Abstract: An ultrasonic fingerprint sensor in a mobile device is operated to capture an initial snapshot of reflection from a finger's surface, of acoustic energy transmitted at a first frequency. Additionally, the ultrasonic fingerprint sensor is operated repeatedly to capture over time, a sequence of sets, each set including one or more additional snapshots of reflection from one or more depths within the finger, of acoustic energy transmitted at a second frequency significantly lower than the first frequency. Measurements in the additional snapshots are processed to determine whether any signal oscillating at a rate in a normal range for heart rate or respiration rate is present. When a signal is found, its rate may be used in several ways, e.g. to enable functionality when a fingerprint in the initial snapshot matches a reference fingerprint, or to identify and track a heart rate (or a respiration rate) based on the signal's rate.

Abstract: An apparatus may include an ultrasonic fingerprint sensor system and a control system. The control system may be configured for obtaining, via a scan of the fingerprint sensor system, current fingerprint image data from a surface of a target object, for extracting current fingerprint features from the current fingerprint image data and for determining whether the current fingerprint features match features of a previously-acquired fingerprint enrollment template. If there is a match, the control system may be configured for obtaining, via one or more additional scans of the fingerprint sensor system, current subsurface image data from a subsurface of the target object, for calculating an estimated biometric age of the target object, based at least in part on the current subsurface image data and for determining whether the estimated biometric age of the target object matches a previously-estimated biometric age.

Abstract: An apparatus may include an ultrasonic fingerprint sensor system and a control system. The control system may be configured for obtaining, via a scan of the fingerprint sensor system, current fingerprint image data from a surface of a target object, for extracting current fingerprint features from the current fingerprint image data and for determining whether the current fingerprint features match features of a previously-acquired fingerprint enrollment template. If there is a match, the control system may be configured for obtaining, via one or more additional scans of the fingerprint sensor system, current subsurface image data from a subsurface of the target object, for calculating an estimated biometric age of the target object, based at least in part on the current subsurface image data and for determining whether the estimated biometric age of the target object matches a previously-estimated biometric age.

Abstract: An ultrasonic fingerprint sensor in a mobile device is operated to capture an initial snapshot of reflection from a finger's surface, of acoustic energy transmitted at a first frequency. Additionally, the ultrasonic fingerprint sensor is operated repeatedly to capture over time, a sequence of sets, each set including one or more additional snapshots of reflection from one or more depths within the finger, of acoustic energy transmitted at a second frequency significantly lower than the first frequency. Measurements in the additional snapshots are processed to determine whether any signal oscillating at a rate in a normal range for heart rate or respiration rate is present. When a signal is found, its rate may be used in several ways, e.g. to enable functionality when a fingerprint in the initial snapshot matches a reference fingerprint, or to identify and track a heart rate (or a respiration rate) based on the signal's rate.

Abstract: Embodiments of apparatuses and methods for detecting a spoof finger are disclosed. In one embodiment, an ultrasonic fingerprint sensor comprises an ultrasonic transmitter configured to transmit an ultrasonic wave to a finger, an ultrasonic sensor array configured to receive a reflected ultrasonic wave from the finger, and a controller configured to determine a reflected acoustic energy of the finger based on a difference between average amplitudes of the reflected ultrasonic wave from ridges and valleys of the finger; and determine whether the finger is a spoof based at least in part on the reflected acoustic energy of the finger.

Abstract: Embodiments of apparatuses and methods for detecting a spoof finger are disclosed. In one embodiment, an ultrasonic fingerprint sensor comprises an ultrasonic transmitter configured to transmit an ultrasonic wave to a finger, an ultrasonic sensor array configured to receive a reflected ultrasonic wave from the finger, and a controller configured to determine a reflected acoustic energy of the finger based on a difference between average amplitudes of the reflected ultrasonic wave from ridges and valleys of the finger; and determine whether the finger is a spoof based at least in part on the reflected acoustic energy of the finger.

Abstract: A method for audio sample rate conversion may include receiving an audio signal at a first rate, the audio signal having a fundamental frequency, determining absolute derivatives of the audio signal at the first rate, and generating a weighted sum of the absolute derivatives to arrive at a combined absolute derivative. The combined absolute derivative may be analyzed to locate a local minimum of the combined absolute derivative, a location in the audio signal may be selected based on the local minimum of the combined absolute derivative and at least one audio sample in the audio signal may be altered at the selected location to develop an audio signal at a second rate.

Abstract: A linear array of sensors includes at least two omni-directional sensors and at least one directional sensor, with the axis of sensitivity of the directional sensor arranged, e.g., perpendicular to the linear axis of the linear array. The omni-directional sensors and directional sensor receive a signal and in response produce output signals. The direction of arrival of the received signal is estimated with a 360° range using the output signals of the omni-directional sensors and directional sensor. For example, two symmetric solutions for the direction of arrival of the received signal may be determined using the output signals of the omni-directional sensors, and the output signal from the directional sensor is used to determine the correct solution.

Abstract: A method for audio sample rate conversion may include receiving an audio signal at a first rate, the audio signal having a fundamental frequency, determining absolute derivatives of the audio signal at the first rate, and generating a weighted sum of the absolute derivatives to arrive at a combined absolute derivative. The combined absolute derivative may be analyzed to locate a local minimum of the combined absolute derivative, a location in the audio signal may be selected based on the local minimum of the combined absolute derivative and at least one audio sample in the audio signal may be altered at the selected location to develop an audio signal at a second rate.