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

Claim 0:
1. A touch sensor, comprising:
a housing having an ultrasound chamber;
a touch structure coupled to the housing and arranged over the ultrasound chamber, wherein the touch structure comprises a touch interface;
a signal generator configured to generate an excitation signal for producing an ultrasonic transmit wave;
a transmitter arranged within the ultrasound chamber, wherein the transmitter is configured to receive the excitation signal and transmit the ultrasonic transmit wave towards the touch structure based on the excitation signal;
a receiver arranged within the ultrasound chamber, wherein the receiver is configured to receive an ultrasonic reflected wave produced by a reflection of the ultrasonic transmit wave at the touch structure,
wherein the transmitter and the receiver are coupled by a capacitive path,
wherein the 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 receiver is configured to generate a measurement signal representative of the capacitive cross-talk; and

a measurement circuit coupled to the receiver and configured to perform a comparison of the measurement signal with a threshold and determine whether a no-touch event or a touch event has occurred at the touch interface based on whether the measurement signal satisfies the threshold.