Abstract: An ultrasonic biometric imaging device comprising: a cover structure having an exposed outer surface, wherein at least a portion of the exposed outer surface forms a sensing surface of the ultrasonic biometric imaging device; and a plurality of ultrasonic transducers attached to an edge portion of the cover structure and configured to emit an ultrasound wave into the cover structure; the cover structure further comprising a reflection reducing layer arranged at a bottom surface of the cover structure, wherein the reflection reducing layer is configured to reduce an amplitude of ultrasonic wave reflections at the bottom surface of the cover structure.

Abstract: A method for controlling a plurality of ultrasonic transducers in a fingerprint sensing system that comprises a cover plate having a sensing surface configured to be touched by a finger, and a plurality of ultrasonic transducers located at the periphery of the cover plate and configured to transmit an acoustic signal propagating in the cover plate, receive an ultrasonic signal having interacted with an object in contact with the sensing surface, and to determine properties of the object based on the received ultrasonic signal. The method comprises: in response to a first input, controlling the plurality of transducers such that at least a portion of the sensing surface has a first feature detection resolution; and in response to a second input, controlling the plurality of transducers such that at least a portion of the sensing surface has a second feature detection resolution, different from the first feature detection resolution.

Abstract: A method for controlling a plurality of ultrasonic transducers in a fingerprint sensing system that comprises a cover plate having a sensing surface configured to be touched by a finger, and a plurality of ultrasonic transducers located at the periphery of the cover plate and configured to transmit an acoustic signal propagating in the cover plate, receive an ultrasonic signal having interacted with an object in contact with the sensing surface, and to determine properties of the object based on the received ultrasonic signal. The method comprises: in response to a first input, controlling the plurality of transducers such that at least a portion of the sensing surface has a first feature detection resolution; and in response to a second input, controlling the plurality of transducers such that at least a portion of the sensing surface has a second feature detection resolution, different from the first feature detection resolution.