Mold for the casting of resin ophthalmic lenses having a prismatic segment
US4163541A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Feb 9, 1978 |
| Grant date | Aug 7, 1979 |
| Priority date | — |
| Expiry date | Feb 9, 1998 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S425/808
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
A mold for casting a resin ophthalmic lens is comprised of a glass disc defining a principal casting surface on one face thereof. The casting surface is a portion of a surface of revolution which has a first axis of symmetry and which has, at a location along such axis, an effective center of curvature. The principal casting surface has, in a selected portion thereof, a bottom surface defining in the mold a minor casting surface which is a portion of a surface of revolution having a second axis of symmetry. The first and second axes, if they intersect at all, intersect at a location on the first axis other than at substantially the center of curvature of the principal casting surface.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.