JPS63107822A - Metallic mold for producing optical product - Google Patents

Abstract

PURPOSE:To permit production of a product which is free from an uneven refractive index by forming metallic molds of laminates, the part of which in contact with the thick part of the optical product is formed of a metal having the heat conductivity larger than the heat conductivity of the part in contact with the thin part. CONSTITUTION:The upper metallic mold 1 and lower metallic mold 2 of a press for producing the optical glass product are formed of the laminates of the metals A and B which are different in the heat conductivity respectively in parallel with the press. The heat conductivity of the metal A constituting the metallic mold part in contact with the thick part of the optical glass product (the central part in this case), designated as Ak, and the heat conductivity of the metal B constituting the metallic mold part in contact with the thin part of the optical product (the peripheral edge part), designated as Bk, are specified to Ak>Bk. The generation of a large difference in the cooling rate between the thick part and thin part of the optical product is thereby prevented and the optical product which is free from the uneven refractive index is obtd.

Description

[Detailed Description of the Invention] The present invention relates to a mold for manufacturing optical products, and more specifically,
The present invention relates to a mold for manufacturing optical products that can manufacture glass products or plastic products, particularly optical glass products such as lenses, without causing unevenness in refractive index.

Ming's technical background and its problems Not only glass products such as lenses and Plus Deck products used in optical systems such as cameras and video cameras, but also optical products such as lenses used for precision printing of IC circuits, etc. Increasingly, high resolution is also required. For this reason, there is a strong demand for preventing uneven refractive index from occurring in these optical products.

By the way, optical products such as lenses as mentioned above are usually
Optical glass or optical plastics have been manufactured into desired shapes by heating to soften them and introducing the resulting softened product into a mold for manufacturing optical products. However, when an optical product such as a convex lens is manufactured using a mold, there is a difference in the cooling rate between the thick part at the center of the convex lens and the thin part at the periphery of the lens.
Thick parts are cooled slowly, while thin parts are cooled rapidly, which has the problem of uneven refractive index between the center and peripheral parts of the lens.

The inventors of the present invention have conducted extensive studies to solve the above-mentioned problems, and have found that if optical products such as lenses are manufactured using a mold with a specific structure, the thick and thin parts of the optical product can be It is possible to prevent large differences in cooling rate between
Therefore, the present inventors have discovered that it is possible to manufacture optical products that do not cause uneven refractive index, and have completed the present invention.

The present invention aims to solve the problems associated with the prior art as described above, and when manufacturing optical products such as lenses, it is necessary to distinguish between thick and thin parts of the optical product. It is an object of the present invention to provide a mold for manufacturing an optical product that can prevent large differences in cooling rate from occurring between the two, and therefore prevent unevenness in the refractive index.

Summary of the Invention The mold for manufacturing an optical product according to the present invention is a laminate of metals having different thermal conductivities in the direction perpendicular to the contact surface with the optical product, and the metal mold is made of a laminate of metals having different thermal conductivities in the direction perpendicular to the contact surface with the optical product. It is characterized in that the thermal conductivity of the metal in the mold part is higher than the thermal conductivity of the metal in the mold part that is in contact with the thin wall part.

The mold for manufacturing optical products according to the present invention is a laminate of metals having different thermal conductivities, and the thermal conductivity of the metal in the mold part that contacts the thick part of the optical product is the same as that of the metal in the mold part that contacts the thin wall part of the optical product. Optical products such as lenses that have a thermal conductivity higher than that of metals, so there is no large difference in the cooling rate between thick and thin parts of the optical product, and therefore there is no uneven refractive index. can be obtained.

DETAILED DESCRIPTION OF THE INVENTION The mold for manufacturing optical products according to the present invention will be specifically described below.

The mold for manufacturing optical products such as lenses according to the present invention may be a press mold or a mold. Glass for forming optical products or plastic deck for forming optical products are introduced into such gold. That is, the optical product of the present invention may be made of glass or plastic.

In the following explanation, for convenience, optical glass products are manufactured using press molds from optical glass! ! ! This will be explained using the case of building as an example.

The press mold for manufacturing optical glass products according to the present invention will be explained by taking, for example, a case where a convex lens is to be manufactured. As shown in a schematic cross-sectional view in FIG. The upper and lower molds 1 and 2 are each a laminate of metals A and B having different thermal conductivities parallel to the pressing direction. For metals A and B, the thermal conductivity of metal A, which constitutes the mold part that is in contact with the thick part of the optical glass product, that is, the central part, is Ak, and the thickness of the product is 3! If the thermal conductivity of the metal B constituting the mold part, that is, the peripheral part in contact with the part is Bk, then Ak is made of a metal having a higher thermal conductivity than Bk.

Specifically, metals with high thermal conductivity include copper, iron,
Aluminum etc. are used.

Further, as the metal with low thermal conductivity, specifically, blue lead, ceramics, etc. are used.

Note that although ceramics are not metals, ceramics are also included in metals in this specification.

In the above description, the press mold for manufacturing optical glass products has a three-layer structure, but the mold can also have a multi-layer structure of three or more layers. In this case as well, the thermal conductivity of the mold portion in contact with the thick portion of the optical glass product is configured to be greater than the thermal conductivity of the mold portion in contact with the thin wall portion.

Furthermore, in the present invention, when a concave lens is to be manufactured using a pair of press molds 3 and 4 for manufacturing optical glass products as shown in FIG. 2, the thick part of the optical glass product is Therefore, the thermal conductivity of the metal C constituting and covering the peripheral portion of the mold is configured to be higher than the thermal conductivity of the metal C constituting the central portion of the mold.

In the present invention, if necessary, metals having different thermal conductivities may be laminated with a heat insulating material interposed therebetween to form a press mold for manufacturing optical glass products.

By placing a heat insulating material between metals with different thermal conductivities, the cooling rate of optical glass products can be made more uniform between thick and thin parts, resulting in optical glass products with uniform refractive index. You will be able to do this.

Further, the surface of the press mold for manufacturing optical glass products according to the present invention may be plated or provided with a different metal in order to improve processing accuracy.

The press mold for manufacturing optical glass products according to the present invention is the same as conventional press molds for manufacturing optical glass products, except that it has a laminated structure made of metal having a specific thermal conductivity. It is possible to maintain the temperature at a high temperature by passing a heat medium through the inside, and the state in which it is used is shown in Fig. 3. In other words, a press upper mold 1 and a lower mold 2 for manufacturing optical glass products are held by a mold 3 and a plunge ring 4, and a hydraulic plunge V5 is provided at the upper part of the upper mold 1. , this hydraulic plunge? 5, the upper mold 1 is pushed down. The upper mold 1 is provided with a heated oil inlet 6 and an outlet lower, and the lower mold 2 is similarly provided with a heated oil inlet and an outlet (not shown).

Of course, softened glass is introduced into the space G between the upper mold 1 and the lower mold 2.

In this way, the press mold for optical glass products "1JFi is made of a laminate of metals with different thermal conductivity coefficients, and the thermal conductivity of the metal in the mold part that is in contact with the thick part of the optical glass product is the same as that of the metal in contact with the thin part of the optical glass product. The thermal conductivity of the metal in the mold part is higher than that of the metal in the mold part. The heat escapes quickly and is cooled quickly, and the heat slowly escapes from the thin part and is cooled slowly, so there is no big difference in the cooling rate between the thick part and the thin part.For this reason, the optical Glass products are now cooled almost uniformly, and optical glass products without uneven refractive index can be produced.

Effects of the Invention The mold for manufacturing optical products according to the present invention is a laminate of metals having different thermal conductivities, and the thermal conductivity of the metal in the mold part that is in contact with the thick part of the optical glass product is in contact with the thin part. Because the thermal conductivity is higher than that of the metal in the mold part, there is no large difference between the cooling rate in the thick part and the cooling rate in the thin part, and therefore there is no unevenness in the refractive index for optical devices such as lenses. You can get the product.

[Brief explanation of the drawing]

1 and 2 are schematic cross-sectional views of a press mold for manufacturing optical glass products according to the present invention, and FIG. 3 is an explanatory diagram showing the state in which the press mold is used. 1... Upper mold 2... Lower mold 3... Upper mold 4... Lower mold A, B, C, D.
...Metal agents with different thermal conductivities that make up the mold Patent attorney Shunichi Suzuki Figure 1 Figure 2

Claims (1)

[Claims] 1) The mold for manufacturing optical products is a laminate of metals with different thermal conductivities in parallel to the direction perpendicular to the contact surface with the optical product, and the thermal conductivity of the metal in the part of the mold that is in contact with the thick part of the optical product A mold for manufacturing optical products, wherein the thermal conductivity is higher than that of the metal in the part of the mold in contact with the thin wall part.