QUALCOMM Incorporated
Ultrasonic fingerprint scanning by means of photoacoustic excitation

Abstract:

The described techniques support a sensing scheme for electromagnetic excitation in ultrasonic imaging sensors. A biological tissue may be sensed and imaged using an electromagnetic excitation process to generate ultrasonic waves, such as, within the tissue. A component of a device may generate one or more pulses of electromagnetic waves, which may encounter and enter the biological tissue. In some examples, the component may be a display interface or may be different from a display interface of the device. The electromagnetic waves may excite the biological tissue and generate ultrasonic waves via expansion and contraction of the tissue upon heating. The ultrasonic waves may propagate within the biological tissue and may be sensed by an ultrasonic receiver array. The sensed ultrasonic waves may be converted to pixel image data of a biometric image and may be used for biometric authentication.