Automatic-exposure control device for optical instruments
US4100558A · kind A · utility
Inventors
Key dates
| Filing date | Oct 17, 1975 |
| Grant date | Jul 11, 1978 |
| Priority date | — |
| Expiry date | Oct 17, 1995 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02K7/14
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
Herein disclosed is an electromagnetic rotary motion device including permanent magnets establishing a pair of spaced concentric and coextensive circular or semicircular air gaps and a rotor unit including armatures which are movable in a circular path in and along the spaced air gaps in response to an electric control signal impressed thereon. A typical application of the rotary motion device is a diaphragm-assisted exposure control arrangement of an optical instrument, such as for example as a still camera, a cinema motion camera or a television camera, wherein the diaphragm is driven by the rotor unit for providing a degree of exposure which is optimum for the brightness of an object to be photographed or televised.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.