Patent ID: 8265307

Claim:
An acoustic transducer which radiates a sound wave into a medium, the acoustic transducer comprising: a shaft member which extends at a center portion of the acoustic transducer; first and second cylindrical acoustic radiation plates which have a cylindrical shape, a central axis of the first and second cylindrical acoustic radiation plates agreeing with a longitudinal axis of the shaft member, the first and second cylindrical acoustic radiation plates alternately arranged in a direction of the central axis; a plurality of connection members which have a ring shape, and connect adjacent first and second acoustic radiation plates to each other; a plurality of bending vibration plates each of which connects the shaft member and one of the connection members to each other; and a plurality of vibrators which are provided on the bending plates, the first acoustic radiation plate having a sectional shape which is curved outwardly in a radial direction thereof, the sectional shape of the first acoustic radiation plate being along a plane including the central axis, and the second acoustic radiation plate having a sectional shape which is curved inwardly in a radial direction thereof, the sectional shape of the second acoustic radiation plate being along a plane including the central axis.