JP2010069600A - Method for manufacturing aspheric lens - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for manufacturing an aspheric lens capable of accurately manufacturing the aspheric lens having a desired shape without impairing productivity and irrespective of a shape of a glass molded body. <P>SOLUTION: The method for manufacturing the aspheric lens is used for forming the aspheric lens by performing press working and machine working of a glass material and includes: a press working step of performing the press working of the glass material and forming the glass molded body having an aspheric surface on one side; a polymerizing step of polymerizing the aspheric surface of the glass molded body which is placed on an aspheric surface of the standard tool having the same aspheric shape with that formed by the press working step; and a machining step of machining the other side of the glass molded body which is polymerized on the standard tool in the polymerizing step and forming a desired surface shape. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a manufacturing method of an aspheric lens, and more particularly to a manufacturing method of an aspheric lens using press working and machining.

  In recent years, aspherical lenses have come to be used as lenses for digital cameras, optical pickup lenses such as DVDs, camera lenses for mobile phones, coupling lenses for optical communication, various mirrors, etc. It is. As a manufacturing method of such an aspherical lens, press working, machining (generic name for cutting, grinding, polishing) and the like are known.

  Pressing is a processing method in which a heat-softened glass material is press-formed with an upper mold and a lower mold. Although this pressing method can form one surface of a lens in a short time, the molding conditions are very strict, and it is not easy to mold both surfaces with high accuracy. In other words, in the conventional technique, it has not been possible to form both surfaces of the aspherical lens only by the pressing method.

  On the other hand, while machining can be performed with high precision, it requires a longer work time than pressing because it requires a long time to perform polishing and the like using an expensive and high-precision special machine tool. There was a drawback. Furthermore, in machining, the spherical surface is processed after the aspheric surface is processed. However, since the optical axis of the aspheric lens is determined only by the aspheric surface, the position of the center of curvature of the spherical surface is determined when processing the spherical surface. Must be processed so that it is correctly on the optical axis. However, this is not easy, and there has been a problem that the optical axes of the aspherical surface and the spherical surface are shifted and decentered.

  Therefore, in order to cope with such problems, various methods for manufacturing aspherical lenses that employ the advantages of conventionally used pressing and high-precision machining have been studied.

For example, first, a glass material is pressed to form a substantially plano-convex glass molded body having a convex aspheric surface on one surface and a flat surface on the other surface. Next, a method for manufacturing a meniscus lens by inserting this glass molded body into a special centering holder and then machining the other flat surface of the glass molded body into a concave spherical surface is known. (For example, refer to Patent Document 1).
JP-A-6-206156

  However, the method described in Patent Document 1 is based on the premise that the shape of a glass molded body that is first press-molded is a substantially plano-convex glass molded body in which one surface is convex and aspherical, and the other surface is flat. There is a problem that it can be adopted only in a method for manufacturing a meniscus lens, which is formed by machining the other surface of the glass molded body into a concave spherical surface.

  In addition, the other flat surface of the glass molded body is superposed on the upper lens holder, and the aspherical optical axis is fixed by bringing the lens optical axis fixing portion into contact with the peripheral edge of the aspherical surface of the glass molded body. Thus, the aspherical optical axis is aligned with the center of the centering holder. Therefore, if the relative positional relationship such as the parallelism between the aspherical surface and the flat surface of the glass molded body is not assured with high accuracy, the optical axes of the aspherical surface and the spherical surface are shifted and deviated when machining the spherical surface. There is a problem of wicking.

  The present invention has been made in view of the above problems, and an aspheric lens capable of manufacturing an aspheric lens having a desired shape with high accuracy regardless of the shape of the glass molded body without impairing productivity. It aims at providing the manufacturing method of.

  The above object is achieved by the invention described in any one of the following items 1 to 4.

1. A manufacturing method of an aspherical lens in which a glass material is pressed and machined to form an aspherical lens,
Pressing the glass material, and a pressing process for forming a glass molded body having one aspheric surface;
A polymerization step of polymerizing the aspherical surface of the glass molding on the aspherical surface of the original jig having the same aspherical shape as the aspherical surface formed in the pressing step;
And a machining step of machining the other surface of the glass molded body superposed on the original jig in the polymerization step to form a predetermined surface shape. .

  2. 2. The aspheric lens according to 1, wherein in the superposition step, superposition is performed so that Newton fringes generated by superposition of the aspherical surface of the original jig and the aspherical surface of the glass molded body approach one color. Production method.

  3. In the machining, the original jig is held by the holding means so that the aspherical core of the original jig matches the rotation axis of the holding means holding the original jig. The manufacturing method of the aspherical lens as described in 1 or 2 above.

  4). 4. The method for manufacturing an aspherical lens according to any one of 1 to 3, wherein the mechanical process includes at least one processing method among cutting, grinding, and polishing.

  According to the present invention, when the other surface of the glass molded body in which one surface is formed into an aspheric surface by press working is machined, the non-molded material formed in the press working process is used as a holding member for the glass molded body. The original jig having the same aspherical shape as the spherical surface was used, and the aspherical surface of the glass molding was superposed on the aspherical surface of the original jig. That is, since the aspheric surfaces of the original jig and the glass molded body are overlapped, the relative positional relationship between the original jig and the glass molded body is uniquely determined, and the optical axis of the aspheric surface of the glass molded body is determined. Will naturally match the core of the original jig, that is, the processing center. Thereby, when the other surface of the glass molded body is machined to form, for example, a spherical surface, the optical axis of the spherical surface can be easily matched with the optical axis of the aspherical surface.

  Moreover, since it was set as the structure which hold | maintains the aspherical surface of the glass molded object shape | molded by the press work process, the other surface shape of the glass molded object shape | molded is not limited to a flat surface like the past, It may be convex or concave. Similarly, the aspherical shape may be a convex surface or a concave surface. Furthermore, the surface shape of the side surface of the glass molded body to be molded is not limited. Thereby, the aspherical lens of a desired shape can be manufactured without being limited to the shape of the glass molded body.

  As a result, it is possible to manufacture an aspherical lens having a desired shape with high accuracy regardless of the shape of the glass molded body without impairing productivity.

  Embodiments of an aspherical lens manufacturing method according to the present invention will be described below with reference to the drawings. In addition, although this invention is demonstrated based on embodiment of illustration, this invention is not limited to this embodiment.

In the method for manufacturing an aspheric lens according to an embodiment of the present invention, first, a glass material is pressed to form a glass molded body having one aspheric surface (pressing step). Next, the aspherical surface of the pressed glass molded body is polymerized on the aspherical surface of the original jig having the same aspherical shape as the aspherical surface of the glass molded body formed by pressing (polymerization step). . Thereafter, the other surface of the pressed glass molded body is machined to form a predetermined surface shape (machining process), thereby manufacturing an aspherical lens. Details will be described below.
(Pressing process)
FIG. 1 shows an example of a glass molded body formed by pressing a glass material. FIG. 1 is a schematic cross-sectional view showing an example of a glass molded body 1.

  As shown in FIG. 1, the glass molded body 1 has one transfer surface 1a formed into an aspherical surface and the other transfer surface 1b formed into a spherical surface by a molding die. In this embodiment, the transfer surface 1a is formed as a convex aspherical surface, and the transfer surface 1b is formed as a convex spherical surface. However, any surface shape is not limited to a convex surface and may be a concave surface.

  As a pressing method, a direct pressing method in which molten glass is directly pressure-molded with a molding die or other known methods can be used.

Moreover, a glass material is not specifically limited, The well-known glass used for an optical use can be selected and used according to a use. For example, phosphate glass, lanthanum glass, and the like can be given.
(Polymerization process)
Initially, the structure of the processing holder holding the glass molded object 1 shape | molded by the press work process is demonstrated using FIG. FIG. 2 is a schematic cross-sectional view showing a schematic configuration of the processing holder 5.

  As shown in FIG. 2, the main part of the processing holder 5 includes a master jig 51 and a chuck 53.

  On the upper surface of the original jig 51, a holding surface 51a having the same aspherical shape as the aspherical surface (transfer surface 1a) of the glass molded body 1 formed in the above-described pressing process is formed, and glass forming is performed on the holding surface 51a. The aspherical surface (transfer surface 1a) of the body 1 is polymerized. On the side opposite to the holding surface 51 of the original jig 51, a holding portion 51h for holding the chuck 53 is provided.

  The chuck 53 includes a collet 531 in which holes are machined in accordance with the shape of the holding portion 51 h of the original jig 51 and cut radially from the center thereof, and a holding portion 51 h loaded in the inner cylinder 531 a of the collet 531. It is a collet chuck comprised from the ring 532 tightened from the outer cylinder 531b side. The chuck 53 is configured so that the core of the aspherical surface (transfer surface 1a) of the original jig 51 coincides with the rotation axis of the chuck 53, that is, the processing center in a state where the original jig 51 is held by the chuck 53. Yes. The means for holding the original jig 51 is not limited to the collet chuck, and any holding means can be used.

The aspherical surface (transfer surface 1a) of the glass molded body 1 is superposed and fixed on the holding surface 51a of the master jig 51 of the processing holder 5 having such a configuration. In addition, superposition | polymerization superposes | polymerizes so that the Newton fringe produced by superposition | polymerization with the holding surface 51a of the original jig 51 and the aspherical surface (transfer surface 1a) of the glass molded object 1 may approach one color. Moreover, fixation can be adhere | attached using a pine resin etc.
(Machining process)
FIG. 3 is a schematic cross-sectional view illustrating a state in which the glass molded body 1 is polymerized and fixed to the original jig 51 of the processing holder 5.

  In such a state, the spherical surface (transfer surface 1b) of the glass molded body 1 is machined and formed into, for example, a concave surface (machined surface 1c) as indicated by a broken line to obtain an aspherical lens 1A. In addition, in this embodiment, although the machining surface 1c is formed in the concave surface, it may be a convex surface, without being limited to a concave surface.

  As the machining method, known processing methods such as cutting, grinding, and polishing can be used.

  Here, since the aspherical holding surface 51a of the original jig 51 and the aspherical surface (transfer surface 1a) of the glass molded body 1 are polymerized, the relative positional relationship between the original jig 51 and the glass molded body 1 is It is uniquely determined, and the optical axis of the aspherical surface (transfer surface 1a) of the glass molded body 1 naturally matches the core of the original jig 51, that is, the processing center. Therefore, by machining the spherical surface (transfer surface 1b) of the glass molded body 1 in such a state, the optical axis of the concave surface (machined surface 1c) can be easily changed to the optical axis of the aspheric surface (transfer surface 1a). Can be matched.

  Thus, in the manufacturing method of the aspherical lens 1A according to the embodiment of the present invention, when the other transfer surface 1b of the glass molded body 1 in which the one transfer surface 1a is formed into an aspheric surface by press working is machined. Further, as the holding member of the glass molded body 1, a master jig 51 having a holding surface 51 a having the same aspheric shape as the aspheric surface (transfer surface 1 a) formed in the press working process is used. The aspherical surface (transfer surface 1a) of the glass molded body 1 was polymerized on the holding surface 51a. That is, since the aspheric surfaces of the original jig 51 and the glass molded body 1 are superposed, the relative positional relationship between the original jig 51 and the glass molded body 1 is uniquely determined, and the glass molded body 1 The optical axis of the aspherical surface (transfer surface 1a) naturally matches the core of the original jig 51, that is, the processing center. Thereby, when the other surface (transfer surface 1b) of the glass molded body 1 is machined to form, for example, a spherical surface, the optical axis of the spherical surface is easily matched with the optical axis of the aspherical surface (transfer surface 1a). be able to.

  Moreover, since it was set as the structure which hold | maintains the aspherical surface (transfer surface 1a) of the glass molded object 1 shape | molded by the press work process, the shape of the other surface (transfer surface 1b) of the glass molded object 1 shape | molded is conventional. The surface is not limited to a flat surface, and may be a convex surface or a concave surface. Similarly, the shape of the aspheric surface (transfer surface 1a) may be a convex surface or a concave surface. Furthermore, the surface shape of the side surface of the glass molded body 1 to be molded is not limited. Thereby, the aspherical lens of a desired shape can be manufactured without being limited to the shape of the glass molded body.

  As a result, it is possible to manufacture an aspherical lens having a desired shape with high accuracy regardless of the shape of the glass molded body without impairing productivity.

  In the above description, an example in which one optical functional surface of the aspherical lens is an aspherical surface has been described. However, the present invention can also be applied to an aspherical lens in which both optical functional surfaces are aspherical.

It is a cross-sectional schematic diagram which shows the glass forming body concerning embodiment of this invention. It is a cross-sectional schematic diagram which shows schematic structure of the processing holder concerning embodiment of this invention. It is a cross-sectional schematic diagram which shows the state by which the glass forming body was superposed | polymerized and fixed to the process holder concerning embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Glass molded object 1A Aspherical lens 1a, 1b Transfer surface 1c Machined surface 5 Processing holder 51 Original equipment jig 51a Holding surface 53 Chuck 531 Collet 532 Tightening ring

Claims (4)

A manufacturing method of an aspherical lens in which a glass material is pressed and machined to form an aspherical lens,
Pressing the glass material, and a pressing process for forming a glass molded body having one aspheric surface;
A polymerization step of polymerizing the aspherical surface of the glass molding on the aspherical surface of the original jig having the same aspherical shape as the aspherical surface formed in the pressing step;
And a machining step of machining the other surface of the glass molded body superposed on the original jig in the polymerization step to form a predetermined surface shape. . 2. The aspheric lens according to claim 1, wherein in the superposition step, superposition is performed so that Newton fringes generated by superposition of the aspherical surface of the original jig and the aspherical surface of the glass molded body approach one color. Manufacturing method. In the machining, the original jig is held by the holding means so that the aspherical core of the original jig matches the rotation axis of the holding means holding the original jig. The manufacturing method of the aspherical lens of Claim 1 or 2. The method for manufacturing an aspheric lens according to claim 1, wherein the mechanical process includes at least one processing method among cutting, grinding, and polishing.

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