Patent ID: 11886668
Assignee: INFINEON TECHNOLOGIES AG
Field: Computer technology (Electrical engineering)
Classification: CPC G | IPC G

Claim 19:
20. A method, comprising:
transmitting an ultrasonic transmit wave towards an inner interface of a touch structure, wherein the inner interface is arranged opposite to a touch interface of the touch structure;
receiving an ultrasonic reflected wave produced from the ultrasonic transmit wave being at least partially reflected by the touch structure;
converting the ultrasonic reflected wave into a measurement signal;
generating an error value representative of a difference between a measured value of the measurement signal and a reference value;
providing a bias voltage to a transmitter or to a receiver;
adjusting the bias voltage to a voltage level that reduces the error value;
measuring the adjusted bias voltage; and
determining whether a no-touch event or a touch event has occurred at the touch interface based on a comparison of the measured adjusted bias voltage and a bias voltage threshold.