Diffractive multi-focal lens
US5760871A · kind A · utility
175Cited by
24References
40Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Nov 30, 1993 |
| Grant date | Jun 2, 1998 |
| Priority date | — |
| Expiry date | Nov 30, 2013 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02C2202/20
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A tri-focal diffractive lens defining three foci, for viewing a band of light having a representative wavelength of .lambda., including a diffractive surface having a number of optical heights, h.sub.o, wherein the difference between the highest and the lowest optical heights is, modulo .lambda., substantially different from .lambda./2, wherein each of the foci receives at least 20% of light incident on the lens.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.