A meniscus lens fixing device and its usage method

Abstract

This invention proposes a meniscus lens fixing device, belonging to the field of optical aspherical surface inspection. It solves the problems of traditional meniscus lens fixing methods, such as easy generation of radial force, the need for readjustment after each disassembly and reassembly, and low reproducibility. It includes a support assembly, an adjustment assembly, a meniscus lens, support blocks, a clamping adjustment assembly, a clamping cover, and a base assembly. Two support blocks are symmetrically arranged on both sides of the meniscus lens. Sloping surfaces are symmetrically arranged on both sides of the meniscus lens, contacting the corresponding support block surfaces. Multiple support components are arranged circumferentially along the axis of the meniscus lens on the base assembly, with all support components contacting the curved surface of the meniscus lens. The clamping cover is connected to the base assembly and has multiple clamping adjustment components corresponding one-to-one with the support components. Each clamping adjustment component is connected to the clamping cover with a fixed torque and abuts against the end face of the meniscus lens. It is mainly used for fixing meniscus lenses.

Description

Technical Field

[0001] This invention belongs to the field of optical aspherical surface detection, and in particular relates to a meniscus lens fixing device. Background Technology

[0002] Currently, the main methods for inspecting the surface shape of convex aspherical mirrors include the Luphscan surface shape inspection instrument, CGH computer holography, and the aberration-free method using meniscus lenses. Because the Luphscan surface shape inspection instrument is expensive, and high-precision CGHs are difficult and costly to manufacture and require advanced design capabilities, meniscus lenses are frequently used in actual production processes to inspect the surface shape of convex aspherical mirrors.

[0003] The method of using a meniscus lens to inspect the shape of a convex aspherical surface dictates that the diameter of the meniscus lens is generally relatively large, while its thickness is relatively small to ensure uniformity. The large diameter-to-thickness ratio of the meniscus lens makes it prone to deformation under external forces. Conventional methods for inspecting the shape of a convex spherical surface require that the center of the convex spherical surface coincide with the focal point of the standard spherical mirror of the laser interferometer. The diameter of a commonly used standard spherical mirror in a laser interferometer is 4 inches (approximately 100 mm), while the diameter of a commonly used convex spherical lens exceeds 4 inches. Therefore, it is impossible to use a conventional standard spherical mirror to inspect the full diameter of a convex surface; only a concave surface can be used to inspect a convex surface. Furthermore, the final use state of the meniscus lens is fixed, requiring repeated assembly and disassembly in this fixed state. Therefore, ensuring the reproducibility of its shape before and after each assembly and disassembly is extremely important.

[0004] The existing method for fixing meniscus lenses involves using a frame and a pressure ring. First, the meniscus lens is placed with its convex side down on a fixture with a circular hole. Then, two parallel PTFE annular pads are placed on the concave side of the flat surface. Four PTFE arc-shaped protective strips are pre-inserted into the annular grooves of the frame. The frame is then placed on top of the meniscus lens. A PTFE annular pad with a bevel is placed on the pressure ring, and the pressure ring is tightened from bottom to top. Finally, the entire frame is rotated 90° and stood upright.

[0005] After the entire frame is erected vertically, a laser interferometer is used to acquire the surface shape of the concave surface. Based on the 45° astigmatism value of the fifth term of the Zernike polynomial, the placement angles of the meniscus lens and the annular pad 1 are continuously adjusted until the astigmatism value is zero. Then, based on the 0° and 90° astigmatism values ​​of the fourth term, the clamping force of the pressure ring is continuously adjusted until the astigmatism value is zero. This is the optimal fixing position for the meniscus lens.

[0006] In the traditional method of fixing the lens frame with a pressure ring, the bottom of the outer ring of the meniscus lens makes point contact with the arc-shaped protective plate. During the tightening of the pressure ring in the vertical position, the meniscus lens can easily rotate around the axis, causing the outer ring of the meniscus lens to randomly contact the arc-shaped protective plate of the inner ring of the lens frame, generating random radial force.

[0007] Traditional methods require a large diameter and a small width for the PTFE annular pad to ensure the light transmission diameter. However, it is difficult to ensure the uniformity and accuracy of its thickness during machining. This results in uneven stress on the meniscus lens when the annular pad is fully pressed against the concave side of the plane.

[0008] The traditional method relies on the astigmatism value in the surface pattern of a laser interferometer to adjust the clamping force of the pressure ring. There is no quantitative adjustment, and the force is different after each disassembly and assembly, requiring readjustment each time.

[0009] In traditional assembly methods, the rotation of the lens body in the pitch and yaw directions within the frame during each assembly will cause the component of gravity to be inconsistent with the support point, resulting in 0° astigmatism. In this case, pressure is increased by inserting a shim at a certain point, which leads to astigmatism caused by each adjustment and assembly, resulting in low reproducibility. Summary of the Invention

[0010] In view of this, the present invention aims to provide a meniscus lens fixing device to solve the problems of traditional meniscus lens fixing easily generating radial force, requiring readjustment each time it is disassembled and re-fixed, and having low reproducibility.

[0011] To achieve the above objectives, according to one aspect of the present invention, a meniscus lens fixing device is provided, comprising a support assembly, an adjustment assembly, a meniscus lens, support blocks, a clamping adjustment assembly, a clamping cover, and a base assembly. Two support blocks are provided and symmetrically arranged on both sides of the meniscus lens. Inclined surfaces are symmetrically arranged on both sides of the meniscus lens and contact the corresponding support block surfaces through the inclined surfaces. Multiple support components are arranged circumferentially along the axis of the meniscus lens on the base assembly. All support components are in contact with the curved surface of the meniscus lens. The clamping cover is connected to the base assembly. Multiple clamping adjustment components, each corresponding to one of the support components, are provided on the clamping cover. Each clamping adjustment component is connected to the clamping cover with a fixed torque and abuts against the end face of the meniscus lens.

[0012] Furthermore, the support component is a support rod, the front end of which is provided with a curved surface that fits against the curved surface of the meniscus lens, and the support rod is connected to the base assembly by a locking screw.

[0013] Furthermore, the support block is a V-shaped block.

[0014] Furthermore, the V-shaped block is provided with an inclined plane at a 90-degree angle to the vertical plane.

[0015] Furthermore, each of the inclined planes is aligned with the inclined surface on the corresponding side.

[0016] Furthermore, the clamping adjustment component is a clamping screw, which is threadedly connected to the clamping cover.

[0017] Furthermore, the base assembly includes an upright plate and a base body, both of which are connected to the upper surface of the base body.

[0018] Furthermore, the clamping cover is detachably connected to the upright plate.

[0019] Furthermore, the support components are provided in three parts. The first line connecting two of the support components coincides with the horizontal diameter of the meniscus lens, and the third support component is located above the first line and perpendicular to the first line formed by the second line connecting the center of the meniscus lens.

[0020] According to another aspect of the present invention, a method for using the above-described meniscus lens fixing device is provided, comprising the following steps:

[0021] S1. Fix multiple support components to the corresponding positions on the upright plate;

[0022] S2. Then place the meniscus lens between the two V-blocks and make each bevel fit perfectly against the corresponding side of the V-block;

[0023] S3. Move the meniscus lens to a position where it fits against all the support components;

[0024] S4. Install the clamping cover on the upright plate;

[0025] S5. Install all the clamping screws on the clamping cover in sequence and clamp the meniscus lens, and record the fixing torque value of all the clamping screws.

[0026] S6. Use a laser interferometer to collect surface shape data of the concave surface of the meniscus lens, and then use an ion beam polisher to correct the astigmatic error introduced during the tightening of the clamping screw.

[0027] S7. Repeat steps S2-S5 multiple times, ensuring that the torque value of tightening all screws is the same as the fixing torque value each time, until the meniscus lens test is completed.

[0028] Compared with the prior art, the beneficial effects of the present invention are:

[0029] 1. This fixing device restricts the rotation of the meniscus lens around the axial direction by symmetrically setting inclined surfaces on both sides of the meniscus lens and having the inclined surfaces contact the support block surfaces on the corresponding sides. This ensures the uniqueness of the position around the axial direction and guarantees the reproducibility of the meniscus lens installation.

[0030] 2. This fixing device, by setting multiple support components to contact the convex surface of the meniscus lens, can ensure the unique determination of the axial position of the meniscus lens, thereby ensuring the reproducibility of the meniscus lens installation;

[0031] 3. This fixing device uses a constant torque installation method by tightening and adjusting the components, eliminating the need to readjust the pressure every time it is reinstalled, thus ensuring the reproducibility of the meniscus lens installation;

[0032] 4. This fixing device restricts the rotation of the meniscus lens in the pitch and offset directions by setting multiple support components to contact the convex surface of the meniscus lens.

[0033] 5. By setting up support blocks, support components, and clamping adjustment components, this fixing device optimizes the testing process, effectively transmits and unifies the testing standards, and improves testing accuracy and efficiency. Attached Figure Description

[0034] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings:

[0035] Figure 1 This is a cross-sectional view of a meniscus lens fixing device according to the present invention;

[0036] Figure 2 This is a three-dimensional structural diagram of the base assembly described in this invention;

[0037] Figure 3 This is a schematic diagram showing the distribution of the support rod and V-block described in this invention;

[0038] Figure 4 This is a schematic diagram of the installation state of the meniscus lens described in this invention;

[0039] Figure 5 This is a schematic diagram showing the state in which the support rod and the meniscus lens of the present invention are in contact.

[0040] Figure 6 This is a schematic diagram showing the clamping cover of the present invention installed on the base assembly;

[0041] Figure 7 This is the optical path diagram for concave surface detection;

[0042] Figure 8 This is the optical path diagram for convex surface detection;

[0043] Figure 9 Optical path diagram for detecting convex aspherical surfaces using a meniscus lens;

[0044] Figure 10This is a schematic diagram showing the distribution of the inclined planes described in this invention;

[0045] Figure 11 A three-dimensional structural diagram of the existing pressure ring fixing method;

[0046] Figure 12 This is a schematic diagram of the planar structure of an existing pressure ring fixing method;

[0047] Figure 13 This is a typical optical path diagram for detecting the shape of a convex spherical surface.

[0048] 1. Support rod; 2. Locking screw; 3. Meniscus lens; 4. V-block; 5. Vertical plate; 6. Pressing screw; 7. Pressing cover; 8. Base body; 9. Inclined surface. Detailed Implementation

[0049] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. It should be noted that, unless otherwise specified, the embodiments and features in the embodiments of the present invention can be combined with each other, and the described embodiments are only some embodiments of the present invention, not all embodiments.

[0050] Referring to the accompanying drawings, this embodiment of the invention provides a meniscus lens fixing device, including a support assembly, an adjustment assembly, a meniscus lens 3, support blocks, a clamping adjustment assembly, a clamping cover 7, and a base assembly. Two support blocks are provided and symmetrically arranged on both sides of the meniscus lens 3. Inclined surfaces 9 are symmetrically arranged on both sides of the meniscus lens 3 and contact the corresponding support block surfaces through the inclined surfaces 9. Multiple support components are arranged circumferentially along the axis of the meniscus lens 3 on the base assembly, and all support components are in contact with the curved surface of the meniscus lens 3. The clamping cover 7 is connected to the base assembly, and multiple clamping adjustment components corresponding one-to-one with the support components are provided on the clamping cover 7. Each clamping adjustment component is connected to the clamping cover 7 with a fixed torque and abuts against the end face of the meniscus lens 3.

[0051] In this embodiment, the support component is a support rod 1. The front end of the support rod 1 has a curved surface that fits into the curved surface of the meniscus lens 3. The support rod 1 is connected to the base assembly by a locking screw 2. By setting a curved surface at the front end of the support rod 1 and fitting it into the curved surface of the meniscus lens 3, the unique axial position of the meniscus lens can be guaranteed, thus ensuring the reproducibility of the meniscus lens installation. At the same time, it can restrict the rotation of the meniscus lens 3 in the pitch and offset directions, ensuring the stability of the meniscus lens 3.

[0052] In this embodiment, the support block is a V-shaped block 4. Two V-shaped blocks 4 are symmetrically distributed left and right, forming a V-shaped limiting space. The meniscus lens 3 is placed in the V-shaped limiting space. The V-shaped blocks 4 are provided with inclined planes at 90 degrees to the vertical plane, and each inclined plane is in contact with the corresponding inclined surface 9. This can restrict the rotation of the meniscus lens 3 around the axial direction, ensure the uniqueness of its position around the axial direction, and ensure the reproducibility of the meniscus lens installation.

[0053] In this embodiment, the clamping adjustment component is a clamping screw 6, which is threadedly connected to the clamping cover 7. By clamping the meniscus lens 3 with the clamping screw 6 and recording the torque after the first clamping, the installation reproducibility of the meniscus lens 3 can be ensured by installing each clamping screw 6 with the same torque during subsequent disassembly and installation.

[0054] In this embodiment, the base assembly includes an upright plate 5 and a base body 8, both of which are connected to the upper surface of the base body 8. The upright plate 5 and the base body 8 form a 90-degree angle.

[0055] In this embodiment, the clamping cover 7 is detachably connected to the upright plate 5. Specifically, it can be connected by bolts, snap-fit ​​connections, or any connection method that can ensure connection strength and ease of disassembly.

[0056] In this embodiment, three support components are provided. The first line connecting two of the support components coincides with the horizontal diameter of the meniscus lens 3. The third support component is located above the first line and the second line formed by the center of the meniscus lens 3 is perpendicular to the first line. Specifically, the upright plate 5 is provided with a square limiting groove. First, the support component is engaged in the limiting groove, and then the support component is fixed by the locking screw 2. The extension height of the three support components is the same, which can ensure stable support for the meniscus lens 3, ensure the unique determination of the axial position of the meniscus lens, and thus ensure the reproducibility of the meniscus lens installation.

[0057] According to another aspect of the present invention, a method for using the above-described meniscus lens fixing device is provided, comprising the following steps:

[0058] S1. Fix multiple support components to the corresponding positions on the upright plate 5;

[0059] S2. Then place the meniscus lens 3 between the two V-blocks 4 and make each bevel 9 fit perfectly with the corresponding side of the V-block 4.

[0060] S3. Move the meniscus lens 3 to a position where it fits against all the support components;

[0061] S4. Install the clamping cover 7 onto the upright plate 5;

[0062] S5. Install all the clamping screws 6 on the clamping cover 7 in sequence and clamp the meniscus lens 3, and record the fixing torque value of all the clamping screws 6.

[0063] S6. Use a laser interferometer to collect surface shape data of the concave surface of the meniscus lens 3, and then use an ion beam polisher to correct the astigmatic error introduced during the clamping process of the clamping screw 6.

[0064] S7. Repeat steps S2-S5 multiple times, ensuring that the torque value of all tightening screws 6 is the same as the fixing torque value each time, until the test of the meniscus lens 3 is completed.

[0065] The methods used by laser interferometers and ion beam polishers to correct astigmatic errors introduced during the clamping process of the clamping screw 6, as well as the sensors, controllers, and control methods that may be used in the above description, are all existing technologies and will not be elaborated here.

[0066] The embodiments of the present invention disclosed above are merely illustrative of the invention. These embodiments do not exhaustively describe all details, nor do they limit the invention to the specific implementations described. Many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention.

Claims

1. A meniscus lens fixing device characterized by: The system includes a support assembly, an adjustment assembly, a meniscus lens (3), a support block, a clamping adjustment assembly, a clamping cover (7), and a base assembly. Two support blocks are provided and symmetrically arranged on both sides of the meniscus lens (3). Inclined surfaces (9) are symmetrically arranged on both sides of the meniscus lens (3) and contact the support block surfaces on the corresponding sides through the inclined surfaces (9). Multiple support assemblies are arranged circumferentially along the axis of the meniscus lens (3) on the base assembly. All of the support assemblies are in contact with the curved surface of the meniscus lens (3). The clamping cover (7) is connected to the base assembly. Multiple clamping adjustment assemblies corresponding one-to-one with the support assemblies are provided on the clamping cover (7). Each clamping adjustment assembly is connected to the clamping cover (7) with a fixed torque and abuts against the end face of the meniscus lens (3).

2. A meniscus lens holding device according to claim 1, characterized in that: The support component is a support rod (1), the front end of the support rod (1) is provided with a curved surface and fits against the curved surface of the meniscus lens (3), and the support rod (1) is connected to the base component by a locking screw (2).

3. A meniscus lens holding device according to claim 1, wherein: The support block is a V-shaped block (4).

4. A meniscus lens holding device according to claim 3, characterized in that: The V-shaped block (4) is provided with an inclined plane at a 90-degree angle to the vertical plane.

5. A meniscus lens holding device according to claim 4, characterized in that: Each of the inclined planes is in contact with the inclined plane (9) on the corresponding side.

6. A meniscus lens holding device according to claim 1, wherein: The clamping adjustment component is a clamping screw (6), which is threadedly connected to the clamping cover (7).

7. The meniscus lens fixing device according to claim 1, characterized in that: The base assembly includes a vertical plate (5) and a base body (8), and both the vertical plate (5) and the support block are connected to the upper surface of the base body (8).

8. A meniscus lens fixing device according to claim 6, characterized in that: The clamping cover (7) is detachably connected to the upright plate (5).

9. A meniscus lens fixing device according to claim 1, characterized in that: The support components are provided in three parts. The first line connecting two of the support components coincides with the horizontal diameter of the meniscus lens (3). The third support component is located above the first line and the second line formed by the center of the meniscus lens (3) is perpendicular to the first line.

10. A method for using a meniscus lens fixing device as described in any one of claims 1-9, characterized in that, Includes the following steps: S1. Fix multiple support components to the corresponding positions on the upright plate (5); S2. Then place the meniscus lens (3) between the two V-blocks (4) and make each bevel (9) fit perfectly with the corresponding V-block (4); S3. Move the meniscus lens (3) to a position where it fits against all the support components; S4. Install the clamping cover (7) on the upright plate (5); S5. Install all the clamping screws (6) on the clamping cover (7) in sequence and clamp the meniscus lens (3), and record the fixing torque value of all the clamping screws (6); S6. Use a laser interferometer to collect surface shape data of the concave surface of the meniscus lens (3), and then use an ion beam polisher to correct the astigmatic error introduced during the clamping process of the clamping screw (6). S7. Repeat steps S2-S5 multiple times, ensuring that the torque value of all tightened screws (6) is the same as the fixed torque value each time, until the test of the meniscus lens (3) is completed.

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