Product for molding glass lenses having difficult shapes
US5762676A · kind A · utility
6Cited by
16References
9Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Apr 29, 1996 |
| Grant date | Jun 9, 1998 |
| Priority date | — |
| Expiry date | Apr 29, 2016 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC03B2215/47
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
An improved tool is provided for pressing glass into a precision optical element having a strong concave surface. The tool is selected from ceramic and metal materials having coefficients of thermal expansion greater than the coefficient of the pressed glass. Preferred tools include a base material selected from Invar, steel and alumina with a surface layer selected from alumina, zirconia, chromium oxide and chromium carbide, having a finished thickness in the range between ten to two thousand angstroms.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.