Method for producing a dioptric photocromic semi-finished lens
US5800744A · kind A · utility
49Cited by
5References
14Claims
0Family size
Inventor
Key dates
| Filing date | Aug 13, 1996 |
| Grant date | Sep 1, 1998 |
| Priority date | — |
| Expiry date | Aug 13, 2016 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB29L2011/0016
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
A method of producing a dioptric photochromic semi-finished lens, a diopter of which is to be imparted by grinding a concave surface of the semi-finished lens. Color concentration between a center portion and a peripheral portion is maintained at a fixed color concentration independent of the diopter of the lens and the lens is shockproof. In the method, after mixing a photochromic material with a thermoplastic polycarbonate resin to make a sheet, the sheet is processed to have a spherical surface sheet, set in a mold and thermoplastic polycarbonate resin is injected in the mold to be bonded with the sheet.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.