Multifocal diffractive lens
US4830481A · kind A · utility
81Cited by
5References
12Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Aug 12, 1988 |
| Grant date | May 16, 1989 |
| Priority date | — |
| Expiry date | Aug 12, 2008 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B5/1876
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A multifocal ophthalmic lens has a plurality of concentric diffractive zones with adjacent zones separated by steps having predetermined heights. Each step has an outer corner and each outer corner has a radius of curvature equal to at least one half the height of the step associated therewith.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.