Patent ID: 7583563

Claim:
An ultrasonic sensor comprising: an ultrasonic transducer including a metal-made housing that includes an inner space, a vibrating planar member that is formed in the housing, wherein an outward surface of the vibrating planar member constitutes an outward surface of the housing and an inward surface of the vibrating planar member faces the inner space; a driving element that is attached on an inward surface of the vibrating planar member for vibrating the vibrating planar member; a casing within which the ultrasonic transducer assembled, wherein at least the outward surface of the vibrating planar member is exposed from the casing; and a vibration isolating member that is located between the casing and the ultrasonic transducer for limiting transmission of vibration from the transducer to the casing, wherein the ultrasonic transducer is attached to a vehicle via the casing so that the outward surface of the vibrating planar member faces to the outside of the vehicle, wherein a resin film is attached using an adhesive member applied on a rear surface of the resin film to cover all the outward surface of the vibrating planar member, and wherein a size of the resin film is equal to or larger than a size of the outward surface of the vibrating planer member, and the resin film dies not contact the casing located outside of the ultrasonic transducer.