JPH0333023A - Method for forming optical glass element - Google Patents

Abstract

PURPOSE:To smoothen the surface of glass in large quantities, to prolong the service life of dies, to shorten forming time and to reduce forming cost by smoothening the surface of machined glass by barrel polishing, softening the glass by heating and press-forming the softened glass. CONSTITUTION:A cut glass disk is machined to a prescribed radius of curvature, prescribed surface roughness and center thickness close to the shape of an end product. The surface of the machined disk is smoothened with a rotary barrel polisher so that it becomes specular and the disk is softened by heating, press-formed with prescribed dies and cooled to a prescribed temp. to obtain an optical glass element.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a method of molding a glass optical element, which manufactures an optical element such as a glass optical lens by press molding.

[Conventional technology]

Conventionally, the surface of the glass material used in the method of molding a glass optical element has been smoothed by general polishing using a polishing plate, as disclosed in Japanese Patent Publication No. 370431/1983.

Further, the molding method disclosed in Japanese Patent Application Laid-Open No. 146723/1984 uses a lens material that has been ground into a spherical shape and is then treated with an acid to give it a predetermined mirror surface.

Furthermore, the method for manufacturing a lens material disclosed in JP-A-61-146721 involves dropping molten glass from the tip of a nozzle and letting it fall until the surface temperature of the glass droplet becomes lower than the softening temperature. This is a method of obtaining unpolished glass gobs.

[Invention tries to solve it! However, in order to smooth the glass material in the lens molding method described in JP-A-63-37043, complicated processes such as pasting, polishing, and peeling are required, and depending on the shape, Since there are cases where only one piece is processed, there are problems such as high processing cost.

In addition, in the forming method described in JP-A No. 61-143723, the crank of the material surface is selectively eroded before acid treatment, which tends to cause waviness on the surface. In addition, there are safety issues such as handling of acid. In addition, there are problems in terms of cost related to disposal after acid treatment.
In the material forming method described in the publication, the shape of the glass gob is spherical, and in order to form the final product shape, it is necessary to create a large flow during press molding, which increases the press molding time and shortens the mold life. There are problems such as increased molding costs and increased molding costs.

Therefore, an object of the present invention is to eliminate the drawbacks of these conventional techniques in the method of molding a glass optical element, and to provide a method of molding a glass optical element with low processing cost.

[! ! l! Means and Effects for Solving the Problems] In order to solve the above-mentioned problems, the present invention has been developed by heating and softening a glass material whose surface has been smoothed by a barrel polishing method, and shaping it into a predetermined shape using a pair of molds. A glass optical element is formed by press molding and cooling to a predetermined temperature.

However, since the barrel polishing method is used in the process of smoothing the surface of the glass material in the method for molding a glass optical element of the present invention, it is possible to process a large amount of glass material at a time, and it is possible to There is little change in shape, and the surface shape before treatment can be approximated to the final shape by grinding, melt molding, etc. Further, the barrel polishing machine used for barrel polishing is relatively inexpensive, has low installation costs, and has few safety problems.

〔Example〕

Examples of the method for molding a glass optical element of the present invention will be described below with reference to the drawings.

(First Embodiment) Figs. 1 to 4 show the first embodiment of the present invention, Figs. It is an explanatory diagram showing a method.

First, in molding a glass material in the molding method of the present invention, as shown in FIG. 1, a rounded and cut glass disk 11 is molded to a predetermined diameter and thickness. next,
A predetermined radius of curvature RA that approximates the desired final product shape
, R1 has a surface roughness of 5 μm or less and a medium thickness t,
Grind. As this grinding process, a curve generator, sanding, fine grinding process using a diamond plate, etc. can be used. In this way, a rough molded product 12 as shown in FIG. 2 is obtained.

Next, barrel polishing is performed using a rotary barrel polishing a13 shown in FIG. That is, in the barrel polishing, a large amount of the rough molded product 12 and the media 15 for gloss polishing are put into the barrel tank 14 . This media 15 is “
Massage J etc. can be used. Therefore, by operating the barrel polishing machine 13 to perform barrel polishing,
As time passes, the surface roughness of the rough molded product 12 improves to approximately 10
After barrel polishing for 0 H, a mirror-like glass material 1 with a surface roughness of 0.05 μm or less can be obtained.

Next, a process of molding an aspherical lens of a predetermined shape using this glass material 1 will be described.

As shown in FIG. 4, the glass material 1 is placed on the molding surface 2a.
3a is mirror-finished to have a surface roughness of 0.03 .mu.m or less and is placed between a pair of molds 2.degree.3 formed into a predetermined shape. Then, the molding chamber 7 is made into a non-oxidizing atmosphere, and the glass material 1 is heated and softened by the heater 8. When this glass material 1 is heated and softened to a predetermined temperature at which it can be press-formed, it is
Press molding is performed using the mold 2.3 at a predetermined pressure and time. Thereafter, heating and holding by the heater 8 is stopped, and the mold 2.3 and the pressure-molded molded product are cooled to a temperature below the transition point. When this cooling is completed, the mold 2.
By removing the molded product from between the three spaces, an aspherical lens of a predetermined shape can be molded.

(Second Embodiment) A second embodiment of the present invention will be described below. In the first embodiment, a glass disk 11 is used as the starting material for the rough molded product
However, a directly pressed product can be used as a cheaper starting material, and in this example, the first
A directly pressed product is used in place of the glass disk 11 of the embodiment.

Thereafter, the process of obtaining the coarse shaped article 12 from this directly pressed product is similar to the first embodiment, but the grinding process can be simplified by improving the surface roughness of the directly pressed product. The barrel polishing and molding steps below are the same as in the first embodiment.

In both the first and second embodiments, the process of forming the glass material is not limited by its material or shape.

Further, barrel polishing can be performed using a centrifugal barrel polishing machine or a vibrating barrel polishing machine other than the embodiments. moreover,
The molding process can also be carried out by a so-called non-isothermal molding method in which the heating temperature of the glass material is higher than the mold temperature.

〔Effect of the invention〕

The present invention is a method for molding a glass optical element using a glass material whose ground glass surface has been smoothed by barrel polishing, which enables mass processing of the smooth surface of the glass material, and which uses a relatively inexpensive processing machine. There are fewer safety issues,
Since the running cost is low, the total cost can be reduced. In addition, since the amount of deformation during the barrel polishing process is small, the shape can be determined during the grinding process, and a glass material that approximates the final shape can be obtained, extending the life of the mold and shortening the molding time. Cost reduction can be achieved.

[Brief explanation of drawings]

1 to 4 show a first embodiment of the present invention, FIGS. 1 to 3 are explanatory diagrams showing a method of molding a glass material, and FIG.
The figure is an explanatory diagram showing a method of press molding a glass material. 1...Glass material 2.3...Molding wall 11...Glass disc 12...Rough molded product 13...Barrel polishing machine 14...Barrel tank 15...Media

Claims (1)

[Claims] (1) Glass optics characterized by molding by heating and softening a glass material whose glass surface has been smoothed by barrel polishing, press-molding it into a predetermined shape with a pair of molds, and cooling it to a predetermined temperature. Element molding method.