Focus condition detecting device using weighted center or contrast evaluation
US4851657A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 28, 1988 |
| Grant date | Jul 25, 1989 |
| Priority date | — |
| Expiry date | Sep 28, 2008 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B7/34
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A focus condition detecting device for a camera is disclosed. The device provides first and second image sensors for calculating correlations between images each having passed through an objective lens of the camera. A plurality of image detecting blocks are defined on the first image sensor in order to execute correlation calculations with respect to each block for detecting focus conditions. A focus condition which indicates the focus condition among those obtained from the correlation calculations with use of each block is employed as the most probable focus condition. In the present invention, correlation calculations unnecessary for finding the rearmost focus condition are omitted.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.