Patent · US Expired

Focus detecting apparatus jointly employing outputs of plural diverse detectors

US5055665A · kind A · utility

11Cited by
6References
38Claims
0Family size

Assignee

Inventors

Key dates

Filing dateMar 21, 1990
Grant dateOct 8, 1991
Priority date
Expiry dateMar 21, 2010

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH04N23/673
  • 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.