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Optical obstruction detector with light barriers having planes of light for controlling automatic doors

  • US 5,410,149 A
  • Filed: 07/14/1993
  • Issued: 04/25/1995
  • Est. Priority Date: 07/14/1993
  • Status: Expired due to Term
First Claim
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1. A method for detecting a presence of an obstruction, comprising:

  • (a) emitting a plane of light toward a floor such that a light pattern having a floorline created at an intersection of said plane of light and said floor is provided;

    (b) detecting said light pattern with a sensor;

    (c) providing a sensor output signal from said sensor in response to said light pattern; and

    (d) determining from said sensor output signal a presence of said obstruction within said plane of light, so that said obstruction in said plane of light causes a change in said light pattern thereby causing a change in said sensor output signal.

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