×

Fingerprint sensor

  • US 4,394,773 A
  • Filed: 07/21/1980
  • Issued: 07/19/1983
  • Est. Priority Date: 07/21/1980
  • Status: Expired due to Term
First Claim
Patent Images

1. A fingerprint sensor for transforming the fingerprint information of a finger under investigation into an electric output signal, comprising in combination:

  • (a) a contact device containing a piezoelectric material, said contact device having surfaces including a contact surface for exercising a contact pressure thereon by means of said finger, thereby changing the density of electric charges on said surfaces according to the fingerprint pattern of said finger; and

    (b) electrical means for providing the electric output signal in accordance with the distribution of said charges on at least one of said surfaces.

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