Focus detecting device
US4878079A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 1, 1988 |
| Grant date | Oct 31, 1989 |
| Priority date | — |
| Expiry date | Aug 1, 2008 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B7/38
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A focus detecting device capable of correcting an error, between an in-focus position of a photographic lens detected by a focus detecting means and an image field position affording the best image. Focus detection is made using plural focus detecting areas provided on and off the optical axis of the photographic lens, to obtain an in-focus position. Then, the thus-obtained in-focus position of the photographic lens is corrected using an appropriate correction value out of those preset and stored in a ROM in the lens according to whether the focus detecting area used in the focus detection is an axial or off-axial area, or according to the focal length of the photographic lens as well as the photographing mode. And the photographic lens is thereby set to the best image field position.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.