Patent ID: 8907544

Claim:
An ultrasonic transducer, comprising: an ultrasonic transmitting and receiving portion; a housing that houses the ultrasonic transmitting and receiving portion inside of the housing, the housing sealing an ultrasonic propagation liquid inside of the housing; a driving device configured to drive the ultrasonic transmitting and receiving portion; a casing that houses the driving device inside of the casing; a first volume compensation mechanism configured to absorb a volume change of the ultrasonic propagation liquid; a diaphragm that divides an internal space of the casing into at least a first internal space and a second internal space and prevents movement of a gas between the first internal space and another space in the internal space of the casing; a ventilating portion configured to ventilate the first internal space to outside of the casing; and a component disposed in a space other than the first internal space in the internal space of the casing, the component including a frame ground that electrically connects to an electrical circuit.