US Patent 9984271 Ultrasonic fingerprint sensor in display bezel

An electronic device that includes an enclosure having an external surface and a first array of ultrasonic transducers arranged along a first direction and a second array of ultrasonic transducers arranged along a second direction. The first array of ultrasonic transducers may be configured to produce a surface wave along the external surface. A set of scattered waves may be created by the touch on the external surface. The second array of ultrasonic transducers may be configured to receive a portion of the set of scattered waves and produce an output. The device may also include a processing unit that is configured to identify the touch using the output. The processing unit may be further configured to create a reconstruction of at least a portion of a fingerprint associated with the touch on the cover, and to identify the fingerprint using the reconstruction.