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Apparatus and method for preventing unauthorized copying of video signals

  • US 5,418,853 A
  • Filed: 07/21/1993
  • Issued: 05/23/1995
  • Est. Priority Date: 07/24/1992
  • Status: Expired
First Claim
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1. A method of transmitting a video signal comprising the steps of:

  • forming a digital code that includes at least a copy protection bit and category information which identifies a type of device from which the video signal is transmitted;

    combining said digital code with a video signal having a vertical blanking interval to form a multiplexed video signal having said digital code in said vertical blanking interval; and

    transmitting said multiplexed video signal.

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