FINGER/NON-FINGER DETERMINATION FOR ACOUSTIC BIOMETRIC SENSORS

摘要

A fingerprint sensing apparatus may include a fingerprint sensor system and a control system. The fingerprint sensor system may include an ultrasonic sensor array. The control system may be capable of receiving fingerprint sensor data from the fingerprint sensor system (601) and of determining whether an object is positioned proximate a portion of the fingerprint sensor system (603). The control system may be capable of determining an acoustic impedance of at least a portion of an object that is positioned proximate the fingerprint sensor system (605). The control system may be capable of determining whether the acoustic impedance is within an acoustic impedance range corresponding to that of skin (607) and of determining, based at least in part on the acoustic impedance, whether the object is a finger (609).