| 摘要 |
PURPOSE:To minimize a change of a sensitivity frequency characteristic due to a change of the supporting pressure of the diaphragm by constituting, with a projection, a vibrator supporting part of the front air chamber plate and the rear air chamber plate which pressures and sandwiches the metallic plate forming the vibrator from upward and downward, forming the traiangular or semicircular cross section and sandwiching in the ring manner a peripheral part of the metallic plate at the peak of the projection. CONSTITUTION:A vibrator composed of a metallic plate and a piezoelectric element 1 is pressured and sandwiched by a vibrator supporting part 15 of a front air chamber plate 8 and a vibrator supporting part 4 of a rear air chamber plate 3. The vibrator supporting parts 14 and 15 are composed of projection, the cross sections become triangular and the construction is executed so as to sandwich the inside from the outer circumference end of the vibrator at the triangular peak. Consequently, the vibrator is not pressured and sandwiched with a plane ring and is pressured and sandwiched with a linear ring. |
