitted light intensity during the rotation stop interval of the rotating device 103. By configuring the controller 105 to cause the rotating device 103 to rotate intermittently and controlling the detector 104 to detect the transmitted light intensity during the intermittent rotation stop interval of the rotating device 103, multiple transmitted light intensity data and multiple rotation angle data can be obtained. Based on these transmitted light intensity data and rotation angle data, the optical axis angle of the optical film 200 can be calculated by data fitting, thus ensuring the detection accuracy of the optical axis angle.

[0076] In some implementations, such as Figure 3 As shown, the controller 105 includes a storage unit 150 and a first data processing unit 151. The storage unit 150 is connected to the rotating device 103 and the detector 104 and is used to acquire rotation angle data and transmitted light intensity data. The first data processing unit 151 is used to obtain the rotation angle corresponding to the theoretical minimum transmitted light intensity by fitting a first built-in function with respect to the rotation angle data and transmitted light intensity data. This rotation angle is the optical axis angle, which is the angle between the optical axis of the optical film and the polarization optical axis of the polarization source.

[0077] In other implementations, such as Figure 3As shown, the correction element 102 is a polarizer whose optical axis direction is calibrated as T, and the rotating device 103 is configured to rotate starting from direction T. The controller 105 includes a storage unit 150 and a second data processing unit 152, wherein the storage unit 150 is connected to the rotating device 103 and the detector 104, and is used to acquire rotation angle data and transmitted light intensity data; the second data processing unit 152 is used to fit the rotation angle data and transmitted light intensity data to obtain the angle of rotation of the rotating device 103 relative to direction T when the transmitted light intensity is 0, which is the optical axis angle, wherein the optical axis angle is the angle between the optical axis of the optical film and direction T.

[0078] The following is for reference. Figure 3 and Figure 4 The method for detecting the optical axis angle of the optical film 200 according to an embodiment of the present invention will be described in detail. The detection method includes the following steps:

[0079] S102: The optical film 200 is clamped between the clamp 130 and the rotating device 103 using the clamp 130 and covers the light-transmitting hole of the rotating device 103, so that the optical film 200 rotates with the rotation of the rotating device 103.

[0080] S104: Control the light source unit to emit light toward the optical film 200;

[0081] S106: The detector 104, located downstream of the rotating device 103, controls the intensity of light transmitted through the light-transmitting hole and optical film 200 after the light emitted by the light source unit passes through the light-transmitting hole.

[0082] S108: The optical axis angle is obtained by data fitting based on the rotation angle data of the rotating device 103 and the transmitted light intensity data measured by the detector 104.

[0083] In this embodiment of the invention, the detection device 100 for the optical film 200 preferably configures the rotating device 103 to rotate intermittently, and the detector 104 detects the transmitted light intensity during the stop intervals of the intermittent rotation of the rotating device 103. In steps S102 and S106, it is preferable to control the rotating device 103 to rotate intermittently and control the detector 104 to detect the transmitted light intensity during the stop intervals of the intermittent rotation of the rotating device 103. By controlling the intermittent rotation of the rotating device 103 and controlling the detector 104 to detect the transmitted light intensity during the stop intervals of the intermittent rotation of the rotating device 103, multiple transmitted light intensity data and multiple rotation angle data can be obtained. Based on these transmitted light intensity data and rotation angle data, the optical axis angle of the optical film 200 can be calculated by data fitting, which can ensure the detection accuracy of the optical axis angle. The detection accuracy is improved from 1° in the prior art to ±0.3°, or even 0.1°.

[0084] The steps for controlling the intermittent rotation of the rotating device 103 may include: controlling the rotating device 103 to rotate a preset single rotation angle, stopping for a preset time period, and repeating the aforementioned steps until the angle rotated by the rotating device 103 reaches a preset total rotation angle threshold. It can be understood that, with the same total rotation angle threshold, the smaller the single rotation angle, the shorter the preset time period, the more detections, the more transmitted light intensity data obtained, the higher the detection accuracy, and the closer the detection effect is to the actual value. However, the total detection time may be longer. The rotation accuracy of the rotating device 103 can be ≤0.05°, the single rotation angle can be, for example, 0.05°, and the total rotation angle threshold can be, for example, 40°-200°. For the rotating device 103, the single rotation angle and the total rotation angle threshold can be set before each use of the detection device 100. In addition, the preset time period and the number of detections of the rotating device 103 can also be set.

[0085] In some embodiments, in the optical axis angle detection method of this invention, step S108, which obtains the optical axis angle based on the rotation angle data of the rotating device 103 and the transmitted light intensity data measured by the detector 104 through data fitting, includes: using a first built-in function to fit and calculate the rotation angle corresponding to the theoretical minimum transmitted light intensity, which is the optical axis angle, wherein the optical axis angle is the angle between the optical axis of the optical film 200 and the polarization optical axis of the polarization light source 101; wherein,

[0086] The first built-in function is:

[0087] y = Asin(Bx + C) + D,

[0088] In the formula, x is the rotation angle, y is the transmitted light intensity, and A, B, C, and D are constants.

[0089] like Figure 3 As shown, the controller 105 of this embodiment includes a storage unit 150 and a first data processing unit 151. The storage unit 150 is connected to the rotating device 103 and the detector 104 and is used to acquire rotation angle data and transmitted light intensity data. The first data processing unit 151 is used to obtain the rotation angle corresponding to the theoretical minimum transmitted light intensity by fitting a first built-in function.

[0090] This implementation method is generally used when the optical axis angle of the optical film 200 has been roughly marked, making it suitable for use in factory assembly line production where the incoming materials are stable.

[0091] In this embodiment, the rotating device 103 can be controlled by the controller 105 to rotate 0.05° each time, and the detector 104 records the transmitted light intensity, for a total of 25 rotations. The rotation angle corresponding to the theoretical minimum transmitted light intensity is calculated using a first built-in function. This rotation angle corresponding to the theoretical minimum transmitted light intensity is the angle between the optical axis of the optical film 200 and the polarization axis of the polarization light source 101. The fitting result of the rotation angle data and the transmitted light intensity data is a sine function curve, such as... Figure 5 As shown, the lowest point on the vertical axis represents the theoretical minimum transmitted light intensity. Figure 5 In this context, the detected power is the light power transmitted through the optical film 200, i.e., the transmitted light intensity. The detection method of this embodiment combines statistical data processing with a fitting function to control the detection accuracy of the optical axis angle to within 0.05°.

[0092] In other embodiments, the correction element 102 is a polarizer whose optical axis direction has been calibrated as T;

[0093] In the method for detecting the optical axis angle, the rotating device 103 is controlled to rotate starting from direction T;

[0094] Step S108, which involves obtaining the optical axis angle based on the rotation angle data of the rotating device 103 and the transmitted light intensity data measured by the detector 104 through data fitting, includes: using a second built-in function to calculate the angle of rotation of the rotating device 103 relative to direction T when the transmitted light intensity is 0, which is the optical axis angle. The optical axis angle is the angle between the optical axis of the optical film 200 and direction T.

[0095] The second built-in function is:

[0096] I = I0cos 2 (θ+t),

[0097] In the formula, I is the transmitted light intensity, I0 and t are constant parameters, and θ is the angle of rotation of the rotating device 103 relative to the direction T.

[0098] The starting direction T of the rotating device 103 is known. This direction T is bound to the optical axis direction of the correction element 102, therefore, this direction T can be considered to have dual attributes of mechanical position and optical absorption axis. After placing the optical film 200 to be tested on the rotating device 103, it starts to rotate from the starting direction T. The angle of rotation of the rotating device 103 relative to the starting direction T is θ. The optical film 200 rotates according to the set parameters. After the optical film 200 has rotated, two sets of data are obtained: the angle of rotation θ of the rotating device 103 relative to direction T and the transmitted light intensity I. The relationship between the two is the second built-in function mentioned above. After fitting, the values ​​of two constant parameters, I0 and t, can be obtained. Then, for the optical film 200, since I0 > 0, cos 2 (θ+t)≥0, the minimum transmitted light intensity corresponds to cos 2 When (θ+t)=0, that is, according to cos 2 According to the trigonometric function properties, when θ + t = 90°, the transmitted light intensity I is minimum, which is 0. At this point, θ... min =90°-t, which is the optical axis angle.

[0099] Continue to refer to Figure 3 The controller 105 may include a storage unit 150 and a second data processing unit 152. The storage unit 150 is connected to the rotating device 103 and the detector 104 and is used to acquire rotation angle data and transmitted light intensity data. The second data processing unit 152 is used to obtain the angle of rotation of the rotating device 103 relative to the direction T when the transmitted light intensity is 0 by fitting a second built-in function.

[0100] This embodiment is generally used when the optical axis angle of the optical film 200 is unknown. In extreme cases, it can even be used to determine the optical axis angle of an optical film 200 with polarization absorption characteristics but of unknown type. Therefore, the marking of the optical axis angle in this embodiment requires the use of a correction element 102 whose optical axis direction has been calibrated as T.

[0101] In this embodiment, for example, if the optical film 200 to be tested is an absorptive polarizer, the controller 105 can control the rotating device 103 to rotate 0.05° at a time, starting from direction T, for a total rotation of 200°. Simultaneously, the controller 105 records the angle θ of the rotation relative to the initial direction T and the corresponding transmitted light intensity, denoted as {θ1, θ2, θ3, ..., θ...}. 4000}、{I1,I2,I3,…,I 4000 Using the second built-in function, the initial angles t and I0 of the rotating device 103 are obtained. Then, the optical axis angle of the absorptive polarizer under test can be determined to be 90°-t, which is the angle between the optical axis of the optical film 200 and direction T. The optical axis direction is the angle θ that the polarizer rotates along the rotating device 103 from direction T. min= 90° - t in the direction.

[0102] In the optical axis angle detection method of this embodiment of the invention, after the step of fixing the optical film 200 and the rotating device 103, the detection method may further include the step of controlling the CCD image sensor 106, which is located downstream of the rotating device 103 and upstream of the detector 104, to start recording the size information of the optical film 200. After the step of obtaining the optical axis angle by data fitting, the detection method further includes the step of calibrating the optical film 200 based on the optical axis angle and size information. As mentioned above, due to the limitations of the inkjet printing method and the scribing method, it is difficult to mark specific optical axis data on the optical film 200. However, the size information of the optical film 200 can be used to calibrate the optical axis well, thereby facilitating the subsequent bonding of the optical film 200 and also facilitating offline query. The specific process of calibrating the optical film 200 based on the optical axis angle and size information can be to determine the optical axis direction of the optical film 200 and the angle between the optical axis direction and the physical edge of the optical film 200 based on the optical axis angle and size information.

[0103] The detection device 100 of this invention can be used independently or integrated into other systems, such as in a membrane bonding device 300.

[0104] like Figure 6 As shown, this embodiment of the invention also provides a film bonding device 300. The film bonding device 300 includes one or more online optical axis angle detection devices 100, which are used to detect the optical axis angles of the multiple optical films 200 before they are bonded together. By including one or more online optical axis angle detection devices 100 that detect the optical axis angles of the multiple optical films 200 before they are bonded together, the film bonding device 300 of this embodiment of the invention enables online detection of the optical axis angles before the optical films 200 are bonded, improving the overall bonding efficiency. Compared with existing physical edge alignment, this film bonding device 300 improves the alignment accuracy of each functional optical film 200, mitigates stray light problems caused by large optical axis angle deviations in the optical module 204, reduces stray light, and optimizes the user viewing experience.

[0105] In the film bonding apparatus 300 of this embodiment, one or more of the online axis angle detection devices 100 are preferably the aforementioned detection devices 100. The optical axis angle can be the light absorption axis angle or the light slow axis angle. The online axis angle detection device 100 can be set at the detection station 303 (see...). Figure 10When there are multiple online axis angle detection devices 100, they can include multiple identical detection devices 100 or multiple detection devices 100 with different structures. In this article, "multiple" means two or more.

[0106] The following is combined Figures 6 to 11 The preferred embodiment of the present invention provides a detailed description of the film bonding apparatus 300 and the film bonding process for bonding an optical film 200 using the film bonding apparatus 300.

[0107] like Figure 10 and Figure 11 As shown, the film bonding apparatus 300 of this embodiment may further include a cleaning device 320, which is used to clean the optical film 200 before it is conveyed to the online axial angle detection device 100. The cleaning device 320 may be a cleaning head disposed at the cleaning station 302, such as... Figure 11 As shown. The cleaned optical film 200 is then conveyed to the inspection station 303 for online inspection.

[0108] Continue to refer to Figure 10 and Figure 11 The film bonding device 300 of this embodiment may further include: an adsorption device 350, which is used to pick up the optical film 200 that has completed online testing, so as to remove the upper protective film and / or lower protective film of the optical film 200 and to bond the optical films 200 that have completed film removal together. The adsorption device 350 may be set at the film removal station 304, such as... Figure 10 As shown, or set at adsorption and bonding station 305, such as Figure 11 As shown. The adsorption device 350 can be an adsorption head. The optical film 200, after completing online testing, is conveyed to the film-peeling station 304, where it is adsorbed by the adsorption head and the protective film is peeled off. The optical film 200 typically has an upper protective film and a lower protective film; therefore, at the film-peeling station 304, the upper and / or lower protective films need to be peeled off to proceed to the next bonding step. It can be understood that the optical film 200 located in the middle layer includes peeling off the upper film via the film-peeling device 391 and peeling off the lower film via the film-peeling device 392, as shown. Figure 11 As shown, the uppermost optical film 200 is only peeled off, while the lowermost optical film 200 is only peeled on.

[0109] In some embodiments, the film bonding apparatus 300 of the present invention may further include: a plurality of hoppers 301, each hopper 301 for holding optical films 200, with different optical films 200 placed in different hoppers 301. Typically, each type of optical film 200 corresponds to one hopper 301. The hoppers 301 may include, for example, a first hopper 311, a second hopper 312, and a third hopper 313 for different types of optical films. Figure 10 As shown, the optical film 200 to be bonded is typically retrieved from the corresponding hopper 301 or hopper using a feeder 307. The prepared optical film 200 is then conveyed to a cleaning station 302 for cleaning.

[0110] In the film bonding equipment 300 of this embodiment, the material hopper 301, cleaning device 320, online axial angle detection device 100, and adsorption device 350 can be arranged in a linear production line, such as... Figure 10 As shown; or the hopper 301, cleaning device 320, online shaft angle detection device 100, and adsorption device 350 can also be arranged in a circular flow line, such as Figure 11 As shown.

[0111] In some embodiments, in the film bonding apparatus 300 of the present invention, the number of cleaning devices 320 is such that one cleaning device 320 corresponds to each type of optical film 200; the number of online axis angle detection devices 100 is such that one online axis angle detection device 100 corresponds to each type of optical film 200; and the number of adsorption devices 350 is such that one adsorption device 350 corresponds to each type of optical film 200. In other embodiments, in the film bonding apparatus 300 of the present invention, the number of cleaning devices 320 is such that one cleaning device 320 corresponds to multiple types of optical films 200; the number of online axis angle detection devices 100 is such that one online axis angle detection device 100 corresponds to multiple types of optical films 200; and the number of adsorption devices 350 is such that one adsorption device 350 corresponds to multiple types of optical films 200. By ensuring that the number of cleaning devices 320 corresponds to one cleaning device 320 for each type of optical film 200, the number of online axis angle detection devices 100 corresponds to one online axis angle detection device 100 for each type of optical film 200, and the number of adsorption devices 350 corresponds to one adsorption device 350 for each type of optical film 200, the film application efficiency can be improved, but the equipment cost will increase.

[0112] The membrane bonding process of this invention is preferably used for membrane bonding in near-eye displays. In some embodiments, such as Figure 9As shown, the multiple optical films 200 to be bonded include an absorptive polarizer 201, a reflective polarizer 202, and a phase retarder 203. In this optical module 204, the number of phase retarders 203 can be one or more. When there are multiple phase retarders 203, each phase retarder 203 is individually tested online.

[0113] like Figure 7 As shown, the membrane bonding process of this embodiment includes the following steps:

[0114] S202: Perform online axial angle detection on multiple optical films 200 to be bonded to obtain the optical axis angles of multiple optical films 200;

[0115] S204: Obtain the size information of multiple optical films 200;

[0116] S206: Multiple optical films 200 are bonded based on optical axis angle and size information.

[0117] The film bonding process of this invention adopts an improved alignment method during the film bonding process. Online axial angle detection is performed on multiple optical films 200 to be bonded, and the size information of multiple optical films 200 is obtained. Then, multiple optical films 200 are bonded based on the optical axis angle and size information. This can improve the alignment accuracy of the optical axis of each functional optical film 200, improve the stray light problem caused by large optical axis angle deviation in the optical module 204, reduce stray light, and optimize the user viewing experience.

[0118] In step S202, the online optical axis angle detection can be performed using the detection method of the aforementioned detection device 100. Specifically, the optical film 200 is clamped between the clamp 130 and the rotating device 103 using a fixture 130, covering the light-transmitting hole of the rotating device 103, so that the optical film 200 rotates with the rotating device 103. The light source unit is controlled to emit light towards the optical film 200. The detector 104, located downstream of the rotating device 103, is controlled to detect the transmitted light intensity after the light emitted by the light source unit passes through the light-transmitting hole and the optical film 200. The optical axis angle is obtained by data fitting based on the rotation angle data of the rotating device 103 and the transmitted light intensity data measured by the detector 104. Preferably, the rotating device 103 is controlled to rotate intermittently, and the detector 104 is controlled to detect the transmitted light intensity during the stop intervals of the intermittent rotation of the rotating device 103.

[0119] In step S204, the size information of the optical film 200 typically includes the physical edge information of the optical film 200, which is usually the short side information and / or long side information of the rectangular optical film 200. As mentioned above, the detection device 100 mainly uses the rotation device 103, detector 104, etc., to detect the optical axis angle of the optical film 200. When the detection device 100 also includes a CCD image sensor 106, the size information of the optical film 200 can be detected simultaneously with the optical axis angle. That is, by using the online axis angle detection device 100 including the CCD image sensor 106, the optical axis angle and size information of the optical film 200 can be obtained simultaneously.

[0120] In some embodiments, step S206, which involves attaching multiple optical films 200 based on optical axis angle and size information, may include:

[0121] The optical axis direction of each optical film 200 and the angle between the optical axis direction and the physical edge of the optical film 200 are determined based on the optical axis angle and size information.

[0122] Using the optical axis direction of one of the multiple optical films 200 as the reference side, and based on the difference in the included angles of the multiple optical films 200, each optical film 200 is positioned according to the required angular relationship.

[0123] 200 optical films are bonded together.

[0124] like Figure 8 As shown, the optical axis direction A corresponding to the optical axis angle of the optical film 200, as well as the short side B and long side C of the optical film 200, are measured using the detection device 100, and the angle m between the optical axis direction A and the short side B of the optical film 200 is recorded. Similarly, the angle between the optical axis direction A and the long side C of the optical film 200 can also be recorded. In the optical module 204, the required angular relationship between each optical film 200, such as perpendicular or parallel, is to be selected and designed by those skilled in the art as needed, and will not be described in detail here.

[0125] Taking multiple optical films 200 in the optical module 204, including an absorptive polarizer 201, a reflective polarizer 202, and a phase retarder 203, as an example: In step S202, the angles of the absorption axis of the absorptive polarizer 201 and the reflective polarizer 202, and the slow axis of the phase retarder 203, are detected respectively. In step S204, the short side and / or long side information of the absorptive polarizer 201, the reflective polarizer 202, and the phase retarder 203 are obtained respectively. Then, using the light absorption axis direction of the absorptive polarizer 201 as the reference side, or the light absorption axis direction of the reflective polarizer 202 as the reference side, or the light slow axis direction of the phase retarder 203 as the reference side, based on the difference between the angle A of the optical axis direction A of the absorptive polarizer 201, the reflective polarizer 202, and the phase retarder 203 and the short side B of the optical film 200, each optical film 200 is positioned according to the required angular relationship. Finally, a reflective polarizer 202 is bonded below the absorptive polarizer 201, and a phase retarder 203 is bonded below the reflective polarizer 202. The structure of the completed optical module 204 is as follows. Figure 9 As shown, the optical module 204 includes an absorptive polarizer 201, a reflective polarizer 202, and a phase retarder 203 arranged sequentially from top to bottom. Here, "top" and "bottom" are reference terms. Figure 9 It is described using the up and down directions.

[0126] After bonding is completed, the finished optical module 204 is usually unloaded into the receiving box 306 using the unloading and unloading device 308. Figure 10 As shown.

[0127] Existing bonding processes achieve a bonding accuracy of ±2° for the absorptive polarizer 201, reflective polarizer 202, and phase retarder 203. However, the bonding accuracy achieved using the film bonding process of this invention is ±0.3°, thus improving bonding accuracy and reducing stray light caused by optical axis angle errors. Figure 12 The image shown is a measured result of bonding using traditional techniques; as shown... Figure 13 The image shown is a measured effect diagram of the bonding process according to an embodiment of the present invention. It can be seen that light leakage is improved and the display effect is significantly optimized.

[0128] In the film bonding process of this embodiment of the invention, before the step of performing online axial angle detection on the multiple optical films 200 to be bonded, the film bonding process further includes the step of cleaning the optical films 200. As mentioned above, the optical films 200 can be cleaned using a cleaning head provided at the cleaning station 302.

[0129] In the film bonding process of this embodiment of the invention, before the step of bonding multiple optical films 200 based on optical axis angle and size information, the film bonding process further includes the step of: peeling off the upper protective film and / or lower protective film of the optical film 200 based on the position of the optical film 200 in the optical module 204. For the optical film 200 located in the middle layer, peeling off both the upper and lower protective films is performed, while for the uppermost optical film 200, only the lower protective film is peeled off, and for the lowermost optical film 200, only the upper protective film is peeled off.

[0130] In some embodiments, in the film bonding process of this invention, multiple optical films 200 are prepared, cleaned, and simultaneously subjected to online axial angle detection and protective film removal. Finally, they are bonded sequentially along the stacking vertical direction according to the stacking order of the multiple optical films 200 in the optical module 204.

[0131] In this embodiment, multiple optical films 200 are processed simultaneously. Figure 9 Taking the optical module 204 as an example, there is a production line for each of the absorptive polarizer 201, the reflective polarizer 202, and the phase retarder 203. The absorptive polarizer 201, the reflective polarizer 202, and the phase retarder 203 are prepared, cleaned, inspected, and peeled off simultaneously until they reach the adsorption and bonding station 305. The absorption axis of the absorptive polarizer 201 and the slow axis of the phase retarder 203 are positioned according to a certain angular relationship that needs to be maintained, such as perpendicular or parallel. Finally, the reflective polarizer 202 is bonded below the absorptive polarizer 201, and the phase retarder 203 is bonded below the reflective polarizer 202.

[0132] In other embodiments, in the film bonding process of this invention, according to the stacking order of the plurality of optical films 200 in the optical module 204 along the stacking vertical direction, the uppermost optical film 200 is controlled to sequentially undergo the processing steps of preparation, cleaning, online axial angle detection, and removal of protective film, while the lowermost optical film 200 is controlled to undergo the processing steps of preparation, cleaning, online axial angle detection, and removal of protective film after the processing steps of the uppermost optical film 200.

[0133] In this embodiment, multiple optical films 200 are processed in a staggered order. This embodiment can be implemented using, for example... Figure 10 The linear production line shown can be used in the form of, but it can also be implemented in the form of, for example, the linear production line shown. Figure 11 The process is carried out in a circular production line manner as shown.

[0134] by Figure 9 Taking the optical module 204 as an example, in Figure 10In the illustrated embodiment, there is only one production line for the absorptive polarizer 201, the reflective polarizer 202, and the phase retarder 203. The absorptive polarizer 201 is retrieved from the first hopper 311 in the order of stacking and then conveyed to the cleaning station 302 for cleaning. At this time, the reflective polarizer 202 can be retrieved from the second hopper 312. Afterward, the absorptive polarizer 201 is conveyed to the inspection station 303 for inspection, while the reflective polarizer 202 is conveyed to the cleaning station 302 for cleaning. Simultaneously, the phase retarder 203 can be retrieved from the third hopper 313. That is, the processing step of the reflective polarizer 202 lags behind the processing step of the absorptive polarizer 201, and the processing step of the phase retarder 203 lags behind the processing step of the reflective polarizer 202, until the absorptive polarizer 201, the reflective polarizer 202, and the phase retarder 203 all reach the adsorption and bonding station 305 for positioning and bonding. The bonded optical module 204 is then placed in the receiving box 306. Alternatively, after the absorptive polarizer 201 and the reflective polarizer 202 reach the adsorption and bonding station 305, these two can be bonded first, and then the phase retarder 203 can be bonded to the bonded absorptive polarizer 201 and the reflective polarizer 202 after the phase retarder 203 reaches the adsorption and bonding station 305.

[0135] Figure 11 The circular production line shown is Figure 10 Compared to the linear production line, the difference lies in the fact that the first hopper 311, the second hopper 312, and the third hopper 313 rotate in a cycle during the production process, passing through the cleaning station 302, the inspection station 303, the film-tearing station 304 in sequence, and then being adsorbed by the adsorption and bonding head. The bonding is completed at the adsorption and bonding station 305, resulting in the finished optical module 204, which is then placed in the receiving box 306.

[0136] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "one example," "some embodiments," or "preferred embodiment," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0137] The embodiments of the present invention have been described in detail above. However, the present invention is not limited to the embodiments described above. Various modifications and substitutions can be applied to the above embodiments without departing from the scope of the present invention.

Claims

1. A method of detecting an optical axis angle of an optical film, characterized by, The detection method comprises the following steps: The optical film is clamped between the clamp and the rotating device and covers the light transmission hole of the rotating device by using the clamp, so that the optical film rotates with the rotation of the rotating device; The light source unit emits light towards the optical film; The detector arranged downstream of the rotating device detects the transmitted light intensity of the light emitted by the light source unit after being transmitted through the light transmission hole and the optical film, and the detector comprises a main detector and at least one auxiliary detector, wherein the main detector and the at least one auxiliary detector are respectively used to detect the transmitted light intensity; The optical axis angle is obtained by data fitting based on the rotation angle data of the rotating device and the transmitted light intensity data measured by the detector, comprising: Each of the transmitted light intensity data detected by the main detector is subjected to ratio processing with a corresponding one of the transmitted light intensity data detected by the auxiliary detector; The optical axis angle is obtained by data fitting based on the obtained ratio data and the rotation angle data of the rotating device.

2. The detection method according to claim 1, wherein In the detection method, the rotating device is controlled to rotate intermittently, and the detector detects the transmitted light intensity during the stop interval of the intermittent rotation of the rotating device.

3. The detection method according to claim 2, characterized in that, The step of controlling the rotating device to rotate intermittently comprises: The rotating device is controlled to stop for a preset time period after rotating a preset single rotation angle, and the operation is repeated until the rotating device rotates through a preset total rotation angle threshold.

4. The detection method according to claim 1 or 2, characterized in that, The light source unit comprises a polarized light source, and the step of obtaining the optical axis angle by data fitting based on the rotation angle data of the rotating device and the transmitted light intensity data measured by the detector comprises: The rotation angle corresponding to the theoretical transmitted light intensity minimum value is calculated by using a first built-in function fitting, which is the optical axis angle, wherein the optical axis angle is the angle between the optical axis of the optical film and the polarization axis of the polarized light source; wherein The first built-in function is: ， In the formula, x is the rotation angle, y is the transmitted light intensity, A, B, C, and D are constants.

5. The detection method according to claim 1 or 2, wherein The light source unit comprises a polarized light source and a correction element, the correction element is a polarizer with a calibrated optical axis direction T and is arranged downstream of the polarized light source; In the detection method, the rotating device is controlled to rotate from direction T; The step of obtaining the optical axis angle by data fitting based on the rotation angle data of the rotating device and the transmitted light intensity data measured by the detector comprises: The angle of the rotating device relative to direction T when the transmitted light intensity is 0 is calculated by using a second built-in function fitting, which is the optical axis angle, wherein the optical axis angle is the angle between the optical axis of the optical film and direction T; wherein The second built-in function is: ， In the formula, I is the transmitted light intensity, I0 and t are constant parameters, and θ is the angle of the rotating device relative to direction T.

6. The detection method according to claim 1 or 2, characterized by, After the step of fixing the optical film and the rotating device, the detection method further comprises the following steps: controlling a CCD image sensor arranged downstream of the rotating device and upstream of the detector to start recording size information of the optical film.

7. The detection method according to claim 6, characterized in that, After the step of obtaining the optical axis angle, the detection method further comprises the following steps: calibrating the optical film based on the optical axis angle and the size information.

8. A film-attaching process, characterized by, The film lamination process comprises the following steps: performing online axis angle detection on the multiple optical films to be laminated to obtain optical axis angles of the multiple optical films, the online axis angle detection being performed by using the detection method according to any one of claims 1-7; obtaining size information of the multiple optical films; laminating the multiple optical films based on the optical axis angles and the size information.

9. The film dolly process of claim 8, wherein, The step of laminating the multiple optical films based on the optical axis angles and the size information comprises: determining, based on the optical axis angles and the size information, an optical axis direction of each of the optical films and an included angle between the optical axis direction and a physical side of the optical film; positioning each of the optical films according to a required angle relationship with reference to the optical axis direction of one of the multiple optical films and according to a difference between the included angles of the multiple optical films; and laminating the multiple optical films.

10. The film dolly process of claim 8 or 9, wherein, Before the step of performing online axis angle detection on the multiple optical films to be laminated, the film lamination process further comprises the following step: cleaning the optical films.

11. The film dolly process of claim 10, wherein, Before the step of laminating the multiple optical films based on the optical axis angles and the size information, the film lamination process further comprises the following step: based on a position of the optical film in an optical module, tearing off an upper protective film and / or a lower protective film of the optical film.

12. The film lamination process according to claim 11, wherein in the film lamination process, the multiple optical films are simultaneously prepared, simultaneously cleaned, simultaneously subjected to online axis angle detection, simultaneously have protective films torn off, and finally laminated in sequence along a stacking up-down direction according to a stacking order of the multiple optical films in an optical module.

13. The film lamination process according to claim 11, wherein in the film lamination process, the optical films located higher are controlled to sequentially pass through the steps of preparation, cleaning, online axis angle detection, and tearing off of protective films along a stacking up-down direction according to a stacking order of the multiple optical films in an optical module, and the optical films located lower lag behind the optical films located higher in the steps of preparation, cleaning, online axis angle detection, and tearing off of protective films.

Images