ULTRASONIC SENSOR

摘要

A piezoelectric element of an ultrasonic sensor comprises: a piezoelectric layer (40) including a transmission region (40N) and a reception region (40M); a common electrode (30); a transmission electrode (20); and a reception electrode (10). The transmission region and the reception region are adjacent to one another with the interposition of an isolation region (40V). The transmission region includes one or a plurality of first unit piezoelectric layers, and the reception region includes one or a plurality of second unit piezoelectric layers. The number of first unit piezoelectric layers included in the transmission region is different from the number of second unit piezoelectric layers included in the reception region, and a floating electrode (70) is provided in the region having the smaller number of layers, from among the transmission region and the reception region. This piezoelectric element makes it possible to suppress the occurrence of corrugations.