Photographic lens system
US5398136A · kind A · utility
11Cited by
5References
18Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Dec 21, 1992 |
| Grant date | Mar 14, 1995 |
| Priority date | — |
| Expiry date | Dec 21, 2012 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B13/06
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A single focal length lens system has a first negative lens element and a last negative lens element. The first negative lens element is disposed at an object side end of the lens system and the object side surface thereof is concave. The last negative lens element is disposed at an image side end of the lens system. The lens system fulfills the following condition: ##EQU1## wherein .phi.f represents the refractive power of the first negative lens element; and .phi.1 represents the refractive power of the last negative lens element.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.