DIAPHRAGM

摘要

PURPOSE:To prevent the change of an effective area with respect to the change of external environmental conditions by a method wherein the height of the mountain of a waveform at the inside of the average radius of the diaphragm is made lower than the height of the mountain at the outside of the average radius of the same. CONSTITUTION:A disk 9a is attached to the central flat part of the diaphragm 9 and the waveform is formed on the annular area between the disk and the peripheral rim 9b of the diaphragm 9. The height of the mountain of the wave at the inside of the average radius R1 of the diaphragm is made lower than the height of the mountain of the wave at the outside of the average radius R2 of the same while the mountains at the inside of the average radius are formed so as to become lower sequentially toward the center of the diaphragm.