Method for manufacturing photochromic lenses
US5531940A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 10, 1993 |
| Grant date | Jul 2, 1996 |
| Priority date | — |
| Expiry date | Dec 10, 2013 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB29D11/0073
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
Methods for making optical quality plastics lenses with photochromic additives are described. According to a first embodiment of the invention, a casting resin is containing photochromic additives is arranged between a mold and a lens preform and then cured. According to a second embodiment of the invention, a casting resin substantially free of photochromic additives is arranged between a mold and a lens preform and then cured. The resin is then impregnated with photochromic additives. In a third embodiment, a layering resin containing a photochromic additive is provided on the surface of a mold and cured to a gel state. Then, a casting resin that is substantially free of photochromic additives is arranged between the coated mold and a lens preform and cured. According to a fourth embodiment, a casting resin that is substantially free of photochromic additive is provided on the surface of a mold and cured to a gel state. Then, a casting resin containing photochromic additives is arranged between the coated mold and a lens preform and cured.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.