Camera viewfinder device
US4256396A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 17, 1978 |
| Grant date | Mar 17, 1981 |
| Priority date | — |
| Expiry date | Oct 17, 1998 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03B13/12
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A camera having at least two objective lenses of different focal lengths, which can be selectively externally manually positioned in the camera photographic optical path includes an inverted Galilean viewfinder optical system consisting of a front negative, divergent lens group and a rear positive, convergent lens group. The divergent lens group consists of two concave lenses which are transferrable between a first position providing a low magnification and a second position providing a high magnification. In the first position both concave lenses are in the viewfinder optical path and the other concave lens remains in the viewfinder optical path and is shifted to a second position axially spaced from its first position along the finder optical axis.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.