Ultrasonic transducer, ultrasonic transducer array, and ultrasonic device
An ultrasonic transducer is configured to transmit or receive ultrasonic waves. The ultrasonic transducer includes a vibrating member and a piezoelectric member coupled to the vibrating member. The piezoelectric member includes a first piezoelectric part configured and arranged to be deformed by applied voltage to vibrate the vibrating member or configured and arranged to be deformed by vibration of the vibrating member to produce a potential difference, and a second piezoelectric part configured and arranged to be deformed by applied voltage to statically deflect the vibrating member.
1. An ultrasonic transducer configured to transmit or receive ultrasonic waves, the ultrasonic transducer comprising:
a vibrating member; and
a piezoelectric member coupled to the vibrating member, the piezoelectric member including
a first piezoelectric part configured and arranged to be deformed by applied voltage to vibrate the vibrating member or configured and arranged to be deformed by vibration of the vibrating member to produce a potential difference, and
a second piezoelectric part configured and arranged to be deformed by applied voltage to statically deflect the vibrating member.
2. The ultrasonic transducer according to claim 1 , wherein
the first piezoelectric part and the second piezoelectric part are integrally formed with each other, the first piezoelectric part being connected to a first electrode and the second piezoelectric part being connected to a second electrode with the first electrode and the second electrode being separated from each other.
3. The ultrasonic transducer according to claim 1 , further comprising
a base having an opening,
the vibrating member covering the opening of the base, and
the first and second piezoelectric parts being disposed on one side of the vibrating member opposite from the base, the first and second piezoelectric parts being disposed in an oscillation region that overlaps the opening of the base when viewed in a direction perpendicular to a main surface of the vibrating member.
4. The ultrasonic transducer according to claim 3 , wherein
the first piezoelectric part is disposed in a center portion of the oscillation region, and the second piezoelectric part is disposed on the periphery of the first piezoelectric part.
5. The ultrasonic transducer according to claim 3 , wherein
the second piezoelectric part is disposed adjacent to a boundary of the oscillation region.
6. The ultrasonic transducer according to claim 1 , wherein
the second piezoelectric part includes a plurality of piezoelectric components.
7. An ultrasonic transducer array including a plurality of the ultrasonic transducers according to claim 1 .
8. An ultrasonic device comprising:
the ultrasonic transducer according to claim 1 ; and
a control unit configured to control input signals input to the ultrasonic transducer and to process output signals output from the ultrasonic transducer.
9. The ultrasonic device according to claim 8 , wherein
the control unit has a first control part configured to control the voltage applied to the first piezoelectric part and to process the potential difference produced by the first piezoelectric part, and a second control part configured to control the voltage applied to the second piezoelectric part.
10. The ultrasonic device according to claim 9 , wherein
the first control part and the second control part are configured to be controlled independently from each other.