Automatic flash photography apparatus
US3994007A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 11, 1974 |
| Grant date | Nov 23, 1976 |
| Priority date | — |
| Expiry date | Sep 11, 1994 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03B7/16
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
The disclosed automatic flash photography apparatus operates with a camera having a shutter in which a diaphragm blade serves as a shutter blade, and the diaphragm diameter is varied by varying the time interval from the moment its blades start opening till the moment they start closing. A switch switches over between separate time constant circuits, one for artificial-light photography, the other for natural-light photography. For flash photography, a resistor which is variable in response to the distance from a light source to an object and the film sensitivity controls the time constant circuits for closing the diaphragm blades. Thus a flash device is illuminated and the amount of light passing the diaphragm aperture is established.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.