Patent ID: 6085592
Filing Date: 2000-07-11
Classification: G01S,G10K,Y10S

Abstract:
An ultrasonic sensor comprising:a housing;a resonance circuit that is placed inside said housing and that includes a coil unit and an ultrasonic resonator, said ultrasonic resonator including a piezoelectric element, said ultrasonic resonator being for emitting a transmission ultrasonic wave signal towards the outside of said housing based on the piezoelectric effect of said piezoelectric element and for receiving a reception ultrasonic wave signal from the outside of said housing, said reception ultrasonic wave signal being a reflection of said transmission ultrasonic wave signal, wherein said coil unit includes a transformer and a conductive casing having an axially extended slit, said transformer being inserted into said conductive casing through said slit; anda conductive ring that is disposed around said casing to be coaxial with said coil unit and to shield said coil unit from an external electromagnetic induction field.