Patent · US Expired

In-focus detection apparatus using video signal

US5225940A · kind A · utility

53Cited by
5References
23Claims
0Family size

Assignee

Inventors

Key dates

Filing dateFeb 27, 1992
Grant dateJul 6, 1993
Priority date
Expiry dateFeb 27, 2012

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH04N23/673
  • WIPO fieldAudio-visual technology
  • WIPO sectorElectrical engineering

Abstract

An in-focus detection apparatus used for a video camera includes edge width detector for detecting a plurality of edge widths of an object, and an calculation device for calculating the amount of driving a lens based on the distribution state of these plurality of edge width data. The apparatus uses a video signal and provides the in-focus state of an actual object with a high accuracy without requiring slight movement of a focusing lens.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.