System and method for detecting relative included angle of optical composite film and medium

Abstract

The embodiment of the invention provides a system and method for detecting the relative included angle of an optical composite film and a medium. The detection system sequentially comprises a light source, a polarizer, a polarization analyzer assembly and an optical power meter in the light transmission direction, and further comprises a controller. Wherein the light source is used for emitting single-wavelength light; a to-be-detected optical composite film assembly is arranged between the polarizer and the polarization analyzer assembly, the to-be-detected optical composite film assembly comprises a to-be-detected optical composite film, the to-be-detected optical composite film comprises a first film layer and a second film layer, and the controller is electrically connected with the optical power meter, the polarization analyzer assembly and the to-be-detected optical composite film assembly. And the control module is used for controlling the polarization analyzer to rotate under the condition that the transmission axis of the first film layer is parallel to the transmission axis of the polarizer and the transmission axis of the polarization analyzer, determining the long-axis azimuth angle of the elliptically polarized light emitted by the second film layer, and determining the relative included angle between the first film layer and the second film layer according to the long-axis azimuth angle of the elliptically polarized light.

Description

Technical Field

[0001] The embodiments of the present application relate to the technical field of composite film detection. More specifically, the embodiments of the present application relate to a detection system, method, and medium for the relative angle of an optical composite film. Background Art

[0002] In the VR Pancake solution, taking the lamination of a QWP film and an RP film as an example, the lamination angle between the QWP film and the RP film has a crucial impact on the imaging quality of the optical module. Therefore, it is particularly necessary to detect the relative angle between the composite films.

[0003] In the prior art, when detecting the relative angle of the QWP and RP composite films in the VR Pancake solution without tearing the film, whether using an expensive polarimeter solution or a relatively economical optical power meter solution, an excitation light source matching the corresponding wavelength of the QWP film needs to be equipped. If it is necessary to detect QWP films with different wavelengths, the corresponding wavelength excitation light source must be replaced, or the entire detection device must be re-customized, which will undoubtedly greatly increase the detection cost and cause unnecessary economic burden. Summary of the Invention

[0004] The purpose of the present application is to provide a new technical solution for a detection system, method, and medium for the relative angle of an optical composite film.

[0005] In a first aspect, the present application provides a detection system for the relative angle of an optical composite film. The detection system sequentially includes, along the light transmission direction: a light source, a polarizer, a polarizer assembly, and an optical power meter. The detection system further includes a controller; wherein:

[0006] The light source is used to emit a single-wavelength light;

[0007] The polarizer assembly includes a polarizer, and the polarizer is rotatable about the optical axis relative to the polarizer;

[0008] The optical composite film component to be measured is arranged between the polarizer and the polarizer assembly. The optical composite film component to be measured includes an optical composite film to be measured. The optical composite film to be measured is configured to be rotatable about the optical axis direction. The optical composite film to be measured includes a first film layer and a second film layer. The first film layer is closer to the polarizer than the second film layer. The first film layer can selectively allow polarized light to pass through, and the second film layer can convert the polarization state of the polarized light;

[0009] The controller is electrically connected to the optical power meter, the polarization analyzer assembly, and the optical composite film assembly to be measured respectively. When the transmission axes of the first film layer, the polarizer, and the polarization analyzer are parallel to each other, the controller is used to control the rotation of the polarization analyzer, determine the major axis azimuth angle of the elliptically polarized light emitted from the second film layer, and determine the relative angle between the first film layer and the second film layer according to the major axis azimuth angle of the elliptically polarized light.

[0010] Optionally, the polarization analyzer assembly further includes a first driving circuit for driving the rotation of the polarization analyzer;

[0011] The controller is electrically connected to the first driving circuit. When the optical composite film assembly to be measured is not disposed between the polarizer and the polarization analyzer, the controller is used to control the first driving circuit to drive the rotation of the polarization analyzer so that the transmission axes of the polarizer and the polarization analyzer are parallel.

[0012] Optionally, the controller is connected to the first driving circuit and is further used to control the rotation of the polarization analyzer to determine the major axis azimuth angle of the elliptically polarized light emitted from the second film layer when the transmission axes of the first film layer, the polarizer, and the polarization analyzer assembly are parallel to each other.

[0013] Optionally, the optical composite film assembly to be measured further includes a second driving circuit for driving the rotation of the optical composite film to be measured;

[0014] The controller is electrically connected to the second driving circuit. When the optical composite film assembly to be measured is disposed between the polarizer and the polarization analyzer, the controller is used to control the second driving circuit to drive the rotation of the optical composite film to be measured so that the transmission axis of the first film layer is parallel to the transmission axes of the polarizer and the polarization analyzer.

[0015] Optionally, the controller includes a first acquisition module, a first data fitting module, a first determination module, and a first control module, and the first acquisition module, the first data fitting module, the first determination module, and the first control module are electrically connected in sequence;

[0016] The first acquisition module is used to acquire the first set of power data sets obtained by the optical power meter and the rotation angle set of the optical composite film to be measured;

[0017] The first data fitting module establishes a first mathematical model based on the first set of power data sets obtained by the optical power meter and the rotation angle set of the optical composite film to be measured;

[0018] The first determination module uses the first mathematical model to obtain the rotation angle of the optical composite film to be measured corresponding to the power eigenvalue;

[0019] The first control module controls the rotation of the optical composite film to be measured according to the rotation angle of the optical composite film to be measured corresponding to the power eigenvalue, so that the transmission axis of the first film layer is parallel to the transmission axis of the polarizer and the transmission axis of the analyzer.

[0020] Optionally, the controller includes a second acquisition module, a second data fitting module, a second determination module, and a second control module, and the second acquisition module, the second data fitting module, the second determination module, and the second control module are electrically connected in sequence;

[0021] The second acquisition module is configured to acquire a second set of power data sets obtained by the optical power meter and the analyzer rotation angle set;

[0022] The second data fitting module establishes a second mathematical model based on the second set of power data sets obtained by the optical power meter and the analyzer rotation angle set;

[0023] The second determination module uses the second mathematical model to obtain the rotation angle of the analyzer corresponding to the maximum power value;

[0024] The second control module determines the long axis azimuth angle of the elliptically polarized light according to the rotation angle of the analyzer corresponding to the maximum power value.

[0025] Optionally, the controller includes a judgment module, and the judgment module is configured to judge whether the wavelength of the second film layer matches the wavelength of the light emitted by the light source;

[0026] When the wavelength of the second film layer matches the wavelength of the light emitted by the light source, the relative angle between the transmission axis of the first film layer and the fast axis of the second film layer is equal to the long axis azimuth angle of the elliptically polarized light emitted by the second film layer;

[0027] When the wavelength of the second film layer does not match the wavelength of the light emitted by the light source, the relative angle θ between the transmission axis of the first film layer and the fast axis of the second film layer satisfies the following formula:

[0028]

[0029] where ψ is the long axis azimuth angle of the elliptically polarized light emitted by the second film layer, δ is the phase delay amount corresponding to the wavelength of the light emitted by the second film layer and the light source, in nm, and λ1 is the wavelength of the light emitted by the light source.

[0030] In a second aspect, an embodiment of the present application further provides a method for detecting a relative angle of an optical composite film. The detection method is applied to a detection system for a relative angle of an optical composite film as described in the first aspect, comprising:

[0031] When the transmission axis of the first film layer is parallel to the transmission axes of the polarizer and the analyzer, the analyzer is controlled to rotate to determine the major axis azimuth of the elliptically polarized light emitted by the second film layer, and the relative angle between the first film layer and the second film layer is determined according to the major axis azimuth of the elliptically polarized light.

[0032] Optionally, the transmission axis of the first film layer is parallel to the transmission axis of the polarizer and the transmission axis of the analyzer, including:

[0033] In a state where the optical composite film assembly to be tested is not arranged between the polarizer and the analyzer, controlling the transmission axis of the analyzer and the transmission axis of the polarizer to be parallel to each other;

[0034] In a state where the optical composite film assembly to be measured is disposed between the polarizer and the analyzer, the transmission axis of the first film layer is controlled to be parallel to the transmission axis of the polarizer and the transmission axis of the analyzer.

[0035] Optionally, in a state where the optical composite film assembly to be tested is disposed between the polarizer and the analyzer, controlling the transmission axis of the first film layer to be parallel to the transmission axis of the polarizer and the transmission axis of the analyzer comprises:

[0036] Acquire a first set of power data obtained by the optical power meter and a set of rotation angles of the optical composite film to be measured;

[0037] Establishing a first mathematical model based on a first set of power data obtained by the optical power meter and a set of rotation angles of the optical composite film to be measured;

[0038] Using the first mathematical model to obtain the rotation angle of the optical composite film to be measured corresponding to the power characteristic value;

[0039] According to the rotation angle of the optical composite film to be measured corresponding to the power characteristic value, the optical composite film to be measured is controlled to rotate so that the transmission axis of the first film layer is parallel to the transmission axis of the polarizer and the transmission axis of the analyzer.

[0040] Optionally, the step of obtaining the rotation angle of the optical composite film to be measured corresponding to the power characteristic value by using the first mathematical model includes:

[0041] The first mathematical model is used to obtain a first rotation angle of the optical composite film to be measured corresponding to a minimum power value, wherein the minimum power value is the power characteristic value.

[0042] Optionally, controlling the rotation of the optical composite film under test according to the rotation angle of the optical composite film under test corresponding to the power eigenvalue, so that the transmission axis of the first film layer is parallel to the transmission axis of the polarizer and the transmission axis of the analyzer includes:

[0043] Controlling the transmission axis of the first film layer to be perpendicular to the transmission axis of the polarizer according to the first rotation angle of the optical composite film under test corresponding to the power eigenvalue;

[0044] Controlling the optical composite film under test to rotate by 90°, so that the transmission axis of the first film layer is parallel to the transmission axis of the polarizer and the transmission axis of the analyzer.

[0045] Optionally, controlling the rotation of the analyzer to determine the major axis azimuth angle of the elliptically polarized light emitted from the second film layer includes:

[0046] Obtaining a second set of power data sets obtained by the optical power meter and the analyzer rotation angle set;

[0047] Based on the second set of power data sets obtained by the optical power meter and the analyzer rotation angle set, establishing a second mathematical model;

[0048] Using the second mathematical model to obtain the rotation angle of the analyzer corresponding to the maximum power;

[0049] Determining the major axis azimuth angle of the elliptically polarized light according to the rotation angle of the analyzer corresponding to the maximum power.

[0050] Optionally, determining the relative angle between the first film layer and the second film layer according to the major axis azimuth angle of the elliptically polarized light includes:

[0051] When the wavelength of the second film layer matches the wavelength of the light emitted by the light source, the relative angle between the transmission axis of the first film layer and the fast axis of the second film layer is equal to the major axis azimuth angle of the elliptically polarized light emitted from the second film layer.

[0052] Optionally, determining the relative angle between the first film layer and the second film layer according to the major axis azimuth angle of the elliptically polarized light includes:

[0053] When the wavelength of the second film layer does not match the wavelength of the light emitted by the light source, the relative angle θ between the transmission axis of the first film layer and the fast axis of the second film layer satisfies the following formula:

[0054]

[0055] Wherein, ψ is the major axis azimuth angle of the elliptically polarized light emitted from the second film layer, δ is the phase delay corresponding to the wavelength of the light emitted from the light source for the second film layer, with the unit of nm, and λ1 is the wavelength of the light emitted from the light source.

[0056] In a third aspect, an embodiment of the present application further provides a detection system for the relative angle of an optical composite film. The controller of the detection system includes a memory and a processor. The memory is used to store computer instructions, and the processor is used to call the computer instructions from the memory to execute the method described in the second aspect.

[0057] In a fourth aspect, an embodiment of the present application further provides a computer-readable storage medium, on which a computer program is stored. The computer program, when executed by a processor, implements the method described in the second aspect.

[0058] In the technical solution provided by the embodiment of the present application, a method is provided that does not require changing the light source type, and without the need to tear the film, under the condition that the detection system meets specific conditions, the major axis azimuth angle of the elliptically polarized light emitted from the second film layer is determined by the rotation angle of the analyzer and the optical power value detected by the optical power meter. According to the major axis azimuth angle of the elliptically polarized light, the relative angle between the first film layer and the second film layer is calculated by the controller. The detection system provided by the embodiment of the present application realizes low-cost detection.

[0059] Other features and advantages of the present specification will become clear through the following detailed description of the exemplary embodiments of the present specification with reference to the accompanying drawings. Description of the Drawings

[0060] The drawings incorporated in the specification and constituting a part of the specification illustrate embodiments of the present specification and, together with the description, are used to explain the principles of the present specification.

[0061] Figure 1 The schematic diagram of the detection system for the relative angle of the optical composite film provided by the embodiment of the present application is shown.

[0062] Figure 2 The structural block diagram of the detection system for the relative angle of the optical composite film provided by the embodiment of the present application is shown.

[0063] Figure 3 The internal structure schematic of the controller in the detection system for the relative angle of the optical composite film provided by the embodiment of the present application is shown Figure 1 .

[0064] Figure 4 The internal structure schematic of the controller in the detection system for the relative angle of the optical composite film provided by the embodiment of the present application is shown Figure 2 .

[0065] Figure 5 The figure shows a flowchart of a method for detecting the relative angle of an optical composite film provided by an embodiment of the present application.

[0066] Figure 6 The figure shows a schematic internal structure of a controller in a detection system for the relative angle of an optical composite film provided by an embodiment of the present application Figure 3 .

[0067] Explanation of reference numerals:

[0068] 1. Light source; 2. Polarizer; 3. Analyzer assembly; 31. Analyzer; 32. First drive circuit; 4. Optical power meter; 5. Controller; 6. Optical composite film assembly to be measured; 61. Optical composite film to be measured; 62. Second drive circuit; 51. First acquisition module; 52. First data fitting module; 53. First determination module; 54. First control module; 55. Second acquisition module; 56. Second data fitting module; 57. Second determination module; 58. Second control module; 71. Memory; 72. Processor. Detailed implementation manners

[0069] Now, various exemplary embodiments of the present application will be described in detail with reference to the accompanying drawings. It should be noted that: unless otherwise specifically stated, the relative arrangements of components and steps, numerical expressions, and numerical values set forth in these embodiments do not limit the scope of the present application.

[0070] The following description of at least one exemplary embodiment is merely illustrative in nature and in no way serves as a limitation to the present application, its application, or its use.

[0071] Technologies and devices known to those of ordinary skill in the relevant art may not be discussed in detail, but where appropriate, such technologies and devices should be regarded as part of the specification.

[0072] In all the examples shown and discussed here, any specific value should be construed as merely exemplary and not as a limitation. Therefore, other examples of the exemplary embodiments may have different values.

[0073] It should be noted that: similar reference numerals and letters denote similar items in the following drawings. Therefore, once an item is defined in one drawing, it does not need to be further discussed in subsequent drawings.

[0074] <System embodiment>

[0075] The present application provides a detection system for the relative angle of an optical composite film. Refer to Figure 1 and Figure 2, the detection system sequentially includes, along the light transmission direction: a light source 1, a polarizer 2, an analyzer assembly 3, and an optical power meter 4. The detection system further includes a controller 5; where:

[0076] The light source 1 is used to emit light of a single wavelength;

[0077] The analyzer assembly 3 includes an analyzer 31, and the analyzer 31 is rotatable about the optical axis relative to the polarizer 2;

[0078] Between the polarizer 2 and the analyzer assembly 3, a to-be-detected optical composite film assembly 6 is arranged. The to-be-detected optical composite film assembly 6 includes a to-be-detected optical composite film 61. The to-be-detected optical composite film 61 is configured to be rotatable about the optical axis direction. The to-be-detected optical composite film 61 includes a first film layer and a second film layer. The first film layer is closer to the polarizer 2 than the second film layer. The first film layer can selectively allow polarized light to pass through, and the second film layer can convert the polarization state of the polarized light;

[0079] The controller 5 is electrically connected to the optical power meter 4, the analyzer assembly 3, and the to-be-detected optical composite film assembly 6 respectively. When the transmission axis of the first film layer, the transmission axis of the polarizer 2, and the transmission axis of the analyzer 31 are parallel to each other, the controller 5 controls the analyzer 31 to rotate, determines the major axis azimuth angle of the elliptically polarized light emitted by the second film layer, and determines the relative included angle between the first film layer and the second film layer according to the major axis azimuth angle of the elliptically polarized light.

[0080] An optical composite film is generally formed by laminating any two of a polarizing film (POL film), a reflective polarizing film (RP film), and a quarter-wave plate (QWP film). Usually, a polarizing film (POL film) and a quarter-wave plate (QWP film) are laminated, or a reflective polarizing film (RP film) and a quarter-wave plate (QWP film) are laminated. The optical composite film and the lens group are combined to form an optical module with a folded optical path. The imaging quality of the optical module is affected by the relative included angle of the optical composite film. Subtle angular differences will seriously affect the imaging effect, and also affect the user experience and the comfort of the eyes. Therefore, it is very necessary to detect the relative included angle of the optical composite film.

[0081] In the embodiment of the present application, a detection system specifically for detecting the relative included angle of an optical composite film is provided. In the subsequent detailed description of the detection system, we will take the optical composite film formed by laminating a QWP film and an RP film as a specific example for illustration.

[0082] In an embodiment of the present application, the detection system includes a light source 1, which is used to emit light of a single wavelength. During the use of the detection system, the transmission path of the light of a single wavelength is as follows: successively passing through a polarizer 2, an optical composite film 61 to be measured, and an analyzer 31, and finally received by a optical power meter 4.

[0083] It should be noted that the detection system exhibits a high degree of flexibility and can be adapted to a second film layer with different wavelength characteristics. In particular, without changing the type of the light source 1 - that is, without generating light of different wavelengths by replacing the light source 1 - the system can still detect an optical composite film composed of a QWP film and an RP film of different wavelengths.

[0084] Exemplarily, the light source 1 is a single - wavelength excitation light source 1.

[0085] In an embodiment of the present application, the detection system further includes a polarizer 2 and an analyzer assembly 3. The analyzer assembly 3 includes an analyzer 31. The analyzer 31 is rotatably arranged relative to the polarizer 2, and the polarizer 2 is fixedly arranged relative to the analyzer 31. The polarizer 2 refers to a device that can change the light originally propagating in all directions into light propagating only in one direction. The analyzer 31 refers to a device that can only allow light vibrating in a specific direction to pass through and cannot allow light vibrating perpendicular to this direction to pass through.

[0086] In this embodiment, the light emitted by the light source 1 is light of a single wavelength (i.e., monochromatic light), and generally, the vibration directions of these lights are random (i.e., non - polarized light). The polarizer 2 is used to obtain linearly polarized light from the light of a single wavelength emitted by the light source 1.

[0087] Whether the analyzer 31 is fixedly arranged or rotatably arranged, the analyzer 31 is used to obtain polarized light consistent with the transmission axis direction of the analyzer 31 from the elliptically polarized light (circularly polarized light is a special type of elliptically polarized light) emitted by the second film layer.

[0088] For the fixedly arranged analyzer 31: when the elliptically polarized light is perpendicularly incident on the fixedly arranged analyzer 31, only the light vibration component consistent with the vibration direction of the analyzer 31 can pass through. Since the vibration direction of the elliptically polarized light has components in two mutually perpendicular directions but the magnitudes of the components are different, the light intensity passing through the analyzer 31 will depend on the angle between the major axis of the elliptically polarized light and the vibration direction of the analyzer 31.

[0089] For the rotatably arranged analyzer 31: when the elliptically polarized light is perpendicularly incident on the rotatable analyzer 31, by rotating the analyzer 31, the angle between its vibration direction and the major axis of the elliptically polarized light can be changed. During the rotation process, the transmitted light intensity will change with the change of the angle, so that the azimuth angle of the major axis of the elliptically polarized light emitted by the second film layer can be determined.

[0090] It should be noted that even if the emitted light is polarized light with a single wavelength, it is necessary to set the polarizer 2 with a known transmission axis direction as the reference for the entire detection system, so as to subsequently make the transmission axis of the analyzer 31 parallel to the transmission axis of the polarizer 2, and make the transmission axis of the first film layer, the transmission axis of the analyzer 31, and the transmission axis of the polarizer 2 parallel.

[0091] The fixed setting of the polarizer 2 relative to the analyzer 31 can be understood as follows: during the use of the detection system, the polarizer 2 is always fixedly set, that is, the setting position of the transmission axis of the polarizer 2 remains unchanged. For example, the transmission axis of the polarizer 2 can form an arbitrary angle with the horizontal axis (the axis perpendicular to the paper surface direction), that is, the transmission axis of the polarizer 2 can be set in any direction. Exemplarily, the transmission axis of the polarizer 2 can be set parallel to the horizontal axis and fixedly set relative to the analyzer 31.

[0092] The rotatable setting of the analyzer 31 relative to the polarizer 2 can be understood as follows: during the use of the detection system, the analyzer 31 is rotatable, that is, the setting position of the transmission axis of the analyzer 31 is adjustable according to the detection requirements. For example, when the optical composite film component 6 to be measured is not arranged between the polarizer 2 and the analyzer 31 and it is required that the transmission axis of the analyzer 31 is parallel to the transmission axis of the polarizer 2, at this time, the analyzer 31 is manipulated, and the analyzer 31 rotates relative to the polarizer 2 so that the transmission axis of the analyzer 31 is parallel to the transmission axis of the polarizer 2. Another example is that when the optical composite film component 6 to be measured is arranged between the polarizer 2 and the analyzer 31 and the transmission axes of the first film layer, the polarizer 2, and the analyzer 31 are parallel to each other, at this time, the analyzer 31 is manipulated to determine the major axis azimuth angle of the elliptically polarized light emitted by the second film layer.

[0093] In the embodiment of the present application, the optical composite film component 6 to be measured is arranged between the polarizer 2 and the analyzer 31. The optical composite film component 6 to be measured includes an optical composite film 61 to be measured, and the optical composite film 61 to be measured is configured to be rotatable around the optical axis direction. In a state where the transmission axes of the polarizer 2 and the analyzer 31 are parallel, the optical composite film component 6 to be measured is arranged between the polarizer 2 and the analyzer 31, and by manipulating the optical composite film 61 to be measured, the transmission axis of the first film layer, the transmission axis of the polarizer 2, and the transmission axis of the analyzer 31 in the optical composite film 61 to be measured are made parallel.

[0094] In this embodiment, the structure of the optical composite film 61 to be measured is composed of a first film layer and a second film layer. Among them, the first film layer is closer to the polarizer 2 than the second film layer and has the function of selectively transmitting polarized light; while the second film layer is responsible for changing the polarization state of the polarized light passing through it. Specifically, when the light emitted by the light source 1 penetrates this optical composite film, it will first pass through the first film layer and then continue to propagate through the second film layer.

[0095] Among them, the first film layer has the function of selectively transmitting polarized light. When the transmission axes of the polarizer 2 and the analyzer 31 are parallel, the optical composite film assembly 6 to be measured is arranged between the polarizer 2 and the analyzer 31. At this time, it is not clear whether the transmission axis of the first film layer is parallel to the transmission axes of the polarizer 2 and the analyzer 31. It is necessary to judge whether the transmission axis of the first film layer is parallel to the transmission axes of the polarizer 2 and the analyzer 31 according to the optical power detected by the optical power meter 4.

[0096] Specifically, the optical composite film 61 to be measured can be rotated. When the optical composite film 61 to be measured is rotated, the transmission axes of the polarizer 2 and the analyzer 31 are parallel to each other and fixed. The position of the transmission axis of the first film layer relative to the transmission axes of the polarizer 2 and the analyzer 31 is determined by the optical power value detected by the optical power meter 4. For example, when the optical composite film 61 to be measured is rotated, when the transmission axis of the first film layer is parallel to the transmission axes of the polarizer 2 and the analyzer 31, the optical power value detected by the optical power meter 4 is the highest. When the optical composite film 61 to be measured is rotated, when the transmission axis of the first film layer is perpendicular to the transmission axes of the polarizer 2 and the analyzer 31, the optical power value detected by the optical power meter 4 is the lowest.

[0097] Among them, the second film layer is responsible for changing the polarization state of the polarized light passing through it. When the operator rotates the optical composite film 61 to be measured so that the transmission axes of the first film layer of the optical composite film 61, the polarizer 2, and the analyzer 31 are parallel to each other, at this time, the operator can rotate the analyzer 31 to change the polarization state of the polarized light passing through the second film layer, determine the major axis azimuth angle of the elliptically polarized light emitted by the second film layer, and determine the relative included angle between the first film layer and the second film layer according to the major axis azimuth angle of the elliptically polarized light.

[0098] In an embodiment of the present application, the controller 5 is electrically connected to the optical power meter 4, the polarization analyzer assembly 3, and the optical composite film assembly 6 to be measured respectively. Among them, the controller 5 is electrically connected to the optical power meter 4, and the controller 5 can be used to receive the power value detected by the optical power meter 4. The controller 5 is electrically connected to the polarization analyzer assembly 3. When the polarization analyzer 31 is manipulated to rotate, the controller 5 can be used to receive the rotation angle of the polarization analyzer 31. The controller 5 is electrically connected to the optical composite film assembly 6 to be measured. When the optical composite film 61 to be measured is manipulated to rotate, the controller 5 can be used to receive the rotation angle of the optical composite film 61 to be measured.

[0099] After the controller 5 is electrically connected to the optical power meter 4, the polarization analyzer assembly 3, and the optical composite film assembly 6 to be measured respectively, the controller 5 is used to control the rotation of the polarization analyzer 31 in a state where the transmission axis of the first film layer is parallel to the transmission axes of the polarizer 2 and the polarization analyzer 31, determine the major axis azimuth angle of the elliptically polarized light emitted from the second film layer, and determine the relative angle between the first film layer and the second film layer according to the major axis azimuth angle of the elliptically polarized light.

[0100] In this embodiment, after the controller 5 is electrically connected to the optical power meter 4, the polarization analyzer assembly 3, and the optical composite film assembly 6 to be measured, and the detection system is adjusted to a specific state, that is, a state where the transmission axis of the first film layer is parallel to the transmission axes of the polarizer 2 and the polarization analyzer 31, under the control of the controller 5, the polarization analyzer 31 starts to rotate. This process is to observe and record the polarization state of the light emitted from the second film layer, especially the major axis azimuth angle of the elliptically polarized light. Through the rotation of the polarization analyzer 31 and the corresponding optical power measurement, the detection system can determine the major axis azimuth angle of the elliptically polarized light emitted from the second film layer. This angle reflects the change in the polarization state of the light after passing through the first film layer and the second film layer. Finally, according to the major axis azimuth angle of the elliptically polarized light, the controller 5 (or the computing device connected thereto) can calculate the relative angle between the first film layer and the second film layer.

[0101] Therefore, in an embodiment of the present application, there is provided a method that does not require changing the type of the light source 1, and without the need to tear the film, under the condition that the detection system meets specific conditions, determines the major axis azimuth angle of the elliptically polarized light emitted from the second film layer through the rotation angle of the polarization analyzer 31 and the optical power value detected by the optical power meter 4, and calculates the relative angle between the first film layer and the second film layer according to the major axis azimuth angle of the elliptically polarized light. The detection system provided by the embodiment of the present application can more simply realize the detection of the relative angle between the first film layer and the second film layer. The detection system provided by the embodiment of the present application realizes low-cost detection.

[0102] In an embodiment of the present application, referring to Figure 2 , the polarization analyzer assembly 3 further includes a first drive circuit 32, and the first drive circuit 32 is used to drive the polarization analyzer 31 to rotate;

[0103] The controller 5 is electrically connected to the first driving circuit 32 and is configured to control the first driving circuit 32 to drive the analyzer 31 to rotate in a state where the optical composite film component 6 to be measured is not provided between the polarizer 2 and the analyzer 31, so that the transmission axes of the polarizer 2 and the analyzer 31 are parallel.

[0104] In this embodiment, the analyzer assembly 3 includes an analyzer 31 and a first driving circuit 32. The input port of the first driving circuit 32 is connected to the controller 5, and the output port is connected to the analyzer 31. With such a design, the controller 5 can instruct the first driving circuit 32 to drive the analyzer 31 to perform a rotation action.

[0105] The premise for the detection system to detect the relative angle between the first film layer and the second film layer in the optical composite film 61 to be measured is to determine that the transmission axes of the polarizer 2 and the analyzer 31 are parallel to each other. In this embodiment, in a state where the optical composite film component 6 to be measured is not provided between the polarizer 2 and the analyzer 31, the controller 5 controls the first driving circuit 32 to drive the analyzer 31 to rotate, so that the transmission axes of the polarizer 2 and the analyzer 31 are parallel.

[0106] Specifically, the controller 5 communicates with the first driving circuit 32 through electrical connection and sends instructions to control the operation of the first driving circuit 32. After receiving the instructions from the controller 5, the first driving circuit 32 drives the analyzer 31 to rotate. The purpose of the rotation is to adjust the transmission axis (i.e., the direction allowing light to pass through) of the analyzer 31 to be parallel to the transmission axis of the polarizer 2. When the two are parallel, the linearly polarized light emitted from the polarizer 2 can pass through the analyzer 31 to the maximum extent, reaching a specific detection condition. When the analyzer 31 rotates, the optical power meter 4 detects the optical power value in real time. According to the optical power value and the rotation angle of the analyzer 31, the transmission axes of the polarizer 2 and the analyzer 31 are made parallel. For example, when the transmission axis of the analyzer 31 is parallel to the transmission axis of the polarizer 2, the optical power value detected by the optical power meter 4 is the highest, and when the transmission axis of the analyzer 31 is perpendicular to the transmission axis of the polarizer 2, the optical power value detected by the optical power meter 4 is the lowest. In a specific example, when the analyzer 31 rotates one week or rotates N weeks, according to the rotation angle corresponding to the highest optical power value detected by the optical power meter 4, the analyzer 31 is adjusted so that the transmission axis of the analyzer 31 is parallel to the transmission axis of the polarizer 2.

[0107] Therefore, in this embodiment, through the coordinated use of the controller 5, the first driving circuit 32, and the analyzer 31, the detection premise that the transmission axes of the analyzer 31 and the polarizer 2 are parallel to each other is achieved.

[0108] After adjusting the transmission axis of the analyzer 31 and the transmission axis of the polarizer 2 of the detection system to be parallel, the detection system needs to place the optical composite film component 6 to be measured between the analyzer 31 and the polarizer 2, and adjust the transmission axis of the first film layer in the optical composite film 61 to be measured to be parallel to the transmission axis of the polarizer 2 and the transmission axis of the analyzer 31. In an embodiment of the present application, referring to Figure 2 , the optical composite film component 6 to be measured further includes a second drive circuit 62, and the second drive circuit 62 is used to drive the optical composite film 61 to be measured to rotate;

[0109] The controller 5 is electrically connected to the second drive circuit 62, and is used to control the second drive circuit 62 to drive the optical composite film 61 to be measured to rotate when the optical composite film component 6 to be measured is disposed between the polarizer 2 and the analyzer 31, so that the transmission axis of the first film layer is parallel to the transmission axis of the polarizer 2 and the transmission axis of the analyzer 31.

[0110] In this embodiment, the optical composite film component 6 to be measured includes an optical composite film 61 to be measured and a second drive circuit 62. The input port of the second drive circuit 62 is connected to the controller 5, and the output port of the second drive circuit 62 is connected to the optical composite film 61 to be measured. Through such a design, the controller 5 can instruct the second drive circuit 62 to drive the optical composite film 61 to be measured to perform a rotation action.

[0111] The detection system adjusts the transmission axis of the first film layer in the optical composite film 61 to be parallel to the transmission axis of the polarizer 2 and the transmission axis of the analyzer 31, so as to detect the relative included angle between the first film layer and the second film layer subsequently.

[0112] Specifically, when the optical composite film component 6 to be measured is disposed between the polarizer 2 and the analyzer 31, the controller 5 controls the second drive circuit 62 to drive the optical composite film 61 to be measured to rotate. During the rotation of the optical composite film 61 to be measured, the positional relationship between the transmission axis of the first film layer and the transmission axis of the polarizer 2 affects the optical power value detected by the optical power meter 4. The second film layer adjusts the polarization state of the polarized light output by the first film layer. When the optical composite film 61 to be measured rotates and the position of the transmission axis of the analyzer 31 does not change, the light emitted by the second film layer does not affect the optical power value detected by the optical power meter 4.

[0113] Therefore, in this embodiment, only the positional relationship between the transmission axis of the first film layer and the transmission axis of the polarizer 2 affects the optical power value detected by the optical power meter 4. According to the optical power value and the rotation angle of the optical composite film 61 to be measured, the transmission axis of the first film layer is made parallel to the transmission axis of the polarizer 2 and the transmission axis of the analyzer 31.

[0114] Exemplarily, when the transmission axis of the first film layer in the optical composite film 61 to be measured is parallel to the transmission axes of the analyzer 31 and the polarizer 2, the optical power value detected by the optical power meter 4 is the highest. When the transmission axis of the first film layer in the optical composite film 61 to be measured is perpendicular to the transmission axes of the analyzer 31 and the polarizer 2, the optical power value detected by the optical power meter 4 is the lowest. In a specific example, when the optical composite film 61 to be measured rotates one week or rotates N weeks, according to the rotation angle corresponding to the highest optical power value detected by the optical power meter 4, the optical composite film 61 to be measured is adjusted so that the transmission axis of the first film layer in the optical composite film 61 is parallel to the transmission axes of the analyzer 31 and the polarizer 2.

[0115] After the transmission axis of the first film layer, the transmission axis of the polarizer 2, and the transmission axis of the analyzer 31 in the optical composite film 61 to be measured are adjusted to be parallel to each other through the detection system, at this time, the analyzer 31 is controlled to rotate, and according to the optical power value detected by the optical power meter 4 and the rotation angle of the analyzer 31, the major axis azimuth angle of the elliptically polarized light emitted from the second film layer is determined. In an embodiment of the present application, referring to Figure 2 , the controller 5 is connected to the first drive circuit 32, and is further configured to control the analyzer 31 to rotate in a state where the transmission axis of the first film layer, the transmission axis of the polarizer 2, and the transmission axis of the analyzer assembly 3 are parallel to each other, so as to determine the major axis azimuth angle of the elliptically polarized light emitted from the second film layer.

[0116] In this embodiment, when the linearly polarized light emitted from the first film layer passes through the second film layer, due to the existence of the phase difference, the emitted light is no longer linearly polarized, but becomes elliptically polarized light. The major axis direction (i.e., the azimuth angle) of the elliptically polarized light depends on the fast axis (or slow axis) direction of the second film layer and the polarization direction of the incident light. By rotating the analyzer 31 and measuring the change in optical power, the major axis direction of the elliptically polarized light can be found.

[0117] Specifically, since the polarization component intensities of the elliptically polarized light in different directions are different, when the transmission axis of the analyzer 31 is consistent with the major axis direction of the elliptically polarized light, the transmitted optical power will reach the maximum. By rotating the analyzer 31 and recording the change in optical power, and combining the rotation angle of the analyzer 31, the major axis direction of the elliptically polarized light can be determined. The rotation angle of the analyzer 31 is the angle between the major axis of the elliptically polarized light and the horizontal axis after passing through the second film layer, that is, the azimuth angle of the elliptically polarized light.

[0118] In an embodiment of the present application, a specific solution for making the transmission axis of the first film layer parallel to the transmission axes of the polarizer 2 and the analyzer 31 is provided.

[0119] Specifically, referring to Figure 3, the controller 5 includes a first acquisition module 51, a first data fitting module 52, a first determination module 53, and a first control module 54, and the first acquisition module 51, the first data fitting module 52, the first determination module 53, and the first control module 54 are electrically connected in sequence;

[0120] The first acquisition module 51 is configured to acquire a first set of power data sets obtained by the optical power meter 4 and the rotation angle set of the optical composite film 61 to be measured;

[0121] The first data fitting module 52 establishes a first mathematical model based on the first set of power data sets obtained by the optical power meter 4 and the rotation angle set of the optical composite film 61 to be measured;

[0122] The first determination module 53 uses the first mathematical model to obtain the rotation angle of the optical composite film 61 to be measured corresponding to the power eigenvalue;

[0123] The first control module 54 controls the rotation of the optical composite film 61 to be measured according to the rotation angle of the optical composite film 61 to be measured corresponding to the power eigenvalue, so that the transmission axis of the first film layer is parallel to the transmission axes of the polarizer 2 and the analyzer 31.

[0124] In this embodiment, in order to make the transmission axis of the first film layer parallel to the transmission axes of the polarizer 2 and the analyzer 31, mainly the controller 5 controls the second drive circuit 62 to drive the rotation of the optical composite film 61 to be measured. During the rotation of the optical composite film 61 to be measured, the optical power value detected by the optical power meter 4 also changes in real time. According to the optical power value and the rotation angle of the optical composite film 61 to be measured, the transmission axis of the first film layer is parallel to the transmission axes of the polarizer 2 and the analyzer 31.

[0125] Specifically, the first acquisition module 51 collects a first set of power data sets output by the optical power meter 4 and the rotation angle set of the optical composite film 61 to be measured recorded at the same time. Each power data in the first set of power data sets can be in one-to-one correspondence with a specific rotation angle in the rotation angle set of the optical composite film 61 to be measured.

[0126] The first data fitting module 52 constructs a first mathematical model based on these two sets of data sets. This model can reveal the relationship between the optical power value and the rotation angle of the optical composite film 61 to be measured.

[0127] Using the first determination module 53, according to this mathematical model, the specific rotation angle of the optical composite film 61 to be measured corresponding to the power eigenvalue (the maximum power value or the minimum power value) is determined.

[0128] The first control module 54 will precisely control the rotation of the optical composite film 61 to be measured according to this specific rotation angle, so as to ensure that the transmission axis of the first film layer is parallel to the transmission axes of the polarizer 2 and the analyzer 31.

[0129] In one example, the power eigenvalue is the minimum power. The first rotation angle of the optical composite film 61 to be measured corresponding to the minimum power value is obtained by using the first mathematical model. According to the first rotation angle of the optical composite film 61 corresponding to the minimum power, the transmission axis of the first film layer in the optical composite film 61 to be measured is controlled to be perpendicular to the transmission axis of the polarizer 2; then the optical composite film 61 to be measured is controlled to rotate 90°, so that the transmission axis of the first film layer is parallel to the transmission axes of the polarizer 2 and the analyzer 31.

[0130] In another example, the power eigenvalue is the maximum power. The second rotation angle of the optical composite film 61 to be measured corresponding to the maximum power value is obtained by using the first mathematical model. According to the second rotation angle of the optical composite film 61 corresponding to the maximum power, the transmission axis of the first film layer in the optical composite film 61 to be measured is directly controlled to be parallel to the transmission axes of the polarizer 2 and the analyzer 31.

[0131] Preferably, the power eigenvalue is the minimum power. Specifically, in the first mathematical model constructed by the optical power value and the rotation angle of the optical composite film 61 to be measured, it is more inclined to select the minimum power value as the key power eigenvalue. The reason is that on this power change curve, the point corresponding to the minimum power value is at the lowest point of the curve. It not only represents the lowest state of the optical power, but also in the actual detection process, such a lowest power point is often clearer, easier to capture and locate. Therefore, by identifying this minimum power value, the angle to which the optical composite film 61 to be measured needs to be rotated can be determined more precisely to ensure that the transmission axis of the first film layer is parallel to the transmission axes of the polarizer 2 and the analyzer 31.

[0132] In the embodiments of the present application, a scheme for specifically determining the major axis azimuth angle of the elliptically polarized light emitted by the second film layer is provided.

[0133] Specifically, referring to Figure 4 , the controller 5 includes a second acquisition module 55, a second data fitting module 56, a second determination module 57 and a second control module 58, and the second acquisition module 55, the second data fitting module 56, the second determination module 57 and the second control module 58 are electrically connected in sequence;

[0134] The second acquisition module 55 is used to acquire the second set of power data sets obtained by the optical power meter 4 and the analyzer 31 rotation angle set;

[0135] The second data fitting module 56 establishes a second mathematical model based on the second set of power data sets obtained by the optical power meter 4 and the rotation angle set of the analyzer 31;

[0136] The second determination module 57 uses the second mathematical model to obtain the rotation angle of the analyzer 31 corresponding to the maximum power;

[0137] The second control module 58 determines the major axis azimuth angle of the elliptically polarized light according to the rotation angle of the analyzer 31 corresponding to the maximum power.

[0138] In this embodiment, in order to determine the major axis azimuth angle of the elliptically polarized light emitted from the second film layer, mainly in the state where the transmission axis of the first film layer is parallel to the transmission axis of the polarizer 2, by controlling the rotation of the analyzer 31, since the polarization component intensities of the elliptically polarized light in different directions are different, during the rotation of the analyzer 31, when the polarization components of the elliptically polarized light in different directions (the light intensities of the polarization components in different directions are different) are consistent with the transmission axis direction of the analyzer 31, the optical power value detected by the optical power meter 4 will also change in real time (in special cases, the light emitted from the second film layer is circularly polarized light, and during the rotation of the analyzer 31, the optical power value detected by the optical power meter 4 remains unchanged). Based on the rotation angle of the analyzer 31 and the optical power value detected by the optical power meter 4, the major axis azimuth angle of the elliptically polarized light is determined.

[0139] Specifically, the second acquisition module 55 is responsible for collecting the second set of power data sets recorded by the optical power meter 4 and the rotation angle set generated during the rotation of the analyzer 31. Each power data in the second set of power data sets can be in one-to-one correspondence with a certain rotation angle in the rotation angle set of the analyzer 31.

[0140] The second data fitting module 56 constructs a second mathematical model based on the above-mentioned collected power data sets and rotation angle sets to describe the relationship between the optical power and the rotation angle of the analyzer 31.

[0141] The second determination module 57 uses this mathematical model to identify the rotation angle of the analyzer 31 corresponding to the maximum power. This angle reflects the included angle between the major axis direction of the elliptically polarized light and the initial position of the analyzer 31. That is to say, during the rotation of the analyzer 31, when the major axis of the elliptically polarized light emitted from the second film layer is consistent with the transmission axis direction of the analyzer 31, the power detected by the optical power meter 4 is the maximum power (the maximum power value detected by the optical power meter 4 during the rotation of the analyzer 31).

[0142] The second control module 58 finally determines the major axis azimuth angle of the elliptically polarized light according to the rotation angle of the analyzer 31 corresponding to the maximum power found by the second determination module.

[0143] After determining the major axis azimuth angle of the elliptically polarized light, the relative angle between the first film layer and the second film layer is determined according to the major axis azimuth angle of the elliptically polarized light. Specifically, in an embodiment of the present application, the controller 5 includes a judgment module (not shown in the figure), and the judgment module is used to judge whether the wavelength of the second film layer matches the wavelength of the light emitted by the light source 1.

[0144] The second film layer is described by taking the QWP film as an example. The performance of the QWP film is closely related to the wavelength of the incident light. For light waves of different wavelengths, the QWP film will exhibit different phase delay effects. In the QWP film, "quarter wavelength" means that the thickness of the film is equal to one quarter of the wavelength of the light wave when it propagates in the material. This wavelength usually refers to the wavelength of the incident light. The ratio of the thickness of the film to the refractive index determines the magnitude of the phase difference. When the phase difference is π / 2 (i.e., the phase difference corresponding to a quarter wavelength), the performance of the film is the best.

[0145] When the wavelength of the second film layer matches the wavelength of the light emitted by the light source 1, the relative angle between the transmission axis of the first film layer and the fast axis of the second film layer is equal to the major axis azimuth angle of the elliptically polarized light emitted by the second film layer. That is to say, when the wavelength of the second film layer matches the wavelength of the light emitted by the light source 1, the relative angle between the fast axis of the second film layer (QWP film) and the transmission axis of the first film layer (RP film) is equal to the major axis azimuth angle of the elliptically polarized light emitted by the second film layer. When the analyzer 31 is rotated through a full circle and the power measured by the optical power meter 4 does not change, it indicates that the emitted light is circularly polarized light, indicating that the relative angle between the fast axis of the second film layer (QWP film) and the transmission axis of the first film layer (RP film) is 45°.

[0146] When the wavelength of the second film layer does not match the wavelength of the light emitted by the light source 1, the relative angle θ between the transmission axis of the first film layer and the fast axis of the second film layer satisfies the following formula:

[0147]

[0148] where ψ is the major axis azimuth angle of the elliptically polarized light emitted by the second film layer, δ is the phase delay amount corresponding to the wavelength of the light emitted by the second film layer and the light source, in nm, and λ1 is the wavelength of the light emitted by the light source 1.

[0149] When the wavelength of the second film layer does not match the wavelength of the light emitted by the light source 1, the relative angle between the first film layer and the second film layer can be calculated according to the above formula.

[0150] In a specific embodiment, the optical composite film assembly 6 to be measured is located between the first film layer and the second film layer. The detection system sequentially includes, along the light transmission direction: a light source 1, a polarizer 2, the optical composite film 61 to be measured, an analyzer 31, and a optical power meter 4. The optical composite film 61 to be measured includes a first film layer and a second film layer, and the first film layer is closer to the polarizer 2 than the second film layer. Taking the first film layer as the RP film and the second film layer as the QWP film as an example:

[0151] During the light transmission process, the Stokes vector of the elliptically polarized light emitted after passing through the QWP film is calculated by the following formula (1):

[0152]

[0153] where θ is the angle between the fast axis of the QWP and the horizontal axis (i.e., the relative angle between the fast axis of the QWP and the RP transmission axis (the RP transmission axis is parallel to the transmission axes of the polarizer 2 and the analyzer 31)), φ is the phase retardation corresponding to the wavelength of the light emitted by the light source 1, and the unit of φ is °; M qwp is the general form of the Mueller matrix of the QWP, and M rp is the Mueller matrix of the horizontal polarizer.

[0154] The following formula (2) represents the relationship between the phase retardation corresponding to the wavelength of the light emitted by the light source 1 and the thickness of the QWP film and the wavelength of the light emitted by the light source 1:

[0155]

[0156] where φ is the phase retardation corresponding to the wavelength of the light emitted by the light source 1, the unit of φ is °, δ is the phase retardation corresponding to the wavelength of the light emitted by the light source and the second film layer, the unit of δ is nm, δ can be provided by the manufacturer or measured by a stress meter, and λ1 is the wavelength of the light emitted by the light source 1.

[0157] According to formula (1), the azimuth angle of the elliptically polarized light emitted after passing through the QWP is the following formula (3):

[0158]

[0159] where ψ is the azimuth angle of the major axis of the emitted elliptically polarized light, θ is the angle between the fast axis of the QWP and the horizontal axis (i.e., the relative angle between the fast axis of the QWP and the RP transmission axis), and φ is the phase retardation corresponding to the wavelength of the light emitted by the light source 1 and the QWP, and the unit of φ is °.

[0160] ① When the wavelength of the QWP matches the wavelength of the light emitted by the light source 1:

[0161]

[0162] cosφ = 0

[0163] It can be obtained that:

[0164] tan2ψ = tan2θ

[0165] θ = ψ

[0166] That is, the relative angle θ between the fast axis of the QWP and the transmission axis of the RP is equal to the major axis azimuth angle ψ of the outgoing elliptically polarized light. When the analyzer 31 is rotated through a full circle and the power measured by the optical power meter 4 does not change, it indicates that the outgoing light is circularly polarized light, indicating that the relative angle between the fast axis of the QWP and the transmission axis of the RP is 45°.

[0167] ② When the wavelength of the QWP does not match the wavelength of the light emitted by the light source 1:

[0168]

[0169] cosφtan 2ψtan 2 2θ - (1 - cosφ)tan 2θ + tan 2ψ = 0

[0170]

[0171] It can be obtained that the relative angle θ between the fast axis of the QWP and the transmission axis of the RP is:

[0172]

[0173] where ψ is the major axis azimuth angle of the outgoing elliptically polarized light, δ is the phase delay corresponding to the wavelength of the light emitted by the light source and the second film layer, with the unit of nm, and λ1 is the wavelength of the light emitted by the light source 1.

[0174] <Method Embodiment>

[0175] The present application also provides a method for detecting the relative angle of an optical composite film. The detection method is applied to the detection system for the relative angle of the optical composite film as described above. Referring to Figure 5 , the detection method includes step S5100:

[0176] S5100: In a state where the transmission axis of the first film layer is parallel to the transmission axis of the polarizer 2 and the transmission axis of the analyzer 31, control the analyzer 31 to rotate, determine the major axis azimuth angle of the elliptically polarized light emitted by the second film layer, and determine the relative angle between the first film layer and the second film layer according to the major axis azimuth angle of the elliptically polarized light.

[0177] In the embodiment of the present application, a detection method is provided for detecting the relative angle between the first film layer and the second film layer without changing the type of light source 1 and without tearing the film. Under the condition that the detection method meets specific conditions, the long-axis azimuth of the elliptically polarized light emitted by the second film layer is determined by the rotation angle of the analyzer 31 and the optical power value detected by the optical power meter 4. According to the long-axis azimuth of the elliptically polarized light, the relative angle between the first film layer and the second film layer is calculated by the controller 5. The detection method provided in the embodiment of the present application more easily realizes the detection of the relative angle between the first film layer and the second film layer. The detection method provided in the embodiment of the present application realizes low-cost detection.

[0178] In one embodiment of the present application, in order to achieve the state defined in step S5100: the state in which the transmission axis of the first film layer is parallel to the transmission axis of the polarizer 2 and the transmission axis of the analyzer 31, the following steps are specifically performed:

[0179] S5200: When the optical composite film assembly 6 to be tested is not disposed between the polarizer 2 and the analyzer 31, the transmission axis of the analyzer 31 and the transmission axis of the polarizer 2 are controlled to be parallel to each other. This step is a prerequisite for the whole detection method to proceed normally.

[0180] After completing step S5200, proceed to step S5300. Specifically, in step S5300, when the optical composite film assembly 6 to be tested is disposed between the polarizer 2 and the analyzer 31, control the transmission axis of the first film layer to be parallel to the transmission axis of the polarizer 2 and the transmission axis of the analyzer 31.

[0181] In one embodiment of the present application, step S5300: in a state where the optical composite film assembly 6 to be tested is disposed between the polarizer 2 and the analyzer 31, controlling the transmission axis of the first film layer to be parallel to the transmission axis of the polarizer 2 and the transmission axis of the analyzer 31 is specifically achieved by the following steps:

[0182] S5301: Acquire a first set of power data obtained by the optical power meter 4 and a set of rotation angles of the optical composite film 61 to be measured;

[0183] S5302: establishing a first mathematical model based on a first set of power data obtained by the optical power meter 4 and a set of rotation angles of the optical composite film 61 to be measured;

[0184] S5303: using the first mathematical model to obtain the rotation angle of the optical composite film 61 to be measured corresponding to the power characteristic value;

[0185] S5304: Control the rotation of the optical composite film 61 to be measured according to the rotation angle of the optical composite film 61 to be measured corresponding to the power eigenvalue, so that the transmission axis of the first film layer is parallel to the transmission axis of the polarizer 2 and the transmission axis of the analyzer 31.

[0186] In an embodiment of the present application, step S5303: The use of the first mathematical model to obtain the rotation angle of the optical composite film 61 to be measured corresponding to the power eigenvalue specifically includes:

[0187] S53031: Use the first mathematical model to obtain the first rotation angle of the optical composite film 61 to be measured corresponding to the minimum power value, and the minimum power value is the power eigenvalue.

[0188] In an embodiment of the present application, step S5304: The control of the rotation of the optical composite film 61 to be measured according to the rotation angle of the optical composite film 61 to be measured corresponding to the power eigenvalue, so that the transmission axis of the first film layer is parallel to the transmission axis of the polarizer 2 and the transmission axis of the analyzer 31, specifically includes:

[0189] S53041: According to the first rotation angle of the optical composite film 61 to be measured corresponding to the power eigenvalue, control the transmission axis of the first film layer to be perpendicular to the transmission axis of the polarizer 2;

[0190] S53042: Control the optical composite film 61 to be measured to rotate 90°, so that the transmission axis of the first film layer is parallel to the transmission axis of the polarizer 2 and the transmission axis of the analyzer 31.

[0191] In an embodiment of the present application, in order to implement a specific sub-step in step S5100: S5101: The control of the rotation of the analyzer 31 to determine the major axis azimuth angle of the elliptically polarized light emitted from the second film layer specifically includes:

[0192] S51011: Obtain the second set of power data sets obtained by the optical power meter 4 and the rotation angle set of the analyzer 31;

[0193] S51012: Based on the second set of power data sets obtained by the optical power meter 4 and the rotation angle set of the analyzer 31, establish a second mathematical model;

[0194] S51013: Use the second mathematical model to obtain the rotation angle of the analyzer 31 corresponding to the maximum power value;

[0195] S51014: Determine the major axis azimuth angle of the elliptically polarized light according to the rotation angle of the analyzer 31 corresponding to the maximum power value.

[0196] In an embodiment of the present application, to implement a specific sub-step in step S5100: S5102: Determining the relative angle between the first film layer and the second film layer according to the major axis azimuth angle of the elliptically polarized light includes:

[0197] S51021: When the wavelength of the second film layer is the same as the wavelength of the light emitted by the light source 1, the relative angle between the transmission axis of the first film layer and the fast axis of the second film layer is equal to the major axis azimuth angle of the elliptically polarized light emitted by the second film layer.

[0198] In an embodiment of the present application, to implement a specific sub-step in step S5100: S5102: Determining the relative angle between the first film layer and the second film layer according to the major axis azimuth angle of the elliptically polarized light includes:

[0199] S51022: When the wavelength of the second film layer does not match the wavelength of the light emitted by the light source 1, the relative angle θ between the transmission axis of the first film layer and the fast axis of the second film layer satisfies the following formula:

[0200]

[0201] where ψ is the major axis azimuth angle of the elliptically polarized light emitted by the second film layer, δ is the phase delay corresponding to the wavelength of the light emitted by the light source for the second film layer, with the unit of nm, and λ1 is the wavelength of the light emitted by the light source 1.

[0202] It should be noted that the specific implementation of the method for detecting the relative angle of the optical composite film in the embodiment of the present application can refer to the embodiments of the detection system for the relative angle of the optical composite film above. Therefore, it has at least all the beneficial effects brought by the technical solutions of the above embodiments, and will not be elaborated one by one here.

[0203] The embodiment of the present application also provides another detection system for the relative angle of the optical composite film. Referring to Figure 6 , in this detection system, the controller 5 includes a memory 71 and a processor 72. The memory 71 is used to store computer instructions, and the processor 72 is used to call the computer instructions from the memory to execute any method for detecting the relative angle of the optical composite film provided in the above method embodiments.

[0204] The present application also provides a computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, it implements any method for detecting the relative angle of the optical composite film provided in the above method embodiments.

[0205] This application can be a system, a method, and / or a computer program product. The computer program product can include a computer-readable storage medium having computer-readable program instructions thereon for causing a processor to implement various aspects of this application.

[0206] A computer-readable storage medium can be a tangible device that can retain and store instructions for use by an instruction execution device. A computer-readable storage medium may be, for example—but not limited to—an electrical storage device, a magnetic storage device, an optical storage device, an electromagnetic storage device, a semiconductor storage device, or any suitable combination of the foregoing. More specific examples (a non-exhaustive list) of the computer-readable storage medium include: a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or Flash memory), a static random access memory (SRAM), a portable compact disc read-only memory (CD-ROM), a digital versatile disc (DVD), a memory stick, a floppy disk, a mechanically encoded device such as a punch card or raised structures in a groove having instructions stored thereon, and any suitable combination of the foregoing. The computer-readable storage medium as used herein is not construed as a transitory signal per se, such as a radio wave or other freely propagating electromagnetic wave, an electromagnetic wave propagating through a waveguide or other transmission medium (e.g., an optical pulse through an optical fiber cable), or an electrical signal transmitted through a wire.

[0207] The computer-readable program instructions described herein can be downloaded to each computing / processing device from the computer-readable storage medium, or can be downloaded to an external computer or an external storage device through a network, such as the Internet, a local area network, a wide area network, and / or a wireless network. The network may include a copper transmission cable, an optical fiber transmission, a wireless transmission, a router, a firewall, a switch, a gateway computer, and / or an edge server. A network adapter card or network interface in each computing / processing device receives the computer-readable program instructions from the network and forwards the computer-readable program instructions for storage in a computer-readable storage medium in each computing / processing device.

[0208] The computer program instructions for performing the operations of the present application may be assembly instructions, instruction set architecture (ISA) instructions, machine instructions, machine-related instructions, microcode, firmware instructions, state setting data, or source code or object code written in any combination of one or more programming languages, including object-oriented programming languages such as Smalltalk, C++, etc., and conventional procedural programming languages such as the "C" language or similar programming languages. The computer-readable program instructions may be executed entirely on the user's computer, partially on the user's computer, executed as a stand-alone software package, partially on the user's computer and partially on a remote computer, or entirely on a remote computer or server. In the case of a remote computer, the remote computer may be connected to the user's computer through any type of network, including a local area network (LAN) or a wide area network (WAN), or may be connected to an external computer (e.g., by using an Internet service provider to connect through the Internet). In some embodiments, by using the state information of the computer-readable program instructions to customize an electronic circuit, such as a programmable logic circuit, a field-programmable gate array (FPGA), or a programmable logic array (PLA), the electronic circuit can execute the computer-readable program instructions to implement various aspects of the present application.

[0209] Aspects of the present application are described herein with reference to the flowchart and / or block diagram of a method, apparatus (system), and computer program product according to embodiments of the present application. It should be understood that each block of the flowchart and / or block diagram, and the combinations of blocks in the flowchart and / or block diagram, can be implemented by computer-readable program instructions.

[0210] These computer-readable program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing device, thereby producing a machine such that when these instructions are executed by the processor of the computer or other programmable data processing device, a device is produced that implements the functions / actions specified in one or more blocks of the flowchart and / or block diagram. These computer-readable program instructions can also be stored in a computer-readable storage medium, and these instructions cause the computer, programmable data processing device, and / or other devices to work in a specific manner. Thus, the computer-readable medium storing the instructions includes a manufactured article that includes instructions for implementing various aspects of the functions / actions specified in one or more blocks of the flowchart and / or block diagram.

[0211] Computer-readable program instructions may also be loaded onto a computer, other programmable data processing apparatus, or other devices to cause a series of operational steps to be performed on the computer, other programmable data processing apparatus, or other devices to produce a computer-implemented process such that the instructions executed on the computer, other programmable data processing apparatus, or other devices implement the functions / acts specified in one or more boxes of the flowchart and / or block diagram.

[0212] The flowcharts and block diagrams in the figures illustrate the architecture, functionality, and operation of possible implementations of systems, methods, and computer program products according to various embodiments of the present application. In this regard, each block in the flowchart or block diagram may represent a module, a segment of a program, or a portion of an instruction, which contains one or more executable instructions for implementing the specified logical function. In some alternative implementations, the functions noted in the blocks may occur out of the order noted in the figures. For example, two consecutive blocks may in fact be executed substantially in parallel, or they may sometimes be executed in the reverse order, depending on the functions involved. It should also be noted that each block of the block diagrams and / or flowcharts, and combinations of blocks in the block diagrams and / or flowcharts, can be implemented by a dedicated hardware-based system that performs the specified functions or acts, or by a combination of dedicated hardware and computer instructions. It is well known to those skilled in the art that implementation by hardware, implementation by software, and implementation by a combination of software and hardware are equivalent.

[0213] The embodiments of the present application have been described above. The above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments. The selection of the terms used herein is intended to best explain the principles of the embodiments, the practical application, or the improvement of technologies in the market, or to enable other ordinary skilled persons in the art to understand the embodiments disclosed herein. The scope of the present application is defined by the appended claims.

Claims

1. An optical composite film relative angle detection system, which successively includes along the light transmission direction: A light source, a polarizer, an analyzer assembly, and a optical power meter, and the detection system further includes a controller; wherein: The light source is configured to emit light of a single wavelength; The analyzer assembly includes an analyzer, and the analyzer is rotatable about the optical axis relative to the polarizer; A to-be-detected optical composite film assembly is disposed between the polarizer and the analyzer assembly. The to-be-detected optical composite film assembly includes a to-be-detected optical composite film, and the to-be-detected optical composite film is configured to be rotatable about the optical axis direction. The to-be-detected optical composite film includes a first film layer and a second film layer. The first film layer is closer to the polarizer than the second film layer. The first film layer is capable of selectively allowing polarized light to pass through, and the second film layer is capable of converting the polarization state of the polarized light; The controller is electrically connected to the optical power meter, the analyzer assembly, and the to-be-detected optical composite film assembly respectively, and is configured to control the rotation of the analyzer in a state where the transmission axis of the first film layer, the transmission axis of the polarizer, and the transmission axis of the analyzer are parallel to each other, determine the major axis azimuth angle of the elliptically polarized light emitted from the second film layer, and determine the relative included angle between the first film layer and the second film layer according to the major axis azimuth angle of the elliptically polarized light.

2. The detection system according to claim 1, wherein The analyzer assembly further includes a first driving circuit, and the first driving circuit is configured to drive the analyzer to rotate; The controller is electrically connected to the first driving circuit, and is configured to control the first driving circuit to drive the analyzer to rotate in a state where the to-be-detected optical composite film assembly is not disposed between the polarizer and the analyzer, so that the transmission axis of the polarizer and the transmission axis of the analyzer are parallel.

3. The detection system according to claim 2, wherein, The controller is connected to the first driving circuit, and is further configured to control the rotation of the analyzer in a state where the transmission axis of the first film layer, the transmission axis of the polarizer, and the transmission axis of the analyzer assembly are parallel to each other, and determine the major axis azimuth angle of the elliptically polarized light emitted from the second film layer.

4. The detection system according to claim 1, wherein The to-be-detected optical composite film assembly further includes a second driving circuit, and the second driving circuit is configured to drive the to-be-detected optical composite film to rotate; The controller is electrically connected to the second driving circuit, and is configured to control the second driving circuit to drive the to-be-detected optical composite film to rotate in a state where the to-be-detected optical composite film assembly is disposed between the polarizer and the analyzer, so that the transmission axis of the first film layer, the transmission axis of the polarizer, and the transmission axis of the analyzer are parallel to each other.

5. The detection system according to claim 1, characterized in that The controller includes a first acquisition module, a first data fitting module, a first determination module, and a first control module, and the first acquisition module, the first data fitting module, the first determination module, and the first control module are electrically connected in sequence; The first acquisition module is configured to acquire a first set of power data sets obtained by the optical power meter and the rotation angle set of the to-be-detected optical composite film; The first data fitting module establishes a first mathematical model based on the first set of power data sets obtained by the optical power meter and the rotation angle set of the to-be-detected optical composite film; The first determination module obtains the rotation angle of the to-be-detected optical composite film corresponding to the power eigenvalue by using the first mathematical model; The first control module controls the rotation of the optical composite film to be measured according to the rotation angle of the optical composite film to be measured corresponding to the power eigenvalue, so that the transmission axis of the first film layer is parallel to the transmission axis of the polarizer and the transmission axis of the analyzer.

6. The detection system according to claim 1, wherein The controller includes a second acquisition module, a second data fitting module, a second determination module, and a second control module, and the second acquisition module, the second data fitting module, the second determination module, and the second control module are electrically connected in sequence; The second acquisition module is used to acquire a second set of power data sets obtained by the optical power meter and the analyzer rotation angle set; The second data fitting module establishes a second mathematical model based on the second set of power data sets obtained by the optical power meter and the analyzer rotation angle set; The second determination module uses the second mathematical model to obtain the rotation angle of the analyzer corresponding to the maximum power; The second control module determines the major axis azimuth angle of the elliptically polarized light according to the rotation angle of the analyzer corresponding to the maximum power.

7. The detection system for the relative included angle of the optical composite film according to claim 1, characterized in that, The controller includes a judgment module, and the judgment module is used to judge whether the wavelength of the second film layer matches the wavelength of the light emitted by the light source; When the wavelength of the second film layer matches the wavelength of the light emitted by the light source, the relative angle between the transmission axis of the first film layer and the fast axis of the second film layer is equal to the major axis azimuth angle of the elliptically polarized light emitted by the second film layer; When the wavelength of the second film layer does not match the wavelength of the light emitted by the light source, the relative angle θ between the transmission axis of the first film layer and the fast axis of the second film layer satisfies the following formula: where ψ is the major axis azimuth angle of the elliptically polarized light emitted by the second film layer, δ is the phase delay amount corresponding to the wavelength of the light emitted by the second film layer and the light source, the unit is nm, and λ1 is the wavelength of the light emitted by the light source.

8. A method for detecting the relative included angle of an optical composite film, characterized in that, Applied to the detection system for the relative angle of the optical composite film according to any one of claims 1-7, including: In a state where the transmission axis of the first film layer is parallel to the transmission axis of the polarizer and the transmission axis of the analyzer, the analyzer is controlled to rotate, the major axis azimuth angle of the elliptically polarized light emitted by the second film layer is determined, and the relative angle between the first film layer and the second film layer is determined according to the major axis azimuth angle of the elliptically polarized light.

9. The detection method according to claim 8, wherein The transmission axis of the first film layer being parallel to the transmission axis of the polarizer and the transmission axis of the analyzer includes: In a state where the optical composite film component to be measured is not provided between the polarizer and the analyzer, the transmission axis of the analyzer and the transmission axis of the polarizer are controlled to be parallel to each other; In a state where the optical composite film component to be measured is provided between the polarizer and the analyzer, the transmission axis of the first film layer is controlled to be parallel to the transmission axis of the polarizer and the transmission axis of the analyzer.

10. The detection method according to claim 9, characterized in that, In a state where the optical composite film component to be measured is provided between the polarizer and the analyzer, controlling the transmission axis of the first film layer to be parallel to the transmission axis of the polarizer and the transmission axis of the analyzer includes: Obtain the first set of power data sets obtained by the optical power meter and the rotation angle set of the optical composite film to be measured; Based on the first set of power data sets obtained by the optical power meter and the rotation angle set of the optical composite film to be measured, establish a first mathematical model; Use the first mathematical model to obtain the rotation angle of the optical composite film to be measured corresponding to the power eigenvalue; According to the rotation angle of the optical composite film to be measured corresponding to the power eigenvalue, control the rotation of the optical composite film to be measured so that the transmission axis of the first film layer is parallel to the transmission axes of the polarizer and the analyzer; 11. The detection method according to claim 10, wherein The using the first mathematical model to obtain the rotation angle of the optical composite film to be measured corresponding to the power eigenvalue includes: Use the first mathematical model to obtain the first rotation angle of the optical composite film to be measured corresponding to the minimum power value, and the minimum power value is the power eigenvalue; 12. The detection method according to claim 11, wherein The controlling the rotation of the optical composite film to be measured according to the rotation angle of the optical composite film to be measured corresponding to the power eigenvalue so that the transmission axis of the first film layer is parallel to the transmission axes of the polarizer and the analyzer includes: According to the first rotation angle of the optical composite film to be measured corresponding to the power eigenvalue, control the transmission axis of the first film layer to be perpendicular to the transmission axis of the polarizer; Control the rotation of the optical composite film to be measured by 90° so that the transmission axis of the first film layer is parallel to the transmission axes of the polarizer and the analyzer; 13. The detection method according to claim 8, wherein The controlling the rotation of the analyzer to determine the major axis azimuth angle of the elliptically polarized light emitted by the second film layer includes: Obtain the second set of power data sets obtained by the optical power meter and the rotation angle set of the analyzer; Based on the second set of power data sets obtained by the optical power meter and the rotation angle set of the analyzer, establish a second mathematical model; Use the second mathematical model to obtain the rotation angle of the analyzer corresponding to the power maximum value; Determine the major axis azimuth angle of the elliptically polarized light according to the rotation angle of the analyzer corresponding to the power maximum value; 14. The detection method according to claim 8, characterized in that, The determining the relative angle between the first film layer and the second film layer according to the major axis azimuth angle of the elliptically polarized light includes: When the wavelength of the second film layer matches the wavelength of the light emitted by the light source, the relative angle between the transmission axis of the first film layer and the fast axis of the second film layer is equal to the major axis azimuth angle of the elliptically polarized light emitted by the second film layer; 15. The detection method according to claim 8, wherein, The determining the relative angle between the first film layer and the second film layer according to the major axis azimuth angle of the elliptically polarized light includes: When the wavelength of the second film layer does not match the wavelength of the light emitted by the light source, the relative angle θ between the transmission axis of the first film layer and the fast axis of the second film layer satisfies the following formula: where ψ is the major axis azimuth angle of the elliptically polarized light emitted by the second film layer, δ is the phase delay corresponding to the wavelength of the light emitted by the second film layer and the light source, with the unit of nm, and λ1 is the wavelength of the light emitted by the light source.

16. A detection system for the relative included angle of an optical composite film, characterized in that, The controller includes a memory and a processor. The memory is used to store computer instructions, and the processor is used to call the computer instructions from the memory to execute the method according to any one of claims 8-15.

17. A computer-readable storage medium, on which a computer program is stored, and the computer program realizes the method according to any one of claims 8-15 when being executed by a processor.

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