The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Mar. 04, 2008
Filed:
May. 27, 2004
Yoshio Nakamura, Neyagawa, JP;
Masahide Onishi, Osaka, JP;
Toshio Inoue, Wako, JP;
Akira Takahashi, Wako, JP;
Yoshio Nakamura, Neyagawa, JP;
Masahide Onishi, Osaka, JP;
Toshio Inoue, Wako, JP;
Akira Takahashi, Wako, JP;
Matsushita Electric Industrial Co., Ltd., Osaka, JP;
Honda Giken Kogyo Kabushiki Kaisha, Tokyo, JP;
Abstract
An active noise control system is provided which cancels a noise using a sound radiated from a speaker driven by an output from an adaptive notch filter. The system employs output signals from an adder or simulation cosine-wave and sine-wave signals, an error signal or an output signal from a microphone, and a compensated signal from the adder or a signal available for acoustically transferring an output from the adaptive notch filter to the microphone in accordance with initial transfer characteristics to update the filter coefficient of the adaptive notch filter. This configuration allows the system to operate with stability even when the acoustic transfer characteristics vary with time or under circumstances where there exists a significant amount of incoming external noises. The system also prevents overcompensation for a noise at the ears of a passenger in a vehicle, thereby proving an ideal noise reduction effect.