Patent ID: 7392705

Claim:
An ultrasonic sensor comprising: an ultrasonic transducer having: a housing in a cylindrical shape with a bottom attached thereto; a piezoelectric device disposed in the housing; a connection pin electrically coupled with the piezoelectric device; and a base made of an insulation material for supporting the connection pin extendingly piercing therethrough, wherein the piezoelectric device is disposed on an inside surface of the bottom of the housing; and a case having an opening for assembly operation of the ultrasonic transducer disposed therein, wherein the piezoelectric device is electrically coupled with a circuit board in the case by using the connection pin when the ultrasonic transducer is assembled in the case, the connection pin is partially protected by a protector portion of the ultrasonic transducer, the protector portion made of an insulation material having waterproofing property, and the case has a guide portion between the ultrasonic transducer and the circuit board for positioning the protector portion in the case.