Patent ID: 11972628
Assignee: FINGERPRINT CARDS ANACATUM IP AB
Field: Computer technology (Electrical engineering)
Classification: CPC G | IPC G

Claim 0:
1. A method for acquiring background data in an ultrasonic biometric imaging device, the method comprising:
detecting a finger in proximity of a touch surface of the imaging device;
determining a target area based on the detected finger;
before the finger makes contact with the touch surface, by a plurality of ultrasonic transducers arranged at a periphery of the touch surface, emitting an ultrasonic signal towards the target area;
by the ultrasonic transducers, receiving reflected ultrasonic echo signals defined by received radio frequency data (RF-data);
determining background RF-data based on the received reflected ultrasonic echo signals; and
detecting a finger in proximity of a touch surfaces of the imaging device is performed using a capacitive touch sensing element.