Claims
- 1. A method of manufacturing an optical glass element, comprising:
preparing a mother glass having a cross-sectional shape substantially similar to a desired cross-sectional shape of said optical glass element; and drawing said mother glass while heating to a predetermined temperature such that said mother glass has a viscosity of 105 to 109 poise.
- 2. The method of claim 1, wherein said mother glass is drawn while heating to a predetermined temperature such that said mother glass has a viscosity of 105 to 109 poise.
- 3. The method of claim 1, wherein said optical glass element is made of BK7, and said predetermined temperature is 660 to 860° C.
- 4. The method of claim 1, wherein said optical glass element is made of BK7, and said predetermined temperature is 660 to 690° C.
- 5. The method of claim 5 to 150 times that of the optical glass element to be obtained.
- 6. The method of claim 5, wherein the cross-sectional area of said mother glass is 10 to 100 times that of said optical glass element to be obtained.
- 7. The method of claim 1, wherein said desired cross-sectional shape is polygonal.
- 8. The method of claim 7, wherein said optical glass element comprises a prism.
- 9. The method of claim 1, wherein said desired cross-sectional shape is circular.
- 10. The method of claim 1, wherein said mother glass is drawn by introducing a lower end part thereof into a heating furnace at a feed speed V0 and pulling said lower end part heated to said predetermined temperature downwards at a drawing speed V1, and wherein said drawing speed V1 are set relative to said feed speed V0 so as to obtain a drawing speed ratio V1/V0 of 25 to 22,500.
- 11. The method of claim 10, wherein said drawing speed ratio V1/V0 of said drawing speed V1 to said feed speed V0 is in a range of 100 to 10,000.
- 12. The method of claim 1, wherein said mother glass is made of a glass selected from the group consisting of BK7, Ultran, FK, PK, PSK, BaLK, ZK, BaK, SK, KF, BaLF, SSK, LaK, LLF, BaF, LF, F, BaSF, LaF, LaSF, SF, TiF, KZF and KZFS.
Priority Claims (1)
Number |
Date |
Country |
Kind |
2000-176042 |
Jun 2000 |
JP |
|
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a division of application Ser. No. 09/874,594.
Divisions (1)
|
Number |
Date |
Country |
Parent |
09874594 |
Jun 2001 |
US |
Child |
10650388 |
Aug 2003 |
US |