Apparatus for detecting a focusing condition of an objective lens
US4483602A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 29, 1982 |
| Grant date | Nov 20, 1984 |
| Priority date | — |
| Expiry date | Mar 29, 2002 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B7/36
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
In a single-lens reflex camera having an objective lens, a focusing screen and a view finder, a photodetector array is arranged to receive a central part of an object image formed by the objective lens and a focusing condition of the objective lens is detected by calculating an evaluation function from image signals supplied from the photodetectors. A presetting dial for selecting given photodetectors whose image signals are used for detecting the focusing condition is provided at such a position that a part of the dial is exposed to the outside through an opening formed in a rear wall of a camera body at a position underneath a film winding lever. A light emitting diode array is provided on the focusing screen so as to be seen by a user through the view finder. Only desired light emitting diodes are lighted on under the control of a signal supplied by the dial to indicate the region of the photodetector array which is used for detecting the focusing condition.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.