Test device and method for improving optical module assembly and adjustment accuracy and field of view angle range

Abstract

The present application discloses a testing device and method for improving the assembly accuracy and field of view angle range of optical modules. The testing device includes a camera detection system, which is arranged on the light-emitting side of the optical module and projects the image information emitted by the optical module onto the camera detection system. The camera detection system images the image information onto a target film; a modulation optical system, which is arranged between the optical module and the camera detection system. The modulation optical system focuses the image information emitted by the optical module so that the effective range of the image imaged onto the target film accounts for a ratio T of 95% to 100% of the target film area. The present application can focus different optical modules to achieve clear imaging, ensuring that the resolution of the test image is maximized when the detection is effective, so that the test image has higher detection accuracy and the largest applicable range on the target film, thereby improving the accuracy of the assembly and adjustment of the optical module.

Description

Technical Field

[0001] The present application relates to the technical field of assembly and adjustment testing of optical modules, and in particular to a testing device and method for improving the assembly and adjustment accuracy and field of view angle range of optical modules. Background Art

[0002] The principle of AR and VR display devices is to use an optical system (optical module) to pull the close-up image produced by the display to a distant place and magnify it, almost filling the human field of vision, thereby creating a sense of immersion. For products such as AR and VR glasses, their optical modules mainly include optical display devices, optical lens assemblies and brackets. To ensure a good display effect of the product, the various components of the optical module must meet strict alignment accuracy requirements. Existing optical module products generally ensure the structural accuracy of the product by controlling the processing accuracy of the above-mentioned optical components, and ensure the assembly alignment accuracy through assembly jigs or manual processes. Finally, unqualified products are eliminated by testing the imaging quality of the finished product, ultimately achieving product quality control.

[0003] Waveguide AR optical modules undergo assembly and adjustment accuracy testing before shipment. This ensures that each optical module is accurately assembled and adjusted during production, ensuring that its performance and functionality meet specification requirements. Assembly and adjustment of optical modules during production are based on the imaging quality of the camera inspection system's film, and the imaging quality of the camera inspection system's film affects the assembly and adjustment accuracy of the optical module.

[0004] The assembly and adjustment of a waveguide AR optical module involves two steps. First, the light emitted from the monocular waveguide is at an infinite object distance. Furthermore, to ensure that the two monocular waveguide AR optical modules can successfully combine images in the human eye, the optical axes of the light emitted from the left and right monoculars at infinite distance must be parallel or form a relatively small horizontal angle, denoted as α (typically <1.3°). During AR optical module assembly and adjustment, the camera detection system is generally located on the light-emitting side of the AR optical module and focused for imaging at infinite distance. For a fixed-focus camera detection system, the size of the image on the film depends on the AR optical module's field of view (Note: For a fixed-focus camera detection system, when imaging an object at infinite distance, the field of view corresponding to the film size is the camera detection system's field of view). When the AR optical module's field of view is smaller than the camera detection system's, the image only occupies a portion of the film, resulting in a waste of resources. When the AR optical module's field of view is larger than the camera detection system's field of view, the image is larger than the film size, exceeding the applicable range of the fixed-focus camera detection system. Summary of the Invention

[0005] In order to solve the above technical problems, the present application provides a testing device and method for improving the assembly and adjustment accuracy and field of view angle range of an optical module.

[0006] The present application provides a testing device and method for improving the assembly and adjustment accuracy and field of view range of an optical module, which adopts the following technical solutions:

[0007] First aspect

[0008] A testing device for improving the assembly and adjustment accuracy and field angle range of an optical module, comprising:

[0009] A camera detection system is provided on the light-emitting side of the optical module and projects the image information emitted by the optical module onto the camera detection system, and the camera detection system images the image information onto a target film;

[0010] A modulation optical system is arranged between the optical module and the camera detection system. The modulation optical system focuses the image information emitted by the optical module so that the effective range of the image imaged on the target film accounts for a ratio T of 95%-100% of the target film area.

[0011] By adopting the above technical solution, the camera detection system collects image information from the optical module to obtain a test image. The modulation optical system can adjust the test image imaged on the target film area so that it can be clearly imaged on the target film. Subsequent personnel can assemble and adjust the optical module based on the imaged image to ensure the accuracy of the optical module. This application can focus different optical modules to obtain clear images, ensuring that the resolution of the test image is maximized while the detection is effective, so that the test image has higher detection accuracy and the largest applicable range on the target film, thereby improving the accuracy of the optical module assembly and adjustment.

[0012] Optionally, the optical module includes two monocular waveguide AR optical modules symmetrically arranged about an axis of symmetry, and the camera detection system includes two monocular detection systems, the two monocular detection systems correspond one-to-one to the two monocular waveguide AR optical modules, each monocular detection system is arranged on the light-emitting side of the corresponding monocular waveguide AR optical module, and the optical axes of the two monocular detection systems are symmetrically arranged about the axis of symmetry.

[0013] By adopting the above technical solution, the imaging effect is ensured to be consistent with the imaging of the human eye, so that the optical module imaging meets the comfort of the human eye.

[0014] Optionally, the modulation optical system and the camera detection system are combined to form a close contact lens group.

[0015] By adopting the above technical solution, the propagation path and focal length of light can be better controlled.

[0016] Optionally, the image effective range and the target film area are preset legends, and the preset legends may be circular or polygonal graphic patterns.

[0017] Optionally, when the focal length f2 of the modulating optical system is less than 0, the modulating optical system is a negative lens system; when the focal length f2 of the modulating optical system is greater than 0, the modulating optical system is a positive lens system.

[0018] By adopting the above technical solution, the modulating optical system is a negative lens system, which changes the distance of the object before entering the camera detection system from infinity to finite distance. Then, through the camera detection system adjustment, a clearer and more magnified image can be obtained compared to a system without the modulating optical system adjustment. The modulating optical system is a positive lens system, which changes the distance of the object before entering the camera detection system from infinity to finite distance. Then, through the camera detection system adjustment, a clearer and more magnified image can be obtained compared to a system without the modulating optical system adjustment.

[0019] Optionally, the focal length f2 of the modulation optical system corresponding to the optical modules with different field angles 2θ is different.

[0020] By adopting this technical solution, by replacing the modulated optical system with a different focal length f2 to match the optical module with the corresponding field of view angle 2θ, a clear image on the target film is ensured. The modulated optical system is easy to replace, which is more efficient and lowers costs than replacing the camera detection system.

[0021] Second aspect

[0022] A testing method for improving the assembly and adjustment accuracy and field of view angle range of an optical module comprises the following steps:

[0023] Obtaining the field of view angle 2θ of the optical module;

[0024] Obtain the field of view angle 2ω and focal length f1 of the camera detection system;

[0025] The focal length f2 of the modulation optical system is calculated based on the ratio T of the effective image range to the target film area, the field of view angle 2θ of the optical module, the field of view angle 2ω of the camera detection system, and the focal length f1;

[0026] A modulating optical system with a focal length of f2 is arranged between the optical module and the camera detection system.

[0027] By adopting the above technical solution, the original parameters of the optical module and the camera detection system are obtained, and based on these parameters and the preset ratio T, the required focal length f2 of the optical system is calculated and set between the optical module and the camera detection system, thereby obtaining the required ratio T. The method of the application can maximize the consistency between the image emitted by the optical module and the test image projected onto the target film, thereby ensuring the accuracy of subsequent detection.

[0028] Optionally, the modulation optical system and the camera detection system are combined to form a close contact lens group.

[0029] Optionally, the calculation of the focal length f2 of the modulation optical system based on the ratio T of the effective image range to the target film area, the field angle 2θ of the optical module, the field angle 2ω of the camera detection system, and the focal length f1 includes:

[0030] f2=f1*(T*tanω) / (tanθ-T*tanω).

[0031] By adopting the above technical solution, the calculation method is simple and fast, and the focal length f2 of the required modulated optical system can be quickly and accurately obtained, so as to facilitate rapid adaptive adjustment.

[0032] Optionally, the ratio T of the effective image range to the target film area includes:

[0033] The image effective range is the diagonal size 2f1*tan(θ) of the image information emitted by the optical module formed on the camera detection system; the target film area is the diagonal size 2f1*tan(ω)+2f2*tan(ω) of the target film.

[0034] By adopting the above technical solution, when the image effective range and the target film area are both rectangular areas, the ratio T of the image effective range to the target film area can be quickly calculated using the diagonal size.

[0035] In summary, this application includes at least one of the following beneficial technical effects:

[0036] 1. This application can focus different optical modules to obtain clear images, ensuring that the resolution of the test image is maximized while the detection is effective, so that the test image has higher detection accuracy and the largest applicable range on the target film, thereby improving the accuracy of the optical module installation.

[0037] 2. The modulating optical system is a negative lens system that changes the distance of objects before entering the camera detection system from infinity to finite distance. The camera detection system then adjusts the distance, resulting in a clearer and more magnified image compared to a system without the modulating optical system. The adjustment system is a positive lens system that changes the distance of objects before entering the camera detection system from infinity to finite distance. The camera detection system then adjusts the distance, resulting in a clearer and more magnified image compared to a system without the modulating optical system.

[0038] 3. The calculation method of the present application solution is simple and quick, and can quickly and accurately obtain the focal length f2 of the required modulated optical system, so as to facilitate rapid adaptive adjustment. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 This is a schematic diagram of the composition of the conventional optical waveguide AR optical module binocular fusion system platform in the related technology.

[0040] Figure 2 It is a schematic diagram of the image formed on the target film.

[0041] Figure 3 Schematic diagram of the composition of the test device in the embodiment of the present application.

[0042] Description of reference numerals:

[0043] 10. Optical module; 11. Monocular vision module; 20. Camera detection system; 21. Target film; 30. Modulation optical system. DETAILED DESCRIPTION

[0044] The technical solution in this application will be described below with reference to the accompanying drawings.

[0045] In the description of the embodiments of this application, unless otherwise specified, " / " represents or. For example, A / B can represent A or B. "And / or" in this article is simply a description of the association relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, in the description of the embodiments of this application, "plurality" means two or more than two.

[0046] In the following, the terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of the technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of this embodiment, unless otherwise specified, "plurality" means two or more.

[0047] Figure 1 This is the composition of a conventional optical waveguide AR optical module binocular fusion system platform. The optical module 10 in the figure includes two monocular vision modules 11 (left and right) and two camera detection systems 20 (left and right). The two monocular vision modules 11 have identical structures and are symmetrical about their axes of symmetry, with a diagonal field of view of 2θ. The optical axes of the two camera detection systems 20 (i.e., axis 1 and axis 2) are calibrated to be completely parallel and have identical focal lengths (denoted as f1). Therefore, Figure 1 The entire optical paths of the left eye module and the right eye module are completely symmetrical. Therefore, the present invention will only use the left eye module as an example to illustrate the optical path process, and it is assumed that the aspect ratio of the target film 21 area and the image formed by the left eye module on the target film 21 is the same.

[0048] The schematic diagram of the image formed on the target film 21 of the left eye detection system is as follows: Figure 2 After passing through the camera detection system 20, the two diagonal edge field rays are imaged at points L1 and L2, with the center point of the two points being L0.

[0049] The rectangular area with corners L1(x1, y1) and L2(x2, y2) is the image of the left-eye detection system's target film 21 formed by the left-eye detection system, with its center at L0(x0, y0). The surrounding gray area in the figure represents the target film 21 area of ​​the camera detection system 20, with its center at L00(x00, y00). Without considering errors, y0=y00, x00-x0≈f1*tan(α / 2). When α=0, x00=x0. α is the difference between the field of view 2ω of the camera detection system 20 and the field of view 2θ of the monocular detection system 11.

[0050] Assuming that the field of view of the camera detection system 20 is 2ω, the diagonal size of the target film 21 is 2f1*tan(ω); the size (diagonal size) of the image formed by the monocular vision module 11 with a field of view of 2θ on the camera detection system 20 is 2f1*tan(θ). When the field of view angle 2θ of the monocular vision module 11 to be assembled is less than 2ω, and 2f1*tan(θ) is less than 2f1*tan(ω), the effective area of ​​the image of the monocular vision module 11 cannot cover the target film 21 of the camera detection system 20 (that is, there is a black invalid area on the edge), especially when 2θ is too small. At this time, the effective area of ​​the image is too small and the resolution is insufficient, thereby affecting the positioning accuracy of L1 and L2 and thus affecting the assembly accuracy; when the field of view angle 2θ of the monocular vision module 11 to be assembled is greater than 2ω, 2f1*tan(θ) is greater than 2f1*tan(ω), the effective area of ​​the image of the monocular vision module 11 is larger than the target film 21 of the camera detection system 20, making it impossible to obtain points L1 and L2 at the same time, and the detection fails.

[0051] It can be seen that the existing testing device cannot accurately meet the requirements of testing the optical module 10.

[0052] Based on this, the embodiment of the present application provides a testing device for improving the assembly and adjustment accuracy of optical modules and the field of view angle range. Figure 2It adds a matching modulation optical system 30 in front of the lens of the camera detection system 20, so that the light with an object distance of ∞ emitted by the optical module 10 is first modulated into light of a limited object distance by the modulation optical system 30 before passing through the camera detection system 20, and then forms an image slightly smaller than the target film 21 after passing through the camera detection system 20 (for example, 95% of the film range can be selected). At this time, the camera detection system 20 needs to focus according to actual conditions to ensure clear imaging, ensuring that the resolution of the image can be maximized while the detection is effective, so that the image has higher detection accuracy and the largest applicable range on the target film 21, thereby improving the accuracy of the assembled optical module 10.

[0053] Reference Figure 3 The testing device includes a camera detection system 20 and a modulation optical system 30. The camera detection system 20 is disposed on the light-emitting side of the optical module 10. The image information emitted by the optical module 10 is projected onto the camera detection system 20, which then images the image information onto a target film 21. The target film 21 is an existing component of the camera detection system 20 and will not be described in detail here.

[0054] At the same time, the modulation optical system 30 is arranged between the camera detection system 20 and the optical module 10, and is used to focus the image information emitted by the optical module 10 so that the effective range of the image imaged on the target film 21 accounts for a ratio T of 95%-100% of the area of ​​the target film 21.

[0055] In this embodiment, the optical module 10 includes two monocular waveguide AR optical modules symmetrically arranged about an axis of symmetry. The monocular waveguide AR optical module only shows the waveguide structure in the figure, and other structures are not shown. The camera detection system 20 includes two monocular detection systems, and the two monocular detection systems correspond one-to-one to the two monocular waveguide AR optical modules. Each monocular detection system is set on the light-emitting side of the corresponding monocular waveguide AR optical module, and the optical axes of the two monocular detection systems are symmetrically arranged about the axis of symmetry. The purpose of this design is to ensure that the imaging effect is consistent with the imaging of the human eye, so that the imaging of the optical module 10 meets the comfort level of the human eye.

[0056] In a preferred embodiment, the modulation optical system 30 and the camera detection system 20 are combined to form a close contact lens group. The modulation optical system 30 can be a lens. By adjusting and replacing different modulation optical systems 30, the field of view of the close contact lens group is matched with the field of view of the optical module 10. This ensures that the effective range of the image formed on the target film 21 accounts for a ratio T of 95%-100% of the target film 21 area, ensuring clear imaging.

[0057] In this embodiment, the field of view angle of the contact lens assembly is adjusted by changing the focal length of the modulation optical system 30. When the focal length f2 of the modulation optical system 30 is less than 0, the modulation optical system 30 is a negative lens system, changing the distance of objects before entering the camera detection system 20 from infinity to finite distance. Adjustment by the camera detection system 20 results in a clearer, more magnified image compared to a system without adjustment by the modulation optical system 30. When the focal length f2 of the modulation optical system 30 is greater than 0, the modulation optical system 30 is a positive lens system, changing the distance of objects before entering the camera detection system 20 from infinity to finite distance. Adjustment by the camera detection system 20 results in a clearer, more magnified image compared to a system without adjustment by the modulation optical system 30.

[0058] Therefore, the focal length f2 of the modulation optical system 30 corresponding to the optical module 10 with different viewing angles 2θ is different. By replacing the modulation optical system 30 with different focal lengths f2 to correspond to the optical module 10 with the corresponding viewing angle 2θ, a clear image on the target film 21 is ensured.

[0059] The image effective range and the target film 21 are preset legends. In this embodiment, the preset legend is a rectangular graphic pattern. In other embodiments, the preset legend may also be a circular or other polygonal graphic pattern.

[0060] The implementation principle of a testing device for improving the assembly and adjustment accuracy and field of view angle range of an optical module in an embodiment of the present application is as follows: the camera detection system 20 collects image information in the optical module 10 to obtain a test image, and the modulation optical system 30 can adjust the test image imaged on the target film 21 area so that it can be clearly imaged on the target film 21. Subsequent personnel can assemble and adjust the optical module 10 according to the imaged image to ensure the accuracy of the optical module 10.

[0061] The present application also discloses a test method for improving the assembly and adjustment accuracy and field of view range of an optical module, comprising the following steps:

[0062] S1. Obtaining the field of view angle 2θ of the optical module 10.

[0063] Specifically, the field of view angle 2θ of the optical module 10 can be calculated by mathematical formulas, precise angle measurement methods, or some professional software (such as Imatest).

[0064] S2 . Obtain the field of view angle 2ω and focal length f1 of the camera detection system 20 .

[0065] Specifically, the field of view angle 2ω and the focal length f1 of the camera detection system 20 can be obtained according to the original parameters of the camera test system.

[0066] S3. Calculate the focal length f2 of the modulation optical system 30 based on the ratio T of the effective image range to the target film 21 area, the field angle 2θ of the optical module 10 , the field angle 2ω of the camera detection system 20 , and the focal length f1 .

[0067] Preferably, the ratio T of the effective image range to the area of ​​the target film 21 includes:

[0068] The effective image range is the diagonal size 2f1*tan(θ) of the image information emitted by the optical module 10 formed on the camera detection system 20; the target film 21 area is the diagonal size 2f1*tan(ω)+2f2*tan(ω) of the target film 21.

[0069] Based on this, the focal length f2 of the modulation optical system 30 can be obtained,

[0070] f2=f1*(T*tanω) / (tanθ-T*tanω).

[0071] The process is derived as follows:

[0072] like Figure 3 As shown, a modulation optical system 30 with a focal length of f2 is added in front of the camera detection system 20; it can first perform an imaging on the parallel light emitted by the optical module 10, such as Figure 3 L′1, L′0, and L′2 correspond to the three fields of view of -θ, 0°, and θ in the light emitted from the optical module 10, respectively; and then after passing through the camera detection system 20, images are formed at L′′1, L′′0, and L′′2.

[0073] The modulation optical system 30 and the camera detection system 20 are combined to form a close contact lens group. The focal length of the close contact lens group is f=f1*f2 / (f1+f2). The size of the image formed by the optical module 10 on the target film 21 is 2*f*tanθ=2*T*f1*tanω, then f2=f1*(T*tanω) / (tanθ-T*tanω).

[0074] When the focal length f2 of the modulation optical system 30 is less than 0, the modulation optical system 30 is a negative lens system, which changes the distance of the object before entering the camera detection system 20 from infinity to finite distance. Adjustment by the camera detection system 20 then produces a clearer and more magnified image compared to a system without adjustment by the modulation optical system 30. When the focal length f2 of the modulation optical system 30 is greater than 0, the modulation optical system 30 is a positive lens system, which changes the distance of the object before entering the camera detection system 20 from infinity to finite distance. Adjustment by the camera detection system 20 then produces a clearer and more magnified image compared to a system without adjustment by the modulation optical system 30.

[0075] According to the optical module 10 with different field angles 2θ, the modulation optical system 30 with different f2 can be selected to obtain an image whose effective range is slightly smaller than the target film 21 and almost fills the entire target film 21 area.

[0076] S4 , placing a modulation optical system 30 with a focal length of f2 between the optical module 10 and the camera detection system 20 .

[0077] Example 1: Assuming that the effective range of the required image occupies a proportion T of 95% of the area of ​​the target film 21, 2θ=30°, 2ω=60°, f1=16mm, T=0.95, then the size of the target film 21 is 2*f1*tanω=18.48mm. After calculation, the required f2=-31.28mm. Before and after adding the modulation optical system 30, the image size on the target film 21 is 2*16*tanθ=8.57mm and T*18.48=17.55mm.

[0078] Example 2: Assuming that the effective range of the required image occupies a proportion T of 95% of the area of ​​the target film 21, 2θ=30°, 2ω=60°, f1=16mm, T=0.95, then the size of the target film 21 is 2*f1*tanω=18.48mm. After calculation, the required f2=57.84mm. Before and after adding the modulation optical system 30, the image size on the target film 21 is 2*16*tanθ=22.41mm and T*18.48=17.55mm.

[0079] It can be seen that through the testing method of the present application, the resolution of the test image on the target film 21 can be maximized, so that the test image has higher detection accuracy and the largest applicable range on the target film 21, so as to improve the accuracy of subsequent assembly and adjustment of the optical module 10.

[0080] The above are all preferred embodiments of the present application, and are not intended to limit the scope of protection of the present application. Therefore, any equivalent changes made based on the structure, shape, and principle of the present application should be included in the scope of protection of the present application.

Claims

1. A testing method for improving the assembly accuracy and viewing angle range of an optical module, characterized in that: A test device is included, the test device comprising: A camera detection system (20) is arranged on the light-emitting side of the optical module (10), and the image information emitted by the optical module (10) is projected onto the camera detection system (20), and the camera detection system (20) forms an image of the image information onto a target film (21); a modulation optical system (30) disposed between the optical module (10) and the camera detection system (20), wherein the modulation optical system (30) focuses the image information emitted by the optical module (10) so that the effective range of the image formed on the target film (21) accounts for a ratio T of 95% to 100% of the area of ​​the target film (21); The test method comprises the following steps: Obtaining the field of view angle 2θ of the optical module (10); Obtain the field of view angle 2ω and focal length f1 of the camera detection system (20); Based on the ratio T of the effective image range to the area of ​​the target film (21), the field angle 2θ of the optical module (10), the field angle 2ω of the camera detection system (20), and the focal length f1, the focal length f2 of the modulation optical system (30) is calculated; A modulation optical system (30) having a focal length of f2 is arranged between the optical module (10) and the camera detection system (20); The modulation optical system (30) and the camera detection system (20) are combined to form a close contact lens group; The focal length f2 of the modulation optical system (30) is calculated based on the ratio T of the effective image range to the area of ​​the target film (21), the field angle 2θ of the optical module (10), the field angle 2ω of the camera detection system (20), and the focal length f1, including: f2=f1*(T*tanω) / (tanθ-T*tanω); The ratio T of the effective image range to the target film (21) area includes: The image effective range is the diagonal size 2f1*tanθ of the image information emitted by the optical module (10) formed on the camera detection system (20); the target film (21) area is the diagonal size 2f1*tanω+2f2*tanω of the target film (21).

2. The testing method for improving the assembly and adjustment accuracy and viewing angle range of an optical module according to claim 1, characterized in that: The optical module (10) includes two monocular waveguide AR optical modules symmetrically arranged about an axis of symmetry, and the camera detection system (20) includes two monocular detection systems, the two monocular detection systems corresponding to the two monocular waveguide AR optical modules one-to-one, each monocular detection system being arranged on the light-emitting side of the corresponding monocular waveguide AR optical module, and the optical axes of the two monocular detection systems being symmetrically arranged about the axis of symmetry.

3. The testing method for improving the assembly accuracy and viewing angle range of an optical module according to claim 1, characterized in that: The image effective range and the target film (21) area are preset legends, and the preset legends are circular or polygonal graphic patterns.

4. The testing method for improving the assembly and adjustment accuracy and viewing angle range of an optical module according to claim 1, characterized in that: When the focal length f2 of the modulating optical system (30) is less than 0, the modulating optical system (30) is a negative lens system; when the focal length f2 of the modulating optical system (30) is greater than 0, the modulating optical system (30) is a positive lens system.

5. The testing method for improving the assembly accuracy and viewing angle range of an optical module according to claim 1, characterized in that: The focal length f2 of the modulation optical system (30) corresponding to the optical module (10) with different viewing angles 2θ is different.

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