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Patent Searching and Data


Title:
MICROPHONE
Document Type and Number:
Japanese Patent JPH0775192
Kind Code:
A
Abstract:

PURPOSE: To remove impulse noise by providing a first electromagnetic induction circuit to convert external sound to an electric signal and to output it, second electromagnetic induction circuit to convert and output an electric signal provided with a polarity inverse to that of the first circuit, and adder circuit.

CONSTITUTION: When anything collides a microphone 1, impulse noise N is transmitted to first and second electromagnetic induction circuits 10 and 20. At the circuit 10, a voice V and the noise N is impressed to a diaphragm 11 and outputted to an adder circuit 30 while oscillating a coil for voice input. On the other hand, at the circuit 20, the noise N is transmitted through a noise- proof wall 25 to a diaphragm 21, a coil 22 for impulse noise detection is oscillated, and an electric signal S2 provided with the polarity inverse to the output characteristic of the coil 12 is outputted. Namely, in the signal S1 to be outputted from the coil 12, the signal S2 provided with the same phase as a signal part corresponding to the impulse noise N and the inverse amplitude is outputted from the coil 22. When the signals S1 and S2 are inputted to the adder circuit 30, the signals S1 and S2 are added, and the part of the impulse noise is removed.


Inventors:
SHIMURA YUJI
Application Number:
JP23908793A
Publication Date:
March 17, 1995
Filing Date:
August 31, 1993
Export Citation:
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Assignee:
NEC CORP
International Classes:
H04R3/00; H04R3/02; (IPC1-7): H04R3/02; H04R3/00
Domestic Patent References:
JPS5625892A1981-03-12
Attorney, Agent or Firm:
Kihei Watanabe