Patent · US Expired

Automatic facusing using slope and peak detection

US4544953A · kind A · utility

10Cited by
6References
16Claims
0Family size

Assignee

Inventor

Key dates

Filing dateMar 28, 1983
Grant dateOct 1, 1985
Priority date
Expiry dateMar 28, 2003

Classification

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

Abstract

There is disclosed a VIDEO AUTOMATIC FOCUSSING SYSTEM in which a video signal from the television camera is directed to a band pass filter and then detected to produce a DC signal indicative of the video signal as band limited. The detected signal is directed to the inputs of a negative slope detector and peak detector. The detectors monitor the slope of the video signal to form the basis for controlling the motor to achieve automatic focussing on command.

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