Patent · US Expired

Copy guard processing detecting apparatus

US5337157A · kind A · utility

18Cited by
7References
4Claims
0Family size

Assignee

Inventor

Key dates

Filing dateJan 15, 1993
Grant dateAug 9, 1994
Priority date
Expiry dateJan 15, 2013

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH04N2005/91314
  • WIPO fieldAudio-visual technology
  • WIPO sectorElectrical engineering

Abstract

A copy guard processing detecting apparatus which can correctly judge whether or not a copy guard is applied to an input video signal and prevents copy guard processing from being applied to a video signal to which a copy guard is not applied. The copy guard processing detecting apparatus comprises a first circuit for receiving an input video signal which includes a plurality of false synchronizing signals for prevention of duplication inserted in a vertical blanking interval thereof and for counting the number of the false synchronizing signals, a second circuit for counting the number of synchronizing signals in an image interval of the input video signal except the vertical blanking interval, and a discriminator for discriminating whether or not copy guard processing is applied to the input video signal from the count values of the first and second circuits.

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