| 摘要 |
PROBLEM TO BE SOLVED: To control a first resonance frequency in a reducing direction by forming a piezoelectric sound generator to be rectangle so as to reduce a dead space in the case of mounting and so as to secure sound pressure property. SOLUTION: In the piezoelectric sound generator 10, a piezoelectric diaphragm 12 obtained by adhering a nearly rectangular piezoelectric element 18 to one main surface of a nearly rectangular diaphragm 14 is supported by a supporter 26. In the diaphragm 14, a pair of short edges 14A are firmly fixed so as to overlap with the short edges 26A of the frame-like edge of the nearly rectangular supporter 26 across the whole width. On the other hand, in the edges 14B on the long edge side of the diaphragm 14, a nearly center is curved inward like a hand-drum so as to make gaps 28 between themselves and the long edge 26B of the supporter 26. The gaps 28 are covered with a flexible and elastic sheet 30 having Young's modulus different from the diaphragm 14, so that the diaphragm 14 moves flexibly and high sound pressure is secured to make it possible to control the first resonance frequency. COPYRIGHT: (C)2006,JPO&NCIPI
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