| 摘要 |
A condenser microphone including an internal air ventilation system is provided to achieve formatting of sensitivity characteristics of the condenser microphone, by preventing sensitivity error due to the closing of an air ventilation path fundamentally. In a condenser microphone including an internal air ventilation system, a metal case has a first through-hole on a bottom part. A diaphragm(20) is formed on the bottom of the metal case, and includes a diaphragm film and a polar ring providing electrical connection between the metal case and the diaphragm film. A spacer ring(30) insulates an upper part of the diaphragm electrically. An insulation base ring insulates the inner surface of the metal case. A back plate(50) has a second through-hole. A metal base ring(60) provides electrical connection to the back plate. A PCB includes an FFT converting an acoustic pressure into an electrical output and a terminal part providing the electrical output to an external circuit. The PCB further includes a first air ventilation pattern. An outer diameter of the metal base ring is smaller than an inner diameter of the insulation base ring. An outer diameter of the back plate is smaller than the inner diameter of the insulation base ring. The insulation base ring is not adhered to the spacer ring tightly. An outer diameter of the diaphragm is smaller than an inner diameter of the metal case. The metal case further includes a second air ventilation pattern. |
