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:
May. 16, 1995
Filed:
May. 25, 1994
Tadashi Tamura, Toyonaka, JP;
Kenichi Terai, Osaka, JP;
Hiroyuki Hashimoto, Daito, JP;
Yasutoshi Nakama, Ikoma, JP;
Matsushita Electric Industrial Co., Ltd., Osaka, JP;
Abstract
The noise control system of this invention includes: a noise detector for detecting a noise generated from a noise source in order to output a noise detection signal; an adaptive filter portion for outputting a control signal based on the noise detection signal so as to cancel the noise; a control loudspeaker for receiving the control signal that is to radiate a control sound to a predetermined region; and an error detector for detecting a residual error of the noise and the control sound in the predetermined region, wherein the adaptive filter portion includes: an adaptive filter for receiving the noise detection signal and processing the noise detection signal to output a control signal; an IIR filter section for receiving the noise detection signal, performing a filtering process to the noise detection signal according to a predetermined frequency characteristic, and outputting a first processing signal; an operation section for receiving the first processing signal, performing convolution with the first processing signal and a predetermined transfer function, and outputting a second processing signal; and a multiplying section for receiving the second processing signal and the error signal, multiplying the second processing signal by the error signal, and outputting an update signal for updating coefficients of the adaptive filter to the adaptive filter, the predetermined frequency characteristic and the predetermined transfer function being determined based on a control transfer characteristic from the control loudspeaker to the error detector.