×

System for detecting ice or snow on surface which specularly reflects light

  • US 5,838,239 A
  • Filed: 09/10/1996
  • Issued: 11/17/1998
  • Est. Priority Date: 10/20/1992
  • Status: Expired due to Fees
First Claim
Patent Images

1. Apparatus for detecting, on a surface which specularly reflects light, the presence of a polarization altering substance on said surface comprising:

  • means for transmitting a pulse of light over a transmitting path to said surface;

    means for receiving transmitted light;

    a receiving path for said transmitted light from said surface and from said substance to said means for receiving;

    means for splitting said transmitted light into a non-isolated portion and an isolated portion;

    means for delaying one of said non-isolated portion and said isolated portion relative to another thereof to produce a first-to-arrive signal and a second-to-arrive signal;

    said first-to-arrive signal being completed at an output of said means for delaying before said second-to-arrive signal arrives at said output;

    means for measuring a first intensity of said first-to-arrive signal and outputting a first signal;

    means for measuring a second intensity of light of said second-to-arrive signal and outputting a second signal; and

    means for comparing said first and second intensities of light to reference data to detect the presence of said substance on said surface.

View all claims
  • 3 Assignments
Timeline View
Assignment View
    ×
    ×