JPS61152437A - Manufacture of optical element - Google Patents

Abstract

PURPOSE:To provide very effective manufacturing method of optical element having complicated and minute configuration by a method wherein the internal space of a tubular body is evacuated or pressurized to form the surface of glass polymer inside of the tubular body into curved surface. CONSTITUTION:A material 1, consisting of glass or polymer, is put on and fixing to a metallic plate 2, ground optically. The material 1 is heated to a temperature, higher than the softening temperature thereof but lower than too much softening temperature, by heaters 5 arranged around the material 1. Next, the end face of the tubular body 3, having a valve 4 and capable of being moved up-and-down, is abutted against the surface of the material 1 and is fixed so that the tubular body does not move. The internal space of the tubular body is evacuated or pressurized to a predetermined pressure by employing an evacuating or a pressurizing machine, provided at the other end of the tubular body 3, and regulating the valve 4. A convex lens is formed by evacuating the internal space of the tubular body while a concave lenses is formed by pressurizing the same. The lens is cooled by natural cooling or proper cooling means so that a strain will never be caused in the optical element.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a method for manufacturing an optical element, and more particularly, to a method for manufacturing an optical element by molding a softened glass or polymer surface into a curved surface using a novel method. Regarding the method.

[Conventional technology]

In recent years, a molding method for glass yaholimers has been developed as a new method for manufacturing optical elements. Although this method requires a large pressure force, making the equipment complex and large-scale, it is an extremely excellent manufacturing method because it reduces manufacturing costs and allows optical elements with complex shapes to be molded in one shot. It can be said that

[Problems to be solved by the present invention]

However, the above manufacturing method has serious drawbacks in producing fine and complicated optical elements. That is, as the optical element becomes finer and more complex, the creation of a mold becomes dramatically more complicated and extremely difficult.

Therefore, the cost of the mold also increases dramatically.

An object of the present invention is to eliminate such drawbacks and provide an extremely effective manufacturing method especially for optical elements having complex and fine shapes.

[Means for solving problems]

In the method for manufacturing an optical element of the present invention, the end face of a cylindrical body having a predetermined cross-sectional shape is brought into contact with the surface of a flat glass or polymer softened by heating, and the inside of the cylindrical body is reduced in pressure or applied. The method includes a step of molding the surface of the glass or polymer inside the cylindrical body into a curved surface by applying pressure.

[Preferred mode for carrying out the invention]

Hereinafter, the method for molding an optical element of the present invention will be explained in detail with reference to the drawings.

FIG. 1 is a schematic diagram showing the steps of an embodiment of the optical element molding method of the present invention.

To mold an optical element according to the present invention, first, a material l made of glass or polymer is placed and fixed on an optically polished metal plate z.

Next, the material 1 is heated by a heater 5 placed around the material 1 to a temperature above the thermal softening temperature of the material 1, but not too softened.Normally, the viscosity of the material 1 is approximately IQ.
It is preferable to heat to about 107 Boaz.

Next, the end face of the cylindrical body 3, which has a valve 4 and is movable up and down, is brought into contact with the surface of the material 1, and the cylindrical body is fixed so that it does not move. The inside of the cylindrical body 3 (hereinafter referred to as the hole) has a circular cross section or the like.

Next, a pressure reducer or pressurizer a installed at the other end of the cylindrical body 3 is
(not shown) and adjust the valve 4 to reduce or increase the pressure in the hole to a predetermined pressure.

A convex lens is formed by reducing the pressure inside the hole, and a concave lens is formed by applying pressure. The shape of the functional surface of the lens to be formed (spherical, parabolic, etc.) and its radius of curvature can be adjusted by the time for depressurization or pressurization and the pressure to be set.

Cooling is performed by natural cooling or an appropriate cooling means so that no distortion occurs in the molded optical element.The above example shows a method for manufacturing a spherical or parabolic lens on only one side from a flat material. However, various applications are possible based on the method used in this example. They are shown below.

(I) By selecting the cross-sectional shape of the hole as desired, a lens shape corresponding to the cross-sectional shape can be obtained. For example, if a tube with a hole with an elliptical cross-section is used, a lens having an ellipsoid of revolution can be formed. can.

(II) By using an optical element material with a curved surface, optical elements with various shapes can be obtained. For example, if a material with a spherical surface (the material may be made by the method of the present invention) is used, The shape of the optical element is one having a spherical surface and a composite surface of spherical surfaces.

(m) Using t materials, not only one cylindrical body but also two
A lens assembly can be integrally molded by pressurizing or reducing pressure from two or more cylindrical bodies at the same time. This method is suitable for manufacturing lens arrays that are in high demand for copying machines and the like.

〔Effect of the invention〕

As explained above, one method for manufacturing an optical element of the present invention is as follows:
Unlike the molding method, there is no need to use complicated and expensive molds, and there is no need for complicated and large-scale equipment, and furthermore, optical elements can be formed with fewer steps.The present invention has the following features: It is particularly effective in creating microlenses.

The optical element manufactured according to the present invention is most suitable for use as an element of information equipment, an image conversion element, etc.

EXAMPLES In order to explain the present invention in more detail, Examples are shown below.

Example A disk-shaped sample of printed optical glass of φ10 mm x t5 mm was heated until the viscosity reached 109 poise.
A lens was formed using the above method. The pressure inside the hole is 10”
torr (reduced pressure) or 1 atm (pressurized), the cross section of the hole used was circular, and the diameter was φ2 layer, φ6■ and φ8 layer■.
There are four types. As a result, a convex lens was formed when the pressure was reduced, and a concave lens was formed when the pressure was applied. It was found that the radius of curvature of the lens becomes smaller as the time for decompression or pressurization is longer, but in the case of any hole, the lens shape converges to a constant value by depressurizing or pressurizing for 5 minutes or more. 5
The lens shapes obtained by depressurization or pressurization for minutes are summarized in the following table.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram showing the steps of an embodiment of the method for manufacturing an optical element of the present invention. l: Material 2: Metal plate 3: Cylindrical body 4: Pulp 5: Heater

Claims (1)

[Claims] The end face of a cylindrical body having a predetermined cross-sectional shape is brought into contact with the surface of a flat glass or polymer softened by heating, and the inside of the cylindrical body is depressurized or pressurized to remove the glass inside the cylindrical body. Or a method for manufacturing an optical element, which includes a step of forming a polymer surface into a curved surface.