| 摘要 |
PURPOSE:To decrease the sound distribution and to make the frequency characteristics flat even at high frequencies, by supporting a piezoelectric sound body oscillated with a bending oscillation mode at the circumference and adding a mass body at the center. CONSTITUTION:A piezoelectric sound body 1 is cylindrical the same as a cylindrical metallic diaphragm 2, and a piezoelectric porcelain plate 3 with smaller outer diameter than that of the diaphragm plate 2 is concentrically sticked. The body 1 is fixed to a circular ring frame 4 made of resin at the outer circumference of the diaphragm plate 2. A mass body 5 such as solder is semi-spherically provided at the center with large oscillation amplitude of the body 1 supported at the outer circumference. |
