US Patent 9613246 Multiple scan element array ultrasonic biometric scanner

An ultrasonic biometric scanner includes an ultrasonic multiple scan element array with multiple scan elements. The array includes piezoelectric material such as lead zirconate titanate or polyvinylidene difluoride with a first electrode on a first surface and a second electrode on a second, opposite surface. At least one of the first electrode or the second electrode include multiple electrodes wherein the number of the multiple electrodes corresponds to a number of the multiple scan elements. A substrate is electrically coupled to the second electrode and/or the first electrode. A cover may be positioned over the first electrode. The cover has an acoustic impedance matching ultrasonic signals emitted by the piezoelectric material.