US Patent 7804742 Ultrasonic transducer for a proximity sensor

An ultrasonic transducer assembly for use in sensing the location of objects in proximity to the transducer. The ultrasonic transducer assembly includes a substrate member, a piezoceramic resonator plate supported on a planar surface of the substrate member adjacent to a peripheral edge of the substrate member, and a coupler connected to a surface of the resonator plate for acoustically coupling the resonator plate to a medium in contact with the coupler.