Abstract: Methods, systems and storage media are described, each of which may be used to generate an image of an object using ultrasonic plane waves. For example, the generated image may be of a target object positioned on a platen surface. The image may be derived from corrected output signals obtained from a plurality of selected sensor pixels. The corrected output signals may adjust for diffraction of reflected ultrasonic plane waves from a target object positioned on the platen surface. The target object may be a finger or a tip of a stylus.

Abstract: An apparatus may include an ultrasonic sensor array and a control system. The control system may be configured to acquire first image data generated by the ultrasonic sensor array corresponding to at least one first reflected ultrasonic wave received by at least a portion of the ultrasonic sensor array from a target object during a first acquisition time window. The control system may be configured to acquire second image data generated by the ultrasonic sensor array corresponding to at least one second reflected ultrasonic wave received by at least a portion of the ultrasonic sensor array from the target object during a second acquisition time window that is longer than the first acquisition time window. The control system may further be configured to initiate an authentication process based on the first image data and the second image data.

Abstract: Systems and methods for multi-spectral ultrasonic imaging are disclosed. In one embodiment, a finger is scanned at a plurality of ultrasonic scan frequencies. Each scan frequency provides an image information set describing a plurality of pixels of the finger including a signal-strength indicating an amount of energy reflected from a surface of a platen on which a finger is provided. For each of the pixels, the pixel output value corresponding to each of the scan frequencies is combined to produce a combined pixel out put value for each pixel. Systems and methods for improving the data capture of multi-spectral ultrasonic imaging are also disclosed.

Abstract: Embodiments of an ultrasonic button and methods for using the ultrasonic button are disclosed. In one embodiment, an ultrasonic button may include an ultrasonic transmitter configured to transmit an ultrasonic wave, a piezoelectric receiver layer configured to receive a reflected wave of the ultrasonic wave, a platen layer configured to protect the ultrasonic transmitter and the piezoelectric receiver layer, a first matching layer configured to match an acoustic impedance of the platen layer with an acoustic impedance of ridges of a finger, and an ultrasonic sensor array configured to detect the finger using the reflected wave.