Patent ID: 11934617
Assignee: INFINEON TECHNOLOGIES AG
Field: Computer technology (Electrical engineering)
Classification: CPC G | IPC G

Claim 19:
20. A touch sensor, comprising:
a housing comprising a frame and a touch structure coupled to the frame to define an ultrasound chamber;
a signal generator configured to generate an excitation signal for producing an ultrasonic transmit wave;
a capacitive ultrasonic transmitter arranged inside the ultrasound chamber, wherein the capacitive ultrasonic transmitter is configured to receive the excitation signal and transmit the ultrasonic transmit wave towards the touch structure based on the excitation signal;
a capacitive ultrasonic receiver arranged inside the ultrasound chamber,
wherein the capacitive ultrasonic transmitter and the capacitive ultrasonic receiver are coupled by a capacitive path,
wherein the capacitive ultrasonic receiver is configured to be influenced by the excitation signal whereby the excitation signal induces a capacitive cross-talk on the capacitive path, and
wherein the capacitive ultrasonic receiver is configured to generate a measurement signal representative of the capacitive cross-talk; and

a measurement circuit coupled to the capacitive ultrasonic receiver to receive the measurement signal, wherein the measurement circuit is configured to determine whether a no-touch event or a touch event has occurred at the touch structure based on whether the measurement signal satisfies a threshold.