| 摘要 |
PURPOSE:To eliminate wind noise and pop noise by installing a unidirectional microphone unit and a bidirectional microphone unit on a same axis and extracting a difference between the unit outputs as an output voltage. CONSTITUTION:The ends of the voice coils 6, 7 of the unidirectional microphone unit 1 and the bidirectional microphone unit 2 are connected together and the beginning terminals are connected to the primary winding of a transformer 3, and the difference of outputs voltage of the microphone units 1, 2 is extracted at the transformer 3. Each microphone unit is provided with a top plate 12 at one magnetic pole of a permanent magnet 11 and a yoke 13 is provided to the other magnetic pole, and a magnetic field forming a magnetic gap 14 between the counter parts of the outer circumference of the top plate 12 and the inner circumference of the yoke 13, and a bobbin 16 having a voice coil 15 are supported, and a diaphragm section where the other end of the bobbin 16 is coupled to the center of a diaphragm 18 supporting the outer circumference to a frame 17 are provided. |
