Zoom lens employing refractive and diffractive optical elements
US5268790A · kind A · utility
53Cited by
7References
8Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Dec 20, 1991 |
| Grant date | Dec 7, 1993 |
| Priority date | — |
| Expiry date | Dec 20, 2011 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B15/144
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A zoom lens (10) has a first lens group (12), a second lens group (14) and a third lens group (16). The first lens group relays an outside scene to an intermediate plane. The second lens group varies magnification of the relayed image from the first lens group. Also, the second lens group includes at least one diffractive optical element. The third lens group compensates for focus shift and focuses the wavefront onto the viewing plane.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.