Water droplet suppression based on spatially distributed CMUT touch sensing of capacitive micromachined ultrasound transducer (CMUT) receivers

The invention relates to water droplet suppression for capacitive micromachined ultrasonic transducer (CMUT) touch sensing based on spatial distribution of capacitive micromachined ultrasonic transducer (CMUT) receivers. An ultrasonic touch sensor includes a touch structure configured to receive a touch; a transmitter arrangement configured to transmit one or more ultrasonic transmit waves to the touch structure; a receiver arrangement configured to receive an ultrasonic reflected wave resulting from reflection of the one or more ultrasonic transmitted waves and to generate a plurality of measurement signals representative of the ultrasonic reflected wave; and a measurement circuit configured to measure a degree of change of the plurality of measurement signals, compare the degree of change with a detection threshold, and determine whether a touch-free event has occurred at the touch structure based on whether the degree of change satisfies the detection threshold. 本公开涉及基于电容式微机械超声换能器(CMUT)接收器的空间分布的CMUT触摸感测的水滴