Photographic camera shutter electromagnetic system for controlling photographic light admitted to camera
US4240728A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 26, 1978 |
| Grant date | Dec 23, 1980 |
| Priority date | — |
| Expiry date | Jun 26, 1998 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03B9/08
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
Photographic camera shutter apparatus having at least one drivable control part arranged for reciprocation for controlling the photographic light admitted to the camera, e.g. a diaphragm aperture ring or a shutter blade ring, and an electromagnetic driving system for reciprocating the control part, including at least one corresponding assembly having opposed coacting reciprocally energizable electromagnetic field coils stationarily arranged in spaced apart relation and providing an intervening magnetic field space therebetween and movable permanent magnets arranged for reciprocation along such intervening field space in response to the corresponding energization of the stationary field coils and operatively connected for driving the control part in question concordantly for reciprocation thereof, whereby to control the photographic light admitted to the camera in dependence upon the energization of the field coils.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.