Waist level finder optical system
US5270758A · kind A · utility
3Cited by
7References
15Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Feb 12, 1992 |
| Grant date | Dec 14, 1993 |
| Priority date | — |
| Expiry date | Feb 12, 2012 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B23/14
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A waist level finder optical system comprising, in order from the object side: an objective lens system for finder comprising a first lens unit having positive refractive power and a second lens unit having negative refractive power; a reflecting member for erecting an image of object formed by the objective lens system; and a field lens having positive refractive power. This finder optical system can have a total length as a whole which is shortened without changing a half angle of incidence, a height of a principal ray as measured on the field lens and a distance as measured from the field lens to an eye point.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.