Compensator system for diaphragm control in a single-lens reflex camera of interchangeable lens type
US4477161A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 30, 1981 |
| Grant date | Oct 16, 1984 |
| Priority date | — |
| Expiry date | Jan 30, 2001 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03B7/085
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A compensator system for diaphragm control in a single-lens reflex camera of interchangeable type having an exposure control circuit responsive to the position of a lever that is operatively coupled to the diaphragm according to a preset position of a diaphragm preset ring. The exposure control circuit is regulated for compensating any errors in illumination intensity in a film plane provided by individual interchangeable lenses and errors in illumination intensity provided by photometric operation through respective lenses mounted on a camera in relation with a specific position of a light receiving element contained in a photometric circuit. A diaphragm preset ring has on the periphery thereof an indication for the automatic diaphragm control at a predetermined angular distance from an indication for the fully closed diaphragm value of an associated lens. An arithmetic factor is provided for exposure control comprising an electric adjustment factor such as a resistance value or binary signal that is selected by the lever when the diaphragm preset ring has been rotated to the automatic diaphragm control position. A signal is provided for detecting a fully closed diaphragm and a fu…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.