| 摘要 |
PURPOSE:To provide an ultrasonic transducer which can select the direction or incidence angle of reception/transmission of ultrasonic wave. CONSTITUTION:A plurality of rod-shaped electrodes 7 are buried along a concentric circle of a spherical recessed surface 3 of the lower edge of an insulation body 5 of a transducer 1. A polyvinylidene fluoride trifluoroethylene layer (P layer) 11 and an aluminum film 13 are formed on the spherical recessed surface 3 in sequence. When a high voltage is applied between a rod-shaped electrode 7 and the aluminum film 13, the P layer 11 in the region between them is polarized and has a piezoelectric effect, thus forming a plurality of piezoelectric elements which are distributed along the concentric circle of the spherical recessed surface 3. These plurality of piezoelectric elements can be activated independently of one another since the electrode 7 is independent. |
