| 摘要 |
A condenser microphone is provided to reduce production cost and to decrease the total thickness of the condenser microphone, by simplifying the assembly process. According to a condenser microphone using capacitance variation of a parallel plate condenser, a vessel type metal case(110) is punctured with a sonic wave inflow hole(112) in the center and fixes internal components. A diaphragm(120) comprises a metal deposition film(125) vibrating according to the sonic wave as being stacked in the metal case and a diaphragm plate fixing the frame of the metal deposition film. A metallic connection ring(140) forms a bottom plane in parallel with the diaphragm, and has an electret film(125) accumulated with semi-permanent charges on the bottom plane. An insulation spacer(130) is inserted between the diaphragm and the connection ring, and maintains a constant gap between the diaphragm and the connection ring. A printed circuit board(150) is electrically connected to the metal case and the connection ring as being located on the uppermost top in the metal case, and comprises a field effect transistor for amplifying and converting potential variation according to the variation of capacitance between the electret film attached to the connection ring and the diaphragm due to the vibration of the diaphragm into an electrical signal. |
