Focal length switch-over camera
US4952955A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 2, 1989 |
| Grant date | Aug 28, 1990 |
| Priority date | — |
| Expiry date | Mar 2, 2009 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03B19/07
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A camera having a photographic optical system capable of switching over a focal length having a control member, a cam operatively connected with the control member, a first cam face defined on the cam for effecting a focus adjustment in a first focal length, a second cam face defined on the cam for switching over from the first focal length to a second focal length, a third cam face defined on the cam for effecting a focus adjustment in the second focal length and a cam follower driven by the first through third cam faces and connected with the photographic optical system to drive the same. The second cam face is aligned in an operative direction of the cam or peripherally relative to the first cam face and the third cam face is aligned in the operative direction of the cam or peripherally relative to the second cam face. Thereby, since the respective cam faces for switching over a focal length and for effecting a focus adjustment in the two focal lengths may be formed having different angles relative to the operative or rotational direction of the cam, a movement amount of the cam follower of the photographic optical system relative to an operative amount of the cam may be conveni…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.