Focal point detection device and camera
US6975810B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Mar 25, 2004 |
| Grant date | Dec 13, 2005 |
| Priority date | — |
| Expiry date | Mar 25, 2024 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B7/36
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A camera comprises a spatial modulation optical filter that is disposed in a viewfinder optical system for subject observation at or near a position optically equivalent to an estimated image forming plane of a photographic optical system and modulates a subject light flux entering via the photographic optical system with transmission characteristics to obtain a light flux having a predetermined spatial frequency; a photoelectric conversion device that outputs a signal corresponding to detected light; an optical element that guides the subject light flux having been modulated at the spatial modulation optical filter to the photoelectric conversion device; and a focal adjustment state calculation means that calculates a focal adjustment state of the photographic optical system based upon the signal output from the photoelectric conversion device having received the modulated subject light flux.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.