CN117213803A

CN117213803A - Detection method and detection system for relative included angle of optical composite film

Info

Publication number: CN117213803A
Application number: CN202311118706.3A
Authority: CN
Inventors: 范宇华; 孙文强; 蔡云峰; 廖吉仁; 金成滨
Original assignee: Goertek Optical Technology Co Ltd
Current assignee: Goertek Optical Technology Co Ltd
Priority date: 2023-08-31
Filing date: 2023-08-31
Publication date: 2023-12-12

Abstract

The embodiment of the application provides a method and a system for detecting a relative included angle of an optical composite film. The method for detecting the relative included angle of the optical composite film is applied to a detection system of the relative included angle of the optical composite film, and the detection system comprises: the optical composite film comprises a first film layer and a second film layer, and the first film layer is arranged close to the light source assembly relative to the second film layer under the condition that the optical composite film is rotatably arranged between the light source assembly and the detection assembly; controlling linearly polarized light of a plurality of view fields to be projected to a detection assembly through an optical composite film; acquiring a straight-edge angle of the optical composite film; acquiring an optical axis angle of the first film layer according to the straight edge angle and the power data measured by the detection assembly; acquiring an optical axis angle of the second film layer according to the optical parameters measured by the detection component; and acquiring a relative included angle of the optical composite film according to the optical axis angle of the first film and the optical axis angle of the second film.

Description

Detection method and detection system for relative included angle of optical composite film

Technical Field

The embodiment of the application relates to the technical field of optical composite film detection, in particular to a detection method and a detection system for a relative included angle of an optical composite film.

Background

Currently, in the field of VR folded optical paths (Pancake), compounding two or more optical films together is a common way of applying films. The composite film-attaching method such as the reflective polarizing film and the phase retardation film is a commonly used film-attaching method. Wherein a slight angle difference of the relative angles of the transmission axis of the reflective polarizing film and the fast axis or slow axis of the phase retarder film will seriously affect the imaging effect. It is therefore necessary to detect the relative angle between two or more optical composite films.

In the prior art, two methods are generally used for detecting the relative included angle of the optical composite film. The first is to detect the relative included angle of the optical composite film by using a polarimeter, but the detection cost is higher by using the polarimeter; the second is a detection scheme adopting a destructive film tearing mode, and the detection scheme is suitable for spot inspection after lens film sticking and film sticking calibration in the research and development stage, and cannot be applied to mass production of a production line.

Therefore, the application provides a detection scheme without tearing films under the condition of reducing the detection cost.

Disclosure of Invention

The application aims to provide a method for detecting a relative included angle of an optical composite film and a novel technical scheme of a detection system.

In a first aspect, the present application provides a method for detecting a relative angle of an optical composite film. Detection system for be applied to optical composite film relative contained angle, detection system includes: the device comprises a light source assembly and a detection assembly, wherein an optical composite film to be detected is arranged between the light source assembly and the detection assembly, the optical composite film comprises a first film layer and a 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;

the first film layer is arranged close to the light source assembly relative to the second film layer under the condition that the optical composite film is rotatably arranged between the light source assembly and the detection assembly;

the detection method comprises the following steps:

controlling linearly polarized light of a plurality of fields of view to be projected to the detection assembly through the optical composite film;

obtaining a straight edge angle of the optical composite film, wherein the straight edge angle is as follows: the included angle between the straight edge of the optical composite film and a datum line is a coordinate axis in the vertical direction in a visual camera coordinate system;

acquiring an optical axis angle of the first film layer according to the straight edge angle and the power data measured by the detection assembly;

Acquiring an optical axis angle of the second film layer according to the optical parameters measured by the detection component;

and acquiring the relative included angle of the optical composite film according to the optical axis angle of the first film and the optical axis angle of the second film.

Optionally, the obtaining the optical axis angle of the first film layer according to the power data measured by the detection component and the straight edge angle of the optical composite film specifically includes:

and establishing a mathematical model by data fitting based on the power data measured by the detection assembly and the straight edge angle of the optical composite film, wherein the straight edge angle of the optical composite film corresponding to the minimum value of the power data obtained by utilizing the mathematical model is the angle of the optical axis of the first film layer.

Optionally, the detection assembly includes: the optical composite film is positioned between the light source component and the phase delay element, and the phase delay element rotates at angular frequency omega;

according to the optical parameters measured by the detection component, the obtaining the optical axis angle of the second film layer specifically comprises:

obtaining polarization parameters of the light emitted by the optical composite film according to the light intensity of the light emitted by the polarizer, which is measured by the detection module;

And acquiring the optical axis angle of the second film layer according to the polarization parameters of the emergent light of the optical composite film and the straight-edge angle.

Optionally, the detection assembly includes: the optical composite film is positioned between the light source component and the analyzer;

according to the change of the power data measured by the optical power meter along with the rotation angle of the analyzer, a data model between the power data and the rotation angle is established, and the rotation angle of the analyzer corresponding to the power data as an extremum is calculated;

and acquiring the optical axis angle of the second film layer according to the rotation angle of the analyzer.

Optionally, the light source component includes a laser, and a wavelength of light emitted by the laser is matched with a wavelength corresponding to the second film layer.

Optionally, the first film layer is a reflective polarizing film or a polarizing film, and the second film layer is a phase retardation film.

Optionally, the phase retarder is a quarter wave plate, and the polarizer is a horizontal linear polarizer.

Optionally, according to the light intensity of the light emitted by the polarizer measured by the detection module, the obtaining the polarization parameter of the light emitted by the optical composite film specifically includes:

when the included angle between the fast axis of the phase delay element and the horizontal direction is alpha, the intensity of the outgoing light of the polarizer is obtained, wherein alpha=ωt, and t is the rotation time of the phase delay element;

according to the intensity of the light emitted by the polarizer, acquiring a Stokes vector of the light emitted by the optical composite film;

and obtaining the polarization parameters of the emergent light of the optical composite film according to the Stokes vector of the emergent light of the optical composite film.

Optionally, according to the intensity of the light emitted by the polarizer, obtaining the stokes vector of the light emitted by the optical composite film specifically includes:

acquiring a relation model existing between the intensity of the light emitted by the polarizer and the Stokes vector of the light emitted by the optical composite film;

performing Fourier transform on the relation model, and acquiring the Fourier transform coefficient according to the intensity of the emergent light of the polarizer;

and acquiring a Stokes vector of the emergent light of the optical composite film according to the Fourier transform coefficient.

Optionally, the obtaining a relation model existing between the intensity of the polarizer emergent ray and the stokes vector of the optical composite film emergent ray specifically includes:

setting a Stokes vector of the emergent light of the optical composite film as Sm;

obtaining Stokes vector S of the light emitted by the phase delay element according to the Stokes vector Sm ^′ ；

According to the Stokes vector S ^′ Acquiring a Stokes vector Sout of the light rays emitted by the polarizer;

and obtaining a relation model existing between the intensity of the polarizer emergent ray and the Stokes vector of the optical composite film emergent ray according to the Stokes vector Sout.

Optionally, a stokes vector S of the light rays emitted by the phase delay element is obtained according to the stokes vector Sm ^′ The method specifically comprises the following steps:

obtaining a Stokes vector S of light rays emitted by the phase delay element according to the Stokes vector Sm and the Mueller matrix of the phase delay element with an included angle alpha between a fast axis and a horizontal direction ^′ 。

Optionally, according to the Stokes vector S ^′ The obtaining the stokes vector Sout of the outgoing light ray of the polarizer specifically includes:

According to the Stokes vector S ^′ And the Mueller matrix of the polarizer, obtaining the Stokes vector Sout of the outgoing light of the polarizer.

Optionally, the rotation of the phase delay element at an angular frequency ω specifically includes:

the phase delay element is driven to rotate at an angular frequency ω by a stepper motor having steps n, steps aj, α=ωt=n×aj.

In a second aspect, a system for detecting a relative angle of an optical composite film is provided. The detection system includes: a light source assembly and a detection assembly;

the light source component is used for emitting linearly polarized light of a plurality of view fields;

the detection component is used for detecting the relative included angle of the optical composite film to be detected;

when the optical composite film to be tested is arranged between the light source component and the detection component, the optical composite film and the detection component are arranged along the same optical axis.

Optionally, the detection assembly includes: the phase delay element rotates at an angular frequency omega;

when the optical composite film to be measured is placed between the light source component and the phase delay element, the optical composite film, the phase delay element, the polarizer and the detection module are sequentially arranged along the same optical axis.

Optionally, the detection assembly includes: an analyzer and an optical power meter;

when the optical composite film to be measured is placed between the light source component and the analyzer, the optical composite film, the analyzer and the optical power meter are sequentially arranged along the same optical axis.

Optionally, the light source assembly includes: a light source, a quick reflector, a lens group and a polarizer, wherein the lens group comprises at least one lens;

light rays emitted by the light source are projected to the optical composite film to be tested through the quick reflector, the lens group and the polarizer in sequence.

Optionally, a stepper motor is also included, which drives the phase delay element to rotate at an angular frequency ω.

In the technical scheme provided by the embodiment of the application, the optical axis angle of the first film layer is determined through the power data measured by the detection component and the straight edge angle of the optical composite film shot by the visual camera; determining the optical axis angle of the second film layer according to the optical parameters measured by the detection component; and determining the relative included angle of the optical composite film according to the optical axis angle of the first film layer and the optical axis angle of the second film layer. The detection method for the relative included angle of the optical composite film, provided by the embodiment of the application, avoids the detection of the destructive film tearing under the condition of reducing the cost, and can be applied to a production line.

Other features of the present specification and its advantages will become apparent from the following detailed description of exemplary embodiments thereof, which proceeds with reference to the accompanying drawings.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the specification and together with the description, serve to explain the principles of the specification.

Fig. 1 is a diagram illustrating a first structure of a system for detecting a relative angle of an optical composite film according to an embodiment of the present application.

Fig. 2 is a diagram showing a second structure of a system for detecting a relative angle of an optical composite film according to an embodiment of the present application.

Reference numerals illustrate:

1. a light source assembly; 10. a light source; 11. a fast mirror; 12. a first lens; 13. a second lens; 14. a polarizer;

2. an optical composite film to be measured; 3. a phase delay element; 4. a polarizer; 5. a detection module; 6. a vision camera; 7. an analyzer; 8. an optical power meter.

Detailed Description

Various exemplary embodiments of the present application will now be described in detail with reference to the accompanying drawings. It should be noted that: the relative arrangement of the components and steps, numerical expressions and numerical values set forth in these embodiments do not limit the scope of the present application unless it is specifically stated otherwise.

The following description of at least one exemplary embodiment is merely exemplary in nature and is in no way intended to limit the application, its application, or uses.

Techniques and equipment known to those of ordinary skill in the relevant art may not be discussed in detail, but should be considered part of the specification where appropriate.

In all examples shown and discussed herein, any specific values should be construed as merely illustrative, and not a limitation. Thus, other examples of exemplary embodiments may have different values.

It should be noted that: like reference numerals and letters denote like items in the following figures, and thus once an item is defined in one figure, no further discussion thereof is necessary in subsequent figures.

VR optical composite films are typically film layers formed by compositing together any two of a polarizing film (POL film), a reflective polarizing film (RP film), and a phase retardation film (QWP film). In which a polarizing film (POL film) and a quarter wave plate (QWP film) are generally combined or a reflective polarizing film (RP film) and a phase retardation film (QWP film) are combined. The VR optics complex film combines with the lens group and constitutes the optical module that has folding light path, and wherein the imaging quality of optical module can receive the influence of optics complex film relative angle, and slight angle difference will seriously influence imaging effect, still can influence user's experience effect and eye's comfort level. Thus, detection of the relative angle of the optical composite film is necessary.

At present, two methods for detecting the relative included angle of the optical composite film exist. The first is to detect the relative included angle of the optical composite film by using a polarimeter, and the second is to detect the relative included angle of the optical composite film by using a destructive film tearing mode.

The optical axis angle information and the relative included angle can be obtained by detecting the relative included angle of the optical composite film through the polarimeter by utilizing the known Stokes vector in a detection light path and the light intensity detected by the detector and detecting the unknown polarized film Mueller matrix by combining a Fourier analysis method.

The detection scheme is suitable for spot inspection after lens film pasting and film pasting calibration in research and development stages, and cannot be applied to mass production of production lines.

Based on the technical problems, the embodiment of the application provides a novel method and a system for detecting the relative included angle of an optical composite film, which can detect the relative included angle of the optical composite film without tearing the film under the condition of reducing the cost. Specifically, the method for detecting the relative included angle of the optical composite film provided by the embodiment of the application is suitable for detecting the optical composite film formed by compositing two or more film layers together.

The method and system for detecting the relative included angle of the optical composite film according to the embodiments of the present application are described in detail below with reference to the accompanying drawings.

According to one embodiment of the application, a method for detecting a relative included angle of an optical composite film is provided. The detection method is applied to a detection system of the relative included angle of the optical composite film. The detection system of the relative included angle of the optical composite film comprises: the light source assembly 1 and the detection assembly are used for arranging an optical composite film 2 to be detected between the light source assembly 1 and the detection assembly, the optical composite film 2 to be detected comprises a first film layer and a 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.

Wherein the light source assembly 1 is adapted to emit linearly polarized light of a plurality of fields of view. The detection component is used for detecting the optical axis angle of a first film layer in the optical composite film and the optical axis angle of a second film layer in the optical composite film, and acquiring the relative included angle of the optical composite film according to the optical axis angle of the first film layer and the optical axis angle of the second film layer.

Wherein the optical composite film includes a first film layer, which may be a reflective polarizing film (RP film) or a polarizing film (POL film), and a second film layer, which may be a phase retardation film (QWP film). For example, the second film layer may be a quarter-phase retarder film.

In the case where the optical composite film 2 to be measured is rotatably disposed between the light source module 1 and the detection module, the first film layer is disposed close to the light source module 1 with respect to the second film layer. Specifically, under the condition that the optical composite film is arranged between the light source assembly 1 and the detection assembly, linearly polarized light emitted by the light source assembly 1 passes through the first film layer and is projected to the detection assembly through the second film layer.

The method for detecting the relative included angle of the optical composite film comprises the following steps:

step 1: controlling linearly polarized light of a plurality of fields of view to be projected to the detection assembly through the optical composite film;

step 2: obtaining a straight edge angle of the optical composite film, wherein the straight edge angle is as follows: the included angle between the straight edge of the optical composite film and a datum line is a coordinate axis in the vertical direction in a visual camera coordinate system;

step 3: acquiring an optical axis angle of the first film layer according to the straight edge angle and the power data measured by the detection assembly;

Step 4: acquiring an optical axis angle of the second film layer according to the optical parameters measured by the detection component;

step 5: and acquiring the relative included angle of the optical composite film according to the optical axis angle of the first film and the optical axis angle of the second film.

In step 1, linearly polarized light of a plurality of fields of view is controlled to pass through the optical composite film 2 to be tested and the detection assembly. For example, the light source assembly 1 emits linearly polarized light with multiple fields of view, and the linearly polarized light with multiple fields of view is finally received by the detection assembly after passing through the optical composite film 2 to be detected.

In a specific embodiment, the optical composite film includes an RP film and a QWP film. The light source component generates linearly polarized light with a plurality of fields of view, so that the linearly polarized light with the plurality of fields of view passes through the RP film and the QWP film in sequence and is finally received by the detection component. Wherein the optical composite film is rotatably disposed between the light source module 1 and the detection module. For example, the optical composite film is rotated by an electric wheel.

Or in another embodiment, the optical composite film includes a POL film and a QWP film. The light source component generates linearly polarized light with a plurality of fields of view, so that the linearly polarized light with the plurality of fields of view passes through the POL film and the QWP film in sequence and is finally received by the detection component. Wherein the optical composite film is rotatably disposed between the light source module 1 and the detection module. For example, the optical composite film is rotated by an electric wheel.

In the embodiments of the present application, an optical composite film is exemplified as an RP film and a QWP film.

In one example, referring to fig. 1, the detection assembly includes a phase delay element 3, a polarizer 4, and a detection module 5, wherein the phase delay element 3 rotates at an angular frequency ω. The linearly polarized light controlling the plurality of fields of view is projected to the detection module 5 through the RP film, the QWP film, the phase retardation element 3, and the polarizer 4 in this order. For example, the light source module 1 emits linearly polarized light of a plurality of fields, and the linearly polarized light of a plurality of fields sequentially passes through the RP film, the QWP film, the phase delay element 3 rotated at the angular frequency ω, and the polarizer 4, and is finally received by the detection module 5. For example, the detection module 5 may be a CCD camera.

In another example, referring to fig. 2, the detection assembly includes an analyzer 7 and an optical power meter 8. Linearly polarized light controlling a plurality of fields of view is projected to the optical power meter 8 through the RP film, the QWP film, and the analyzer 7 in this order. For example, the light source unit 1 emits linearly polarized light of a plurality of fields, and the linearly polarized light of a plurality of fields sequentially passes through the RP film, the QWP film, and the analyzer 7, and is finally received by the optical power meter 8.

In step 2, obtaining a straight edge angle of the optical composite film, wherein the straight edge angle is as follows: the included angle between the straight edge of the optical composite film and a datum line is a coordinate axis in the vertical direction in a visual camera coordinate system;

In this step, the angle between the straight-side section of the optical composite film and the vertical direction coordinate axis determined by the coordinates of the vision camera 6 itself is obtained by the vision camera 6.

In a specific embodiment, a surface light source is provided, the surface light source shines on the side edge of the optical composite film, the vision camera 6 shoots the straight edge section of the optical composite film, and the included angle between the straight edge section of the optical composite film and the vertical coordinate axis determined by the self coordinates of the vision camera 6 is obtained. For example, the optical composite film comprises a first film layer and a second film layer, the first film layer and the second film layer are attached together, and the straight edge section of the first film layer and the straight edge section of the second film layer are attached together to form the straight edge section of the optical composite film.

Specifically, after the POL film, the RP film, and the QWP film are fed, each of the POL film, the RP film, and the QWP film includes an arc portion and a straight edge section connected to the arc portion. Wherein the straight edge segments may be formed by cutting, for example by cutting a circular film, to form an optical film having straight edge segments. The optical films having the straight edge sections are compounded together to form an optical composite film having the straight edge sections.

The optical composite film 2 to be tested is rotatably arranged between the light source component and the detection component, and the straight edge section of the optical composite film rotates along with the optical composite film in the rotation process of the optical composite film, so that the straight edge angle of the optical composite film acquired by the optical camera 6 also changes in real time. For example, based on rotation of the light source composite film, the straight edge angle of the optical composite film may be regularly tapered or tapered, or the straight edge angle of the optical composite film may be irregularly changed.

In step 3, the optical axis angle of the first film layer is obtained according to the straight edge angle and the power data measured by the detection component. For example, the straight edge angle of the optical composite film is obtained through the vision camera 6, meanwhile, the power data of the emergent light rays of the optical composite film are measured through the detection assembly, and the straight edge angle of the first film layer is obtained according to the straight edge angle and the power data.

Specifically, in the process that the optical composite film rotates between the light source component 1 and the detection component, the vision camera 6 and the detection component work synchronously, the straight-edge angle of the optical composite film is obtained through the vision camera 6, and meanwhile, the power data of the emergent light rays of the optical composite film are measured through the detection component.

It should be noted that, in the embodiment of the present application, the setting positions of the first film layer and the second film layer are defined, the linearly polarized light emitted from the light source assembly needs to pass through the first film layer and then pass through the second film layer, where the first film layer can selectively allow a certain polarized light to pass through, and the second film layer can change the polarization state of the polarized light. Therefore, after the linearly polarized light emitted from the light source assembly passes through the first film layer, the power of the polarized light is not changed, and the power data measured by the detection assembly is the power of the polarized light emitted from the first film layer.

For example, referring to fig. 1, in one example, the detection assembly includes a phase delay element, 3, a polarizer 4, and a detection module 5, and the detection module 5 may be a CCD camera. The linearly polarized light emitted from the light source assembly passes through the RP film and then sequentially passes through the QWP film, the phase delay element 3, the polarizer 4 and the detection module 5, wherein the power of the polarized light emitted from the RP film is identical to the power of the polarized light emitted from the QWP film, the power of the polarized light emitted from the phase delay element and the power of the polarized light emitted from the polarizer, that is, the power of the emitted light detected by the CCD camera is also the power of the polarized light emitted from the RP film.

Or in another example, referring to fig. 2, the detection assembly includes an analyzer 7 and an optical power meter 8. The linearly polarized light emitted from the light source assembly passes through the RP film and then sequentially passes through the QWP film, the analyzer 7 and the optical power meter 8, wherein the power of the polarized light emitted from the RP film is identical to the power of the polarized light emitted from the QWP film and the power of the polarized light emitted from the analyzer 7, that is, the power of the emitted light detected by the optical power meter 8 is also the power of the polarized light emitted from the RP film.

In this step, the optical axis angle of the first film layer is obtained based on the straight edge angle and the power data measured by the detection assembly. Specifically, a curve is fitted by using the detected power data and the straight-edge angle data, and the straight-edge angle corresponding to the minimum value of the detected optical power is the angle of the optical axis of the first film layer.

In a specific example, a mathematical model is established by data fitting based on the power data measured by the detection component and the straight edge angle of the optical composite film, and the straight edge angle of the optical composite film corresponding to the minimum value of the power data obtained by using the mathematical model is the angle of the optical axis of the first film layer.

In the process of rotating the optical composite film, the detection component measures multiple sets of power data in real time, the vision camera 6 measures multiple sets of straight edge angles in real time, multiple sets of power data and multiple sets of straight edge angles are fitted to establish a mathematical model, and the mathematical model established by fitting the multiple sets of power data and the multiple sets of straight edge angles accords with a parabolic equation. Substituting the minimum value of the power data into the mathematical model, wherein the straight-edge angle of the corresponding optical composite film is the angle of the optical axis of the first film layer.

In a specific embodiment, referring to fig. 1, the detection assembly includes a phase delay element, 3, a polarizer 4, and a detection module 5, and the detection module 5 may be a CCD camera. When the RP transmission axis angle is detected, the optical composite film 2 (RP+QWP) to be detected is rotated, the power of emergent light is detected through a CCD camera, and meanwhile, the optical camera shoots, so that an included angle between the straight edge of the optical composite film 2 to be detected and the vertical direction determined by the self coordinates of the camera is given. Fitting a curve by using the detected power data and the straight-edge angle data, wherein the straight-edge angle corresponding to the minimum value of the detected optical power is the deviation angle of the actual value of the RP transmission axis relative to the ideal value, namely the optical axis angle of the RP film.

In another specific embodiment, referring to fig. 2, the detection assembly includes an analyzer 7 and an optical power meter 8. When the RP transmission axis angle is detected, the analyzer 7 is rotated to adjust the transmission axis direction of the analyzer 7 to be parallel to the polarizer transmission axis direction. And rotating the optical composite film to be tested, detecting the power of emergent light by an optical power meter, and shooting by a visual camera to obtain an included angle between the straight edge of the optical composite film to be tested and the vertical direction determined by the self coordinates of the camera. Fitting a curve by using the detected power data and the straight-edge angle data, wherein the straight-edge angle corresponding to the minimum value of the detected optical power is the deviation angle of the actual value of the RP transmission axis relative to the ideal value, namely the optical axis angle of the RP film.

In step 4, the optical axis angle of the second film layer is obtained according to the optical parameter measured by the detection component.

In this step, the optical axis angle of the second film layer is obtained according to the optical parameter measured by the detection component. For example, according to the detection components with different combinations, different optical parameters are measured, and then according to the measured optical parameters, the optical axis angle of the second film layer is obtained.

In one example, referring to fig. 1, the detection assembly includes a phase retardation element, 3, a polarizer 4, and a detection module 5, which are sequentially disposed, with an optical composite film between the light source assembly and the phase retardation element, which rotates at an angular frequency ω.

In this example, the optical axis angle of the second film layer is determined based on the azimuth angle and the straight-side angle of the outgoing light of the optical composite film. Specifically, according to the optical parameters measured by the detection component, the method for obtaining the optical axis angle of the second film layer specifically includes the following steps:

step 401: and obtaining the polarization parameters of the light emitted by the optical composite film according to the light intensity of the light emitted by the polarizer, which is measured by the detection module.

Step 402: and acquiring the optical axis angle of the second film layer according to the polarization parameters of the emergent light of the optical composite film and the straight-edge angle.

In step 401, according to the light intensity of the polarizer emergent light measured by the detection module, the polarization parameter of the optical composite film emergent light is obtained. Wherein the polarization parameter is azimuth.

Specifically, the intensity of the outgoing light of the polarizer 4 received by the detection module 5 obtains the azimuth angle of the outgoing light of the optical composite film based on the stokes vector and the muller matrix. Because the optical composite film is rotatably arranged on the light source component and the phase delay element 3, and the phase delay element 3 rotates at the angular frequency omega, the intensity of the light emitted by the polarizer 4 received by the detection module 5 is also changed in real time based on the Stokes vector and the Mueller matrix calculated azimuth angle of the light emitted by the optical composite film. The azimuth angle of the outgoing polarized light of the optical composite film may be regularly tapered or irregularly changed, for example, based on the rotation of the optical composite film and the rotation of the phase delay element 3.

When the detection module 5 detects that the angle between the fast axis of the phase delay element 3 and the horizontal direction is α (α=ωt), the azimuth angle of the polarized light emitted by the optical composite film is calculated based on stokes vectors and mueller matrices according to the intensities of the polarized light of the multiple fields emitted by the polarizer 4. For example, the optical composite film is a composite film layer of an RP film and a QWP film, and the azimuth angle of polarized light emitted from the optical composite film is calculated. For example, the polarized light may be circularly polarized light, or elliptically polarized light. When the polarized light is elliptical polarized light, the azimuth angle of the long axis of the elliptical polarized light is calculated.

In step 402, the optical axis angle of the second film layer is obtained according to the polarization parameter and the straight edge angle of the outgoing light of the optical composite film. For example, a relation model is established according to the azimuth angle and the straight-edge angle of the emergent light of the optical composite film, and the optical axis angle of the second film layer is determined according to the relation model.

Specifically, the straight-side angle of the optical composite film is obtained by the vision camera 6, and the azimuth angle of the outgoing light of the optical composite film is obtained by the detection module 5, which are performed synchronously, so that the obtained straight-side angle and the obtained azimuth angle of the outgoing light of the optical composite film are in one-to-one correspondence at the same time. And fitting the acquired azimuth angle of the emergent light of the optical composite film to be detected and the straight-edge angle of the optical composite film shot by the visual camera 6, so as to obtain a relation model between the azimuth angle of the emergent light of the optical composite film and the straight-edge angle.

Since the optical composite film is rotatably disposed between the light source module and the phase delay member 3, the vision camera 6 acquires straight-side angles of a plurality of optical composite films during rotation of the optical composite film in step 02. The acquired plurality of straight edge angles is defined as a straight edge angle group, for example.

Since the optical composite film is rotatably disposed between the optical component and the retarder 3 is rotatably disposed, in step 02, the azimuth angles of the light rays emitted from the plurality of optical composite films are acquired during the rotation of the optical composite film and the retarder 3. For example, the azimuth angles of the acquired light rays exiting the plurality of different optical composite films are defined as azimuth angle groups.

And carrying out data fitting through the straight-edge angle groups and the azimuth angle groups which are in one-to-one correspondence, and determining the optical axis angle of the second optical axis according to the fitted relation model. Specifically, the azimuth angle of the ideal outgoing light of the optical composite film 2 to be measured is input, and the straight edge angle of the optical composite film 2 to be measured can be obtained, wherein the straight edge angle of the optical composite film can represent the angle between the polarizing axis and the horizontal axis of the second film layer, and the optical axis angle of the second film layer can be represented.

In a specific embodiment, the wavelength of the laser in the light source assembly corresponds to the wavelength of the QWP film, and the optical composite film is a composite film of an RP film and a QWP film. The phase delay element is a quarter wave plate, the polarizer is a horizontal linear polarizer, and the detection module is a CCD camera.

When the fast axis or slow axis angle of the QWP film is detected, the optical composite film 2 to be detected is rotated, and elliptical polarized light or circular polarized light is emitted after the incident linear polarized light passes through the optical composite film. When circularly polarized light is detected, it is indicated that the QWP fast and slow axes are at 45 relative to the RP transmission axis. When elliptical polarized light is detected, the major axis and the minor axis of the elliptical polarized light coincide with the directions of the fast axis and the slow axis of the QWP, the fast axis and the slow axis of the QWP are mutually perpendicular, the incident linear polarized light is decomposed into two components along a coordinate system formed by the fast axis and the slow axis of the QWP, and the component in which direction is larger is the direction of the major axis of the elliptical polarized light correspondingly. For example, a quarter wave plate rotating at angular frequency omega, a horizontal linear polaroid and a CCD camera can directly detect the azimuth angle of the long axis of emergent elliptical polarized light, and in the rotating process of the optical composite film 2 to be detected, the visual camera shoots simultaneously to give an included angle between the straight edge of the optical composite film to be detected and the vertical direction determined by the self coordinates of the camera, so that the straight edge angle corresponding to the QWP fast axis or slow axis ideal value can be obtained, namely the QWP fast axis or slow axis angle.

Or in another example, referring to fig. 2, the detection assembly includes: and the optical composite film is positioned between the light source component and the analyzer 7.

In this example, the optical axis angle of the second film layer is determined based on the power parameter acquired by the optical power meter and the rotation angle of the analyzer. Specifically, according to the optical parameters measured by the detection component, the method for obtaining the optical axis angle of the second film layer specifically includes the following steps:

step 411: according to the change of the power data measured by the optical power meter 8 along with the rotation angle of the analyzer 7, a data model between the power data and the rotation angle is established, and the rotation angle of the analyzer 7 corresponding to the power data as an extremum is calculated;

step 412: and acquiring the optical axis angle of the second film layer according to the rotation angle of the analyzer 7.

In a specific embodiment, the wavelength of the light source 10 (the light source may be a laser) in the light source assembly corresponds to the QWP film wavelength, and the light source assembly includes a polarizer. The optical composite film is a composite film of an RP film and a QWP film.

Specifically, when the RP transmission axis angle is detected, the analyzer 7 is rotated, and the transmission axis direction of the analyzer 7 is adjusted to be parallel to the polarizer transmission axis direction. In the process of rotating the optical composite film 2 to be tested, the optical power meter 8 detects the power of emergent light, and meanwhile, the visual camera shoots, so that the included angle between the straight edge of the optical composite film 2 to be tested and the vertical direction determined by the coordinates of the camera is given. Fitting a curve by using the detected power data and straight-edge angle data, wherein the straight-edge angle corresponding to the minimum value of the detected optical power is the RP transmission axis angle.

Before detecting the QWP fast axis or slow axis angle, the optical composite film to be measured is rotated by 90 ° (wherein the position of the optical composite film is taken as the initial position when the RP transmission axis angle is detected), and the light intensity passing through the optical composite film to be measured 2 is maximized.

In the process of rotating the optical composite film 2 to be measured, elliptical polarized light or circularly polarized light is emitted after the incident linear polarized light passes through the optical composite film. The analyzer 7 was rotated through a full circle, and when there was no change in power detected by the optical power meter 8, it indicated that the outgoing light was circularly polarized light, indicating that the relative angles of the QWP fast and slow axes and the RP transmission axis were 45 °. When the emergent light is elliptical polarized light, the major axis and the minor axis of the elliptical polarized light are overlapped with the directions of the fast axis and the slow axis of the QWP, the fast axis and the slow axis of the QWP are mutually perpendicular, the incident linear polarized light is decomposed into two components along a coordinate system formed by the fast axis and the slow axis of the QWP, and the component in which direction is larger is the direction of the major axis of the elliptical polarized light correspondingly. And rotating the analyzer 7 in a whole circle, determining the positions of the maximum power value and the minimum power value, and recording the rotation angle from the analyzer 7 to the positions of the maximum power value or the minimum power value, wherein the rotation angle of the analyzer 7 is the angle of the QWP fast axis or the QWP slow axis plus or minus the angle detected by the RP transmission axis.

In step 5, the relative included angle of the optical composite film is obtained according to the optical axis angle of the first film layer and the optical axis angle of the second film layer.

In this step, the optical axis angle of the first film layer and the optical axis angle of the second film layer are made to be different, so that the relative included angle of the optical composite film can be obtained.

When the detection components are the analyzer 7 and the optical power meter 8, the rotation angle of the analyzer 7 to the maximum or minimum power position is recorded, and the rotation angle of the analyzer 7 is the relative angle between the QWP fast axis or slow axis and the RP transmission axis.

Therefore, in the embodiment of the application, the optical axis angle of the first film layer is determined by the power data measured by the detection component and the straight edge angle of the optical composite film shot by the visual camera; determining the optical axis angle of the second film layer according to the optical parameters measured by the detection component; and determining the relative included angle of the optical composite film according to the optical axis angle of the first film layer and the optical axis angle of the second film layer. The detection method for the relative included angle of the optical composite film, provided by the embodiment of the application, avoids the detection of the destructive film tearing under the condition of reducing the cost, and can be applied to a production line.

In one example, the light source assembly includes a laser that emits light at a wavelength that matches a wavelength corresponding to the second film layer.

In this embodiment, the light source assembly includes a laser defining the wavelength of the laser exit light relative to the QWP wavelength. Therefore, when incident linearly polarized light passes through the RP+QWP optical composite film and then exits circularly polarized light, the relative angles of the fast axis and the slow axis of QWP and the RP transmission axis are 45 degrees, and the detection process is simplified.

For example, when the wave plate of the laser emergent light is not matched with the QWP wavelength, and when the relative angles of the QWP fast axis and slow axis and the RP transmission axis are 45 degrees, the incident linear polarized light will not emit the circular polarized light after passing through the rp+qwp optical composite film, thus complicating the detection process.

In one example, the phase retarder is a quarter wave plate and the polarizer is a horizontal linear polarizer.

In this embodiment, the types of the phase delay element 3 and the polarizer 4 are defined, wherein the mueller matrix of the quarter-wave plate and the horizontal linear polarizer is simpler, and the difficulty of acquiring the azimuth angle of the outgoing light of the optical composite film can be reduced.

In one example, according to the light intensity of the light emitted by the polarizer measured by the detection module, the method for obtaining the polarization parameter of the light emitted by the optical composite film specifically includes the following steps:

Step 01: when the included angle between the fast axis of the phase delay element and the horizontal direction is alpha, the intensity of the outgoing light of the polarizer is obtained, wherein alpha=ωt, and t is the rotation time of the phase delay element;

step 02: according to the intensity of the light emitted by the polarizer, acquiring a Stokes vector of the light emitted by the optical composite film;

step 03: and obtaining the polarization parameters of the emergent light of the optical composite film according to the Stokes vector of the emergent light of the optical composite film.

Specifically, according to the light intensity of the light emitted by the polarizer 4 measured by the detection module 5, the polarization parameter of the light emitted by the optical composite film is obtained, wherein the polarization parameter is the azimuth angle of the light emitted by the optical composite film.

In step 01, the intensity of the light emitted from the polarizer 4 is obtained when the fast axis of the retarder 3 forms an angle α with the horizontal direction, where α=ωt. Specifically, polarized light of a plurality of fields of view exiting from the polarizer 4 is finally received by the detection module 5. Since the retarder 3 rotates at the angular frequency ω, the detecting module 5 can detect the intensities of the polarized light rays of the multiple fields of view emitted by the polarizer 4 when the angle α between the fast axis of the retarder 3 and the horizontal direction is detected in real time.

In step 02, when the detection module 5 detects that the angle between the fast axis of the retarder 3 and the horizontal direction is α, the stokes vector of the light emitted from the optical composite film can be obtained according to the intensities of the polarized light of the multiple fields emitted from the polarizer 4 under the condition that the polarized light of the multiple fields emitted from the polarizer 4. Wherein the stokes vector of the outgoing light of the optical composite film is a polarization state and intensity which can characterize the light beam.

For example, the stokes vector for obtaining the outgoing light of the optical composite film is Sm.

Wherein S is ₀ Representing the total light intensity, S ₁ Representing the light intensity difference between the horizontally linearly polarized light and the vertically linearly polarized light; s is S ₂ Representing the light intensity difference between 45-degree linearly polarized light and-45-degree linearly polarized light; s is S ₃ Indicating the light intensity difference between right circularly polarized light and left circularly polarized light.

Wherein S is ₀ 、S ₁ 、S ₂ And S is ₃ Are each represented by the intensity of the polarized light of multiple fields of view that can be emitted by polarizer 4.

In step 03, the azimuth angle of the outgoing light of the optical composite film can be obtained according to the stokes vector Sm of the outgoing light of the optical composite film obtained through calculation. For example, the azimuth angle of the outgoing light of the optical composite film is psi.

The azimuth angle psi of the emergent light of the optical composite film can be obtained through a formula (2);

Therefore, in the embodiment of the present application, according to the intensities of the light rays of multiple fields of view emitted from the polarizer 4 when the angle between the fast axis of the retarder 3 and the horizontal direction is α, which is obtained by the detection module, each element (S) in the formula (1) is calculated ₀ 、S ₁ 、S ₂ And S is ₃ ) Wherein each element (S ₀ 、S ₁ 、S ₂ And S is ₃ ) Is also related to the angle alpha between the fast axis of the phase delay element 3 and the horizontal direction; and then calculating the azimuth angle of the emergent light of the optical composite film according to the formula (2) in the numerical value of each element calculated according to the formula (1).

In this embodiment, the phase delay element 3 rotating at the angular frequency ω is combined with the polarizer 4 and the detection module 5 to detect the azimuth angle of the outgoing light of the optical composite film, so that the azimuth angle of the outgoing light of the optical composite film can be detected quickly, accurately and at low cost. And determining the optical axis angle of the second film layer according to the determined azimuth angle of the emergent light of the optical composite film.

In one example, according to the intensity of the light emitted by the polarizer, the stokes vector of the light emitted by the optical composite film is obtained specifically includes the following steps:

step 001: acquiring a relation model existing between the intensity of the light emitted by the polarizer and the Stokes vector of the light emitted by the optical composite film;

Step 002: performing Fourier transform on the relation model, and acquiring the Fourier transform coefficient according to the intensity of the emergent light of the polarizer;

step 003: and acquiring a Stokes vector of the emergent light of the optical composite film according to the Fourier transform coefficient.

In step S001, the intensity of the light emitted from the polarizer 4 is related to the stokes vector of the light emitted from the optical composite film and the rotation angle of the phase delay element 3. The angle between the fast axis of the phase delay element 3 and the horizontal direction is α, α=ωt.

For example, in the case where the retarder 3 is a quarter-wave plate and the polarizer 4 is a horizontal linear polarizer, the expression of the relationship between the intensity of the light emitted from the polarizer 4 and the stokes vector of the light emitted from the optical composite film is:

wherein in formula (3), α is an angle between the fast axis of the phase delay element 3 and the horizontal direction, S ₀ 、S ₁ 、S ₂ And S is ₃ Are all elements in the Stokes vector matrix of the emergent rays of the optical composite film.

In step S002, the fourier transform is performed on equation (3), and a fourier transform coefficient is obtained from the intensity of the light emitted from the polarizer 4. Specifically, by fourier transform, a relationship between the fourier transform coefficient and the intensity of the detected polarizer-exiting light can be obtained.

For example, formula (3) is written as a fourier series form, where the fourier series form corresponding to formula (3) is formula (4):

then, in the fourier transform of the formula (4), the relation between the fourier transform coefficients A, B, C and D and the intensity of the detected light exiting the polarizer 4 can be obtained. Equation (5) below shows the relationship between the fourier transform coefficient a and the intensity of the detected polarizer exit light, equation (6) shows the relationship between the fourier transform coefficient B and the intensity of the detected polarizer exit light, equation (7) shows the relationship between the fourier transform coefficient C and the intensity of the detected polarizer exit light, and equation (8) shows the relationship between the fourier transform coefficient D and the intensity of the detected polarizer exit light. Wherein the method comprises the steps of

In step S003, a stokes vector of the outgoing light of the optical composite film is obtained according to the fourier transform coefficient. Specifically, according to the above formulas (5) - (8), parameters in a stokes vector matrix of the outgoing light of the optical composite film are obtained.

Specifically, from the formulas (3) and (4), the fourier transform coefficients A, B, C and D can be known, together with the element S in the stokes vector matrix of the outgoing light of the optical composite film ₀ 、S ₁ 、S ₂ And S is ₃ Relationship between, wherein:

B＝S ₃ (10)

from the formula (9) -the formula (12), it can be known that:

S ₀ ＝A-C (13)

S ₁ ＝2C (14)

S ₂ ＝2D (15)

S ₃ ＝B (16)

therefore, according to the formulas (5) - (8) and (13) - (16), parameters in the stokes vector matrix of the outgoing light rays of the optical composite film can be obtained, and the stokes vector of the outgoing light rays of the optical composite film can be obtained. And (3) calculating the azimuth angle of the emergent light of the optical composite film according to the Stokes vector of the emergent light of the optical composite film and by combining the formula (2).

In one example, obtaining a model of a relationship existing between the intensity of the polarizer exit light and the stokes vector of the optical composite film exit light specifically includes the steps of:

step 0001: setting a Stokes vector of the emergent light of the optical composite film as Sm;

step 0002: obtaining Stokes vector S of the light emitted by the phase delay element according to the Stokes vector Sm ^′ ；

Step 0003: according to the Stokes vector S ^′ Acquiring a Stokes vector Sout of the light rays emitted by the polarizer;

step 0004: and obtaining a relation model existing between the intensity of the polarizer emergent ray and the Stokes vector of the optical composite film emergent ray according to the Stokes vector Sout.

Specifically, in step S0001, the stokes vector of the outgoing light of the optical composite film is first set to Sm.

Let the stokes vector of the outgoing light of the optical composite film be:

wherein S is ₀ Representing the total light intensity, S ₁ Representing the light intensity difference between the horizontally linearly polarized light and the vertically linearly polarized light; s is S ₁ Representing the light intensity difference between 45-degree linearly polarized light and-45-degree linearly polarized light; s is S ₃ Indicating the light intensity difference between right circularly polarized light and left circularly polarized light.

In step S0002, the light emitted from the phase delay element 3 is obtained from the stokes vector SmStokes vector S of line ^′ Specifically, the stokes vector of the light emitted from the phase delay element 3 is obtained based on the theory that the stokes vector of the light emitted from a certain component is the product of the mueller matrix of the component and the stokes vector of the light emitted from the previous component.

For example, the stokes vector S of the light emitted by the phase delay element 3 is obtained according to the stokes vector Sm and the mueller matrix of the phase delay element 3 with the angle alpha between the fast axis and the horizontal direction ^′ 。

In a specific embodiment, the phase delay element 3 is a quarter-wave plate, and the muller matrix of the quarter-wave plate with the fast axis having an angle α with respect to the horizontal direction can be expressed as formula (17):

The quarter wave plate rotates at an angular velocity ω (α=ωt).

After the emergent light of the optical composite film passes through the rotated quarter wave plate, the Stokes vector of the emergent light is shown as formula (18):

the following are to be described: the phase delay element 3 may also be a half-wave plate, the half-wave plate allows the optical composite film to emit, and the light emitted from the half-wave plate is linearly polarized light, and after the optical composite film emits light through the rotated half-wave plate, the stokes vector of the emitted light is the product of the mueller matrix of the half-wave plate and the stokes vector of the light emitted from the optical composite film.

In step S0003, according to said Stokes vector S ^′ Acquiring a Stokes vector S of light rays emitted by the polarizer 4 _out The method comprises the steps of carrying out a first treatment on the surface of the Specifically, the stokes vector based on the emergent ray of a certain component is the product of the Mueller matrix of the component and the stokes vector of the emergent ray of the upper componentThe stokes vector of the outgoing light of the polarizer is obtained theoretically.

For example according to the Stokes vector S ^′ And the mueller matrix of the polarizer 4, resulting in a stokes vector S of the light rays exiting the polarizer 4 _out 。

In a specific embodiment, polarizer 4 is a horizontally linear polarizer. The mueller matrix of the horizontal linear polarizer (i.e., the mueller matrix of the light transmission axis of the horizontal linear polarizer in the horizontal direction) is expressed as formula (19):

The relation between the emergent light passing through the horizontal linear polaroid and the emergent light of the optical composite film is as follows:

S _out ＝NMS _VR (20)

the light exiting through the horizontal linear polarizer is expressed as stokes vector of the light exiting through the horizontal linear polarizer is expressed as:

the polarizer 4 may be a circular polarizer. According to the principles set forth above, the Stokes vector of light rays exiting through the circular polarizer can be obtained.

In step S0004, according to said Stokes vector S _out And acquiring a relational expression existing between the intensity of the light rays emitted by the polarizer 4 and the Stokes vector of the light rays emitted by the optical composite film.

Specifically, only the outgoing light S is calculated _out The first component of (a) i.e. the total intensity can be detected, S' ₀ ＝I(α)

Thus, go upThe formula (3) shows the relationship between the intensity of the light emitted from the polarizer 4 and the Stokes vector of the light emitted from the optical composite film, wherein in the formula (3), α is the angle between the fast axis of the retarder 3 and the horizontal direction, S ₀ 、S ₁ 、S ₂ And S is ₃ Are all elements in the Stokes vector matrix of the emergent rays of the optical composite film. And then carrying out Fourier transform on the formula (3), and acquiring the Fourier transform coefficient according to the intensity of the emergent light of the polarizer 4. Specifically, by fourier transform, a relationship between the fourier transform coefficient and the intensity of the detected polarizer-exiting light can be obtained. Then, the relation between the fourier transform coefficients A, B, C and D and the intensity of the detected light emitted from the polarizer 4 can be obtained by fourier transform on the above formula (4). For example, equation (5) above shows the relationship between the fourier transform coefficient a and the intensity of the detected polarizer exit light, equation (6) shows the relationship between the fourier transform coefficient B and the intensity of the detected polarizer exit light, equation (7) shows the relationship between the fourier transform coefficient C and the intensity of the detected polarizer exit light, and equation (8) shows the relationship between the fourier transform coefficient D and the intensity of the detected polarizer exit light.

Therefore, according to the above formula (5) -formula (8) and the above formula (13) -formula (16), parameters in the stokes vector matrix of the outgoing light of the optical composite film can be obtained, and the stokes vector of the outgoing light of the optical composite film can be obtained. And (3) calculating the azimuth angle of the emergent light of the optical composite film according to the Stokes vector of the emergent light of the optical composite film and by combining the formula (2).

In one example, the phase delay element rotating at an angular frequency ω specifically includes:

In a specific embodiment, the phase delay element 3 is driven in rotation by a stepper motor. The quarter wave plate is driven in rotation, for example by a stepper motor.

Specifically, the quarter wave plate is placed on a fixed base, and can be driven to rotate through a stepping motor in n steps: ωt=nα _j (α _j Step size, N is the total number of steps). Wherein according to α=ωt=nα _j The equation (22) can be obtained by transforming the equation (4).

Wherein the relationship between the fourier transform coefficients A, B, C and D and the intensity of the detected light exiting the polarizer 4 can be obtained by fourier transform, wherein equations (23) - (26) show the relationship between the fourier transform coefficients A, B, C and D and the intensity of the detected light exiting the polarizer 4.

Thus, in the embodiment of the present application, the stokes vector of the outgoing light of the optical composite film can be obtained given the step size and the step number of the stepping motor and the intensity of the detected outgoing light of the polarizer 4. And then acquiring the azimuth angle of the emergent light of the optical composite film according to the Stokes vector of the emergent light of the optical composite film.

In the embodiment of the application, the optical axis angle of the first film layer and the optical axis angle of the second film layer are measured by the detection assembly, and the relative included angle of the optical composite film is determined according to the optical axis angle of the first film layer and the optical axis angle of the second film layer. The detection system for the relative included angle of the optical composite film, provided by the embodiment of the application, avoids the detection of the destructive film tearing under the condition of reducing the cost, and can be applied to a production line.

In one example, the detection assembly includes: the phase delay element rotates at an angular frequency omega;

In this embodiment, the power data and the optical parameters are detected by a combination of a phase retardation element rotating at an angular frequency ω and a polarizer and a detection module, and the straight edge angle of the optical composite film is obtained by the vision camera 6, the optical axis angle of the first film layer is determined from the power data and the straight edge angle, and the optical axis angle of the second film layer is determined from the optical parameters. And finally, determining the relative included angle of the optical composite film according to the optical axis angle of the first film and the optical axis angle of the second film.

In one example, the detection assembly includes: an analyzer 7 and an optical power meter 8;

when the optical composite film 2 to be measured is placed between the light source assembly 1 and the analyzer 7, the optical composite film, the analyzer 7 and the optical power meter 8 are sequentially arranged along the same optical axis.

In this embodiment, by rotating the analyzer 7, the optical axis angle of the first film layer and the optical axis angle of the second film layer are determined from the power data acquired by the optical power meter 8. And finally, determining the relative included angle of the optical composite film according to the optical axis angle of the first film and the optical axis angle of the second film.

In one example, referring to fig. 1, the light source assembly 1 includes: a light source 10, a quick mirror 11, a lens group comprising at least one lens, and a polarizer 14;

the light emitted from the light source 10 is projected to the optical composite film 2 to be measured through the quick reflector 11, the lens group and the polarizer 14 in sequence.

Specifically, the lens group includes a first lens 12 and a second lens 13, and light emitted from the laser passes through the fast mirror 11, the first lens 12 and the second lens 13, where in fig. 1, F1 and F2 are focal lengths of the first lens 12 and the second lens 13, respectively, and then passes through the polarizer 14 to generate linearly polarized light with multiple fields of view.

Or in an alternative embodiment, referring to fig. 2, the light source assembly 1 comprises a light source 10 and a polarizer 14.

In one example, a stepper motor is also included that drives the phase delay element to rotate at an angular frequency ω.

In the embodiment of the present application, the phase delay element 3 is driven by a stepping motor, wherein the stokes vector of the outgoing light of the optical composite film can be obtained given the step size and the step number of the stepping motor, and the intensity of the detected outgoing light of the polarizer 4. And then obtaining the polarization parameters of the optical composite film according to the Stokes vector of the emergent light of the optical composite film. And finally, acquiring the optical axis angle of the second film layer according to the polarization parameters of the optical composite film.

The specific implementation manner of the optical composite film relative included angle detection system according to the embodiment of the present application may refer to each embodiment of the optical composite film relative included angle detection method, so that the optical composite film relative included angle detection system at least has all the beneficial effects brought by the technical solutions of the embodiments, and will not be described in detail herein.

The foregoing embodiments mainly describe differences between the embodiments, and as long as there is no contradiction between different optimization features of the embodiments, the embodiments may be combined to form a better embodiment, and in consideration of brevity of line text, no further description is given here.

While certain specific embodiments of the application have been described in detail by way of example, it will be appreciated by those skilled in the art that the above examples are for illustration only and are not intended to limit the scope of the application. It will be appreciated by those skilled in the art that modifications may be made to the above embodiments without departing from the scope and spirit of the application. The scope of the application is defined by the appended claims.

Claims

1. The method for detecting the relative included angle of the optical composite film is characterized by being applied to a detection system of the relative included angle of the optical composite film, and the detection system comprises the following steps: the device comprises a light source assembly and a detection assembly, wherein an optical composite film to be detected is arranged between the light source assembly and the detection assembly, the optical composite film comprises a first film layer and a 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;

the detection method comprises the following steps:

2. The method according to claim 1, wherein obtaining the optical axis angle of the first film layer according to the power data measured by the detecting component and the straight edge angle of the optical composite film specifically includes:

3. The method of claim 1, wherein the detection assembly comprises: the optical composite film is positioned between the light source component and the phase delay element, and the phase delay element rotates at angular frequency omega;

4. The method of claim 1, wherein the detection assembly comprises: the optical composite film is positioned between the light source component and the analyzer;

5. The method of claim 1, wherein the light source assembly comprises a laser having a wavelength of light that matches a wavelength corresponding to the second film layer.

6. The method of claim 1, wherein the first film layer is a reflective polarizing film or a polarizing film, and the second film layer is a phase retardation film.

7. A method of detecting according to claim 3, wherein the phase retarder is a quarter wave plate and the polarizer is a horizontal linear polarizer.

8. The method according to claim 3, wherein obtaining the polarization parameter of the light exiting the optical composite film according to the light intensity of the light exiting the polarizer measured by the detection module specifically includes:

9. The method according to claim 8, wherein obtaining the stokes vector of the outgoing light of the optical composite film according to the intensity of the outgoing light of the polarizer specifically comprises:

10. The method according to claim 9, wherein obtaining a model of a relationship existing between the intensity of the polarizer outgoing light and the stokes vector of the optical composite film outgoing light specifically comprises:

11. The method according to claim 10, wherein a stokes vector S of the light emitted from the phase delay element is obtained from the stokes vector Sm ^′ The method specifically comprises the following steps:

12. The detection method according to claim 10, characterized in that according to the stokes vector S ^′ The obtaining the stokes vector Sout of the outgoing light ray of the polarizer specifically includes:

13. A detection method according to claim 3, wherein the rotation of the phase delay element at an angular frequency ω comprises:

14. A system for detecting a relative angle of an optical composite film, the system comprising: a light source assembly and a detection assembly;

15. The detection system of claim 14, wherein the detection assembly comprises: the phase delay element rotates at an angular frequency omega;

16. The detection system of claim 14, wherein the detection assembly comprises: an analyzer and an optical power meter;

17. The detection system of claim 14, wherein the light source assembly comprises: a light source, a quick reflector, a lens group and a polarizer, wherein the lens group comprises at least one lens;

18. The detection system of claim 15, further comprising a stepper motor that drives the phase delay element to rotate at an angular frequency ω.