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Door sensor system

  • US 4,967,083 A
  • Filed: 04/14/1989
  • Issued: 10/30/1990
  • Est. Priority Date: 04/14/1989
  • Status: Expired due to Term
First Claim
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1. A sensor system for an automatic door system comprising:

  • a plurality of sensor units, each said sensor unit comprising;

    transmitter means for emitting infrared radiation so as to define a detection zone Zd;

    receiver means for receiving reflected radiation from zone Zd;

    presence zone means for defining a presence zone Zp in said zone Zd;

    motion zone means for defining a motion zone Zm in said zone Zd;

    detection logic means responsive to said receiver means for detecting the presence of a foreign object in zone Zp and the motion of a foreign object in zone Zm and generating a detection signal indicative thereof;

    hold open output means responsive to said detection output signal for generating a hold open output signal for a pre-established time interval;

    synchronization means for synchronizing the operation of said sensor units; and

    mounting means for mounting said sensor units so that at least a pair of said zones Zp intersect.

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