Patent · US Expired

Automatic focusing camera with automatic focusing function for automatically matching focus in response to video signal

US5075777A · kind A · utility

12Cited by
13References
10Claims
0Family size

Assignee

Inventor

Key dates

Filing dateSep 25, 1990
Grant dateDec 24, 1991
Priority date
Expiry dateSep 25, 2010

Classification

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

Abstract

In an electric still camera with an automatic focusing function, when a user operates a releasing switch (21), a focusing operation relative to an object is initiated. During this focusing operation, a CCD (45) is driven by a timing generator (27) in accordance with a first driving method. According to this first driving method, signal charges are read out five times for one field and therefore five focus evaluating values are obtained for one field. These focus evaluating values enable the high speed driving of a focusing motor (3) at the time of focusing operation. After the focusing operation is completed, the CCD (45) is driven by the timing generator (27) in accordance with a second driving method which is a normal driving method, a regular video signal is output from an image sensing circuit 4 and recorded in a video floppy 26.

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