Glass lens blank for polishing, manufacturing method therefore, and optical lens manufacturing method

Patent metadata

Field	Value
Publication number	US-9868661-B2
Application number	US-201414768161-A
Country	US
Kind code	B2
Filing date	Feb 25, 2014
Priority date	Feb 25, 2013
Publication date	Jan 16, 2018
Grant date	Jan 16, 2018

Abstract

A glass lens blank for polishing in which a thickness of a defect-containing layer is suppressed to a minimum and thus it is possible to shorten the processing time required for grinding and polishing the glass lens blank for polishing after press-molding, a method of manufacturing the same, and a method of manufacturing an optical lens. A glass lens blank for polishing of which at least a main surface is a press-molding surface, wherein a defect-containing layer formed on the main surface has a thickness of 50 μm or less.

First claim

What is claimed is:

1. A glass lens blank for polishing, comprising at least a main surface that is a press-molded surface,
wherein a defect-containing layer formed on the main surface has a thickness of 50 μm or less, and
the main surface has a surface roughness Rz of 12 μm or more.

2. The glass lens blank according to claim 1 , wherein the main surface has a surface roughness Rz of 14 μm or more.

3. A method of manufacturing an optical lens wherein an optical lens is obtained by performing a spherical grinding processing, a smoothing processing and a polishing processing on the glass lens blank for polishing according to claim 1 , wherein the smoothing processing is performed using a resin-bonded grindstone without using a metal-bonded grindstone.

4. A method of manufacturing an optical lens wherein the optical lens is obtained by performing a smoothing processing and a polishing processing, without performing a spherical grinding processing, on the glass lens blank for polishing according to claim 1 .

5. The glass lens blank according to claim 1 , wherein the main surface has a surface roughness Rz of 20 μm or more.

6. The glass lens blank according to claim 1 , wherein the main surface has a surface roughness Rz of 25 μm or more.

7. The glass lens blank according to claim 1 , wherein the main surface has a surface roughness Rz of 50 μm or less.

8. The glass lens blank according to claim 1 , wherein the main surface has a surface roughness Rz of 40 μm or less.

9. The glass lens blank according to claim 1 , wherein the main surface has a surface roughness Rz of 30 μm or less.

10. The glass lens blank according to claim 1 , wherein the defect-containing layer to be formed on the main surface has a thickness of 30 μm or less.

11. The glass lens blank according to claim 1 , wherein the defect-containing layer to be formed on the main surface has a thickness of 20 μm or less.

12. The glass lens blank according to claim 1 , wherein the defect-containing layer to be formed on the main surface has a thickness of 15 μm or less.

13. The glass lens blank according to claim 1 having a weight of 5 grams or more.

14. The glass lens blank according to claim 1 having a lens diameter of 30 mm or more.

15. A method of manufacturing a glass blank for polishing, comprising the steps of:
receiving a molten glass from a nozzle comprising a mold;
molding the molten glass with the mold to obtain a glass gob;
reheating the glass gob to a viscosity from 10 4 to 10 6 dPa·s under an air atmosphere while maintaining a surface state thereof; and
press-molding the reheated glass gob with a mold for press-molding under an air atmosphere, thereby obtaining a glass-molded article having a press-molded surface in at least a main surface thereof,
wherein a defect-containing layer formed on the main surface of the glass-molded article obtained by the press-molding step has a thickness of 50 μm or less, and the main surface has a surface roughness Rz of 12 μm or more.

16. The method according to claim 15 , further comprising a step of applying a release agent to at least any one surface of the glass gob before the reheating step, and holding recesses for placing the glass gob therein during the reheating step.

17. The method according to claim 15 , wherein a molding surface of the mold has a surface roughness Rz of 12 μm to 50 μm.

Assignees

• Ikenishi Mikio
• Shoji Akihiro
• Tanno Yoshitake
• Tanaka Isao
• Hoya Corp

Inventors

• Ikenishi Mikio
• Shoji Akihiro
• Tanno Yoshitake
• Tanaka Isao

Classifications

• Y02P40/57

  Improving the yield, e-g- reduction of reject rates · CPC title

• C03B2215/61

  Positioning the glass to be pressed with respect to the press dies or press axis · CPC title

• C03B2215/47

  Bi-concave · CPC title

• C03B2215/46

  Lenses, e.g. bi-convex · CPC title

• B24B13/0037

  the lenses being worked by different tools, e.g. for rough-grinding, fine-grinding, polishing · CPC title