A precision manufacturing method of an ultra-wide-angle special aspherical surface lens

Abstract

The application provides a precision manufacturing method of an ultra-wide-angle special-shaped aspheric lens. The ultra-wide-angle special-shaped aspheric lens is a lens with a convex surface of high-order aspheric surface, a concave spherical surface close to a half sphere, and an asymmetric shape angle and linear size. The method comprises the following steps: adjusting a milling and grinding machine tool shaft to process a lens blank, and coarsely grinding and forming the concave spherical surface; using a high force point grinding and polishing mold and lens sticking mold to precisely grind and polish the concave spherical surface; centering the aspheric surface on an edge grinding joint; sticking the concave spherical surface platform on the aspheric surface mold, and milling, polishing and correcting the aspheric surface; sticking the aspheric surface on a concave glass auxiliary block, and milling the edge of the concave spherical surface platform to form a special-shaped angle; adjusting the angle of the concave spherical surface platform, and repeating the milling process to form several special-shaped angles; and cleaning and detecting. The precision manufacturing method of the ultra-wide-angle special-shaped aspheric lens has the advantages of realizing the precision manufacturing of a complex special-shaped asymmetric lens.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of optical component manufacturing, and particularly to a precision manufacturing method of an ultra-wide-angle special-shaped aspheric lens. BACKGROUND

[0002] The ultra-wide-angle special-shaped aspheric lens is mainly used in optical systems such as large-field imaging and laser radar, and is a key lens of the optical systems. Due to the limitation of the imaging role in the system and the installation size and position in the structure, the shape is designed to be asymmetric in angle and size, and the convex surface of the two lens surfaces is selected to be a 16-order high-order aspheric surface, and the concave surface is a deep-via high spherical surface close to a hemisphere, so the processing difficulty is extremely great. The common aspheric lens processing technology cannot complete the realization of the technical indexes of such a lens. SUMMARY

[0003] In view of the above defects or deficiencies in the prior art, it is desirable to provide a precision manufacturing method of an ultra-wide-angle special-shaped aspheric lens to solve the above problems.

[0004] The present application provides a precision manufacturing method of an ultra-wide-angle special-shaped aspheric lens, the ultra-wide-angle special-shaped aspheric lens comprising a convex surface and a concave surface, the convex surface being a high-order aspheric surface, and the concave surface being a concave spherical surface close to a hemisphere, comprising the following steps:

[0005] S1: adjusting a milling and grinding machine tool shaft to process a lens blank, rough grinding and forming the concave spherical surface, and controlling the eccentricity of the concave spherical surface to be less than 0.05 mm;

[0006] S2: precisely grinding and polishing the concave spherical surface, using a high-force point grinding and polishing mold and lens mold sticking, and controlling the eccentricity of the concave spherical surface to be less than 0.05 mm;

[0007] S3, centering the aspheric surface on an edge grinding joint and grinding the outer circle of the concave spherical surface platform;

[0008] S4, sticking the concave spherical surface platform on the aspheric grinding mold, milling, polishing and correcting the aspheric surface;

[0009] S5, sticking the aspheric surface on a concave glass auxiliary block, clamping the auxiliary block, and milling the edge of the concave spherical surface platform to form a special-shaped angle;

[0010] S6, adjusting the angle of the concave spherical surface platform and repeating the milling process of step S5 to form a plurality of special-shaped angles;

[0011] S7, cleaning and detecting.

[0012] According to the technical scheme provided by the embodiment of the present application, in step S2, the surface shape precision of the concave spherical surface is controlled to be 3, and the surface defect level is controlled to be IV.

[0013] According to the technical scheme provided by the embodiment of the application, in step S3, the control joint corrects the runout to be less than 0.005 mm, and controls the concave spherical surface eccentricity to be less than 0.009 mm.

[0014] According to the technical scheme provided by the embodiment of the application, in step S4, the milling and grinding of the aspherical surface specifically includes first milling and grinding the height size of the lens, and then trimming the aspherical surface by a small grinding head to adjust the center thickness, surface shape accuracy and surface defect level of the lens.

[0015] According to the technical scheme provided by the embodiment of the application, in step S4, the spindle speed of the small grinding head is set to 400 rpm, the tool shaft speed is set to 450 rpm, the feed speed is set to 2 mm / min, and the step distance is set to 0.2 mm.

[0016] According to the technical scheme provided by the embodiment of the application, in step S4, the center thickness is controlled to be 4.65±0.3, the surface shape accuracy is controlled to be less than or equal to 5 μm, and the surface defect level is controlled to be IV.

[0017] According to the technical scheme provided by the embodiment of the application, in step S5, before the aspherical surface is bonded to the concave glass auxiliary block, protective paint is coated on the concave spherical surface and the aspherical surface, and protective stickers are attached to the aspherical surface.

[0018] According to the technical scheme provided by the embodiment of the application, in step S5, the rotation speed of the milling tool is set to 2000 rpm, the feed speed is set to 70 mm / min, and the feed depth is set to 0.5 mm.

[0019] Compared with the prior art, the beneficial effects of the application are that: by using the rough grinding forming method provided by the application, the problem of large eccentricity between the rough grinding forming deep sag concave spherical surface of the lens and the outer circle of the lens in the processing process is effectively solved; by using the high force point grinding and polishing mold and the lens sticking mold, the interference between the lens edge platform and the polishing tool in the grinding and polishing process of the concave spherical surface is reduced, and the high-order aspherical surface trimming can reach the index of surface shape accuracy; by using the glass auxiliary block to bond the aspherical surface and the reliable clamping method for concentric positioning, the precise machining of the shape of the asymmetric lens angle and size and many other technical problems are solved. The precision manufacturing method of the super-wide-angle special aspherical surface lens provided by the application has the advantages of realizing the precision manufacturing of complex special asymmetric lenses. BRIEF DESCRIPTION OF DRAWINGS

[0020] Other features, objects and advantages of the application will become more apparent from the following detailed description of non-limiting embodiments made with reference to the accompanying drawings:

[0021] Figure 1 The flowchart of the precision machining method of the super-wide-angle special aspherical surface lens provided by the application;

[0022] Figure 2 Structure diagram of rough grinding of the concave spherical surface of the lens in the present application;

[0023] Figure 3 Structure diagram of polishing of the concave spherical surface of the lens in the present application;

[0024] Figure 4 Structure diagram of glass auxiliary block bonding in the present application;

[0025] Figure 5 Structure diagram of adjusting the milling and grinding angle in the present application;

[0026] Figure 6 Structure diagram of the ultra-wide-angle special aspherical lens processed in the present application;

[0027] Figure 7 is a left view structure diagram of the ultra-wide-angle special aspherical lens shown in Figure 6

[0028] is a top view structure diagram of the ultra-wide-angle special aspherical lens shown in Figure 8 Figure 6 DETAILED DESCRIPTION

[0029] The present application will be further described in detail below with reference to the accompanying drawings and examples. It should be understood that the specific examples described herein are intended to be illustrative only and are not to be limiting of the present application. In addition, it should be noted that for ease of description, only the parts related to the present application are shown in the drawings.

[0030] It should be noted that the examples in the present application and the features in the examples can be combined with each other without conflict. The present application will be described in detail below with reference to the accompanying drawings and examples.

[0031] Referring to Figure 1 , the present application provides a precision manufacturing method of an ultra-wide-angle special aspherical lens, the ultra-wide-angle special aspherical lens comprising a convex surface and a concave surface, the convex surface being a high-order aspherical surface, and the concave surface being a concave spherical surface approximating to a half sphere, comprising the following steps:

[0032] S1, adjusting the tool shaft of the milling and grinding machine to process a lens blank, rough grinding the concave spherical surface to form a shape, and controlling the eccentricity of the concave spherical surface to be less than 0.05 mm;

[0033] ​​Specifically, in an embodiment, a round glass lens blank Φ40x13±0.2 is placed on a milling machine joint, the milling machine tool shaft angle is adjusted, a cup-shaped diamond grinding wheel with a diameter of Φ10 is used to roughen the concave spherical surface to form a concave spherical surface, the eccentricity is controlled to be less than 0.05 mm, and the completed size is as shown in Figure 2 .

[0034] S2, precisely grinding and polishing the concave spherical surface, using a high force point grinding and polishing mold and a lens sticking mold, and controlling the eccentricity of the concave spherical surface to be less than 0.05 mm.

[0035] Specifically, the concave spherical surface of the lens blank after rough surface forming is precisely ground and polished, a high force point grinding and polishing mold and a lens sticking mold are used, the purpose is to avoid interference between the lens edge platform and the polishing tool during the grinding and polishing process of the deep sag concave spherical surface, the surface shape accuracy N=3, the local error ΔN=0.3, the surface defect level B=IV, the eccentricity is controlled to be less than or equal to 0.05 mm, and the completed size is as shown in Figure 3 .

[0036] S3, centering the aspherical surface on the edge grinding joint and grinding the outer circle of the concave spherical surface platform.

[0037] Specifically, after the concave spherical surface grinding and polishing, the lens is stuck on the edge grinding joint with the to-be-ground flat surface as the basis of the aspherical surface, the joint trimming runout is controlled to be less than 0.005 mm, optical centering is performed through a autocollimator, and the concave spherical surface platform is ground according to the size requirement, and the eccentricity of the concave spherical surface is controlled to be less than 0.009 mm.

[0038] S4, sticking the concave spherical surface platform on the aspherical surface mold, milling, polishing and correcting the aspherical surface.

[0039] Specifically, the concave flat platform of the lens after centering and edge grinding is stuck on the aspherical surface mold, the aspherical surface is milled to the required height size, the surface shape accuracy PV≤10μm is controlled, then the aspherical surface is polished and trimmed to the required center height, surface shape accuracy and surface defect level through a small grinding head, wherein the spindle speed of the small grinding head is set to 400 rpm, the tool shaft speed is set to 450 rpm, the feed speed is set to 2 mm / min, and the step distance is set to 0.2 mm. The process of small grinding head polishing is repeated 3-4 times.

[0040] S5, sticking the aspherical surface on the concave glass auxiliary block, clamping the auxiliary block, and milling the edge of the concave spherical surface platform to form a special-shaped angle.

[0041] Specifically, please refer to Figure 4After the aspheric surface is finished, the aspheric surface and the concave spherical surface of the lens are coated with protective paint, and protective paper is attached to the aspheric surface to prevent damage to the lens surface during subsequent processing; the concave glass auxiliary block and the lens are sleeved with an auxiliary sleeve to ensure that the lens and the concave glass auxiliary block are concentrically arranged, and then the aspheric surface is bonded to the concave glass auxiliary block, the concave glass auxiliary block has a smaller curvature than the aspheric surface, and the difference in curvature is within a set range, and after the lens is bonded, the sleeve is removed.

[0042] Please refer to Figure 5 The concave glass auxiliary block is clamped on the numerical control machining equipment by a rigid clamp, the concave spherical surface platform is adjusted, and a shaped angle cutting edge is milled and ground at the edge of the concave spherical surface platform by a cup-shaped diamond grinding wheel, wherein the rotation shaft speed of the cup-shaped diamond grinding wheel is set to 2000 rpm, the feed speed is set to 70 mm / min, and the feed depth is set to 0.5 mm.

[0043] S6, adjusting the angle of the concave spherical surface platform, repeating the milling and grinding process of step S5 to form a plurality of shaped angles;

[0044] Specifically, the angle of the concave spherical surface platform is adjusted, and the polishing is repeated according to the polishing method of step S5 to form a plurality of shaped angles. In an embodiment, the shaped angles are four and are arranged uniformly along the circumference of the concave spherical surface platform. After polishing all the shaped angles, the desired shaped aspheric lens is obtained, as shown in Figures 6-8 .

[0045] S7, cleaning and detecting;

[0046] Specifically, the shaped aspheric lens after milling and grinding is removed from the concave glass auxiliary block, and after cleaning, the shape size and surface quality are inspected, and the angular accuracy and shape size of the lens are measured by a universal tool microscope.

[0047] Working principle: through the rough grinding forming method provided by the application, the problem of large eccentricity between the rough grinding forming deep sag concave spherical surface of the lens and the outer circle of the lens is effectively solved; by using a high force point grinding and polishing mold and lens sticking mold, the interference between the lens edge platform and the polishing tool during the grinding and polishing of the concave spherical surface is reduced, and the high-order aspheric surface shape finishing can reach the index of surface shape precision; through the bonding of the aspheric surface by the glass auxiliary block and the reliable clamping method for concentric positioning, the accurate machining of the shape of the asymmetric lens angle and size and many other technical difficulties are solved. The precision manufacturing method of the shaped aspheric lens provided by the application has the advantage of realizing the precision manufacturing of complex shaped asymmetric lenses.

[0048] The above description is only the preferred embodiment of the present application and the explanation of the technical principles. It should be understood by those skilled in the art that the scope of the protection of the present application is not limited to the technical solutions formed by the specific combinations of the above technical features. It should also cover other technical solutions formed by the combinations of the above technical features or their equivalent features without departing from the concept of the present application. For example, the technical solutions formed by the mutual replacements of the above features and the technical features disclosed in the present application (but not limited to) with similar functions.

Claims

1. A precision manufacturing method for an ultra-wide-angle irregular aspherical lens, wherein the ultra-wide-angle irregular aspherical lens is a lens with a convex surface that is a high-order aspherical surface and a concave spherical surface that is nearly hemispherical, and has an asymmetrical shape, angle, and linear dimensions, characterized in that... Includes the following steps: S1: Adjust the milling machine tool shaft to process the lens blank, and perform rough grinding on the concave spherical surface to control the eccentricity difference of the concave spherical surface to be less than 0.05mm; S2: The concave spherical surface is precisely ground and polished using a high-force grinding and polishing mold and a lens bonding mold, and the eccentricity difference of the concave spherical surface is controlled to be less than 0.05mm. S3. The aspherical surface is bonded to the grinding joint for centering, and the outer circle of the concave spherical platform is ground. S4. Attach the concave spherical platform to the aspherical abrasive, and mill, polish, and correct the aspherical surface; S5. Adhere the aspherical surface to the concave glass auxiliary block, clamp the concave glass auxiliary block, and mill the edge of the concave spherical platform to form an irregular angle. S6. Adjust the angle of the concave spherical platform and repeat the milling process of step S5 to form several irregular angles; S7. Clean and inspect; In step S2, the surface shape accuracy of the concave spherical surface is controlled to be 3, and the surface defect level is IV; In step S3, the runout of the control joint is controlled to be less than 0.005 mm, and the eccentricity difference of the concave spherical surface is controlled to be less than 0.009 mm. Step S4, milling the aspherical surface specifically includes first milling the height dimension of the lens, and then using a small grinding head to trim the aspherical surface to adjust the center thickness, surface accuracy, and surface defect level of the lens; In step S4, the spindle speed of the small grinding head is set to 400 rpm, the tool spindle speed is set to 450 rpm, the feed rate is set to 2 mm / min, and the step distance is set to 0.2 mm. In step S4, the control center thickness is 4.65±0.3, the surface shape accuracy is less than or equal to 5μm, and the surface defect level is IV; In step S5, before the aspherical surface is bonded to the concave glass auxiliary block, a protective paint is applied to the concave spherical surface and the aspherical surface, and a protective sticker is applied to the aspherical surface. In step S5, the milling tool's rotation speed is set to 2000 rpm, the feed rate is set to 70 mm / min, and the depth of cut is set to 0.5 mm.

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