Test tool
By designing the fixture slider and fixture housing structure in the test fixture, the problem of test surface position offset after fixture flipping was solved, realizing accurate testing of EPM transmittance and reflectance, and improving the reliability and efficiency of testing.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-04-23
- Publication Date
- 2026-04-03
AI Technical Summary
In the prior art, when using a single fixture to test the transmittance and reflectance of EPM, it is difficult to keep the position of the test surface consistent after the fixture is flipped, resulting in inaccurate test results.
A testing fixture was designed, including a testing module, a fixture housing, and a fixture slider. By sliding the fixture slider and flipping the fixture housing, the center of the testing surface of the prescription mirror module is ensured to coincide with the light convergence center, thus avoiding the need to replace the fixture.
This technology enables accurate testing of the transmittance and reflectance of different test surfaces of a prescription mirror module without changing the fixture, thus improving the accuracy and efficiency of the test.
Smart Images
Figure CN224081175U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of AR lens testing technology, and in particular to a testing fixture. Background Technology
[0002] Transmittance and reflectance are important indicators for evaluating the optical performance of an EPM (Eye Piece Module). Specifically, the optical performance of the EPM needs to be evaluated based on the transmittance and reflectance of the myopia lens and grating surface at different viewing angles. In existing technologies, a common method for testing the transmittance and reflectance of the EPM at different viewing angles is to fix the EPM to a fixture and control the light source to rotate around the center of the EPM's test surface so that the EPM receives light from different viewing angles. Simultaneously, a detector is placed on the other side of the EPM, which uses a scanning method to test the light energy within a specific field of view at different viewing angles.
[0003] To ensure the accuracy and authenticity of data during batch testing, the light source is installed in a pre-set circular arc track, and the fixture is positioned at the center of this track. When using a single fixture, to measure the transmittance and reflectance of the two test surfaces of the EPM, the fixture must be flipped once. However, the thickness of different EPM models varies, making it difficult to ensure that the positions of the test surfaces are the same before and after flipping. This causes the light emitted by the light source to deviate from the center of the test surfaces at different field of view angles, resulting in inaccurate test results. Utility Model Content
[0004] The existing EPM testing method using a single fixture suffers from test surface offset after flipping, affecting the accuracy of test data. Therefore, it is necessary to provide a test fixture.
[0005] A testing fixture for testing the transmittance and reflectance of a prescription lens module at different field of view angles, comprising:
[0006] The test module has a light converging center, multiple emitting surfaces arranged at intervals around the light converging center and facing the light converging center, and a receiving surface for receiving light.
[0007] A clamp housing, rotatably disposed between the emitting surface and the receiving surface, the clamp housing having an optical channel for light to pass through; and
[0008] A clamping slider is slidably mounted within the optical channel and used to clamp the prescription mirror module.
[0009] With this configuration, by arranging a sliding fixture slider in the fixture housing, when testing one test surface of the prescription mirror module and then needing to test another test surface, the center of the test surface of the prescription mirror module can be aligned with the light convergence center by moving the fixture slider, without the need to change the fixture, thus facilitating user operation.
[0010] In one embodiment, the sliding distance of the clamp slider is equal to the difference between the center distance between the two test surfaces of the prescription mirror module and twice the distance between the flip center of the clamp housing and the light convergence center.
[0011] With this configuration, when the clamp slider is located at one end of the optical channel, the clamp slider is used to make the center of one of the test surfaces of the prescription mirror module coincide with the light convergence center; when the clamp housing is flipped, the clamp slider slides to the other end of the optical channel to make the center of the other test surface of the prescription mirror module coincide with the light convergence center, thereby realizing the accurate testing of the transmittance and reflectance of different test surfaces of the prescription mirror module using a single clamp.
[0012] In one embodiment, the flipping center of the clamp housing coincides with the light converging center.
[0013] With this configuration, the sliding distance of the fixture slider is equal to the center-to-center distance between the two test surfaces of the prescription mirror module, which facilitates the design of the length of the optical channel and the size of the fixture slider.
[0014] In one embodiment, the clamp housing has a first positioning groove and a second positioning groove spaced apart along the extension direction of the optical channel, and the clamp slider includes a clamping body and an elastic positioning block fixedly connected to the outer periphery of the clamping body, the elastic positioning block abutting against the inner wall of the optical channel;
[0015] The elastic positioning block engages with the first positioning groove to make the center of one of the test surfaces of the prescription mirror module overlap with the light converging center, and the elastic positioning block engages with the second positioning groove to make the center of the other test surface of the prescription mirror module overlap with the light converging center.
[0016] This configuration ensures the certainty of the relative position between the fixture slider and the fixture housing in both the pre- and post-flip test conditions, preventing misalignment between the test surface and the light convergence center of the prescription mirror module due to sliding errors.
[0017] In one embodiment, the elastic positioning block has a first positioning protrusion for engaging with the first positioning groove and a second positioning protrusion for engaging with the second positioning groove.
[0018] The first positioning protrusion engages with the first positioning groove so that the center of one of the test surfaces of the prescription mirror module overlaps with the light converging center, and the second positioning protrusion engages with the second positioning groove so that the center of the other test surface of the prescription mirror module overlaps with the light converging center.
[0019] This design helps to increase the stability of the relative position between the clamp slider and the clamp housing, and prevents the clamp slider from shaking during adjustment.
[0020] In one embodiment, the elastic positioning block extends from the clamping body along the edge of the clamping body to form a cantilever end, with the first positioning protrusion and the second positioning protrusion located at the cantilever end, respectively.
[0021] This design increases the elasticity of the elastic positioning block, making it easier to push the positioning protrusion of the clamp slider out of the positioning groove.
[0022] In one embodiment, the fixture housing includes an upper cover and a lower cover, the lower cover being detachably mounted on the upper cover, the upper cover having a first receiving groove and a first window penetrating the bottom of the first receiving groove, and the lower cover having a second receiving groove and a second window penetrating the bottom of the second receiving groove to form the light channel.
[0023] This design, with its separate upper and lower covers, facilitates the installation of the clamp slider into the clamp housing.
[0024] In one embodiment, the clamp housing further includes a first magnetic body mounted on the upper cover and a second magnetic body mounted on the lower cover, the second magnetic body being magnetically connected to the first magnetic body.
[0025] This design, utilizing the automatic adsorption properties of the magnetic material, makes disassembly and assembly more convenient, eliminating the need for external tools and improving the testing efficiency of the prescription mirror module.
[0026] In one embodiment, the lower cover has a limiting hole, the second magnetic body is housed in the limiting hole, and the shape of the first magnetic body matches the shape of the limiting hole and is movably inserted into the limiting hole.
[0027] This design, through the cooperation of the limiting hole and the first magnetic body, enables precise assembly of the upper and lower covers, avoiding misalignment of the upper and lower covers from affecting the test accuracy of the reflectivity and transmittance of the prescription mirror module.
[0028] In one embodiment, the upper cover has a pair of first clamping and positioning holes symmetrically arranged with respect to the optical channel; and / or
[0029] The lower cover has a pair of second clamping and positioning holes arranged symmetrically with respect to the optical channel.
[0030] This design, with its two clamping and positioning holes, increases the certainty of the fixture housing's installation position, thus helping to accurately align the center of the test surface of the prescription mirror module with the light convergence center. In addition, the clamping and positioning holes facilitate the disassembly of the upper and lower covers by the operator. Especially when using a magnetic assembly scheme, the clamping and positioning holes can also assist the operator in separating the upper and lower covers.
[0031] In one embodiment, the test module includes a light source and a detector rotatably disposed on both sides of the fixture housing, the emitting surface being located on the light source and the receiving surface being located on the detector, and the light source having an arc-shaped sliding track centered on the light convergence center.
[0032] With this setup, the light source rotates along an arc track to simulate the transmission and reflectivity tests of the prescription mirror module under any field of view. The detector can rotate to achieve precise scanning of light energy within a specific field of view under different field of view angles. Attached Figure Description
[0033] Figure 1 A schematic diagram of the test fixture in one embodiment of this utility model;
[0034] Figure 2 for Figure 1 The exploded structure diagram of the test fixture shown;
[0035] Figure 3 for Figure 2 The diagram shows the structural schematic of the test fixture at the elastic positioning block.
[0036] Figure 4 for Figure 1 The diagram shows the structure of the test fixture on one side of the top cover;
[0037] Figure 5 for Figure 4 The test fixture shown is in cross-sectional view along the AA direction;
[0038] Figure 6 for Figure 5 A schematic diagram of the structure of the clamp slider and prescription mirror module;
[0039] Figure 7 for Figure 4 The test fixture shown is a cross-sectional view at BB.
[0040] Figure 8 for Figure 7 A magnified view of the area at point X in the middle.
[0041] Figure label:
[0042] 10. Test module; 101. Light converging center; 102. Arc track; 11. Light source; 12. Detector; 20. Fixture housing; 201. Light channel; 202. Flip center; 203. First positioning groove; 204. Second positioning groove; 205. Limiting hole; 206. First clamping positioning hole; 207. Second clamping positioning hole; 21. Top cover; 2101. First window; 22. Bottom cover; 2201. Second window; 23. First magnetic body; 24. Second magnetic body; 30. Fixture slider; 31. Clamping body; 311. First clamping body; 312. Second clamping body; 313. Fastening bolt; 32. Elastic positioning block; 321. First positioning protrusion; 322. Second positioning protrusion; 40. Prescription lens module; 41. Center of myopia lens; 42. Center of grating surface. Detailed Implementation
[0043] To make the above-mentioned objects, features, and advantages of this utility model more apparent and understandable, the specific embodiments of this utility model will be described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a full understanding of this utility model. However, this utility model can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this utility model. Therefore, this utility model is not limited to the specific embodiments disclosed below.
[0044] In the description of this utility model, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this utility model and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model.
[0045] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this utility model, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.
[0046] In this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; 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; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.
[0047] In this utility model, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.
[0048] It should be noted that when an element is referred to as being "fixed to" or "set on" another element, it can be directly on the other element or there may be an intervening element. When an element is considered to be "connected to" another element, it can be directly connected to the other element or there may be an intervening element. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only possible implementation.
[0049] Transmittance and reflectance are important indicators for evaluating the optical performance of an EPM (Eye Piece Module). Specifically, the optical performance of the EPM needs to be evaluated based on the transmittance and reflectance of its two test surfaces (the myopia lens surface and the grating surface) at different field of view angles. In existing technologies, a common method for testing the transmittance and reflectance of the EPM at different field of view angles is to fix the EPM to a fixture and control the light source to rotate around the center of the EPM's test surface so that the EPM receives light from different field of view angles. Simultaneously, a detector 12 is placed on the other side of the EPM, and this detector 12 uses a scanning method to test the light energy within a specific field of view range at different field of view angles.
[0050] To ensure the accuracy and authenticity of data during batch testing, the light source is installed in a pre-set circular arc track, and the fixture is positioned at the center of this track. When using a single fixture, to measure the transmittance and reflectance of the two test surfaces of the EPM, the fixture must be flipped once. However, the thickness of different EPM models varies, making it difficult to ensure that the positions of the test surfaces are the same before and after flipping. This causes the light emitted by the light source to deviate from the center of the test surfaces at different field of view angles, resulting in inaccurate test results.
[0051] Therefore, it is necessary to provide a test fixture that can ensure that the center of the test surface of the EPM is located at the convergence center of multiple light sources.
[0052] Please see Figures 1 to 5 , Figure 1 This is a schematic diagram of the test fixture in one embodiment of the present invention. Figure 2 for Figure 1 The diagram shows the exploded structure of the test fixture. Figure 3 for Figure 2 The diagram shows the structure of the test fixture at the elastic positioning block 32. Figure 4 for Figure 1 The diagram shown is a structural schematic of the test fixture on one side of the upper cover 21. Figure 5 for Figure 4 The test fixture shown is in cross-sectional view along the AA direction.
[0053] The testing fixture provided in this application includes a testing module 10, a fixture housing 20, and a fixture slider 30. The testing module 10 has a light converging center 101, multiple emitting surfaces arranged at intervals around the light converging center 101 and facing the light converging center 101, and a receiving surface for receiving light. The fixture housing 20 is rotatably disposed between the emitting surface and the receiving surface, and the fixture housing 20 has a light channel 201 for light to pass through. The fixture slider 30 is slidably installed in the light channel 201 and is used to hold the prescription mirror module 40. By arranging the slidable fixture slider 30 in the fixture housing 20, when one test surface of the prescription mirror module 40 has been tested and another test surface of the prescription mirror module 40 needs to be tested, the center of the test surface of the prescription mirror module 40 can be made to coincide with the light converging center 101 by moving the fixture slider 30, without the need to change the fixture, which facilitates user operation.
[0054] According to one aspect of this application, please refer to Figure 5 and Figure 6 , Figure 6 for Figure 5A schematic diagram of the structure of the clamp slider 30 and the prescription lens module 40. In order to achieve the accuracy of aligning the center of the test surface of the prescription lens module 40 with the light convergence center 101, the sliding distance of the clamp slider 30 is equal to the difference between the center distance d between the two test surfaces of the prescription lens module 40 (the distance between the center 41 of the myopia lens and the center 42 of the grating surface) and twice the distance between the flip center 202 of the clamp housing 20 and the light convergence center 101. In actual use, the prescription lens module 40 is fixedly connected to the clamp slider 30. When the clamp slider 30 is located at one end of the light channel 201, it is used to make the center of one of the test surfaces of the prescription lens module 40 (one of the myopia lens center 41 and the grating surface center 42) coincide with the light convergence center 101. When the clamp housing 20 is flipped, the clamp slider 30 slides to the other end of the light channel 201 to make the center of the other test surface of the prescription lens module 40 (the other of the myopia lens center 41 and the grating surface center 42) coincide with the light convergence center 101, thereby enabling a single clamp to accurately test the transmittance and reflectance of different test surfaces of the prescription lens module 40. Preferably, to facilitate the design of the slider distance, in one embodiment provided in this application, the flipping center 202 coincides with the light convergence center 101, so that the sliding distance of the clamp slider 30 is equal to the center-to-center distance between the two test surfaces of the prescription lens module 40.
[0055] According to another aspect of this application, please refer to Figure 2 , Figure 3 , Figure 7 and Figure 8 , Figure 7 for Figure 4 The test fixture shown is a cross-sectional view at BB. Figure 8 for Figure 7A magnified view of part X in the middle. Optionally, in order to ensure the certainty of the relative position between the clamp slider 30 and the clamp housing 20, and to avoid the misalignment of the test surface of the prescription mirror module 40 with the light converging center 101 caused by sliding errors, in one embodiment provided in this application, the clamp housing 20 has a first positioning groove 203 and a second positioning groove 204 arranged at intervals along the extension direction of the light channel 201. The clamp slider 30 includes a clamping body 31 and an elastic positioning block 32 fixedly connected to the outer periphery of the clamping body 31. The elastic positioning block 32 abuts against the inner wall of the light channel 201. The elastic positioning block 32 is engaged in the first positioning groove 203 to make the center of one of the test surfaces of the prescription mirror module 40 overlap with the light converging center 101, and the elastic positioning block 32 is engaged in the second positioning groove 204 to make the center of the other test surface of the prescription mirror module 40 overlap with the light converging center 101. It is understandable that, in order to enable the testing of multiple prescription mirror modules 40 of different thicknesses to be adapted in the same fixture housing 20, a third positioning groove, or even a fourth or fifth positioning groove, can be provided on the fixture housing 20. The position of the positioning groove in the optical channel 201 can be designed according to the sliding distance of the fixture slider 30.
[0056] Furthermore, in order to increase the stability of the relative position between the clamp slider 30 and the clamp housing 20 and to prevent the clamp slider 30 from shaking during the sliding adjustment process, in one embodiment provided in this application, the elastic positioning block 32 has a first positioning protrusion 321 for engaging with the first positioning groove 203 and a second positioning protrusion 322 for engaging with the second positioning groove 204; the first positioning protrusion 321 engages with the first positioning groove 203 so that the center of one of the test surfaces of the prescription mirror module 40 overlaps with the light converging center 101, and the second positioning protrusion 322 engages with the second positioning groove 204 so that the center of the other test surface of the prescription mirror module 40 overlaps with the light converging center 101. Preferably, in order to ensure the smoothness of the clamp slider 30 during the sliding process, in one embodiment provided in this application, the first positioning groove 203 and the second positioning groove 204 are respectively located at both ends of the optical channel 201, and the first positioning protrusion 321 and the second positioning protrusion 322 are respectively located at the edges of two surfaces of the clamp slider 30 along the extension direction of the optical channel 201. In this way, the distance between the first positioning protrusion 321 and the second positioning protrusion 322 is maximized. Since the first positioning protrusion 321 and the second positioning protrusion 322 act as fulcrums during the sliding process of the clamp slider 30, this can reduce the wobble and tilting problems generated by the clamp slider 30 during the sliding process, which is beneficial to prevent the clamp slider 30 from getting stuck, thereby improving the smoothness of the clamp slider 30 sliding in the optical channel 201.
[0057] Furthermore, to increase the elasticity of the elastic positioning block 32 and reduce the jamming problem of the clamp slider 30 during sliding, in one embodiment provided in this application, the elastic positioning block 32 extends from the clamping body 31 along the edge of the clamping body 31 to form a cantilever end, with the first positioning protrusion 321 and the second positioning protrusion 322 respectively located at the cantilever end. By designing the elastic positioning block 32 as a cantilever structure, the elasticity of the elastic positioning block 32 is increased, facilitating the pushing of the positioning protrusion of the clamp slider 30 out of the positioning groove.
[0058] In order to reduce the deformation of the clamp housing 20 and increase the elasticity of the clamp slider 30, in one embodiment provided in this application, the clamp housing 20 is made of metal material such as aluminum alloy, and the clamp slider 30 is made of PC material.
[0059] Please refer to it again. Figure 2 To facilitate the installation of the clamp slider 30 into the clamp housing 20, in one embodiment of this application, the clamp housing 20 includes an upper cover 21 and a lower cover 22. The lower cover 22 is detachably installed on the upper cover 21. The upper cover 21 has a first receiving groove and a first window 2101 penetrating the bottom of the first receiving groove, and the lower cover 22 has a second receiving groove and a second window 2201 penetrating the bottom of the second receiving groove to form a light channel 201. Furthermore, for ease of assembly and disassembly, the clamp housing 20 also includes a first magnetic body 23 installed on the upper cover 21 and a second magnetic body 24 installed on the lower cover 22. The second magnetic body 24 is magnetically connected to the first magnetic body 23. Specifically, in one embodiment of this application, the first magnetic body 23 is a magnet, and the second magnetic body 24 is an iron bolt. Optionally, to facilitate fixing the prescription mirror module 40 to the clamp slider 30, the clamping body 31 of the clamp slider 30 includes a first clamping body 311 and a second clamping body 312. The two clamping bodies are respectively provided with a first contour groove and a second contour groove that match the shape of the prescription mirror module 40 to form an accommodating space for accommodating the prescription mirror module 40. The two clamping bodies are connected by fastening bolts 313 to achieve clamping and fixing of the prescription mirror module 40.
[0060] like Figure 2 As shown, the lower cover 22 also has a limiting hole 205. The second magnetic body 24 is housed in the limiting hole 205. The shape of the first magnetic body 23 matches the shape of the limiting hole 205 and is movably inserted into the limiting hole 205. In this way, the cooperation between the first magnetic body 23 and the limiting hole 205 can prevent misalignment between the upper cover 21 and the lower cover 22, thus increasing the stability of the upper cover 21 and the lower cover 22 after assembly.
[0061] like Figure 2As shown, optionally, to facilitate the installation of the clamp housing 20, in one embodiment provided in this application, the upper cover 21 has a pair of first clamping positioning holes 206 symmetrically arranged with respect to the optical channel 201, and the lower cover 22 has a pair of second clamping positioning holes 207 symmetrically arranged with respect to the optical channel 201. Furthermore, the arrangement of the first clamping positioning holes 206 and the second clamping positioning holes 207 also facilitates the operator's disassembly and assembly of the upper cover 21 and the lower cover 22 of the clamp housing 20, especially when disassembling the magnetic clamp housing 20, by staggering the arrangement of the first clamping positioning holes 206 and the second clamping positioning holes 207, or as... Figure 1 and Figure 2 As shown, two clamping positioning holes are arranged on different sides of the upper cover 21 and the lower cover 22, which facilitates the operator to apply a pulling force to separate the upper cover 21 and the lower cover 22.
[0062] Please refer to the following: Figure 2 and Figure 5 Specifically, the test module 10 includes a light source 11 and a detector 12 rotatably disposed on both sides of the fixture housing 20. The emitting surface is located on the light source 11, and the receiving surface is located on the detector 12. The light source 11 has an arc-shaped sliding track centered on the light convergence center 101. The light source 11 rotates along the arc track 102 to simulate the test of the transmittance and reflectance of the prescription mirror module 40 under any field of view. The detector 12 is rotatable to achieve accurate scanning of light energy within a specific field of view under different field of view angles. It is understood that in other embodiments, there can be multiple light source elements 11, each with its own emitting surface. Optionally, in one embodiment provided in this application, the test fixture also provides a mounting groove for fixing the fixture housing 20. When flipping is required, the fixture housing 20 can be pulled out of the mounting groove and manually flipped. It is understood that in other embodiments, to achieve flipping, a rotating stage can also be provided at the light convergence center 101, and the fixture housing 20 can be fixed to the rotating stage.
[0063] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.
[0064] The embodiments described above are merely illustrative of several implementations of this utility model, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the utility model patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this utility model, and these all fall within the protection scope of this utility model. Therefore, the protection scope of this utility model patent should be determined by the appended claims.
Claims
1. A testing fixture for testing the transmittance and reflectance of a prescription mirror module at different viewing angles, characterized in that, include: The test module has a light converging center, multiple emitting surfaces arranged at intervals around the light converging center and facing the light converging center, and a receiving surface for receiving light. A clamp housing is rotatably disposed between the emitting surface and the receiving surface, and the clamp housing has an optical channel for light to pass through; as well as A clamping slider is slidably mounted within the optical channel and used to clamp the prescription mirror module.
2. The test fixture according to claim 1, characterized in that, The sliding distance of the clamp slider is equal to the difference between the center distance between the two test surfaces of the prescription mirror module and twice the distance between the flip center of the clamp housing and the light converging center; and / or The flipping center of the fixture housing coincides with the light converging center.
3. The testing fixture according to claim 1, characterized in that, The fixture housing has a first positioning groove and a second positioning groove arranged at intervals along the extension direction of the optical channel. The fixture slider includes a clamping body and an elastic positioning block fixedly connected to the outer periphery of the clamping body. The elastic positioning block abuts against the inner wall of the optical channel. The elastic positioning block engages with the first positioning groove to make the center of one of the test surfaces of the prescription mirror module overlap with the light converging center, and the elastic positioning block engages with the second positioning groove to make the center of the other test surface of the prescription mirror module overlap with the light converging center.
4. The testing fixture according to claim 3, characterized in that, The elastic positioning block has a first positioning protrusion for engaging with the first positioning groove and a second positioning protrusion for engaging with the second positioning groove. The first positioning protrusion engages with the first positioning groove so that the center of one of the test surfaces of the prescription mirror module overlaps with the light converging center, and the second positioning protrusion engages with the second positioning groove so that the center of the other test surface of the prescription mirror module overlaps with the light converging center.
5. The testing fixture according to claim 4, characterized in that, The elastic positioning block extends from the clamping body along the edge of the clamping body to form a cantilever end, and the first positioning protrusion and the second positioning protrusion are respectively located at the cantilever end.
6. The test fixture according to any one of claims 1 to 5, characterized in that, The fixture housing includes an upper cover and a lower cover. The lower cover is detachably mounted on the upper cover. The upper cover has a first receiving groove and a first window penetrating the bottom of the first receiving groove, and the lower cover has a second receiving groove and a second window penetrating the bottom of the second receiving groove to form the light channel.
7. The test fixture according to claim 6, characterized in that, The clamp housing also includes a first magnetic body mounted on the upper cover and a second magnetic body mounted on the lower cover, wherein the second magnetic body is magnetically connected to the first magnetic body.
8. The test fixture according to claim 7, characterized in that, The lower cover has a limiting hole, the second magnetic body is housed in the limiting hole, and the shape of the first magnetic body matches the shape of the limiting hole and is movably inserted into the limiting hole.
9. The test fixture according to claim 6, characterized in that, The upper cover has a pair of first clamping and positioning holes symmetrically arranged with respect to the optical channel; and / or The lower cover has a pair of second clamping and positioning holes arranged symmetrically with respect to the optical channel.
10. The test fixture according to any one of claims 1 to 5, characterized in that, The test module includes a light source and a detector rotatably disposed on both sides of the fixture housing. The emitting surface is located on the light source, and the receiving surface is located on the detector. The light source has an arc-shaped sliding track centered on the light convergence center.