Fine-tuning fixture for optical lens surface shape inspection

Abstract

This utility model relates to a fine-tuning fixture for optical lens surface shape inspection, comprising a base plate and an upper plate. Two fine-tuning devices are mounted on the base plate, arranged parallel to each other. Each fine-tuning device includes a copper nut and a linear guide rail fixed to the base plate, with a limit block mounted on the linear guide rail. A screw is movably connected to the copper nut, forming a threaded pair. A handwheel is connected to the tail end of the screw, and a guide block is connected to the front end of the screw via a spherical bearing. The guide block is slidably mounted on the linear guide rail and has sloped grooves. Several ball bearing casters are mounted on the bottom of the upper plate, with the balls of the casters embedded in the grooves of the guide blocks. Several tension springs connect the base plate and the upper plate. Thus, the threaded pair formed by the screw and copper nut provides adjustment with a self-locking function, ensuring stable positioning after adjustment and achieving high-precision adjustment at the 0.14-micron level, meeting the stringent positional accuracy requirements of optical lens surface shape inspection.

Description

Technical Field

[0001] This utility model relates to a fine-tuning fixture, and more particularly to a fine-tuning fixture for detecting the surface shape of optical lenses. Background Technology

[0002] In the field of optical lens manufacturing, surface shape accuracy inspection is a crucial step in ensuring the imaging quality of optical systems. High-precision alignment between the lens and the interferometer's optical path requires fine-tuning of the tooling. Current technologies for optical lens orientation adjustment devices generally face the challenge of balancing precision control, ease of operation, and manufacturing costs, particularly exhibiting significant shortcomings in multi-degree-of-freedom precision control and elimination of mechanical backlash.

[0003] Chinese patent CN217090705U discloses a micro-adjustment optical lens skin detector. It uses a gear transmission structure to drive the lens in a telescopic motion, thereby adjusting the detection distance. However, its adjustment dimension is limited to single-axis translation, lacking precise control of multi-directional angles and a dedicated gap elimination mechanism, making it difficult to meet the posture adjustment requirements of high-precision optical lens surface shape detection.

[0004] Meanwhile, Chinese patent CN213239417U discloses a laser interferometer for optical lens inspection that can improve displacement magnification. It optimizes lens clamping stability through a spring-buffered structure, but this structure emphasizes passive protection and lacks an active adjustment mechanical transmission component, still relying on manual coarse adjustment to achieve optical path alignment, resulting in limited adjustment efficiency and accuracy.

[0005] Furthermore, Chinese patent CN220825986U discloses an optical lens mounting fixture. Although it achieves height adjustment through a servo motor and screw structure, its core function lies in lens clamping and fixing. The degree of freedom and precision control of adjustment are fundamentally different from the micron-level angle fine-tuning required for surface shape detection.

[0006] The main shortcomings of existing technologies are concentrated in three aspects: First, the adjustment dimension is limited, mostly employing single-axis translation or simple lifting structures, which cannot achieve multi-degree-of-freedom precise control of lens posture. Second, mechanical transmission backlash is not effectively eliminated, resulting in idle travel during adjustment, affecting detection repeatability and accuracy stability. Third, high-precision adjustment devices often rely on complex servo drive systems, leading to high manufacturing costs and making them difficult to adapt to the needs of rapid detection scenarios.

[0007] In view of the above-mentioned shortcomings, the designer has actively researched and innovated in order to create a fine-tuning fixture for the inspection of optical lens surface shape, making it more valuable for industrial applications. Utility Model Content

[0008] To solve the above-mentioned technical problems, the purpose of this utility model is to provide a fine-tuning fixture for optical lens surface shape inspection.

[0009] This utility model discloses a fine-tuning fixture for optical lens surface shape inspection, comprising a base plate and an upper plate. The base plate has two fine-tuning devices mounted on it, arranged parallel to each other. Each fine-tuning device includes a copper nut and a linear guide rail fixed to the base plate, with a limit block mounted on the linear guide rail. A screw is movably connected to the copper nut, forming a threaded pair. A handwheel is connected to the tail end of the screw, and a guide block is connected to the front end of the screw via a spherical bearing. The guide block is slidably mounted on the linear guide rail and has sloped grooves. The bottom of the upper plate has several ball bearing casters, with the balls of the casters embedded in the grooves of the guide blocks. Several tension springs connect the base plate and the upper plate.

[0010] Furthermore, in the aforementioned fine-tuning fixture for optical lens surface shape inspection, the guide block has a groove slope of 10:1.

[0011] Furthermore, in the aforementioned fine-tuning fixture for optical lens surface shape inspection, the slope direction of the slide is parallel to the extension direction of the linear guide rail.

[0012] Furthermore, in the aforementioned fine-tuning fixture for optical lens surface shape inspection, the pitch of the threaded pair is less than 1 mm.

[0013] Furthermore, in the aforementioned fine-tuning fixture for optical lens surface shape inspection, the two ends of the tension spring are respectively connected to the base plate and the upper plate via pins.

[0014] Furthermore, in the aforementioned fine-tuning fixture for optical lens surface shape inspection, the limiting block has an L-shaped structure or a "U"-shaped structure.

[0015] Furthermore, in the aforementioned fine-tuning fixture for optical lens surface shape inspection, the linear guide rail is provided with a guide groove, and the lower end of the guide block is provided with mating protrusions, which are movably embedded in the guide groove.

[0016] Furthermore, in the aforementioned fine-tuning fixture for optical lens surface shape inspection, an adjustment handle is mounted on the handwheel.

[0017] Furthermore, in the aforementioned fine-tuning fixture for optical lens surface shape inspection, the copper nut first extends to a docking base, which is connected to the base plate by a locking screw.

[0018] By means of the above solution, this utility model has at least the following advantages:

[0019] 1. The adjustment is achieved by using a threaded pair consisting of a screw and a copper nut, which also has a self-locking function. The position is stable after adjustment, and the pitch is only 0.5mm. Combined with the 10:1 slope of the guide block slide, it can achieve high-precision adjustment at the 0.14-micron level, which meets the stringent position accuracy requirements of optical lens surface inspection.

[0020] 2. Except for the base plate and top plate, which need to be customized according to actual testing requirements, the rest of the components, such as copper nuts, linear guides, limit blocks, screws, handwheels, spherical bearings, ball casters, tension springs, and pins, are all standard market products and do not require special processing, which greatly reduces the manufacturing cost of the tooling.

[0021] 3. The adjustment process can be completed simply by manually turning the handwheel, making it simple and convenient to operate. It does not require a complex electronic control system, making it suitable for rapid testing scenarios and reducing the skill requirements for testing personnel.

[0022] 4. The guide block's groove can strictly control the movement direction of the balls, and combined with the adaptive angle of the spherical bearing, it makes the adjustment process of the upper plate smooth and stable without any jamming.

[0023] 5. The tension spring effectively eliminates the gaps between the moving parts, further improving the adjustment accuracy and the overall stability of the tooling.

[0024] The above description is only an overview of the technical solution of this utility model. In order to better understand the technical means of this utility model and to implement it in accordance with the contents of the specification, the preferred embodiments of this utility model are described in detail below with reference to the accompanying drawings. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the overall structure of a fine-tuning fixture used for optical lens surface shape inspection.

[0026] Figure 2 This is an exploded view of the fine-tuning fixture used for optical lens surface shape inspection.

[0027] Figure 3 This is a schematic diagram of the tension spring assembly.

[0028] Figure 4 This is a schematic diagram of the guide block.

[0029] The meanings of the labels in the figures are as follows.

[0030] Detailed Implementation

[0031] The specific embodiments of this utility model will be described in further detail below with reference to the accompanying drawings and examples. The following examples are used to illustrate this utility model, but are not intended to limit its scope.

[0032] like Figures 1 to 4 A fine-tuning fixture for inspecting the surface shape of optical lenses includes a base plate 1 and an upper plate 2. Its unique feature is that two identical fine-tuning devices are mounted on the base plate 1, parallel to each other along the length (or width, depending on the actual installation requirements) of the base plate 1, allowing for angle adjustment of the upper plate 2 in two different directions. This ensures that the inspection lens subsequently installed on the upper plate 2 is precisely aligned with the interferometer. Specifically, each fine-tuning device includes a copper nut 5 and a linear guide rail 8, both fixedly mounted on the base plate 1. The bottom of the copper nut 5 has an integrally formed base, which is either integrally molded with the copper nut 5 or fixedly connected by welding. This allows the base to be tightly connected to the surface of the base plate 1 via locking screws, ensuring the installation stability of the copper nut 5 on the base plate 1 and preventing displacement of the copper nut 5 during adjustment. Simultaneously, the linear guide rail 8 uses a standard linear guide assembly 8, which is fixed to the base plate 1 by screws, and the extension direction of the linear guide rail 8 is consistent with the parallel direction of the two fine-tuning devices. Furthermore, a limiting block 11 is installed at each end of the linear guide rail 8, and the two fine-tuning devices have a total of four limiting blocks 11. The limiting blocks 11 are fixed to the base plate 1 with screws to limit the sliding range of the subsequent guide block 9 on the linear guide rail 8. This prevents the guide block 9 from detaching from the linear guide rail 8 and causing damage to the tooling. In order to achieve effective limiting, the limiting block 11 used in this utility model can be L-shaped or U-shaped. In this embodiment, the L-shaped structure is preferred. One side of the L-shaped block is attached to the end of the linear guide rail 8, and the other side is fixed to the base plate 1 with screws. This makes installation convenient and the limiting reliable.

[0033] According to a preferred embodiment of this invention, each fine-tuning device is equipped with a screw 4, which is movably connected to a copper nut 5 to form a threaded pair. The pitch of this threaded pair is 0.5mm, which can be less than 1mm, to meet the requirements of high-precision adjustment. Simultaneously, the threaded pair has a self-locking function, preventing the screw 4 from rotating on its own due to external vibrations, collisions, or other environmental factors once the position is adjusted to the correct position. This ensures the stability of the tooling position, eliminating the need for an additional locking mechanism.

[0034] For ease of operation, a handwheel 3 with a circular structure is fixedly connected to the tail end of the screw 4. A detachable adjustment handle can be installed on the handwheel 3 for easy gripping and application of force, reducing the effort required to rotate the handwheel 3. In this way, the operator can rotate the screw 4 around its own axis by turning the handwheel 3. The front end of the screw 4 is connected to the guide block 9 via a spherical bearing 7. This spherical bearing 7 can accommodate slight changes in the angle between the screw 4 and the guide block 9, preventing jamming caused by installation errors or force offset when the screw 4 drives the guide block 9 to slide, thus ensuring smooth adjustment.

[0035] Furthermore, the guide block 9 is slidably mounted on the linear guide rail 8. A guide groove extending along the direction of extension can be formed on the top of the linear guide rail 8, and a mating protrusion matching the guide groove is integrally formed on the lower end face of the guide block 9. The mating protrusion is movably embedded in the guide groove. In this way, the sliding direction of the guide block 9 is restricted by the cooperation of the guide groove and the mating protrusion, ensuring that the guide block 9 can only move along the extension direction of the linear guide rail 8, and preventing the guide block 9 from shifting laterally. As an optimization, a sliding groove extending along the length direction can be formed on the top of the guide block 9. The sliding groove has a preset slope of 10:1, that is, for every 1mm translation of the guide block 9 along the linear guide rail 8, the height of the bottom of the sliding groove changes by 0.1mm. Moreover, the slope direction of the sliding groove is parallel to the extension direction of the linear guide rail 8, so that when the guide block 9 slides along the linear guide rail 8, the balls in the sliding groove can move stably along the slope direction, thereby driving the upper plate 2 to achieve a smooth height change. During implementation, the inner wall of the chute is polished to a surface roughness Ra≤0.8μm, which reduces the frictional resistance between the balls and the inner wall of the chute, ensures the smoothness of the ball movement, and improves the sensitivity of adjustment.

[0036] In practical implementation, two ball casters 10 are fixedly installed at the bottom of the upper plate 2. Each ball caster 10 corresponds one-to-one with a guide block 9 in one of the two fine-tuning devices. The ball of each ball caster 10 is embedded in the groove of the corresponding guide block 9, ensuring close contact between the ball and the inner wall of the groove. Simultaneously, the ball can only move along the length of the groove, i.e., the slope direction. Thus, through the slope constraint of the groove, the horizontal sliding of the guide block 9 is converted into a vertical height change of the ball, thereby driving the upper plate 2 to achieve up-and-down movement. For ease of implementation, the ball casters 10 use standard commercially available products, with balls made of high-hardness alloy steel and surface-hardened, exhibiting good wear resistance and impact resistance, extending the service life of the tooling.

[0037] Meanwhile, two tension springs 6 are connected between the base plate 1 and the upper plate 2. The two ends of the tension springs 6 are connected to the base plate 1 and the upper plate 2 respectively via pins 12. Specifically, both the base plate 1 and the upper plate 2 have pre-set mounting holes that match the pins 12. The pins 12 pass through the hooks at the ends of the tension springs 6 and are inserted into the mounting holes, enabling a detachable connection of the tension springs 6, facilitating subsequent maintenance or replacement. In this way, when the tension springs 6 are in a pre-stretched state, they can apply a continuous tension force to the base plate 1 and the upper plate 2, ensuring that the balls of the ball caster 10 are always tightly fitted against the bottom of the guide block 9's groove. This eliminates the free travel caused by component gaps during adjustment, ensuring adjustment accuracy, and preventing the upper plate 2 from loosening or shaking during adjustment.

[0038] Furthermore, the base plate 1 and the upper plate 2 are connected by a spherical bearing 7. The outer ring of the spherical bearing 7 is fixed to the base plate 1, and the inner ring is fixed to the upper plate 2, serving as a fulcrum for the relative rotation of the base plate 1 and the upper plate 2. In this way, the upper plate 2 can be deflected angularly around the spherical bearing 7. With the independent adjustment of the two fine-tuning devices, the angle of the upper plate 2 can be finely adjusted in two different directions, thereby ensuring that the optical lens mounted on the upper plate 2 can be accurately aligned with the detection optical path of the interferometer.

[0039] The working process of the fine-tuning fixture in this embodiment is as follows: When the position of the optical lens needs to be finely adjusted, the operator rotates the handwheels 3 on the two fine-tuning devices according to the detection requirements of the interferometer. The handwheels 3 drive the screw 4 to rotate around the copper nut 5. Since the screw 4 and the copper nut 5 form a threaded pair, the screw 4 will move linearly along its own axis while rotating, and then push or pull the guide block 9 along the linear guide rail 8 through the joint bearing 7 at the front end. When the guide block 9 slides, the balls in its groove will be displaced vertically under the action of the slope, causing the upper plate 2 to move up and down or deflect at an angle around the joint bearing 7 between the bottom plate 1 and the upper plate 2.

[0040] Because the slope of the chute is 10:1 and the pitch of the threaded pair is 0.5mm, when the handwheel 3 rotates one revolution, the screw 4 moves 0.5mm along the axis, causing the guide block 9 to translate by 0.5mm. The vertical height change of the ball is 0.5mm × (1 / 10) = 0.05mm. That is to say, if the handwheel 3 rotates 1° (one revolution is 360°), the screw 4 moves a distance of 0.5mm / 360≈0.00139mm, and the ball height changes by 0.00139mm × (1 / 10)≈0.00014mm (i.e., 0.14 micrometers), which can achieve extremely high adjustment accuracy. During the adjustment process, the tension spring 6 always maintains a tight connection between the base plate 1 and the upper plate 2, eliminating gap errors. The limit block 11 prevents the guide block 9 from sliding out of the linear guide rail 8, ensuring the safety of the tooling.

[0041] Furthermore, the directions or positional relationships described in this utility model are based on the directions or positional relationships shown in the accompanying drawings. They are only for the purpose of facilitating the description of this utility model and simplifying the description, and are not intended to indicate or imply that the device or structure referred to must have a specific orientation, or to operate in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0042] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present utility model, and these improvements and modifications should also be considered within the protection scope of the present utility model.

Claims

1. A fine-tuning fixture for inspecting the surface shape of optical lenses, comprising a base plate (1) and an upper plate (2), characterized in that: Two fine-tuning devices are installed on the base plate (1), which are distributed in parallel to each other; The fine-tuning device includes a copper nut (5) and a linear guide rail (8) fixed on the base plate (1). A limit block (11) is installed on the linear guide rail (8). A screw (4) is movably connected to the copper nut (5) to form a threaded pair. The screw (4) is connected to a handwheel (3) at its tail end, and the screw (4) is connected to a guide block (9) via a spherical bearing (7). The guide block (9) is slidably mounted on the linear guide rail (8), and the guide block (9) is provided with sloping grooves; The bottom of the upper plate (2) is equipped with several ball casters (10), and the balls of the ball casters (10) are embedded in the grooves of the guide block (9); Several tension springs (6) connect the bottom plate (1) and the top plate (2).

2. A fine adjustment tool for the detection of the face shape of an optical lens according to claim 1, characterized in that: The slope of the guide block (9) is 10:

1.

3. A fine adjustment tool for the detection of the face shape of an optical lens according to claim 1, characterized in that: The slope direction of the chute is parallel to the extension direction of the linear guide rail (8).

4. A fine adjustment tool for the detection of the face shape of an optical lens according to claim 1, characterized in that: The pitch of the threaded pair is less than 1 mm.

5. A fine adjustment tool for optical lens face form detection according to claim 1 characterized in that: The two ends of the tension spring (6) are connected to the base plate (1) and the upper plate (2) respectively by pins (12).

6. A fine adjustment tool for optical lens face form detection according to claim 1 characterized in that: The limiting block (11) has an L-shaped structure or a "U"-shaped structure.

7. The fine-tuning fixture for optical lens surface shape inspection according to claim 1, characterized in that: The linear guide rail (8) has a guide groove, and the lower end of the guide block (9) has a docking protrusion, which is movably embedded in the guide groove.

8. A fine adjustment tool for the testing of the face shape of an optical lens according to claim 1, characterized in that: An adjustment handle is installed on the handwheel (3).

9. A fine adjustment tool for the testing of the face shape of an optical lens according to claim 1, characterized in that: The copper nut (5) first extends to a docking base, which is connected to the base plate (1) by a locking screw.

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