| 摘要 |
PROBLEM TO BE SOLVED: To obtain an ultrasonic sensor having its responsiveness and reverberation improved. SOLUTION: The ultrasonic sensor is provided with: an approximately cylindrical acoustic matching material 11 having a ceiling surface part 11a on one side and having an aperture part 11b on the other; and a piezoelectric element 12 of an expanding oscillation mode provided on the inside of the ceiling surface part 11a of the acoustic matching material 11. The ultrasonic sensor uses the thickness oscillation mode of the ceiling surface part 11a and a bending oscillation mode of the entire acoustic matching material 11. A damping material 15 having an acoustic impedance higher than that of the acoustic matching material 11 is provided in the aperture part 11b of the acoustic matching material 11 so as not to come into contact with the piezoelectric element 12. COPYRIGHT: (C)2005,JPO&NCIPI
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