Method for modifying a copy protected video signal with a negative amplitude pulse

  • US 7,085,380 B2
  • Filed: 09/26/2001
  • Issued: 08/01/2006
  • Est. Priority Date: 05/17/1993
  • Status: Expired due to Fees
First Claim
Patent Images

1. A method of modifying a copy protected video signal, wherein the copy protected video signal includes selected copy protection signals which cause a reduced amplitude in a recording of the copy protected video signal, the method comprising the act of:

  • adding a pulse having a selected negative amplitude to a selected position in a back porch region following a horizontal sync pulse wherein the copy protection of the video signal is enhanced by the added negative pulse.

View all claims

    Thank you for your feedback