Diffractive optical element testing device

Abstract

The utility model relates to the technical field of diffractive optical elements, and discloses a diffractive optical element testing device, a tested diffractive optical element is projected onto a projection screen through a light source module to form a pattern of the tested diffractive optical element, and the pattern of the tested diffractive optical element is acquired by using a camera module. The working distance between the light source and the tested diffractive optical element is limited through the thickness of the gasket assembly, and the assembly precision between the diffractive optical element and the light source is achieved. The position of the lens does not need to be finely regulated and controlled by adopting a high-precision displacement table, so that the cost of the testing device is reduced, the low-cost discrete testing of the diffractive optical element lens is realized, and the universality and the flexibility of the diffractive optical element testing device are improved.

Description

Technical Field

[0001] This application relates to the field of diffractive optical element technology, and in particular to a diffractive optical element testing device. Background Technology

[0002] With the development of smart devices, the demand for optical sensing is increasing daily. Therefore, projection devices based on diffractive optical elements (DOEs) have experienced rapid development. Their ability to arbitrarily shape light beams allows for directional projection according to the sensing image requirements, thereby obtaining high-quality light sensing signals.

[0003] To ensure the quality of the projection module, an efficient and reliable testing system for diffractive optical elements is required. Since diffractive optical elements are highly customized devices, a large number of customized functional and structural components are needed to provide a system for testing their performance. This results in poor versatility and low flexibility of the testing system. Utility Model Content

[0004] This application provides a testing device for diffractive optical elements, which solves the technical problems of poor versatility and low flexibility of diffractive optical element testing systems.

[0005] In view of this, this application provides a testing device for diffractive optical elements, including: a testing stage; a light source module, a projection screen and a camera module are mounted on the testing stage;

[0006] The light source module and the camera module are respectively located on both sides of the projection screen;

[0007] The light source module includes a light source carrier plate, a spacer assembly, and a light source for mounting the diffractive optical element under test.

[0008] The light source is mounted on the light source carrier plate;

[0009] The spacer assembly is installed between the light source carrier and the diffractive optical element under test, and the working distance between the light source and the diffractive optical element under test is limited by the thickness of the spacer assembly.

[0010] Preferably, the test bench includes a test frame with a frame structure;

[0011] The test framework includes an outer frame;

[0012] The outer frame has a light source fixing frame for mounting the light source module, a screen fixing frame for mounting the projection screen, and a camera fixing frame for mounting the camera module inside.

[0013] Preferably, the device further includes: a light source support; the light source support includes a first lead screw guide rail, a displacement stage, a connecting rod, and a glass slide clamping frame;

[0014] The bottom of the displacement stage is slidably connected to the first lead screw guide rail;

[0015] The top of the displacement stage is fixedly connected to the slide holder via the connecting rod;

[0016] The light source carrier plate is fixed on the glass slide holder.

[0017] Preferably, the diffractive optical element under test includes a lens carrier, a diffractive optical element lens, and a lens cover plate;

[0018] The lens carrier plate is fixedly connected to the light source carrier plate;

[0019] The lens carrier plate has a groove that matches the size and structure of the diffractive optical element lens;

[0020] The diffractive optical element lens is fixedly embedded in the groove;

[0021] The lens cover plate covers the groove and is fixed to the lens carrier plate.

[0022] Preferably, the device further includes: a camera bracket;

[0023] The camera bracket includes a second lead screw guide rail, a telescopic connecting rod, and a universal joint fixing base;

[0024] The lower end of the telescopic connecting rod is slidably connected to the second lead screw guide rail;

[0025] The top end of the telescopic extension rod is fixedly connected to the universal joint fixing base;

[0026] The camera module is fixedly mounted on the universal joint mounting base.

[0027] Preferably, the camera module includes an industrial camera and a camera lens, with the camera lens mounted on the industrial camera.

[0028] Preferably, the bottom of the test platform is provided with casters.

[0029] Preferably, the bottom of the test bench is provided with a shock absorption mechanism.

[0030] Preferably, both the light source module and the camera module are equipped with a collimating laser, which is used to emit a laser beam and project it onto the projection screen.

[0031] Preferably, the device further includes an image processing module, which is electrically connected to the camera module;

[0032] The image processing module is used to perform test processing on the projected image of the diffractive optical element under test acquired by the camera module.

[0033] As can be seen from the above technical solutions, the embodiments of this application project the diffractive optical element under test onto the projection screen through the light source module to form a pattern of the diffractive optical element under test. The camera module acquires the pattern of the diffractive optical element under test to perform test processing on the pattern of the diffractive optical element under test, thereby realizing the performance test of the diffractive optical element under test. The working distance between the light source and the diffractive optical element under test is limited by the thickness of the shim assembly, thereby achieving the assembly accuracy between the diffractive optical element and the light source. There is no need to use a high-precision displacement stage to finely adjust the position of the lens, which reduces the cost of the test device. This enables low-cost discrete testing of diffractive optical element lenses and improves the versatility and flexibility of the diffractive optical element test device. Attached Figure Description

[0034] Figure 1A A three-dimensional structural schematic diagram of a testing device for diffractive optical elements;

[0035] Figure 1B This is a front view schematic diagram of a diffractive optical element testing device;

[0036] Figure 2 This is an exploded view of the light source module;

[0037] Figure 3 This is a schematic diagram of the test framework.

[0038] Figure 4 This is a schematic diagram of the light source support structure;

[0039] Figure 5 This is a schematic diagram of the camera bracket structure;

[0040] Figure 6 The testing principle of the diffractive optical element testing device;

[0041] Figure 7a , Figure 7b These are all schematic diagrams of light spots captured during photography.

[0042] Figure label:

[0043] 1. Test stand; 2. Projection screen; 3. Light source module; 4. Camera module; 11. Outer frame; 12. Screen fixing frame; 13. Light source fixing frame; 14. Camera fixing frame; 31. First lead screw guide rail; 32. Displacement stage; 33. Connecting rod; 34. Glass slide holder; 41. Second lead screw guide rail; 42. Telescopic connecting rod; 43. Universal joint fixing base; 51. Light source carrier plate; 53. Light source; 54. Gasket assembly; 55. Lens carrier plate; 56. Diffractive optical element lens; 57. Lens cover plate; 61. Industrial camera; 62. Camera lens. Detailed Implementation

[0044] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present application.

[0045] In the description of the embodiments of this application, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of this application. In addition, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0046] In the description of the embodiments of this application, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a replaceable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of this application based on the specific circumstances.

[0047] like Figures 1A-1B As shown, this application provides a testing device for diffractive optical elements, including: a test stage 1; a light source module 3, a projection screen 2 and a camera module 4 are installed on the test stage 1;

[0048] The light source module 3 and the camera module 4 are respectively located on both sides of the projection screen 2;

[0049] Among them, the projection screen 2 can be a diffuse transmission screen with Lambertian transmission characteristics.

[0050] like Figure 2 As shown, the light source module 3 includes a light source carrier plate 51 for mounting the diffractive optical element under test, a spacer assembly 54, and a light source 53.

[0051] The light source 53 is mounted on the light source carrier plate 51;

[0052] The spacer assembly 54 is installed between the light source carrier plate 51 and the diffractive optical element under test. The working distance between the light source 53 and the diffractive optical element under test is limited by the thickness of the spacer assembly 54.

[0053] The spacer assembly 54 includes multiple rigid sheets, which are stacked together. The thickness of the spacer assembly 54 is limited by the number of rigid sheets, thereby limiting the working distance between the light source carrier 51 and the diffractive optical element under test.

[0054] It is understood that the diffractive optical element testing device provided in this application projection module projects the diffractive optical element under test onto a projection screen to form a pattern of the diffractive optical element under test. The camera module acquires the pattern of the diffractive optical element under test for testing and processing, thereby realizing performance testing of the diffractive optical element under test. The working distance between the light source and the diffractive optical element under test is limited by the thickness of the spacer assembly, thereby achieving the assembly accuracy between the diffractive optical element and the light source. It eliminates the need for a high-precision displacement stage to finely adjust the position of the lens, reducing the cost of the testing device. This enables low-cost discrete testing of diffractive optical element lenses, improving the versatility and flexibility of the diffractive optical element testing device.

[0055] In some embodiments, such as Figure 3 As shown, test bench 1 includes a test frame with a frame structure;

[0056] The test framework includes an outer frame 11;

[0057] The outer frame 11 has a light source fixing frame 13 for mounting the light source module, a screen fixing frame 12 for mounting the projection screen, and a camera fixing frame 14 for mounting the camera module inside.

[0058] In order to provide a darkroom testing environment, a darkroom cover cloth can be fixed to the outer frame 11 to cover the entire testing device.

[0059] In some embodiments, such as Figure 4 As shown, the device also includes: a light source support; the light source support includes a first lead screw guide rail 31, a displacement stage 32, a connecting rod 33, and a glass slide clamping frame 34;

[0060] The bottom of the displacement stage 32 is slidably connected to the first lead screw guide rail 31;

[0061] The top of the displacement stage 32 is fixedly connected to the slide holder 34 via a connecting rod 33;

[0062] The light source carrier plate 51 is fixed on the glass slide holder 34.

[0063] The first lead screw guide rail 31 can be controlled manually or by a stepper motor. The movement of the displacement stage 32 is controlled by manual or stepper motor, which in turn drives the glass slide holder 34 to move relative to it, thereby improving the projection flexibility.

[0064] like Figure 2 As shown, the diffractive optical element under test includes a lens carrier plate 55, a diffractive optical element lens 56, and a lens cover plate 57.

[0065] The lens carrier plate 55 is fixedly connected to the light source carrier plate 51;

[0066] The lens carrier plate 55 has a groove that matches the size and structure of the diffractive optical element lens 56;

[0067] The diffractive optical element lens 56 is fixedly embedded in the groove;

[0068] The lens cover plate 57 covers the groove and is fixed to the lens carrier plate 51.

[0069] In practical applications, the light source carrier plate 51 can provide a power supply interface for the light source, and has four screw holes for connection to the gasket assembly 54 and the lens carrier plate 55 respectively. The lens carrier plate 55 consists of a lens placement area and a carrier plate fixing area. The lens placement area consists of a groove that matches the size of the diffractive optical element lens 56, providing a tolerance margin that matches the packaging accuracy. At the same time, the lens placement area has two small screw holes for fixing the lens cover plate 57. The carrier plate fixing area has four screw holes that match the light source carrier plate 51.

[0070] The center of the lens cover plate 57 has a light-transmitting area that is slightly smaller than the size of the diffractive optical element lens 56, and the edge has two small screw holes that match the lens carrier plate 55.

[0071] Specifically, the light source carrier plate 51 has four screw holes for fixing the lens carrier plate 55; the lens carrier plate 55 also has four screw holes at corresponding positions, and the center of the lens carrier plate 55 has a lens placement area that matches the size of the diffractive optical element lens 56; after being fixed to the light source carrier plate 51 by the four screws, high-precision xy-plane alignment accuracy is provided; before fixing, a suitable shim assembly 54 is selected and placed between the light source carrier plate 51 and the lens carrier plate 55, thereby providing high-precision working distance accuracy; after the diffractive optical element is placed in the loading area of ​​the light source carrier plate 51, the lens cover plate 57 is fixed to the lens carrier plate by the lens fixing frame.

[0072] like Figure 5 As shown, this device also includes: a camera bracket;

[0073] The camera bracket includes a second lead screw guide rail 41, a telescopic extension rod 42, and a universal joint fixing base 43;

[0074] The lower end of the telescopic extension rod 42 is slidably connected to the second lead screw guide rail 41;

[0075] The telescopic extension rod 42 includes two connecting rods that are connected end to end. The two connecting rods are slidably connected, thereby allowing the length of the telescopic extension rod 42 to be adjusted.

[0076] The top end of the telescopic extension rod 42 is fixedly connected to the universal joint base 43;

[0077] The camera module 6 is fixedly mounted on the universal joint mounting base 43.

[0078] The universal joint mounting base 43 has a universal joint at its bottom, which allows the universal joint mounting base 43 to move more flexibly.

[0079] Among them, such as Figure 5 As shown, camera module 4 includes an industrial camera 61 and a camera lens 62, with the camera lens 62 mounted on the industrial camera 61.

[0080] The second lead screw guide rail 41 can be controlled manually or by a stepper motor. The universal joint fixed base 43 is moved by the manual or stepper motor, which in turn drives the camera module 4 to move relative to it, thereby improving the flexibility of camera movement.

[0081] In some embodiments, the test stand 1 is provided with casters at the bottom to provide mobility.

[0082] In some embodiments, the bottom of the test bench 1 is provided with a shock-absorbing mechanism to improve the stability of the device.

[0083] In some embodiments, both the light source module 3 and the camera module 4 are equipped with collimated lasers, which are used to emit laser beams that are projected onto the projection screen 2.

[0084] Among them, a laser beam emitted by a collimating laser is projected onto the projection screen 2 to provide a test reference point and improve the overall test accuracy.

[0085] In some embodiments, the device further includes an image processing module electrically connected to the camera module 4;

[0086] The image processing module is used to test and process the projected image of the diffractive optical element under test acquired by the camera module 4.

[0087] The image processing module can be a computer host.

[0088] The aluminum profiles, projection screens, lead screws, displacement stages, connecting rods, glass slide holders, telescopic extension rods, universal joint bases, industrial cameras, and industrial camera lenses used in the testing device provided in this application are all industrial standard product components with high reusability, which makes the overall device cost significantly more advantageous than customized solutions.

[0089] The discrete test light source module for diffractive optical elements provided in this application embodiment precisely controls the distance between the lens and the light source through the spacer assembly 54; the overall processing difficulty is relatively low; if a traditional discrete alignment scheme is used, a multi-axis displacement stage and a custom mold are required, which would be more costly.

[0090] The installation / debugging process of the diffraction optical element testing device provided in this application embodiment is as follows:

[0091] 1) Assemble the aluminum profile frame, using corner blocks to ensure the verticality of all connections.

[0092] 2) Install the projection screen, ensuring that the screen frame portion based on the aluminum profile frame is perpendicular to the central axis;

[0093] 3) Install the lead screw guide rail, and ensure that it is on the central axis by adjusting and locking the position of the light source bracket and camera bracket on the aluminum profile frame. Mark the position of the central axis to install the light source bracket and camera bracket.

[0094] 4) Calibrate the relative illumination and distortion of the camera and lens; after completion, place it on the camera bracket; move the lead screw guide of the camera bracket to fix the distance between the camera and the projection screen; change the shooting angle of the camera by adjusting the universal joint, observe the image on the projection screen and adjust the angle to ensure that the camera optical axis is perpendicular to the projection screen.

[0095] During installation and commissioning, a laser reflection device can be used to calibrate the verticality and parallelism of the structure, thereby improving the assembly accuracy of the testing device.

[0096] 5) Complete installation and debugging.

[0097] like Figure 6 As shown, the testing procedure of the diffraction optical element testing device provided in this application embodiment is as follows:

[0098] 1) Fix the carrier plate carrying the standard projection light source module to the light source side using a glass slide holder, power the light source module through external wiring, so that it projects a standard pattern on the projection screen, and use a camera to capture the image for calibration testing.

[0099] 2) The light source carrier plate carrying the projection module of the diffractive optical element is fixed to the light source side by a glass slide holder; or the diffractive optical element lens is fixed to the carrier plate carrying the light source by a gasket assembly, a lens carrier plate and a lens fixing frame, and then the whole is fixed to the light source side by a glass slide holder.

[0100] Before testing, the lead screws of the light source bracket and camera bracket can be adjusted to change the projection distance and image capture distance of the test.

[0101] 3) Power the light source module through external wiring so that it projects the test pattern on the diffuse screen; adjust and calibrate the position of the component through the displacement stage, and ensure that it meets the test requirements through the image center.

[0102] 4) The projection image of the diffuse screen captured by the industrial camera is read by software, thereby obtaining the projection pattern of the diffractive optical element, such as... Figure 7a The image shows the light spot.

[0103] 5) Obtain the grayscale distribution of the projection pattern of the diffractive optical element through the image processing module, and then calculate the performance index of the diffractive optical element.

[0104] The above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit it. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application.

Claims

1. A diffractive optical element testing apparatus characterized by comprising: The utility model relates to a kind of test platform for diffractive optical element, including: Test platform; Light source module, projection screen and camera module are installed on the test platform; The light source module and the camera module are respectively arranged at the two sides of the projection screen; The light source module includes light source carrier plate for loading the diffractive optical element to be tested, gasket assembly and light source; The light source is installed on the light source carrier plate; The gasket assembly is installed between the light source carrier plate and the diffractive optical element to be tested, and the working distance of the light source and the diffractive optical element to be tested is defined by the thickness of the gasket assembly.

2. The diffractive optical element testing apparatus according to claim 1, wherein The test platform includes a test frame of frame structure; The test frame includes an outer frame; The inner part of the outer frame is provided with a light source fixing frame for installing the light source module, a screen fixing frame for installing the projection screen and a camera fixing frame for installing the camera module.

3. The diffractive optical element testing apparatus of claim 1, wherein Further comprising: A light source support, the light source support includes a first screw rod guide rail, a displacement table, a connecting rod and a slide clamping frame; The bottom of the displacement table is slidably connected with the first screw rod guide rail; The top of the displacement table is fixedly connected with the slide clamping frame through the connecting rod; The light source carrier plate is fixed on the slide clamping frame.

4. The diffractive optical element testing apparatus according to claim 1 or 3, characterized by The diffractive optical element to be tested includes a lens carrier plate, a diffractive optical element lens and a lens cover plate; The lens carrier plate is fixedly connected to the light source carrier plate; The lens carrier plate is provided with a groove matching the size structure of the diffractive optical element lens; The diffractive optical element lens is fixedly embedded in the groove; The lens cover plate covers the groove and is fixed to the lens carrier plate.

5. The diffractive optical element testing apparatus of claim 1, wherein, Further comprising: A camera support; The camera support includes a second screw rod guide rail, a telescopic connecting rod and a universal shaft fixing base; The lower end of the telescopic connecting rod is slidably connected with the second screw rod guide rail; The top end of the telescopic connecting rod is fixedly connected with the universal shaft fixing base; The camera module is fixedly installed on the universal shaft fixing base.

6. The diffractive optical element testing apparatus according to claim 1 or 5, characterized by The camera module includes an industrial camera and a camera lens, and the camera lens is installed on the industrial camera.

7. The diffractive optical element testing apparatus of claim 1, wherein, The bottom of the test platform is provided with a roller.

8. The diffractive optical element testing apparatus of claim 1, wherein, The bottom of the test platform is provided with a damping mechanism.

9. The diffractive optical element testing apparatus of claim 1, wherein, The light source module and the camera module are both provided with a collimated laser, which is used to emit a laser beam to project on the projection screen.

10. The diffractive optical element testing apparatus of claim 1, wherein, Further comprising: An image processing module, which is electrically connected with the camera module; The image processing module is used for testing and processing the projection image of the diffractive optical element to be tested acquired by the camera module.

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