公开(公告)号：AU4132697A

公开(公告)日：1998-03-06

申请号：AU4132697

申请日：1997-08-12

Applicant: FINGERMATRIX INC

Inventor： MARCUS DANIEL H ,  PEKCAN HAKAN I ,  CHILCOTT WILLIAM ,  SCHLANG ARTHUR

IPC: G06K9/00 ,  G07C9/00 ,  G02F1/01 ,  G06K9/74 ,  B42D15/00

Abstract: A fingerprint enhancement system has a platen with a liquid contacting and finger-touching surface. Two collimated interrogating light beams lie below and are opposite sides of the finger-touching surface. The horizontal extensions of the light beams assume an angle of approximately forty-five degrees with the finger longitudinal axis. Side surfaces of the platen are oriented normal to the incident colliminated light beams prior to interrogation. The light beam modulated by the fingerprint passes to a reflecting mirror, imaging means and a scanner below the platen. A polarizing filter lies between the platen and reflecting mirror. A second polarizing filter lies above the platen. A contrast enhancement circuit increases the modulation of the scanned fingerprint signal and automatically adjusts the level of the modulated signal without saturation. Circuit filtering eliminates spurious input signals. Finger position sensing by a light emitting diode and photo transistor is also provided.