| 摘要 |
PURPOSE:To prevent the production of distortion in sound, so that large amplitude oscillation can be obtained at the center of a diaphragm, by incorporating a diaphragm bent symmetrical to the center and a diaphragm sticked with a piezoelectric element through center coupling. CONSTITUTION:A disc shape piezoelectric element 4 provided with holes at the center is bonded on a flat metallic plate 5. Edge and cone shape are formed to a thin film metallic plate 6 with contraction, and the center of the metallic plate 6 and that of the plate 5 are welded. The surrounding of this metallic plate 5 is clipped with an elastic member 7 and a support 10. A dust proof sheet 8 having a number of small holes and a cover 9 having sound hole are fixed to the support 10. By supporting the surrounding the metallic plate 6 as the diaphragm with an elastic member 7, oscillation with large amplitude is produced at the center without distortion, allowing to reduce sound distortion. |
