| 摘要 |
An ultrasonic device including a piezoelectric vibrator for converting an electric signal. The piezoelectric vibrator consists of a pillar-like piezoelectric ceramic and a pair of electrodes, A and B, positioned thereon on both end surfaces, ZA and ZB respectively, perpendicular to the polarization axis of the piezoelectric ceramic. The electrode A consists of at least two parts, namely electrodes A1 and A2, such that the electrodes A1 and A2 are not connected to each other. The electrode B consists of at least two parts, namely electrodes B1 and B2, such that the electrodes B1 and B2 are not connected to each other. If the ultrasonic signal converter is connected to a circuit X through the electrodes A1 and A2 and a circuit Y through the electrodes B1 and B2, then when a high-frequency electric signal S1 with a voltage V1 is applied from the circuit X to the piezoelectric ceramic, the piezoelectric vibrator can be vibrated effectively at a frequency, almost the same as the resonance frequency of the piezoelectric ceramic. This vibration of the piezoelectric vibrator is converted to an electric signal S2 with a voltage V2 having almost the same frequency as the resonance frequency of the piezoelectric ceramic. The electric signal S2 is then delivered toward the circuit Y. Thus, the ultrasonic signal converter makes it possible to convert an electric signal and an acoustic vibration to each other with a large efficiency.
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