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Digital compact disc player security system reproducing method and apparatus

  • US 6,304,971 B1
  • Filed: 08/16/1999
  • Issued: 10/16/2001
  • Est. Priority Date: 11/18/1994
  • Status: Expired due to Term
First Claim
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1. A device for reading digitally encoded data comprising:

  • first and second optical receivers positioned above a nominal track position on a recording medium and receiving optical reflections from the recording medium to produce corresponding signals, respectively; and

    a device for comparing the signals received from the first and second optical receivers for identifying a physical offset modulation of a plurality of data bits from the nominal track position.

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  • 4 Assignments
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