| 摘要 |
<P>PROBLEM TO BE SOLVED: To reduce the number of lines in an ultrasonic transducer. Ž<P>SOLUTION: The ultrasonic transducer 1 is composed of an inorganic transmission piezoelectric layer T and an organic receiving piezoelectric layer R layered on each other. In the ultrasonic transducer 1, an intermediate electrode P between the two layers is an individual electrode, and individual signal electrodes Q for respective piezoelectric elements A are formed in the receiving piezoelectric layer R, and a common GND electrode S is formed in the transmission piezoelectric layer T. The ultrasonic transducer 1 has photosensitive layers OP1 and OP2, whose state can be shifted to a conductive state or to a shielded state in response to the light irradiation, formed on side faces of the two piezoelectric layers T and R, and also has light sources L1 and L2. A control circuit 2 makes the light sources L1 and L2 perform conflicting motions in response to the transmission/receiving. Accordingly, if the light source L1 is lighted and the light source L2 is extinguished as indicated in Fig.(a), the transmission motion using the transmission piezoelectric layer T is possible. If the light source L2 is lighted and the light source L1 is extinguished as indicated in Fig.(b), the receiving motion using the receiving piezoelectric layer R is possible. In this way, a signal line can be shared for transmission/receiving. Ž<P>COPYRIGHT: (C)2010,JPO&INPIT Ž
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