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Video encryption system

  • US 4,598,318 A
  • Filed: 06/10/1983
  • Issued: 07/01/1986
  • Est. Priority Date: 06/10/1983
  • Status: Expired due to Term
First Claim
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1. In combination in a scrambled composite video signal distribution system;

  • signal originating encrypting means including selective inversion means for selectively inverting the video information content of video lines about an inversion reference level and for not inverting the video information content of other lines, signal distribution means for distributing the output signal produced by said selective inversion means, and means for distributing a measure of said inversion reference level with the composite video signal distributed by said signal distribution means; and

    signal recovering decrypting means for receiving said composite video signal from said signal distribution means, said decrypting means including inversion reference means for recovering the received inversion reference level, and means for selectively reinverting the video information content of inverted video lines about the recovered inversion reference of said inversion reference means.

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