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Electronic article surveillance transmitter control using target range

  • US 6,307,473 B1
  • Filed: 08/24/1999
  • Issued: 10/23/2001
  • Est. Priority Date: 08/24/1999
  • Status: Expired due to Term
First Claim
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1. An electronic article surveillance system responsive to the distance to a target within an interrogation zone, comprising:

  • means for defining an interrogation zone, said means including an antenna;

    means, connected to said antenna, for generating an electromagnetic field at a level;

    a marker securable to an article for passage through said interrogation zone, said marker being adapted to be detectable when in said electromagnetic field;

    detection means for detecting said marker;

    means for measuring a distance from said antenna to a target within said interrogation zone; and

    , means for controlling the level of said electromagnetic field, wherein the level is selected according to the distance to said target.

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