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Fingerprint identification system using a pliable optical prism

  • US 4,120,585 A
  • Filed: 11/19/1976
  • Issued: 10/17/1978
  • Est. Priority Date: 11/19/1976
  • Status: Expired due to Term
First Claim
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1. A fingerprint based identification terminal including:

  • sensor means;

    optically clear, pliable, resilient prism means;

    light source means for shining onto one internal surface of said prism means and being internally reflected onto said sensor means in accordance with the topographic configuration of any member contacting the external surface corresponding to said one internal surface and any resulting deformation of said one internal surface;

    whereby when a finger contacts a planar surface of said prism means corresponding to said one internal surface, said planar surface and thereby said internal surface will deform to partially mirror the ridge-valley configuration of the contacting finger to give a greater area of contact resulting in a high contrast image being reflected onto said sensor means due to absorption of light at said one internal surface where said planar surface is contacted by the finger.

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