Device for automatic diaphragm setting in photographic cameras
US3988749A · kind A · utility
5Cited by
5References
21Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Apr 21, 1975 |
| Grant date | Oct 26, 1976 |
| Priority date | — |
| Expiry date | Apr 21, 1995 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03B9/08
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
An automatic diaphragm control for camera lenses having independent diaphragm and shutter speed rings in which a reversible motor is positioned to drive the diaphragm ring, and a gear engaging the diaphragm ring drives a potentiometer. A light-sensor is in circuit with the motor and the potentiometer to drive the diaphragm ring to cause the potentiometer to balance the light-sensor output. The position of the diaphragm ring and the potentiometer is adjustable for film speed and for the selected shutter speed.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.