Patent · US Expired

Video signal copy guard apparatus and method

US6222978A · kind A · utility

13Cited by
3References
8Claims
0Family size

Assignee

Inventor

Key dates

Filing dateMay 12, 1997
Grant dateApr 24, 2001
Priority date
Expiry dateMay 12, 2017

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH04N2005/91371
  • WIPO fieldAudio-visual technology
  • WIPO sectorElectrical engineering

Abstract

A video signal copy guard system in which a special color burst signal (or "copy prohibition signal") is inserted into the video signal to be copy protected so that the protected signal includes both a special color burst signal and a normal color burst signal. The special color burst signal is placed adjacent to the normal color burst signal, and its phase, frequency, and/or amplitude is varied with respect to the normal color burst signal. The special color burst signal interferes with the normal color burst signal when an analog VCR attempts to process the protected signal. Thereby, preventing unauthorized dubbing of the protected signal.

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