High-precision lens measurement supporting device for Luphoscan contourgraph

Abstract

The utility model discloses a high-precision lens measurement supporting device for a Luphoscan contourgraph. The supporting device comprises a positioning clamping ring, an adsorption pad, a horizontal adjusting screw and a measurement base. The measuring base is detachably connected with the Luphoscan contourgraph aligning platform through a horizontal adjusting screw; a supporting ring is arranged in the center of the measuring base; an arc-shaped supporting surface is arranged on the top surface of the supporting ring and is attached to and supported by a to-be-tested lens; the adsorption pad is adhered to the arc-shaped supporting surface; a to-be-measured lens is adsorbed on the adsorption pad and is positioned by the positioning clamping ring; the positioning clamping ring covers the supporting circular ring; and the outer ring of the to-be-measured lens is clamped on the side wall of the positioning clamping ring. After the lens is fixed by the device, the consistency of the surface shape measurement result of the Luphoscan contourgraph can be obviously improved, the error of the measurement result is reduced, and the repeatability of the measurement result is improved.

Description

Technical Field

[0001] The present application relates to the technical field of optical device processing, and in particular to a high-precision lens measurement support device for a Luphoscan profilometer. Background Art

[0002] With the development of optoelectronic technology, the requirements for the surface shape of optical lenses are getting higher and higher. In order to achieve the ultra-long working distance of the satellite-borne optoelectronic system, its optical system requires large aperture and high precision. At present, the lens materials used in satellite infrared payloads cover various major infrared optical materials such as germanium, silicon, zinc sulfide, zinc selenide and chalcogenide glass. The aperture of the front-end optical lens has exceeded Φ200mm, and the surface shape requirements are as high as PV≤0.2μm, RMS≤0.03μm, or even higher.

[0003] The surface requirements of conventional infrared optical lenses are only PV (0.4 ~ 0.6) μm, RMS (0.06 ~ 0.1) μm. The high-precision requirements pose new challenges to the processing and surface measurement of infrared optical lenses. High-precision measurement can effectively ensure that the processing accuracy meets the requirements. Large errors in the measurement results will seriously affect the accurate feedback of the processing accuracy.

[0004] The existing conventional contact profilometers, such as the PGI 1240 profilometer produced by Taylor-Hobson, can no longer meet the surface measurement requirements. The non-contact Luphoscan profilometer must be used for measurement. The Luphoscan profilometer is a high-speed non-contact 3D aspheric optical surface measurement system based on multi-wavelength interferometric sensing technology. The profilometer uses the laser ranging method for measurement. The measurement principle is referenced Figure 1 ,Depend on Figure 1 It can be seen that the profilometer includes: Luphoscan probe 1', centering and adjustment platform 2', and fine-tuning knob 3'; the workpiece 4' to be measured is set on the centering and adjustment platform 2'; the position of the sensor probe is controlled by the R, Z and T axes, and the probe scans the surface of the lens to be measured according to the preset path. At the same time, the lens to be measured rotates around its own C axis on the C axis, and the probe performs a spiral scan of the entire surface. During the scanning process, the probe is always perpendicular to the surface to be measured to ensure that the distance between the probe and the measured point remains constant. Multi-wavelength interference sensing technology is used to flexibly measure absolute distance. Because it is not affected by beam discontinuities, surface detection can be achieved even if there are gaps on the surface of the optical lens to be measured. When using the Luphoscan profilometer for surface measurement, the lens to be measured needs to be placed on the profiler turntable and rotate with the turntable. At this time, the support of the lens has a direct impact on the measurement accuracy.

[0005] As we all know, except for silicon single crystal, the density of infrared optical materials is relatively high. For example, the density of germanium is 5.33g / cm 3 , the density of zinc selenide is 5.42g / cm 3, a germanium or zinc selenide lens with an aperture of about Φ200mm can weigh several thousand grams. Under the weight of the lens, the supporting structure squeezes the lens, causing its shape to deform slightly; and when the detection accuracy is required to be RMS≤0.03μm, nanometer-level measurement errors can affect the accuracy of the judgment result of whether the lens is qualified or not.

[0006] For materials with poor strength (for example, the hardness and bending strength of zinc selenide are only about half of those of zinc sulfide, and the strength of chalcogenide glass is even lower), the support method has a greater impact on the deformation of the lens. It can be said that different support methods directly affect the accuracy of the surface measurement results, and this impact is more significant for large-aperture, high-precision lenses.

[0007] See also Figure 1 During the measurement process, the lens rotates horizontally with the main axis. When the concave surface is facing downward, the lens can be placed directly on the profiler turntable for surface measurement. When the convex surface is facing downward, a corresponding supporting device must be designed to support the lens for accurate measurement.

[0008] The influence of the support method used in the existing measurement method on the measurement results: First, after the lens is placed on the measurement support device, the optical axis of the lens is not concentric with the axis of the support ring of the support device, causing the lens to be eccentric and unevenly stressed; second, under the action of the lens's own gravity, the position and width of the support ring affect the deformation position and degree of the lens, causing the measured value of the lens's radius of curvature to increase or decrease, and introducing a measurement error of the radius of curvature; third, the surface error of the support ring support surface is large, causing the contact between the lens and the support surface to be concentrated in certain local areas, causing the lens to be unevenly distributed and causing local deformation, and the surface measurement results are unreliable or have poor repeatability; fourth, the lens rotates during the measurement process, causing a slight relative displacement or vibration between the lens and the support device, introducing a measurement error. The above factors lead to poor consistency, large errors, and poor repeatability in the measurement results when using the Luphoscan profilometer to measure the surface shape of high-precision infrared lenses.

[0009] During actual measurement, it was found that when the convex surface of the lens to be measured is facing downward, the existing supporting device is a cylinder, and the lens is only placed on the cylinder. Not only is the efficiency of centering and leveling during measurement low, but careless operation may damage the lens surface, and the consistency of the measurement results is poor. In addition, due to the introduction of lens deformation into the measurement results, in most cases the measurement results are greater than the actual surface shape measurement results of the lens.

[0010] The information disclosed in the background technology section is only intended to increase the understanding of the overall background of the utility model, and should not be regarded as acknowledging or suggesting in any form that the information constitutes the prior art already known to ordinary technicians in the field. Utility Model Content

[0011] In response to the above-mentioned technical problems, the present application provides a high-precision lens measurement support device for a Luphoscan profilometer. The device can be used in the measurement process of the Luphoscan profilometer to effectively improve the coaxiality of the support component and the lens during the lens measurement process, reduce the time for installing and adjusting the support component, and reduce the influence of the support component on the curvature radius of the lens; avoid local stress concentration on the lens during detection, effectively reduce the error of the measurement result of the Luphoscan profilometer, and improve the consistency and repeatability of the measurement result.

[0012] Another aspect of the present application provides a high-precision lens measurement support device for a Luphoscan profiler, including: a positioning collar, an adsorption pad, a horizontal adjustment screw, and a measuring base; the measuring base is detachably connected to the Luphoscan profiler centering platform via a horizontal adjustment screw; a supporting ring is arranged at the center of the measuring base; an arc-shaped supporting surface is arranged on the top surface of the supporting ring to fit and support the lens to be measured, and the adsorption pad is adhered to the arc-shaped supporting surface; the lens to be measured is adsorbed on the adsorption pad and positioned by the positioning collar; the positioning collar is covered on the supporting ring; the outer ring of the lens to be measured is clamped on the side wall of the positioning collar;.

[0013] Preferably, the positioning collar comprises: a ring body and a plurality of slots formed on the ring body; the periphery of the lens to be tested is snapped into the slots.

[0014] Preferably, the gap between the inner wall of the positioning collar and the side wall of the lens to be tested is in the range of 0.03 mm to 0.1 mm.

[0015] Preferably, the measuring base comprises: a disc body and a boss; the boss is arranged in the central area of ​​the disc body; the supporting ring is arranged in the central area of ​​the boss; a plurality of mounting holes are arranged on the periphery of the disc body; and the horizontal adjustment screw is passed through the mounting hole.

[0016] Preferably, at least one air conducting hole is provided on the side surface of the supporting ring.

[0017] Preferably, the central axis of the positioning collar 1 , the central axis of the supporting ring 42 , and the central axis of the boss 41 coincide with each other.

[0018] Preferably, the height of the supporting ring is as small as possible while ensuring that there is a gap of 3 mm to 5 mm between the surface of the lens to be measured and the surface of the measuring base.

[0019] Preferably, the radius of curvature of the arc-shaped supporting surface is equal to the radius of curvature of the supporting surface of the lens to be tested.

[0020] Preferably, the surface of the arc-shaped support surface in contact with the lens to be tested is machined by high-precision single-point diamond lathe cutting, and the surface error is controlled within PV≤1μm; preferably, the thickness of the adsorption pad is between 0.5mm and 1mm;

[0021] Preferably, the width of the adsorption pad is smaller than the width of the supporting ring, and at least one notch is provided on the periphery of the adsorption pad;

[0022] Preferably, the inner surface roughness of the positioning collar is better than Ra3.2.

[0023] The beneficial effects of this application include:

[0024] 1) The high-precision lens measurement support device for the Luphoscan profilometer provided in the present application adopts a positioning collar to effectively improve the coaxiality of the high-precision infrared lens and the support ring on the Luphoscan profilometer, without the need to adjust the coaxiality separately, effectively saving adjustment time; the deformation caused by the support device to the lens is determined by simulation software calculation and simulation, and the specific position and width of the ring are determined according to the principle of minimum deformation, so that the support of the support device has the least effect on the radius of curvature of the lens, which is beneficial to improving the accuracy of the measurement results of the radius of curvature of the lens; the device adopts single-point diamond cutting to process the contact surface with the lens, ensuring that the surface shape accuracy of the contact surface is PV≤1μm, and avoiding stress concentration to the greatest extent; an adsorption pad is used between the lens and the device, which can not only increase the friction between the lens and the support device, improve the stability of the lens during rotation, but also ensure that the working surface of the lens is not scratched by metal.

[0025] 2) The high-precision lens measurement support device for the Luphoscan profilometer provided in this application can significantly improve the consistency of the surface measurement results of the Luphoscan profilometer, reduce the error of the measurement results, and improve the repeatability of the measurement results after the lens is fixed by the device. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a schematic diagram of the measurement principle of Luphoscan profilometer in the prior art;

[0027] Figure 2 The infrared lens to be tested in the embodiment of this application

[0028] Figure 3 A schematic cross-sectional view of the measuring device provided in this application;

[0029] Figure 4 This is a schematic cross-sectional view of a measuring base in an embodiment of the present application;

[0030] Figure 5 A schematic diagram of the positioning collar structure provided for this application;

[0031] Figure 6 A schematic diagram of the adjusting screw structure provided for this application;

[0032] Figure 7 Axonometric exploded diagram of the measuring device provided for this application;

[0033] Legend:

[0034] Positioning collar 1, adsorption pad 2, horizontal adjustment screw 3, measuring base 4, boss 41, supporting ring 42, arc-shaped supporting surface 43, slot 11. DETAILED DESCRIPTION

[0035] In order to make the purpose, technical scheme and advantages of the embodiments of the present invention clearer, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. The components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0036] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present invention.

[0037] The controller used in this embodiment is an existing structure, and the control circuit can be implemented through simple programming by technicians in this field. It belongs to the common knowledge in this field. It is only used without modification, so the control method and circuit connection are not described in detail.

[0038] The technical means that are not described in detail in this application and are not used to solve the technical problems of this application are all set according to the common knowledge in the field, and can be implemented in a variety of common knowledge settings.

[0039] See also Figures 1 to 7 The present application provides a high-precision lens measurement support device for a Luphoscan profiler, the support device comprising: a positioning collar 1, an adsorption pad 2, a horizontal adjustment screw 3, and a measuring base 4; the measuring base 4 is detachably connected to the centering platform of the Luphoscan profiler through the horizontal adjustment screw 3; a support ring 42 is arranged at the center of the measuring base 4; an arc-shaped support surface 43 is arranged on the top surface of the support ring 42 to fit and support the lens to be measured, and the adsorption pad 2 is adhered to the arc-shaped support surface 43; the lens to be measured is adsorbed on the adsorption pad 2 and positioned by the positioning collar 1; the positioning collar 1 is covered on the support ring 42; the outer ring of the lens to be measured is clamped on the side wall of the positioning collar 1;

[0040] In a specific embodiment, the diameter and width of the supporting ring 42 are obtained by the following method:

[0041] According to the material and shape of the lens to be tested, the simulation software was used to calculate: when the lens is placed horizontally on the supporting ring, the deformation of the lens caused by the supporting force of the ring under the action of the lens's own weight is obtained. The single-factor experimental method is used to simulate and analyze the ring diameter and width respectively, and the optimal ring diameter and width corresponding to the minimum deformation result are obtained.

[0042] The optimal ring diameter and width obtained by this method can effectively reduce the deformation of the lens caused by the ring support force during measurement to the minimum. The height of the support ring is related to the lens structure. Under the condition of ensuring a gap of 3mm to 5mm between the lens surface and the base surface, the height of the support ring should be reduced as much as possible. The simulation software can be various commonly used simulation software, such as ANASYS Workbench. In the support device of this structure, the arc-shaped support surface 43 on the top surface of the support ring 41 matches the optical surface of the lens to be measured, and an adsorption pad 2 is pasted on it to ensure full contact between the lens and the support surface.

[0043] The measuring device is not limited to the surface shape measurement of large-diameter, high-precision optical lenses to be measured, but is also applicable to large-diameter, high-precision reflectors when their supporting surfaces are curved surfaces.

[0044] Preferably, the positioning collar 1 comprises: a ring body and a plurality of slots 11 formed on the ring body; the periphery of the lens to be tested is clamped in the slots 11. By providing the slot 11 structure, the installation reliability of the lens to be tested during the rotation test can be improved, micro displacement can be avoided, the accuracy of the measurement result can be effectively improved, and excessive errors can be avoided. In a specific embodiment, at least two slots 11 are provided on the upper part of the positioning collar 1, and the slots 11 are symmetrically distributed relative to the center of the positioning collar 1, and the width is greater than the width of the operator's finger. This allows the operator to take the lens to be tested that is clamped in the positioning collar 1.

[0045] In a specific embodiment, the positioning collar 1 is fixedly connected to the measuring base 4 during the measurement process without affecting the measurement. The positioning collar 1 and the measuring base 4 can also be designed as an integral measuring base.

[0046] In a specific embodiment, the positioning collar 1 is made of aluminum alloy and has a guaranteed thickness so that the positioning collar 1 will not be deformed due to processing stress, thereby preventing the positioning collar 1 from affecting the installation and positioning accuracy of the lens to be tested.

[0047] Preferably, the inner diameter of the positioning collar 1 matches the outer diameter of the lens to be tested; specifically, the gap between the inner wall of the positioning collar 1 and the side wall of the lens to be tested is in the range of 0.03mm to 0.1mm. This arrangement can achieve the fixing of the lens to be tested by the positioning collar 1 and prevent the lens to be tested from being stuck in the positioning collar 1.

[0048] Preferably, the measuring base 4 comprises: a disc body, a boss 41; the boss 41 is arranged in the central area of ​​the disc body; the supporting ring 42 is arranged in the central area of ​​the boss 41; a plurality of mounting holes are provided on the periphery of the disc body; and the horizontal adjustment screw 3 is passed through the mounting hole.

[0049] Preferably, the support ring 42 has at least one air-conducting hole; after the lens to be tested is placed on the support ring, a closed space is formed between the lens to be tested and the support ring 42. Once there is a difference between the pressure in the space and the external atmospheric pressure, the additional pressure will cause a slight deformation of the lens to be tested, affecting the accuracy of the surface shape measurement and interfering with the installation and removal of the lens to be tested. By providing the air-conducting hole, the air pressure of the closed space and the external air is ensured to be the same, thereby preventing the lens to be tested from deforming.

[0050] In a specific embodiment, the support ring 42 can be a completely closed cylindrical structure or a separated structure. If it is a separated structure, the parts of the support ring 42 should be centrally symmetrically distributed. In this case, the space between the lens to be tested and the support ring 42 has become an open space, and there is no need to open a gas guide hole on the side of the support ring 42.

[0051] Preferably, the central axis of the positioning collar 1, the central axis of the supporting ring 42, and the central axis of the boss 41 coincide with each other, effectively ensuring that the lens to be measured and the supporting ring 42 are concentric, thereby effectively reducing the measurement error.

[0052] In a specific embodiment, the measuring base 3 is made of aluminum alloy or similar metal materials, and the disk can be round or square. The edge of the measuring base 4 has 3 to 4 horizontal adjustment screws. The horizontal adjustment screws 3 can adjust the inclination of the measuring base 4 to ensure that the lens to be measured rotates in the horizontal plane.

[0053] The horizontal adjustment screw 3 is symmetrically distributed relative to the center of the measuring base 4. The screw head has a mesh knurling structure to increase friction and facilitate twisting and rotating with fingers. The bottom of the screw is round. The size and length of the screw are determined according to the weight of the specific lens to be measured and the measuring base. Rotating the screw can achieve the tilt adjustment of the measuring base to ensure that the lens to be measured rotates in the horizontal plane.

[0054] Preferably, the height of the support ring 42 is related to the structure of the lens to be measured, and the height of the support ring 42 is as small as possible under the condition that there is a 3mm to 5mm gap between the surface of the lens to be measured and the surface of the measuring base 4. This setting can effectively ensure the surface of the lens to be measured, while reducing the height of the support ring 42, reducing the possibility of slight displacement of the lens to be measured during rotation measurement, and improving measurement accuracy.

[0055] Preferably, the curvature radius of the arc-shaped support surface 43 is equal to the curvature radius of the support surface of the lens to be measured, so as to effectively provide reliable support for rotation measurement.

[0056] In a specific embodiment, the arc-shaped supporting surface 43 is provided on the top surface of the supporting ring 42 to fit and support the lens to be tested, which means that the surface shape of the arc-shaped supporting surface 43 in contact with the lens to be tested matches the supporting surface of the lens to be tested, and when the lens to be tested is convex, the arc-shaped supporting surface 43 is concave; conversely, when the lens to be tested is concave, the arc-shaped supporting surface 43 is convex, and the curvature radii are equal.

[0057] Preferably, the surface of the arc-shaped support surface 43 in contact with the lens to be measured is machined by a high-precision single-point diamond lathe, and the surface error is controlled at PV≤1μm, which can be obtained by precision single-point diamond machine tool cutting, so that the surface of the lens to be measured is fully in contact with the arc-shaped support surface 43, avoiding that the lens to be measured is only in contact with a local position of the arc-shaped support surface 43, and avoiding the phenomenon of support stress concentration to the greatest extent. Effectively improve the measurement accuracy and effectively reduce the damage to the lens.

[0058] In a specific embodiment, the thickness of the adsorption pad 2 is between 0.5 mm and 1 mm. The adhesive side of the adsorption pad 2 is adhered to the arc-shaped support surface 43 of the support ring 42, and the adhesive-free side faces outwards, and is in direct contact with the working surface of the lens to be measured during measurement, so as to prevent the metal surface from scratching the working surface of the lens to be measured, and fix the lens to be measured at the same time.

[0059] Preferably, the width of the adsorption pad 2 is smaller than the width of the supporting ring 42, and at least one notch is provided on the periphery of the adsorption pad 2. When the adsorption pad 2 is cut, one or more symmetrically distributed notches must be retained, and the width of the notch should be no greater than 1 mm. These notches, on the one hand, ensure that no extrusion bulge is generated when the adsorption pad 2 is pasted, thereby avoiding the generation of stress concentration points that may cause damage to the lens to be tested, and on the other hand, ensure that the supporting force is symmetrically distributed, so that the lens to be tested is evenly stressed and does not cause local deformation.

[0060] In a specific embodiment, the positioning collar 1 is a cylindrical structure, and its inner diameter matches the outer diameter of the lens to be measured, the gap is controlled between 0.03mm and 0.1mm, and the inner surface roughness of the positioning collar is better than Ra3.2. The bottom of the positioning collar 1 matches the boss 41 when measuring the base 4, and the boss 41 and the support ring 42 are coaxial, thereby ensuring that the positioning collar 1 and the support ring 42 are initially coaxial, saving time for subsequent precision adjustment and improving measurement efficiency.

[0061] In a specific embodiment, the height of the positioning collar 1 is related to the height of the support ring 42 and the structure of the lens to be tested. The lens to be tested is placed above the support ring 42, and the thickness of the edge of the lens to be tested can be exposed by no less than 0.5 mm from the positioning collar 1. This arrangement can effectively protect the lens to be tested from being damaged at the periphery of the lens to be tested.

[0062] When the above device is used for measuring high-precision lenses, it includes the following steps:

[0063] Step S1: Processing, cleaning and drying the components of the supporting device of the above structure;

[0064] Step S2: cutting the adsorption pad according to the shape of the support ring, pasting the adsorption pad to the arc-shaped support surface of the support ring, and pressing the adsorption pad repeatedly and slowly and evenly with fingers or other elastic objects until the adsorption pad is firmly pasted without local bulges;

[0065] Step S3: Install the positioning collar and the horizontal adjustment screw on the measuring base, clean the lens to be tested, and the operator wearing latex gloves faces the surface to be tested of the lens to be tested upward, firmly clamps the lens to be tested with both hands, aligns with the positioning collar, and slowly inserts the lens to be tested vertically downward into the positioning collar, with the bottom of the lens to be tested placed on the arc-shaped supporting surface of the supporting ring, and gently presses the lens to be tested through the groove on the supporting ring until the lens to be tested is in full contact with the surface of the supporting ring. If necessary, the positioning collar can be removed, and the lens to be tested can be gently pressed to ensure that the lens to be tested is in full contact with the arc-shaped supporting surface of the supporting ring;

[0066] Step S4: calibrate the Luphoscan profilometer according to the operating requirements of the Luphoscan profilometer, disassemble and connect the measuring base and the lens to be measured as a whole to the Luphoscan profilometer centering platform through the horizontal adjustment screw, visually observe to make the center of the support ring coincide with the center of the turntable, adjust the horizontal adjustment screw or the fine-tuning mechanism on the turntable of the profilometer according to the measurement result of the level meter, and judge through the feedback signal to make the center of the lens to be measured coincide with the center of the turntable, and the axis of the rotating surface of the lens to be measured be perpendicular to the plane of the turntable;

[0067] Step S5: Measure the surface shape of the lens to be tested according to the operating requirements of the Luphoscan profilometer. After the measurement is completed, remove the lens to be tested and store it for future use.

[0068] In a specific embodiment, if after the test in step S5 is completed according to the detection requirements, it is necessary to test again, remove the positioning collar (when the collar is kept on the measuring base during the measurement), remove the lens to be tested by hand, install the positioning collar on the measuring base again, and operate according to steps S3 to 4. If the lens to be tested is too heavy to be operated, the measuring base and the lens to be tested can be moved as a whole to a workbench that is convenient for operation, remove the lens to be tested according to this step, and then put the lens to be tested back in as needed.

[0069] In a specific embodiment, after the measurement is completed, the lens to be measured is removed and placed in a container in a designated area, and the entire set of measurement bases is stored in a dry and clean environment for later use.

[0070] Preferably, in step S2, if the contact surface between the lens to be tested and the supporting ring is a plane, a flat crystal with a larger diameter than the supporting ring may be pressed on the adsorption pad for several hours to ensure reliable adhesion of the adsorption pad.

[0071] In a specific embodiment, one side of the inner diameter of the positioning collar 1 has an arc chamfer with a radius R2 to prevent the edge of the lens to be tested from chipping.

[0072] Example

[0073] In this embodiment, the lens to be measured is a zinc selenide infrared lens with a diameter of Φ172.8 mm, a center thickness of 14.77 mm, and an edge thickness of 9.59 mm. The specific size and structure are as follows: Figure 2 The convex surface to be measured has a curvature radius of R251.92mm, and the other side (bonding surface) is concave with a curvature radius of R317.81mm. The surface accuracy requirements are PV≤0.25μm, RMS≤0.035μm, which is 2 times or more higher than that of general infrared lens surface accuracy.

[0074] During the measurement process, if the lens is not properly supported, it will cause uneven stress distribution, causing slight deformation, affecting the accuracy of the measurement results, and causing the infrared lens surface accuracy to fail to meet the requirements. In order to overcome the above defects, a support device with the above structure is used. For the specific structure, see Figure 7 The support device can avoid slight deformation caused by uneven force, so as to improve the consistency of measurement results (such as Figure 3 As shown). The stress distribution of the lens support is simulated and analyzed by ANASYS Workbench professional software, and the optimization result of the support ring size is obtained. According to the result, the outer diameter of the support ring is set to Φ112mm. When the width is 13mm, the lens deformation is minimal. According to the optimization result and the lens structure, the convex arc height and edge thickness parameters of the lens are set. According to the design result, the measurement base 4 is obtained. Figure 4 The supporting device includes: a measuring base 4 (see Figure 4 )、Adsorption pad 2、Positioning collar 1 (see Figure 5 ), level adjustment screw 3 (see Figure 6 ), the three-dimensional schematic diagram of the measuring device is shown in Figure 7 The support surface of the support ring 42 is roughly machined by a conventional machine tool and then cut by a single-point diamond precision machine tool. The surface shape is complementary to the lens support surface, and the surface shape accuracy PV ≤ 1 μm.

[0075] Cut the corresponding adsorption pad 2 according to the size of the support ring 42 and paste it on the surface of the support ring 42. Note that a fine gap needs to be left for the adsorption pad 2. The base diameter of the measuring base 4 is 226 mm. There are four centrally symmetrical M6 threaded holes on the circumference at 210 mm, and corresponding 4 M6 level adjustment screws 3, with a thread length of 16 mm, a head size of 10 mm × 5 mm, and a reticulated knurling on the side.

[0076] There is a circular step concentric with the support ring at the lens aperture of Ф172.8mm, with a height of 6mm. This circular step is the positioning and installation reference of the positioning clamp ring. The inner diameter of the positioning clamp ring is Ф172.8mm, the outer diameter is Ф192.8mm, the height is 28mm, and there are four centrally symmetrical grooves with a groove depth of 10mm and a relative center angle of 30° (the width is greater than 35mm, which meets the requirement of being greater than the width of a finger). The upper edge of the positioning clamp ring 1 is located in the middle of the thickness of the edge of the lens to be tested after the lens to be tested is installed. There is an arc chamfer with a radius of R2 on one side of the inner diameter of the positioning clamp ring 1 to prevent the lens from contacting the positioning clamp ring 1 when the lens is placed, causing the edge of the lens to collapse. The optical lens is placed on the adsorption pad 2 set in the support ring 42 along the edge of the positioning clamp ring 1. Considering that after the lens is placed on the measuring base 4, a closed space will be formed between the optical lens and the supporting ring 42 due to the close contact effect of the adsorption pad 2. In order to avoid the influence of the different air pressure in this closed space and the outside air pressure on the measurement, there are 4 Φ4mm semicircular through holes distributed symmetrically on the bottom surface of the connection between the side of the supporting ring and the measuring base, so that the air in the closed space is connected with the outside world and the air pressure inside and outside is kept consistent.

[0077] Comparative Example

[0078] The difference from the embodiment is that the lens to be measured is directly placed on the centering and adjusting platform of the Luphoscan profilometer for surface measurement.

[0079] For example Figure 2 The lens shown was measured for surface shape according to the comparative example and under the condition of using the support device provided by the present application. Each measurement item was repeated 3 times. The results are shown in the following table:

[0080]

[0081] After using the support device provided by the present application, the fluctuation of the surface shape measurement result of the lens is much lower than the measurement result in the comparative example without using the support device, which shows that the use of the device can effectively reduce the error of the lens measurement result and improve the measurement accuracy, consistency and repeatability.

[0082] Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments, or make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A high-precision lens measurement support device for Luphoscan profilometer, characterized in that: The supporting device comprises: a positioning collar, an adsorption pad, a horizontal adjustment screw, and a measuring base; the measuring base is detachably connected to the centering platform of the Luphoscan profilometer through the horizontal adjustment screw; a supporting ring is arranged at the center of the measuring base; an arc-shaped supporting surface is arranged on the top surface of the supporting ring to fit and support the lens to be measured, and the adsorption pad is pasted on the arc-shaped supporting surface; the lens to be measured is adsorbed on the adsorption pad and positioned by the positioning collar; the positioning collar is covered on the supporting ring; the outer ring of the lens to be measured is clamped on the side wall of the positioning collar.

2. The high-precision lens measurement support device for Luphoscan profilometer according to claim 1, characterized in that: The positioning clamp ring comprises: a ring body and a plurality of slots formed on the ring body; the periphery of the lens to be tested is clamped in the slots.

3. The high-precision lens measurement support device for Luphoscan profilometer according to claim 1, characterized in that: The gap between the inner wall of the positioning collar and the side wall of the lens to be measured is in the range of 0.03 mm to 0.1 mm.

4. The high-precision lens measurement support device for Luphoscan profilometer according to claim 1, characterized in that: The measuring base comprises: a disc body and a boss; the boss is arranged in the central area of ​​the disc body; the supporting ring is arranged in the central area of ​​the boss; a plurality of mounting holes are arranged on the periphery of the disc body; and the horizontal adjustment screws are passed through the mounting holes.

5. The high-precision lens measurement support device for Luphoscan profilometer according to claim 1, characterized in that: At least one air guide hole is arranged on the side surface of the supporting ring.

6. The high-precision lens measurement support device for Luphoscan profilometer according to claim 1, characterized in that: The central axis of the positioning collar (1), the central axis of the supporting ring (42) 2, and the central axis of the boss (41) coincide with each other.

7. The high-precision lens measurement support device for Luphoscan profilometer according to claim 1, characterized in that: The curvature radius of the arc-shaped supporting surface is equal to the curvature radius of the supporting surface of the lens to be measured.

8. The high-precision lens measurement support device for Luphoscan profilometer according to claim 1, characterized in that: The arc-shaped support surface in contact with the lens to be tested is machined by high-precision single-point diamond lathe, and the surface error is controlled within PV≤1μm; The thickness of the adsorption pad is between 0.5mm and 1mm; The width of the adsorption pad is smaller than the width of the supporting ring, and at least one notch is arranged on the periphery of the adsorption pad.

9. The high-precision lens measurement support device for Luphoscan profilometer according to claim 1, characterized in that: The inner surface roughness of the positioning collar is better than Ra3.2.

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