CN118009924A

CN118009924A - High-precision lens measuring supporting device and measuring method for Luphoscan profiler

Info

Publication number: CN118009924A
Application number: CN202410328910.6A
Authority: CN
Inventors: 谢启明; 康杰; 马峰亮; 刘尧; 李陈涛; 张敬东; 李秉胜; 游津京; 王宇彤; 周涛; 吕敏
Original assignee: Yunnan North Optical Technology Co ltd
Current assignee: Yunnan North Optical Technology Co ltd
Priority date: 2024-03-21
Filing date: 2024-03-21
Publication date: 2024-05-10

Abstract

The application discloses a high-precision lens measuring and supporting device and a measuring method for Luphoscan profilers, wherein the supporting device comprises: the device comprises a positioning clamping ring, an adsorption pad, a horizontal adjusting screw and a measuring base; the measuring base is detachably connected with the Luphoscan profiler aligning platform through a horizontal adjusting screw; a supporting circular ring is arranged at the center of the measuring base; the top surface of the supporting ring is provided with an arc supporting surface which is attached to and supported by the lens to be tested, and the adsorption pad is attached to the arc supporting surface; the lens to be measured is adsorbed on the adsorption pad and is positioned by the positioning clamping ring; 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 clamping ring. After the lens is fixed by the device, the consistency of the surface shape measurement result of the Luphoscan profiler can be obviously improved, the error of the measurement result is reduced, and the repeatability of the measurement result is improved.

Description

High-precision lens measuring supporting device and measuring method for Luphoscan profiler

Technical Field

The application relates to the technical field of optical device processing, in particular to a high-precision lens measuring and supporting device for Luphoscan profilers and a measuring method.

Background

With the development of photoelectric technology, the surface shape of an optical lens is more and more required. In order to realize the ultra-long acting distance of the satellite-borne photoelectric system, the optical system of the satellite-borne photoelectric system is required to be large in caliber and high in precision. At present, the lens materials used for satellite infrared load cover various main infrared optical materials such as germanium, silicon, zinc sulfide, zinc selenide, chalcogenide glass and the like, the caliber of the front-end optical lens is more than phi 200mm, the surface shape requirement is as high as PV less than or equal to 0.2 mu m, RMS less than or equal to 0.03 mu m, and even higher.

Whereas the surface shape of conventional infrared optical lenses requires only PV (0.4-0.6) μm and RMS (0.06-0.1) μm. The requirement of high precision presents new challenges for the processing and surface shape measurement of infrared optical lenses. The high-precision measurement can effectively ensure that the machining precision meets the requirement, and the error of the measurement result is large, so that the accurate feedback of the machining precision can be seriously influenced.

The conventional contact profilometer, such as PGI 1240 profilometer manufactured by Taylor-Hopkinson, cannot meet the surface shape measurement requirement, and the non-contact Luphoscan profilometer must be used for measurement; the Luphoscan profilometer is a high-speed non-contact type 3D aspheric optical surface shape measuring system based on a multi-wavelength interference sensing technology, the profilometer is measured by a laser ranging method, the measuring principle is shown in fig. 1, the position of a sensor measuring head is controlled by R, Z and a T axis, the measuring head scans the surface of a measured lens according to a preset path, meanwhile, the measured lens rotates around the C axis of the measured lens, and the measuring head performs spiral scanning on the whole surface shape. The measuring head is always perpendicular to the surface to be measured in the scanning process, so that the distance between the measuring head and the measured point is kept constant. The absolute distance is flexibly measured by utilizing the multi-wavelength interference sensing technology, and the surface shape detection can be realized even if a gap exists on the surface of the optical lens to be detected because the absolute distance is not influenced by the interruption of the light beam. When the Luphoscan profilometer is used for surface shape measurement, the lens to be measured needs to be placed on the profilometer turntable and rotates along with the turntable, and at the moment, the support of the lens directly affects the measurement precision.

It is known that, besides silicon single crystal, the infrared optical material has a high density, for example, the density of germanium is 5.33g/cm ³, the density of zinc selenide is 5.42g/cm ³, the weight of germanium or zinc selenide lens with caliber phi of 200mm can reach thousands of grams, and under the action of the dead weight of the lens, the supporting structure extrudes the lens to cause the shape of the lens to slightly deform; when the detection precision is less than or equal to 0.03 mu m, the accuracy of the judging result of whether the lens is qualified or not can be influenced by the nano-scale measurement error.

The influence of the supporting mode on the deformation of the lens is larger on materials with poor strength (for example, the hardness and the bending strength of zinc selenide are only about half of that of zinc sulfide, and the strength of chalcogenide glass is lower), so that the accuracy of the surface shape measurement result can be directly influenced by different supporting modes, and the influence is more remarkable on a large-caliber high-precision lens.

Referring to fig. 1, in the measuring process, the lens rotates horizontally along with the main shaft, when the concave surface is downward, the lens can be directly placed on the profiler turntable to perform surface shape measurement, and when the convex surface is downward, a corresponding supporting device must be designed to support the lens to perform accurate measurement.

Influence of the supporting mode used in the existing measuring method on the measuring result: the first lens is arranged on the measuring supporting device, and the optical axis of the lens is not concentric with the axis of the supporting ring supported by the supporting device, so that the lens is eccentric and is stressed unevenly; secondly, under the action of self gravity, the position and the width of the supporting ring influence the deformation part and the deformation degree of the lens, so that the curvature radius measured value of the lens is increased or decreased, and curvature radius measuring errors are introduced; thirdly, the surface shape error of the supporting ring supporting surface is larger, so that the contact between the lens and the supporting surface is concentrated in a certain partial area, the partial deformation is caused by uneven stress distribution of the lens, and the surface shape measurement result is unreliable or has poor repeatability; fourth, the lens and the support device are slightly displaced or vibrated relative to each other due to rotation during the measurement process, and measurement errors are introduced. The factors cause poor consistency, large error and poor repeatability of the measurement result when the Luphoscan profiler is used for carrying out surface shape measurement on the high-precision infrared lens.

When the convex surface of the lens to be measured faces downwards, the conventional supporting device is a cylinder, and the lens is only placed on the cylinder, so that the aligning and leveling efficiency is low, the surface of the lens can be damaged due to careless operation, the consistency of the measurement result is poor, and the measurement result is larger than the actual surface shape measurement result of the lens in most cases due to the fact that the deformation of the lens is introduced into the measurement result.

The information disclosed in the background section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person of ordinary skill in the art.

Disclosure of Invention

Aiming at the technical problems, the application provides a high-precision lens measurement supporting device and a high-precision lens measurement method for Luphoscan profilers, which can be used in the Luphoscan profiler measurement process, effectively improve the coaxiality of a supporting part and a lens in the lens measurement process, reduce the time for installing and adjusting the supporting part and reduce the influence of the supporting part on the curvature radius of the lens; the local stress concentration of the lens during detection is avoided, the error of the measuring result of the Luphoscan profiler is effectively reduced, and the consistency and repeatability of the measuring result are improved.

In another aspect, the present application provides a high-precision lens measurement support device for Luphoscan profilers, comprising: the device comprises a positioning clamping ring, an adsorption pad, a horizontal adjusting screw and a measuring base; the measuring base is detachably connected with the Luphoscan profiler aligning platform through a horizontal adjusting screw; a supporting circular ring is arranged at the center of the measuring base; the top surface of the supporting ring is provided with an arc supporting surface which is attached to and supported by the lens to be tested, and the adsorption pad is attached to the arc supporting surface; the lens to be measured is adsorbed on the adsorption pad and is positioned by the positioning clamping ring; 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 clamping ring;

The caliber and width of the ring of the supporting ring are obtained by the following method:

According to the material and shape of the lens to be measured, the material and shape are calculated by simulation software: when the lens is horizontally placed on the supporting ring, under the action of dead weight of the lens, the deformation of the lens caused by the supporting force of the ring is analyzed by simulation on the caliber and the width of the ring respectively by adopting a single-factor experiment method, and the optimal caliber and the width of the ring corresponding to the minimum deformation result are obtained.

Preferably, the positioning collar comprises: the ring body and a plurality of slots are formed in the ring body; the periphery of the lens to be tested is clamped in the slot.

Preferably, 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-0.1 mm.

Preferably, the measuring base includes: a tray body and a boss; the boss is arranged in the central area of the tray body; the supporting ring is arranged in the center area of the boss; the periphery of the tray body is provided with a plurality of mounting holes; the horizontal adjusting screw penetrates through the mounting hole.

Preferably, the side surface of the supporting circular ring is provided with at least one air guide through hole.

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.

Preferably, the height of the supporting ring is as small as possible under the condition that a gap of 3 mm-5 mm is reserved between the surface of the lens to be measured and the surface of the measuring base.

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 measured.

Preferably, the surface of the arc-shaped supporting surface contacted with the lens to be detected is cut by adopting a high-precision single-point diamond lathe, and the surface shape error is controlled to be less than or equal to 1 mu m; preferably, the thickness of the adsorption pad is between 0.5mm and 1 mm;

Preferably, 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;

preferably, the roughness of the inner surface of the positioning collar is better than Ra3.2.

In another aspect, the present application provides a high-precision lens measurement method, including the steps of:

Step S1: processing, cleaning and drying the components of the support device of the structure according to any one of claims 1 to 9;

Step S2: cutting the adsorption pad according to the shape of the support ring, adhering the adsorption pad to an arc-shaped support surface of the support ring, and slowly, uniformly and repeatedly pressing the adsorption pad with fingers or other elastic objects until the adsorption pad is reliably adhered without local bulge;

Step S3: installing a positioning collar and a horizontal adjusting screw on a measuring base, cleaning a lens to be measured, wearing latex gloves by an operator to enable the surface to be measured of the lens to be measured upwards, reliably clamping the lens to be measured by both hands, aligning the positioning collar, vertically and downwards slowly placing the lens to be measured into the positioning collar, placing the bottom of the lens to be measured on an arc-shaped supporting surface of a supporting circular ring, lightly pressing the lens to be measured through a groove on the supporting circular ring until the lens to be measured is fully contacted with the surface of the supporting circular ring, and removing the positioning collar and lightly pressing the lens to be measured to ensure that the lens to be measured is fully contacted with the arc-shaped supporting surface of the supporting circular ring if necessary;

step S4: calibrating Luphoscan the profiler according to the operation requirement of Luphoscan the profiler;

Step S5: the measuring base and the whole lens to be measured are detachably connected with a Luphoscan profiler aligning platform through a horizontal adjusting screw, the center of a supporting ring is overlapped with the center of a turntable through visual observation, the horizontal adjusting screw or a fine adjustment mechanism on the profiler turntable is adjusted according to the measuring result of the level meter, the center of the lens to be measured is overlapped with the center of the turntable through judgment of a feedback signal, and the axis of the rotating surface of the lens to be measured is vertical to the plane of the turntable;

Step S6: and measuring the surface shape of the lens to be measured according to the operation requirement of the Luphoscan profiler, and taking down the lens to be measured after the measurement is finished and storing the lens to be measured for standby.

The application has the beneficial effects that:

1) According to the high-precision lens measurement supporting device for the Luphoscan profiler, the positioning clamping ring is adopted to effectively improve the coaxiality of the high-precision infrared lens and the supporting circular ring on the Luphoscan profiler, the coaxiality is not required to be independently adjusted, and the adjustment time is effectively saved; the deformation of the lens caused by the supporting device is calculated and simulated through simulation software, the specific position and the width of the circular ring are determined according to the principle of minimum deformation, the influence of the supporting device on the curvature radius of the lens is minimum, and the accuracy of the measurement result of the curvature radius of the lens is improved; the device adopts single-point diamond cutting to process the contact surface of the lens, ensures that the surface shape precision PV of the contact surface is less than or equal to 1 mu m, and avoids the occurrence of stress concentration to the greatest extent; the adsorption pad is adopted between the lens and the device, so that the friction force between the lens and the supporting device can be increased, the stability of the lens in rotation is improved, and the working surface of the lens can be prevented from being scratched by metal.

2) The high-precision lens measurement supporting device for the Luphoscan profiler, provided by the application, can obviously improve the consistency of the surface shape measurement result of the Luphoscan profiler, reduce the error of the measurement result and improve the repeatability of the measurement result after the lens is fixed by adopting the device.

Drawings

FIG. 1 is a schematic diagram of a prior art Luphoscan profiler measurement principle;

FIG. 2 is a diagram of an infrared lens to be measured according to an embodiment of the present application

FIG. 3 is a schematic cross-sectional view of a measuring device according to the present application;

FIG. 4 is a schematic cross-sectional view of a measuring base in an embodiment of the application;

FIG. 5 is a schematic view of a retainer collar structure provided by the present application;

FIG. 6 is a schematic view of the structure of the adjusting screw according to the present application;

FIG. 7 is a schematic diagram of an axial explosion of the measuring device according to the present application;

FIG. 8 shows the result of repeating the measurement 3 times for the lens of FIG. 2 in an embodiment of the present application, a) being the first measurement; b) For the second measurement; c) For the third measurement;

FIG. 9 is a graph of the application providing a comparison of 3 repeated measurements of the lens of FIG. 2, a) being the first measurement; b) For the second measurement; c) For the third measurement;

Legend description:

the device comprises a positioning clamping ring 1, an adsorption pad 2, a horizontal adjusting screw 3, a measuring base 4, a boss 41, a supporting ring 42, an arc-shaped supporting surface 43 and a slot 11.

Detailed Description

For the purpose of making the objects, technical solutions and advantages of the embodiments of the present invention more apparent, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention, and it is apparent that the described embodiments are some embodiments of the present invention, but not all embodiments. The components of the embodiments of the present invention generally described and illustrated in the figures herein may be arranged and designed in a wide variety of different configurations.

Thus, the following detailed description of the embodiments of the invention, as presented in the figures, is not intended to limit the scope of the invention, as claimed, but is merely representative of selected embodiments of the invention. All other embodiments, based on the embodiments of the invention, which are apparent to those of ordinary skill in the art without inventive faculty, are intended to be within the scope of the invention.

The controller used in this embodiment is an existing structure, and the control circuit can be implemented by simple programming by a person skilled in the art, and it is common knowledge in the art that the controller is only used, and is not modified, so that the control mode and circuit connection will not be described in detail.

The technical means which are not described in detail and are not used for solving the technical problems of the application are all arranged according to common general knowledge in the field, and various common general knowledge arrangement modes can be realized.

Referring to fig. 1 to 7, the present application provides a high-precision lens measurement support device for Luphoscan profilers, the support device comprising: the device comprises a positioning clamping ring 1, an adsorption pad 2, a horizontal adjusting screw 3 and a measuring base 4; the measuring base 4 is detachably connected with the Luphoscan profiler aligning platform through a horizontal adjusting screw 3; a supporting circular ring 42 is arranged at the center of the measuring base 4; the top surface of the supporting circular ring 42 is provided with an arc-shaped supporting surface 43 which is attached to and supported by the lens to be tested, and the adsorption pad 2 is attached to the arc-shaped supporting surface 43; the lens to be measured is adsorbed on the adsorption pad 2 and is positioned by the positioning clamping ring 1; the positioning collar 1 covers the supporting circular ring 42; the outer ring of the lens to be measured is clamped on the side wall of the positioning clamping ring 1;

The diameter and width of the ring of the support ring 42 are obtained as follows:

The optimal caliber and width of the circular ring obtained by the method can effectively reduce the deformation of the lens caused by the supporting force of the circular ring during measurement, so that the deformation is minimized, the height of the supporting circular ring is related to the structure of the lens, and the height of the supporting circular ring is reduced as far as possible under the condition that the gap of 3 mm-5 mm exists between the surface of the lens and the surface of the base. The simulation software can be various common simulation software, such as ANASYS Workbench. In the supporting device of the structure, the arc-shaped supporting surface 43 for supporting the top surface of the circular ring 41 is matched with the optical surface of the lens to be detected, and the adsorption pad 2 is adhered on the arc-shaped supporting surface, so that the lens and the supporting surface are fully contacted.

The measuring device is not limited to the surface shape measurement of the large-caliber and high-precision optical lens to be measured, and is also applicable to the large-caliber and high-precision reflecting mirror when the supporting surface of the reflecting mirror is a curved surface.

Preferably, the positioning collar 1 comprises: the ring body and a plurality of slots 11 arranged on the ring body; the periphery of the lens to be tested is clamped in the slot 11. Through setting up fluting 11 structures, can improve the lens that awaits measuring and rotate the installation reliability of test in-process, avoid taking place the micro displacement, effectively improve measuring result accuracy, avoid the error too big. In a specific embodiment, the upper part of the positioning collar 1 is provided with at least two grooves 11, the grooves 11 are symmetrically distributed relative to the center of the positioning collar 1, and the width is larger than the width of the fingers of an operator. So that the operator takes the lens to be measured that is snapped into the positioning collar 1.

In a specific embodiment, the positioning collar 1 is fixedly connected to the measuring base 4 during the measurement without affecting the measurement, it is also possible to design the positioning collar 1 and the measuring base 4 as a one-piece measuring base.

In a specific embodiment, the positioning collar 1 is made of aluminum alloy, and the thickness is ensured, so that the positioning collar 1 is not deformed due to processing stress, and the installation and positioning accuracy of the lens to be measured are affected.

Preferably, the inner diameter of the positioning collar 1 is matched with the outer diameter of the lens to be measured; specifically, the clearance between the inner wall of the positioning collar 1 and the side wall of the lens to be measured is in the range of 0.03 mm-0.1 mm. The arrangement can realize the fixation of the positioning collar 1 to the lens to be tested and can also avoid the lens to be tested from being in the positioning collar 1

Preferably, the measuring base 4 comprises: a tray body and a boss 41; the boss 41 is arranged in the central area of the tray body; the supporting circular ring 42 is arranged in the center area of the boss 41; the periphery of the tray body is provided with a plurality of mounting holes; the horizontal adjusting screw 3 is arranged in the mounting hole in a penetrating way.

Preferably, the supporting ring 42 is provided with at least one air guide through hole; since the lens to be measured is placed on the supporting ring, a closed space is formed between the lens to be measured and the supporting ring 42, and when the space pressure and the external atmospheric pressure are different, additional pressure is formed to cause micro deformation of the lens to be measured, which affects the surface shape measurement accuracy and also causes interference to installation and removal of the lens to be measured. Through setting up the air guide through-hole, guarantee that airtight space is the same with external air atmospheric pressure, avoid the lens of awaiting measuring to produce deformation.

In one embodiment, the support ring 42 may be a completely closed cylinder structure or a separate structure. If the structure is a separation structure, the parts of the supporting ring 42 should be distributed in a central symmetry manner, and the space between the lens to be measured and the supporting ring 42 is already an open space, so that the air guide holes do not need to be opened on the side surface of the supporting ring 42.

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 are coincident, so that the concentricity of the lens to be tested and the supporting ring 42 is effectively ensured. And the measurement error is effectively reduced.

In a specific embodiment, the measuring base 3 is made of aluminum alloy or similar metal materials, the disc body is round or square, 3 to 4 horizontal adjusting screws are arranged at the edge part of the measuring base 4, and the inclination of the measuring base 4 can be adjusted by the horizontal adjusting screws 3, so that the lens to be measured can rotate in the horizontal plane.

The horizontal adjusting screws 3 are symmetrically distributed relative to the center of the measuring base 4, the heads of the screws are of net-shaped knurled structures, friction force is increased, and the screws are convenient to twist and rotate by fingers. The bottom of the screw is circular, the size and the length of the screw are determined according to the weight of a specific lens to be measured and the weight of the measuring base, and the inclination adjustment of the measuring base can be realized by rotating the screw, so that the lens to be measured can be rotated on the horizontal plane.

Preferably, the height of the supporting ring 42 is as small as possible in relation to the lens structure to be measured, while ensuring that the surface of the lens to be measured and the surface of the measuring base 4 have a gap of 3mm to 5 mm. According to the arrangement, the surface of the lens to be measured can be effectively ensured, the height of the supporting ring 42 is reduced, the possibility of micro displacement and offset of the lens to be measured in rotation measurement is reduced, and the measurement accuracy is improved.

Preferably, the radius of curvature of the arc-shaped supporting surface 43 is equal to the radius of curvature of the supporting surface of the lens to be measured. To effectively provide a reliable support for rotation measurements.

In one embodiment, the arrangement of the arc-shaped supporting surface 43 on the top surface of the supporting ring 42 and the fitting supporting of the lens to be tested means: the surface shape of the arc-shaped supporting surface 43 contacted with the lens to be tested is matched with that of the lens to be tested, and when the lens to be tested is a convex surface, the arc-shaped supporting surface 43 is a concave surface; on the contrary, when the lens to be measured is concave, the arc-shaped supporting surface 43 is convex, and the curvature radii are equal.

Preferably, the surface of the arc-shaped supporting surface 43 contacted with the lens to be detected is cut by adopting a high-precision single-point diamond lathe, the surface shape error is controlled to be less than or equal to 1 mu m, and the surface shape error can be obtained by adopting the precise single-point diamond lathe to cut, so that the surface of the lens to be detected is fully contacted with the surface of the arc-shaped supporting surface 43, the lens to be detected is prevented from being contacted with the local position of the arc-shaped supporting surface 43 only, and the phenomenon of supporting stress concentration is avoided to the greatest extent. The accuracy of measurement is effectively improved, and the damage to the lens can be effectively reduced.

In one embodiment, the thickness of the absorbent pad 2 is between 0.5mm and 1 mm. The surface of the adsorption pad 2 with glue is stuck on the surface of the arc-shaped supporting surface 43 of the supporting ring 42, the surface without glue is outwards, and the adsorption pad is in direct contact with the working surface of the lens to be measured during measurement, so that the working surface of the lens to be measured is prevented from being scratched by the metal surface, and the lens to be measured is fixed.

Preferably, the width of the adsorption pad 2 is smaller than the width of the supporting ring 42, and at least one notch is arranged on the periphery of the adsorption pad 2. The adsorption pad 2 needs to keep one or more gaps symmetrically distributed when being cut, and the gap width is not more than 1mm. On one hand, the gaps ensure that the adsorption pad 2 is not extruded and raised when being stuck, so that the damage to the lens to be tested caused by the concentrated stress is avoided, and on the other hand, the symmetrical distribution of supporting force can be ensured, so that the lens to be tested is uniformly stressed and cannot be deformed locally.

In a specific embodiment, the positioning collar 1 is of a cylindrical structure, the inner diameter of the positioning collar is matched with the outer diameter of the lens to be measured, the gap is controlled between 0.03mm and 0.1mm, and the roughness of the inner surface of the positioning collar is superior to Ra3.2. The boss 41 cooperation when location rand 1 bottom and measuring base 4, boss 41 and support ring 42 are coaxial, and then guarantee that location rand 1 and support ring 42 are preliminary coaxial, save time for follow-up fine adjustment, improve measurement of efficiency.

In one embodiment, the height of the positioning collar 1 is related to the height of the supporting ring 42 and the structure of the lens to be measured, the lens to be measured is placed above the supporting ring 42, and the thickness portion of the edge of the lens to be measured can be exposed to the positioning collar 1 by not less than 0.5mm. According to the arrangement, the lens to be tested can be effectively protected from being damaged at the periphery of the lens to be tested.

step S1: processing, cleaning and drying the parts of the supporting device with the structure;

step S4: calibrating Luphoscan profiler according to operation requirement of Luphoscan profiler, detaching and connecting the whole measuring base and the lens to be measured with the aligning platform of Luphoscan profiler by a horizontal adjusting screw, visually observing to enable the center of the supporting ring to coincide with the center of the turntable, adjusting the horizontal adjusting screw or a fine adjustment mechanism on the turntable of the profiler according to measurement result of the profiler, judging by a feedback signal to enable the center of the lens to be measured to coincide with the center of the turntable, and enabling the axis of the rotating surface of the lens to be measured to be perpendicular to the plane of the turntable;

Step S5: and measuring the surface shape of the lens to be measured according to the operation requirement of the Luphoscan profiler, and taking down the lens to be measured after the measurement is finished and storing the lens to be measured for standby.

In a specific embodiment, if the test is completed in step S5 according to the test requirement, the test is performed again, the positioning collar (in the case that the collar remains on the measurement base during the measurement) is removed, the lens to be tested is removed by hand, and the positioning collar is mounted on the measurement base again, and the steps S3 to 4 are performed. If the lens to be measured is too heavy to operate, the measuring base and the lens to be measured can be integrally moved to a workbench convenient to operate, the lens to be measured is taken down according to the step, and then the lens to be measured is put into the lens to be measured again according to the requirement.

In one embodiment, after the measurement is completed, the lens to be measured is removed and placed in a vessel in a designated area, and the whole set of measurement base is stored in a dry and clean environment for later use.

Preferably, in step S2, if the contact surface between the lens to be tested and the supporting ring is a plane, the flat crystal with the caliber larger than that of the supporting ring can be pressed on the adsorption pad for several hours, so as to ensure the reliable adhesion of the adsorption pad.

In a specific embodiment, the inner diameter side of the positioning collar 1 is provided with an arc chamfer with a radius R2, so that edge breakage of the lens to be tested is avoided.

Examples

In the embodiment, the lens to be measured is a zinc selenide infrared lens, the diameter is phi 172.8mm, the center thickness is 14.77mm, the edge thickness is 9.59mm, and the specific size structure is shown in fig. 2. The curvature radius of the surface shape convex surface to be measured is R251.92mm, the curvature radius of the other surface (bonding surface) is R317.81mm, the surface shape precision is required to be less than or equal to 0.25 mu m, RMS is less than or equal to 0.035 mu m, and the surface shape precision of the infrared lens is improved by 2 times or more than that of a common infrared lens.

In the measuring process, if the lens is supported improperly, uneven stress distribution can be caused, tiny deformation is caused, the accuracy of a measuring result is affected, and the accuracy of the infrared lens surface is not satisfied. In order to overcome the above-mentioned drawbacks, a supporting device with the above-mentioned structure, particularly referring to fig. 7, is used, which can avoid minor deformation caused by uneven stress, so as to improve the consistency of the measurement results (as shown in fig. 3). And carrying out stress distribution simulation analysis on the support of the lens through ANASYS Workbench professional software to obtain a support ring size optimization result, setting the outer diameter of the support ring to phi 112mm according to the result, setting the minimum lens deformation when the width is 13mm, setting the convex arc height and the edge thickness parameters of the lens according to the optimization result and the lens structure, and processing according to the design result to obtain the measurement base 4, as shown in fig. 4. The support device includes: the measuring base 4 (see fig. 4), the adsorption pad 2, the positioning collar 1 (see fig. 5), the horizontal adjusting screw 3 (see fig. 6), and the three-dimensional schematic diagram of the measuring device is shown in fig. 7. The supporting surface of the supporting ring 42 is finished by a conventional machine tool, then is cut by a single-point diamond precise machine tool, the surface shape is complementary with the lens supporting surface, and the surface shape precision PV is less than or equal to 1 mu m.

The corresponding adsorption pad 2 is cut according to the size of the support ring 42, and is adhered to the surface of the support ring 42, and a fine seam is required to be reserved on the adsorption pad 2. The caliber of the disk body base of the measuring base 4 is phi 226mm, four M6 threaded holes which are symmetrical in the center are formed in the circumference of the phi 210mm, the length of the threads is 16mm, the head size is phi 10mm multiplied by 5mm, and the side surface is knurled with reticulate patterns.

A circular step concentric with the supporting circular ring is arranged at the position of the aperture phi 172.8mm of the lens, the height is 6mm, and the circular step is a positioning installation reference of the positioning clamping ring. The inner diameter of the positioning collar is phi 172.8mm, the outer diameter is phi 192.8mm, the height is 28mm, four slots are formed in a central symmetry mode, the slot depth is 10mm, the relative central opening angle is 30 degrees (the width is larger than 35mm and is larger than the width of a finger), and the upper edge of the positioning collar 1 is positioned in the middle position of the edge thickness of the lens to be measured after the lens to be measured is installed. The inner diameter side of the positioning clamping ring 1 is provided with an arc chamfer with a radius R2, so that the lens is prevented from being broken by contact with the positioning clamping ring 1 when the lens is placed. The optical lens is placed on the suction pad 2 arranged in the support ring 42 along the edge of the positioning collar 1. Considering that the lens is placed on the measuring base 4, the optical lens and the supporting ring 42 form a closed space between the lens and the measuring base 4 due to the close-contact effect of the adsorption pad 2, in order to avoid the influence of the difference of the air pressure of the closed space and the external air pressure on the measurement, 4 phi 4mm semicircle through holes which are symmetrically distributed at the center are formed on the side surface of the supporting ring and the bottom surface of the connecting part of the measuring base, so that the air of the closed space is communicated with the external, and the pressure of the internal air and the external air is kept consistent.

Comparative example

The difference from the embodiment is that the lens to be measured is directly placed on the aligning and aligning platform of Luphoscan profiler to perform surface shape measurement.

For the lens shown in fig. 2, surface shape measurement was performed respectively in comparative examples and under the condition of providing a supporting means by the present application, and each measurement item was repeated 3 times, and the obtained results are shown in the following table:

The results of each repetition of the test of the examples are shown in fig. 8 a-b); comparative examples the results of the respective replicates are shown in figures 9 a-b).

As can be seen from the above table and the comparison of fig. 8 to 9, the surface shape measurement result of the lens after the supporting device provided by the present application fluctuates much lower than that in the comparative example in which the supporting device is not used. The device can effectively reduce errors of lens measurement results and improve measurement accuracy, consistency and repeatability.

Although the present invention has been described with reference to the foregoing embodiments, it will be apparent to those skilled in the art that modifications may be made to the embodiments described, or equivalents may be substituted for elements thereof, and any modifications, equivalents, improvements and changes may be made without departing from the spirit and principles of the present invention.

Claims

1. A high precision lens measurement support device for Luphoscan profiler, the support device comprising: the device comprises a positioning clamping ring, an adsorption pad, a horizontal adjusting screw and a measuring base; the measuring base is detachably connected with the Luphoscan profiler aligning platform through a horizontal adjusting screw; a supporting circular ring is arranged at the center of the measuring base; the top surface of the supporting ring is provided with an arc supporting surface which is attached to and supported by the lens to be tested, and the adsorption pad is attached to the arc supporting surface; the lens to be measured is adsorbed on the adsorption pad and is positioned by the positioning clamping ring; 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 clamping ring;

2. The high precision lens measurement support apparatus for a Luphoscan profiler as set forth in claim 1, wherein the positioning collar comprises: the ring body and a plurality of slots are formed in the ring body; the periphery of the lens to be tested is clamped in the slot.

3. The high-precision lens measurement support apparatus for Luphoscan profiler as set forth in claim 1, wherein 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 0.03mm to 0.1 mm.

4. The high-precision lens measurement support apparatus for Luphoscan profiler as set forth in claim 1, wherein the measurement base includes: a tray body and a boss; the boss is arranged in the central area of the tray body; the supporting ring is arranged in the center area of the boss; the periphery of the tray body is provided with a plurality of mounting holes; the horizontal adjusting screw penetrates through the mounting hole.

5. The high-precision lens measurement support device for Luphoscan profiler as set forth in claim 1, wherein the support ring has at least one air-guide hole formed in a side surface thereof.

6. The high-precision lens measurement support device for Luphoscan profiler as set forth in claim 1, wherein the center axis of the positioning collar 1, the center axis of the support ring 42, and the center axis of the boss 41 coincide.

7. The high-precision lens measurement support device for Luphoscan profiler as set forth in claim 1, wherein the height of the support ring is as small as possible while ensuring a gap of 3mm to 5mm between the surface of the lens to be measured and the surface of the measurement base.

8. The high-precision lens measurement support device for Luphoscan profiler as set forth in claim 1, wherein the radius of curvature of the arcuate support surface is equal to the radius of curvature of the support surface of the lens under test.

9. The high-precision lens measurement supporting device for Luphoscan profiler as set forth in claim 1, wherein the arc supporting surface contacting with the lens to be measured is machined by high-precision single-point diamond lathe, and the surface shape error is controlled at PV less than or equal to 1 μm;

Preferably, the thickness of the adsorption pad is between 0.5mm and 1 mm;

10. A high precision lens measurement method, comprising the steps of: