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Device for ultrasonic identification of fingerprints

  • US 5,563,345 A
  • Filed: 12/29/1994
  • Issued: 10/08/1996
  • Est. Priority Date: 04/30/1993
  • Status: Expired due to Fees
First Claim
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1. A device for identifying fingerprints by use of ultrasound comprising:

  • a hollow cylinder, said cylinder being closed at ends thereof by a cover and a base plate having a center and being filled by a fluid, said cover being provided centrally thereof with a supporting surface for a finger to be identified;

    an ultrasonic transmitter and an ultrasonic receiver being provided on the base plate;

    said ultrasonic receiver being arranged as an individual receiver in the center of said base plate;

    said ultrasonic transmitter being formed by at least one annular transmitter being arranged concentrically around said individual receiver;

    an ultrasonic lens being arranged in said cover below said supporting surface so that ultrasound emitted by said ultrasonic transmitter and reflected at said supporting surface is imaged by said ultrasonic lens upon the ultrasonic transmitter; and

    evaluating means responsive to a signal generated by said ultrasonic receiver based on sonic pressure of received ultrasound for evaluating the fingerprint of the finger to be identified.

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