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:
Dec. 27, 1994
Filed:
Sep. 08, 1993
Kenichi Terai, Osaka, JP;
Yasutoshi Nakama, Ikoma, JP;
Hiroyuki Hashimoto, Daitou, JP;
Tadashi Tamura, Toyonaka, JP;
Matsushita Electric Industrial Co., Ltd., Osaka, JP;
Abstract
An active noise controller includes a prediction filter which includes a delayer for delaying the noise or error detection signal by a predetermined period of time, a first adaptive filter for processing the output of the delayer to deliver its periodic component, and a subtractor for subtracting the output of the first adaptive filter from the noise detection signal to deliver a random component of the signal. More specifically, the prediction filter is capable of dividing the noise or error detection signal into two, periodic and random, components. In addition, two, second and third, adaptive filters are provided for processing the periodic and random components respectively. Accordingly, the second and third adaptive filters become responsive precisely to their respective periodic and random components regardless of the ratio in level between the two components, whereby any undesired noise consisting of the two discrete components will be suppressed.