Electomagnetic rotary motion device and exposure control device using the same
US3971963A · kind A · utility
Inventors
Key dates
| Filing date | Sep 11, 1973 |
| Grant date | Jul 27, 1976 |
| Priority date | — |
| Expiry date | Sep 11, 1993 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02K41/0358
- 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, 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.