Totally opened F. value information input system of lens for a camera with interchangeable lenses
US4118713A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 7, 1977 |
| Grant date | Oct 3, 1978 |
| Priority date | — |
| Expiry date | Apr 7, 1997 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03B7/20
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
At the side of the camera body, switches for treating the totally opened F value information of the photographic lens as coded digital information of a certain determined number of bits are connected to the digital exposure operation circuit. At the side of each of the photographic lens which is made interchangeable for the camera body, a signal pin is arranged for indicating the totally opened F value proper to the photographic lens as coded digital information of the above mentioned determined number of bits in such a manner that at the time of mounting the photographic lens on the camera body, the switches at the side of the camera body are closed in selected combination in accordance with the totally opened F value of the lens. Accordingly the totally opened F value of the photographic lens is put into the digital exposure operation circuit.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.