Ultrasonic sensor for use in obstacle detection device e.g. vehicle, has waveguides guiding ultrasonic wave between outer side and outer layers, where opening edges of openings of waveguides are smaller than surface of layers

摘要

The sensor (100) has a piezoelectric vibration element (110) contacting an inner surface of a base of a housing (120). Multiple waveguides (130) conduct and guide an ultrasonic wave between an outer side of a movable object and outer layers (123) of the housing. Opening edges (133) of openings of the waveguides are smaller than a surface of the layers, and distance between two adjacent openings is smaller than distance between two adjacent layers. Ends of the waveguides provide a sending and receiving surfaces for the ultrasonic wave, where length of the tubes is adjusted.