| 摘要 |
PURPOSE:To improve the performance and reliability of diaphragm part supporting structure as much as possible, by inserting conductive rubber between the top side of a holding ring and a case, and thus uniforming the adhesion between the case and holding ring securely through simple constitution. CONSTITUTION:Even if respective parts stacked in the case 11 have variance in size in the calking of the bottom part of the case 11, the conductive rubber 16 inserted between the case 11 and holding ring 15 eliminates the gap between the both substantially to uniform their adhesion and also absorb and relieve stress in calking, so variance of frequency characteristics and sensitivity is eliminated to obtain stability. Further, this contributes to the uniforming of the gap between a fixed electrode 13 and a diaphragm (movable electrode) 14, so the undesired attraction of the diaphragm 14 in operation is prevented. |
