| 摘要 |
PROBLEM TO BE SOLVED: To provide an acoustic vibration generating piezoelectric bimorph element in which frequency characteristic control of vibration generating force is enabled without an increase in a cubic volume in constituents of the piezoelectric bimorph element, and there is provided a useful means for improving performance of an acoustic system that employs the piezoelectric bimorph element as a vibration driving source. SOLUTION: A plurality of proper-size holes 2 are periodically formed in a shim plate 1 located at the center of the piezoelectric bimorph element in a longitudinal direction of a main surface and in a direction perpendicular to the foregoing direction. As a result, weightρS per axial length of the piezoelectric bimorph element and an elastic coefficient K of flexural rigidity thereof are allowed to have distribution to thereby enable the frequency characteristic control of the vibration generating force without the increase in the cubic volume and performance deterioration in vibration generating force. COPYRIGHT: (C)2006,JPO&NCIPI
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