Convex mirror surface shape detection device and method

Abstract

The present invention provides a convex mirror surface shape detection device and method. A single beam of light emitted by a light source is converted into multiple beams of light with equal spatial angles through a grating. The multiple beams of light are then reflected by a polarizer onto a convex mirror. The convex mirror then reflects the multiple linear beams of light onto a plane reflector, which then returns to the convex mirror along the same path. The beams are then reflected through the polarizer and converge at a point on the camera imaging surface. By rotating the convex mirror, the detection aperture can be changed, and the surface shape of the convex mirror can be determined to be qualified, thereby reconstructing the convex mirror's shape. By recording the adjustment amount of each actuator, the present invention can obtain the slope change introduced by the convex surface on each light ray, avoiding complex spatial angle calculations and achieving zero-position detection. Replacing the varying components with unchanging components greatly simplifies the slope calculation process.

Description

Technical Field

[0001] The present invention relates to the technical field of convex mirror surface shape detection, and specifically provides a convex mirror surface shape detection device and method. Background Art

[0002] With the rapid development of astronomical research hotspots such as black holes, dark matter and dark energy, the origin of the universe, the origin of celestial bodies, and the origin of life in the universe, deeper and more detailed exploration of the universe requires the use of large-aperture telescopes to achieve higher light-collecting areas and higher resolutions. Large-aperture convex mirrors, as key components of large-aperture telescopes, have also grown in size. However, the current manufacturing of large-aperture convex mirrors still presents numerous technical challenges. Large-aperture convex mirrors inevitably exhibit irregular shapes, and telescopes constructed using these mirrors can also suffer from precision issues.

[0003] Therefore, surface shape detection for large-aperture convex mirrors is particularly critical. However, existing technologies for this purpose are incomplete, with most approaches focusing on plane mirror shape detection. Existing large-aperture convex mirror shape detection is complex and requires extensive equipment. Mirror shape detection typically uses spherical waves to perform sub-aperture shape detection on the mirror surface, followed by surface shape splicing of the sub-aperture detection results. However, this process is complex and can only determine whether the mirror shape meets requirements, providing little assistance in mirror shape reconstruction. Summary of the Invention

[0004] In order to solve the above problems, the present invention provides a convex mirror surface shape detection device, which mainly includes: a light source, a grating, a polarizer, a convex mirror, a substrate, a camera, an actuator and a plane reflector;

[0005] A grating and a polarizer are sequentially arranged on the light path of the light source. The grating is used to convert the single beam of light emitted by the light source into multiple beams of light with equal angular distribution in space.

[0006] There are at least three actuators connected to a plane mirror, and the actuators can be displaced on the substrate and the displacement distance can be recorded;

[0007] The base is arranged above the convex mirror, and the base is a concave spherical surface;

[0008] The camera is used to receive the reflected light.

[0009] The present invention specifically provides:

[0010] Preferably, the light beam emitted by the light source is incident on the polarizer and reflected by the polarizer onto the convex mirror. The convex mirror reflects the light beam to the plane mirror. The plane mirror reflects the light beam along the incident light path onto the convex mirror, and is then reflected by the convex mirror to the polarizer and converges onto the imaging surface of the camera through the polarizer.

[0011] Preferably, a scale is provided on the substrate for recording the displacement vector of the actuator.

[0012] Preferably, a polarizer and a narrowband filter are further included, and both the polarizer and the narrowband filter are arranged between the light source and the grating to improve the signal-to-noise ratio of the surface shape detection result.

[0013] A convex mirror shape detection method is provided, which uses a convex mirror shape detection device to perform convex mirror shape detection, and specifically comprises the following steps:

[0014] S1. The light source emits a single beam of light, the grating converts the single beam of light into multiple beams of light with equal angular distribution in space, and the polarizer reflects the multiple beams of light to the convex mirror;

[0015] S2. Displace the actuator along the substrate so that multiple beams of light are respectively irradiated on the plane mirrors on different actuators, and the positions of the actuators are respectively recorded. It is ensured that the multiple beams of light are reflected by the plane mirror back to the original reflection position of the convex mirror, and then reflected by the convex mirror and transmitted through the polarizer to converge onto the imaging surface of the camera. This point is recorded as the reference point, and the surface slope of the sub-aperture can be obtained;

[0016] S3, rotating the convex mirror concentrically to detect the next sub-aperture;

[0017] If the position of the reference point shifts, adjust the actuator so that the multiple beams converge to the reference point, and record the adjustment amount of the actuator respectively;

[0018] If the position of the reference point remains unchanged after one rotation, the convex mirror surface shape test is qualified.

[0019] Preferably, the slope change caused by the aperture change of the convex mirror can be calculated based on the adjustment amount, and the slope of the surface at the corresponding point can be determined.

[0020] Compared with the prior art, the present invention can achieve the following beneficial effects:

[0021] The present invention utilizes multiple light beams to replace traditional wavefront light, thereby realizing pure geometric optical detection. Compared with methods such as interference or diffraction, the present invention is simpler in calculation for surface shape detection.

[0022] The present invention ensures that the position of the imaging surface of the camera where multiple light beams converge remains unchanged by adjusting the actuators. The slope change of each light beam introduced by the convex surface can be obtained by recording the adjustment amount of each actuator. Since the transmission light path does not change significantly, the present invention avoids complex spatial angle calculations and realizes zero-position detection, and replaces the changing components with unchanged components. Therefore, the present invention greatly simplifies the calculation process of the slope information. In the prior art, the curvature information of the convex mirror is deduced by changing the imaging position, and calculation and analysis of each transmission point on the light path are required, which is very complicated and prone to interference and errors.

[0023] The present invention can not only perform surface shape qualification detection, but also the calculated data can be used in the surface shape reconstruction process of the convex mirror. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 2 is a simplified structural diagram of a convex mirror shape detection device according to an embodiment of the present invention;

[0025] Figure 2 4 is a flow chart of a convex mirror shape detection method provided according to an embodiment of the present invention.

[0026] Reference numerals include:

[0027] Light source 1, grating 2, polarizer 3, convex mirror 4, substrate 5, plane mirror 6, actuator 7, camera 8. DETAILED DESCRIPTION

[0028] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In the following description, identical modules are denoted by identical reference numerals. In the case of identical reference numerals, their names and functions are also identical. Therefore, their detailed description will not be repeated.

[0029] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and do not constitute a limitation of the present invention.

[0030] Figure 1 The structure of a convex mirror surface shape detection device provided according to an embodiment of the present invention is shown.

[0031] like Figure 1 As shown, the convex mirror surface shape detection device provided by the embodiment of the present invention specifically includes: a light source 1, a grating 2, a polarizer 3, a convex mirror 4, a substrate 5, a plane reflector 6, an actuator 7, and a camera 8, wherein:

[0032] Light source 1 can be a laser with good beam quality. A grating 2 and a polarizer 3 are sequentially placed along the light path of light source 1. Light source 1 emits a single beam. This single beam passes through grating 2, whose surface pores are evenly spaced. After processing by grating 2, this single beam is converted into multiple beams of light with spatially equiangular distribution. Based on geometric theorems, multiple beams of light are at least three linear beams. Furthermore, a polarizer and a narrowband filter can be sequentially placed along the light path between light source 1 and grating 2. These filters can filter out background and interference light, preventing them from interfering with the surface detection results, effectively improving the signal-to-noise ratio of surface detection.

[0033] This embodiment is only described with three linear light beams. The three linear light beams are irradiated to the polarizer 3. The polarizer 3 only allows light of a specific angle to be transmitted. The polarizer 3 reflects the three linear light beams to the convex mirror 4, and defines the reflection points of the three linear light beams on the convex mirror 4 as the slope calculation points. The three linear light beams are reflected to the substrate 5. The substrate 5 is arranged above the convex mirror 4. The substrate 5 is a concave spherical surface. The substrate 5 is provided with a scale for recording the displacement vector of the actuator 7. The number of actuators 7 is equal to the number of linear light beams. In this embodiment, the actuator 7 is three, and a plane mirror 6 is connected to the actuator 7. The actuator 7 is adjusted so that the three beams of linear light are vertically irradiated to the plane mirror 6 fixed on the actuator 7, so that the three beams of linear light return along the original light path. The plane mirror 6 reflects the three beams of linear light back to the slope calculation point on the convex mirror 4, and then reflects them to the polarizer 3 through the convex mirror 4. At this time, the incident angle of the three beams of linear light is the incident angle of light allowed to pass through the polarizer 3. After passing through the polarizer 3, the three beams of linear light converge at a point on the imaging surface of the camera 8, and this point is recorded as the reference point.

[0034] In the present invention, the distance and setting angle between the various elements can be selected according to specific needs and will not be described in detail here.

[0035] Figure 2 The flowchart of the convex mirror shape detection method provided by an embodiment of the present invention is shown.

[0036] like Figure 2 As shown, based on the convex mirror shape detection device, the convex mirror shape detection method provided by the embodiment of the present invention specifically includes the following steps:

[0037] S1. Determine the initial position of each component according to specific needs, start the light source 1 to emit a single beam of light, and the single beam of light passes through the polarizer and narrow-band filter set between the light source 1 and the grating 2 in turn. The polarizer and narrow-band filter can filter out background light and interference light to avoid their interference with the surface detection results, which can effectively improve the signal-to-noise ratio of the surface detection system. The single beam of light is then converted into multiple linear beams with equal angles in space through the grating 2. The multiple linear beams of light are incident on the polarizer 3. The incident angle ensures that the multiple linear beams of light cannot be transmitted, and the polarizer 3 reflects the multiple linear beams of light to the convex mirror 4.

[0038] S2: Convex mirror 4 reflects multiple linear light beams toward substrate 5. Actuator 7 is adjusted along substrate 5 so that the multiple linear light beams are perpendicularly irradiated on the plane reflectors 6 of different actuators 7. The positions of the actuators 7 after movement are recorded. This ensures that the multiple linear light beams are reflected by the plane reflector 6 back to the original reflection position of convex mirror 4, i.e., the reflection point of the first reflection. This ensures that the multiple linear light beams return along the original path and are reflected again by convex mirror 4. At this time, the multiple linear light beams are incident on polarizer 3 at an angle that ensures smooth transmission of the light. After passing through polarizer 3, the multiple linear light beams converge onto the imaging surface of camera 8, and this point is recorded as a reference point. Based on the position of the reference point and the position of actuator 7, the surface slope of convex mirror 4 at the reflection point of this sub-aperture can be obtained. At this point, the initial convex mirror shape detection is completed.

[0039] S3, rotating the convex mirror 4 concentrically and detecting the next sub-aperture;

[0040] If the reference point shifts, it indicates that the sub-aperture's surface shape has changed. Actuator 7 is adjusted to converge the multiple linear beams back to the reference point, and the adjustment amount of actuator 7 is recorded. The adjustment amount is calculated based on the initial and adjusted positions of actuator 7. The slope change caused by the change in convex mirror 4's aperture can be calculated based on the adjustment amount, and the surface slope at the corresponding point can be determined. If the reference point remains unchanged after one rotation, the convex mirror 4 has passed the surface shape test.

[0041] The present invention uses multiple light beams to replace traditional wavefront light, realizing pure geometric optical detection. Compared with interference or diffraction methods, the actuator 7 is adjusted to ensure that multiple beams of linear light converge to a reference point on the imaging surface of the camera 8. The slope change of the multiple beams of linear light introduced by the convex surface can be obtained by recording the adjustment amount of each actuator 7. Since the front-end optical path does not change significantly, the present invention avoids complex spatial angle calculations and realizes zero-position detection, and replaces the changing components with unchanging components, greatly simplifying the slope calculation process, avoiding the traditional method of back-calculating the curvature information of the convex mirror by changing the imaging position. The traditional method requires calculation and analysis of each transmission point on the optical path, which is very complicated and prone to interference and errors. In addition, the traditional method requires sub-aperture splicing, and the splicing process will introduce large errors.

[0042] In addition, the present invention can not only perform surface shape qualification detection, but the calculated surface slope data can also be used in the surface shape reconstruction process of the convex mirror 4. The device of the present invention has a simple structure, low cost, and better accuracy.

[0043] Although the embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art may make changes, modifications, substitutions, and variations to the above embodiments within the scope of the present invention.

[0044] The above specific embodiments of the present invention do not constitute a limitation on the scope of protection of the present invention. Any other corresponding changes and modifications made based on the technical concept of the present invention should be included in the scope of protection of the claims of the present invention.

Claims

1. A method for detecting the shape of a convex mirror, characterized in that: The method is realized by using a convex mirror surface shape detection device, which includes: a light source, a grating, a polarizer, a convex mirror, a substrate, a camera, an actuator and a plane reflector; The grating and the polarizer are sequentially arranged on the optical path of the emitted light of the light source, and the grating is used to convert the single beam of light emitted by the light source into multiple beams of light with spatial equiangular distribution; There are at least three actuators connected to the plane reflector, and the actuators are displaced on the substrate and the displacement distance is recorded; The base is arranged above the convex mirror, and the base is a concave spherical surface; The camera is used to receive reflected light; The light beam emitted by the light source is incident on the polarizer and reflected by the polarizer to the convex mirror. The convex mirror reflects the light beam to the plane reflector. The plane reflector reflects the light beam along the incident light path to the convex mirror. The light beam is then reflected by the convex mirror to the polarizer and converges onto the imaging surface of the camera through the polarizer. The convex mirror shape detection device is used to detect the convex mirror shape, which specifically includes the following steps: S1. The light source emits a single beam of light, the grating converts the single beam of light into multiple beams of light with equal angular distribution in space, and the polarizer reflects the multiple beams of light to the convex mirror; S2. Displace the actuator along the substrate so that multiple beams of light are respectively irradiated on the plane mirrors on different actuators, and the positions of the actuators are respectively recorded. The multiple beams of light are ensured to be reflected by the plane mirrors back to the original reflection positions of the convex mirror, then reflected by the convex mirror, transmitted through the polarizer, and converged onto the imaging surface of the camera. The convergence point is recorded as a reference point, and the surface slope of the current sub-aperture is obtained. S3, rotating the convex mirror concentrically to detect the next sub-aperture; If the position of the reference point is offset, the actuator is adjusted to converge the multiple beams of light to the reference point, and the adjustment amount of the actuator is recorded respectively; If the position of the reference point remains unchanged after one rotation, the convex mirror shape test is qualified.

2. The convex mirror surface shape detection method according to claim 1, wherein: The slope change caused by the change of the sub-aperture of the convex mirror is calculated according to the adjustment amount, and the surface slope of the sub-aperture is determined.

3. The convex mirror surface shape detection method according to claim 1, wherein: The substrate is provided with a scale for recording the displacement vector of the actuator.

4. The convex mirror surface shape detection method according to claim 1, wherein: The convex mirror surface shape detection device further includes a polarizer and a narrowband filter. Both the polarizer and the narrowband filter are arranged between the light source and the grating to improve the signal-to-noise ratio of the surface shape detection result.

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