Focus condition detecting device
US4903065A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 13, 1988 |
| Grant date | Feb 20, 1990 |
| Priority date | — |
| Expiry date | May 13, 2008 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03B7/09972
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A focus condition detecting device which eliminates a wasteful operation thereof to obtain optical results of detection in a shortest period of time and wherein it can be discriminated correctly depending upon data read from a lens regarding an exit pupil of the lens whether or not detection of a focus condition is possible. The device comprises an optical means which forms a plurality of pairs of light images from beams of light from pairs of areas of an exit pupil plane of an interchangeable lens. Relative displacements between the light images are detected by a plurality of focus condition detecting means. Data regarding optical characteristics of the lens are read from the lens, and in accordance with the data thus read, those ones of the focus condition detecting means for which detection of a focus condition is possible are selected from an optical relationship between the optical means and the exit pupil of the lens. An in-focus condition is finally determined from focus condition signals produced from the selected focus condition detecting means.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.