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:
Aug. 04, 2015
Filed:
Oct. 17, 2011
Satoshi Sekine, Hamamatsu, JP;
Rento Tanase, Iwata, JP;
Keiichi Fukatsu, Hamamatsu, JP;
Shinichi Kato, Hamamatsu, JP;
Atsushi Yoshida, Hamamatsu, JP;
Satoshi Sekine, Hamamatsu, JP;
Rento Tanase, Iwata, JP;
Keiichi Fukatsu, Hamamatsu, JP;
Shinichi Kato, Hamamatsu, JP;
Atsushi Yoshida, Hamamatsu, JP;
Yamaha Corporation, Hamamatsu, JP;
Abstract
A standing wave attenuation device is installed in a cabin of a vehicle so as to reduce a standing wave caused by external noise such as road noise. The standing wave attenuation device provides a closed loop including a feedback comb filter with a feedback loop, a microphone, a speaker, and a delay element. The delay element adjusts the phase of the output signal of the feedback comb filter such that the time needed for one-time circulation of a signal through the feedback loop matches a half period of the standing wave. An original sound including the standing wave is picked up by the microphone and subjected to processing so that the speaker produces a sound wave with the inverse phase against the phase of a sound wave constituting the standing wave, so that the standing wave is canceled out by the sound wave emitted from the speaker.