| 摘要 |
PROBLEM TO BE SOLVED: To improve the transmission and reception sensitivities of an ultrasonic transducer by a lower voltage device. SOLUTION: The ultrasonic transducer (UT) 27 includes a soft relaxer-based first piezoelectric body (Ps) 35, a hard-based second piezoelectric body (Ph) 36, first and second electrodes 37, 38, and a third electrode 39 serving also as the upper surface electrode of Ps 35 and the lower surface electrode Ph 36. The first electrode 37 is connected with a pulsar 44 via a first switch (SWa) 41, the second electrode 38 with a reception amplifier 45 via a second switch (SWb) 42, and the third electrode 39 with a gland via a third switch (SWc) 43, respectively. When the ultrasonic waves are transmitted, the pulsar 44 applies an exciting pulse only to the Ps 35. When the ultrasonic waves are received, the Ps 35 and Ph 36 are connected together in series, and the total of their detection signals are input to the reception amplifier 45. COPYRIGHT: (C)2011,JPO&INPIT
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