Camera exposure control circuit
US3956757A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 18, 1973 |
| Grant date | May 11, 1976 |
| Priority date | — |
| Expiry date | Dec 18, 1993 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03B7/083
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
An automatic exposure control circuit for a camera including a light receiving element positioned internally of the camera for receiving light passing through the camera objective. The light receiving element converts the incident light into a corresponding electrical quantity. A diaphragm information device is available for producing an electrical quantity corresponding to the diaphragm setting. An operational amplifier combines the aforementioned two electrical quantities and provides a combined electrical output signal which is utilized in the determination of exposure time. A capacitor, interconnected with the operational amplifier by a switch, stores the combined electrical output signal. The switch can be automatically controlled in synchronism with the photographing operation of the camera, or can be manually controlled by the operator by operation of an arrangement external to the camera.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.