Micro lens centering edging chuck

Abstract

The utility model discloses a micro lens centering edging chuck which is provided with a spherical end face structure, the curvature radius of the chuck is matched with the curvature radius of a concave surface of a processed lens, a clamping angle required by mechanical centering is obtained, and meanwhile, due to the fact that the design size is properly enlarged, the trimming work of a metal pipe barrel part becomes simple and easy to implement. The ball head structure can be used for conveniently carrying out centering and edge grinding on the micro-lens with at least one small-aperture concave surface, the ball head structure can be realized by using a polishing ball or a lens, the polishing ball or the lens is convenient to obtain, low in cost and high in adaptability to the curvature radius of the concave surface of the processed lens, and the concave surface of the processed lens is not damaged; when the chuck structure is used for centring edging production, the efficiency is high, the percent of pass is high, and the chuck structure has remarkable economic value.

Description

Technical Field

[0001] The present invention relates to the processing technology of optical lenses, and particularly to a centering and edge-grinding clamping mechanism for a micro lens. Background Art

[0002] For the processing of optical lenses, centering and edge-grinding (also called core cutting) is a basic process. Almost all lenses with a circular light-transmitting cross-section need centering and edge-grinding. While obtaining the required outer diameter, the line connecting the centers of the two end faces of the lens is made to coincide with the mechanical axis.

[0003] There are various curved surface shapes of lenses, such as double convex, plano concave, meniscus, etc. As Figure 1 shown, in order to perform centering and edge-grinding on lens 1, usually on the end faces on both sides of the lens, a chuck (or called a connector) 2 and a chuck 3 with an elastic pressing function along the axis are used to clamp the lens 1 respectively, driving the lens 1 to rotate along the axis, and a grinding wheel 4 is used to grind the outer cylinder of the lens 1. If the lens 1 has a suitable clamping angle (usually more than 12°), mechanical centering can generally be used. If the lens 1 cannot provide a suitable clamping angle, an optical centering method can also be used. The head structure of the chuck 2 in contact with the lens 1 is usually made into a metal tube shape, and the end is ground into a smooth round head 21, so that the chuck 2 makes a circular line contact with the end face of the lens 1 to be processed. The above content can be seen in the optical processing technology manual.

[0004] However, in modern precision optical instruments such as endoscopes, the lenses are very tiny. The first objective lens of an endoscope is usually a plano concave lens. For example, Figure 1 the lens 1 in it has an outer diameter of 1.0 mm, a thickness of 0.4 mm, a concave surface R of 0.5 mm on the right side, and a concave surface light-transmitting aperture of 0.6 mm. For a lens with such a small size, optical centering is almost impossible to operate, and for mechanical centering, if the chuck 3 is still made into a tube shape, it is impossible due to the small size. If you want to clamp the non-light-transmitting part of the plane outside the concave surface, the lens 1 cannot provide the required clamping angle. Summary of the Invention

[0005] The technical problem to be solved by the present application is to provide a mechanical centering chuck structure for the centering and edge-grinding of a micro lens with at least one small-aperture concave surface, which can provide the clamping angle required for axis self-adaptive adjustment, is easy to operate, has low cost, and does not damage the concave surface of the lens.

[0006] The specific content is as follows:

[0007] The present application discloses a micro-lens centering and edge-grinding chuck, characterized in that the chuck has a spherical end face structure. For a lens with at least one small-aperture concave surface, the radius of curvature of the spherical end face of the chuck is adapted to the radius of curvature of the concave surface of the lens. The spherical end face of the chuck fits with the concave surface of the lens to form a surface contact, and the chuck presses the lens along the axis and drives the lens to rotate together.

[0008] Further, the radius of curvature of the spherical end face of the chuck is adapted to the radius of curvature of the concave surface of the lens, characterized in that the radius of curvature of the spherical surface of the chuck is greater than or equal to the absolute value of the radius of curvature of the concave surface of the lens, and the increase range of the radius of curvature of the spherical surface of the chuck compared to the absolute value of the radius of curvature of the concave surface of the lens does not exceed 0.01 mm.

[0009] Preferably, the chuck with a spherical end face is characterized in that it is a combination of a polished microsphere and a metal tube. The polished microsphere is a glass sphere, a metal sphere or a ceramic sphere.

[0010] Preferably, the chuck with a spherical end face is characterized in that it is a combination of a cylindrical clens with a convex spherical surface at one end and a metal tube.

[0011] Preferably, for the chuck with a spherical end face, the polished microsphere or the cylindrical clens is pre-connected to the metal tube as a whole, and the convex spherical surface of the polished microsphere or the cylindrical clens presses the lens. Alternatively, the convex spherical surface of the polished microsphere or the cylindrical clens is pre-connected to the lens as a whole, and the metal tube presses the polished microsphere or the cylindrical clens.

[0012] The micro-lens centering and edge-grinding chuck disclosed in the present application can obtain the following beneficial effects compared with the prior art:

[0013] Clamping is implemented with a ball head structure adapted to the radius of curvature of the concave surface of the lens to be processed. The concave surface of the lens to be processed is in surface contact with the ball head surface. While obtaining the clamping angle required for mechanical centering, due to the appropriate enlargement of the design size, the trimming work of the metal tube part becomes simple and easy, and it is convenient to perform centering edge grinding on a micro-lens with at least one small-aperture concave surface.

[0014] The ball head structure can be realized by a polished ball or a clens. The polished ball or the clens is convenient to obtain, has a low cost, has strong adaptability to the radius of curvature of the concave surface of the lens to be processed, and does not damage the concave surface of the lens to be processed. Using the chuck structure of the present application for centering edge grinding production has high efficiency and high qualification rate, and has significant economic value. Description of the Drawings

[0015] Figure 1 Schematic diagram for centering edge grinding of a micro-lens with a small-aperture concave surface;

[0016] Figure 2 Schematic diagram of a chuck with a ball head structure for use on the concave surface of a microlens;

[0017] Figure 3 Schematic diagram of obtaining a chuck with a ball head structure using a polished ball;

[0018] Figure 4 Schematic diagram of obtaining a chuck with a ball head structure using a clens;

[0019] Figure 5 Schematic diagram of centering and edge grinding a meniscus microlens. Detailed implementation manners

[0020] The present application will be further described in detail below with reference to the accompanying drawings and embodiments. It can be understood that the specific embodiments described herein are only used to explain the present application, rather than limiting the present application.

[0021] In order to solve Figure 1 the problem that in [[ ]], since the size of the lens 1 is tiny, the collet chuck 3 towards the concave surface on the right side cannot be realized in the mechanical structure, Figure 2 An exemplary implementation manner is given, that is, the tightening chuck 5 on the right side is made solid, and the end of the chuck 5 is made into a ball head (the ball top can be made into a platform), and the radius of curvature of the ball head is adapted to the radius of curvature of the concave surface of the lens to be processed (simply put, the radii of curvature are equal). In this way, when the chuck tightens the lens, the ball head 5 of the chuck and the concave surface of the lens 1 are in toroidal contact.

[0022] Figure 2 There are two problems in the embodiment: one is that it is difficult to trim the spherical surface shape of the chuck 5 to perfectly fit the concave surface of the lens 1, resulting in poor mechanical centering effect or high trimming processing cost; the other is that for the different concave surface radii of curvature of different specifications of lenses 1, the turned and polished chuck 5 cannot be universal and must be replaced and remade, that is, the adaptability is poor.

[0023] Figure 3 An improved embodiment is given, that is, the solid ball head structure on the right side is specifically realized by a polished glass ball 6. The glass ball 6 can be pre-connected to the metal tube 2 on the right side to form an integral body (for example, glued), and the lens 1 is pressed on the left side, or it can be pre-connected to the lens 1 to be processed to form an integral body (for example, wax glued), and the right side is pressed by the metal tube 2. Due to the transition of the glass ball 6, the size of the metal tube 2 on the right side becomes larger, which is easy to process and realize.

[0024] Figure 3 The embodiment solves the problem that the chuck "can both provide sufficient clamping angle and is easy to realize in structure". The glass ball is easy to manufacture and has a low cost, and its sphericity and radius of curvature accuracy can be conveniently achieved at the level of ±1um, which improves Figure 2Disadvantages of the embodiment: On the one hand, the spherical surface shape can perfectly fit the concave surface of the lens 1. On the other hand, glass balls with different curvature radii can be used to adapt to the different concave curvature radii of lenses 1 with different specifications.

[0025] In actual implementation, the curvature radius of the glass ball 6 is selected to be slightly larger than the curvature radius of the tightened concave surface (absolute value, regardless of positive or negative). For example, if the curvature radius of the tightened concave surface is 0.500 mm, the curvature radius of the glass ball 6 is selected as 0.503 mm. At this time, the concave surface and the glass ball are in toroidal contact around the perimeter, and the center of the concave surface and the ball top are not in contact microscopically. This can effectively prevent the polished concave surface from being damaged by the glass ball 6. The range by which the curvature radius of the glass ball increases compared to the absolute value of the concave surface curvature radius usually does not exceed 0.01 mm.

[0026] In actual implementation, the glass ball 6 can be selected from a batch of produced glass balls. For example, after processing a batch of glass balls, select those with a curvature radius of 0.503 mm to process lenses with a concave curvature radius of 0.500 mm, and select those with a curvature radius of 0.500 mm to process lenses with a concave curvature radius of 0.496 mm. Therefore, for lenses with different specifications and similar concave curvature radii, the glass ball is convenient to adapt, and the cost of the glass ball itself is low.

[0027] In actual implementation, the glass ball 6 needs to be cleaned well to prevent scratching the concave surface of the tightened lens. Substances such as oil, grease, wax, and thin films can be added between the glass ball and the tightened concave surface to improve the fitting effect. For example, glycerol can be added, or the glass ball 6 and the lens 1 can be glued together with wax first and then ground. These are all conventional operations and do not change the idea of this application. Obviously, the idea and embodiments of this application are not limited to using polished glass balls, and polished metal balls or ceramic balls can also be used.

[0028] The glass ball can also change its form, such as Figure 4 As shown, when the concave curvature radius of the processed lens is relatively large, in order to avoid structural interference caused by the diameter of the glass ball exceeding the outer diameter of the lens 1, the glass ball can be replaced by a cylindrical plano-convex glass lens 7. This cylindrical plano-convex glass lens 7 is called a clens in the optical communication industry. Its spherical surface is polished, and the curvature radius is accurate to the order of 0.1 um, and the cost is also low. The right tube 2 used in combination with the clens lens can be made into the shape shown in the figure with its end face in contact with the plane of the clens, or can be made into a solid flat end face and glued to the clens lens to form a whole.

[0029] Such as Figure 5As shown, for the meniscus lens 1 with little change in thickness from the center to the periphery, if the two ends are directly clamped tightly by the tube chuck 2, the clamping angle is very small and it is extremely difficult to process. If the idea of this application is adopted to fit the small-aperture concave surface with the glass ball 6 and then grind the edge, and the meniscus lens 1 and the glass ball 6 are regarded as a whole biconvex lens, the clamping angle can be easily increased to more than 12°. The "axis angle adaptive adjustment" has a good effect. Therefore, in essence, the embodiment can be understood as increasing the clamping angle of the lens to be processed, which is particularly important for the processing of meniscus lenses.

[0030] In the above several embodiments, the polishing microsphere or the columnar clens can be pre-connected to the metal tube as a whole, and the convex spherical surface of the polishing microsphere or the columnar clens is used to press the lens. Or, the convex spherical surface of the polishing microsphere or the columnar clens is pre-connected to the lens to be processed as a whole, and the metal tube is used to press the polishing microsphere or the columnar clens. In short, the polishing microsphere or the columnar clens and the metal tube can be connected or separated.

[0031] It should be noted that the idea of using a suitable ball head structure to fit the small-aperture concave surface and then perform centering grinding on the lens in this application, as well as the above embodiments, are all for micro-lenses with a clear aperture diameter of about 1 mm. Obviously, this idea and embodiments can also be applied to process lenses with a clear aperture diameter that is not too small, such as a lens with a diameter of 3 mm.

[0032] The above are only the preferred embodiments of this application and the technical principles applied. For those skilled in the art, without departing from the inventive concept of the present invention, more other equivalent embodiments can be generated, and the protection scope of the present invention is determined by the scope of the appended claims.

Claims

1. A micro-lens centering and edge-grinding chuck, characterized in that, The chuck has a spherical end face structure. For a lens with at least one small-aperture concave surface, the radius of curvature of the spherical end face of the chuck is adapted to the radius of curvature of the concave surface of the lens. The spherical end face of the chuck is in surface contact with the concave surface of the lens, and the chuck presses the lens along the axis and drives the lens to rotate together.

2. The micro-lens centering and edge-grinding chuck according to claim 1, characterized in that, The radius of curvature of the spherical surface of the chuck is greater than or equal to the absolute value of the radius of curvature of the concave surface of the lens, and the range of increase of the radius of curvature of the spherical surface of the chuck compared to the absolute value of the radius of curvature of the concave surface of the lens does not exceed 0.01 mm.

3. The micro-lens centering and edge-grinding chuck according to claim 1, characterized in that, The chuck with a spherical end face is a combination of a polished microsphere and a metal tube. The polished microsphere is a glass sphere, a metal sphere or a ceramic sphere.

4. The micro-lens centering and edge-grinding chuck according to claim 1, characterized in that, The chuck with a spherical end face is a combination of a cylindrical clens with a convex spherical surface at one end and a metal tube.

5. A micro-lens centering and edge-grinding chuck according to claim 3 or 4, characterized in that, The polished microsphere or the cylindrical clens is pre-connected to the metal tube as a whole, and the convex spherical surface of the polished microsphere or the cylindrical clens presses the lens. Alternatively, the convex spherical surface of the polished microsphere or the cylindrical clens is pre-connected to the lens as a whole, and the metal tube presses the polished microsphere or the cylindrical clens.

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