公开(公告)号：DE50106733D1

公开(公告)日：2005-08-18

申请号：DE50106733

申请日：2001-02-07

Applicant: INFINEON TECHNOLOGIES AG

Inventor： BASSE PAUL-WERNER ,  MARKSTEINER STEPHAN

IPC: G06T1/00 ,  A61B5/117 ,  G06K9/00 ,  G06K9/20

Abstract: A circuit and method are provided for ensuring that a fingerprint sensor is started automatically when a finger is rested thereon such that a sufficiently contrasting image can be produced. A difference between a maximum and a minimum value of the sensor signals is generated wherein, if the difference is sufficiently large, indicating a sufficient contrast of an image to be produced, a normal scanning operation of the fingerprint sensor is initiated, thus ensuring that the complete fingerprint image is produced, a normal scanning operation of the fingerprint sensor is initiated, thus ensuring that the complete fingerprint images produced are of satisfactory quality.