Focus detecting apparatus independent of object image contrast
US4804831A · kind A · utility
124Cited by
5References
56Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Oct 24, 1986 |
| Grant date | Feb 14, 1989 |
| Priority date | — |
| Expiry date | Oct 24, 2006 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B7/36
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
In an automatic focusing apparatus, a focus detecting device having detecting means for detecting the width of the edge part of the image of an object to be photographed and discriminating means for discriminating a focused state on the basis of the size of the detected width is arranged to determine by the discriminating means the apparatus to be out of focus when the width of the edge part of the object image is wide and to be in focus when the width of the edge part is narrow, so that the focus detecting device can operate without being affected by difference in the kind and the contrast of the object to be photographed.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.