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. 15, 1994
Filed:
Oct. 06, 1992
Hareo Hamada, Musashino-shi, Tokyo, JP;
Tanetoshi Miura, Kokubunji-shi, Tokyo, JP;
Akio Kinoshita, Fujisawa, JP;
Noriharu Sato, Katsuta, JP;
Keiichiro Mizuno, Tokyo, JP;
Minoru Takahashi, Tokyo, JP;
Abstract
A method for electrically attenuating a noise in an area for a sound wave to be propagatable in a three dimensional direction by making up a drive signal from the information on the noise and previously given filter coefficients by use of an adaptive digital filter and then generating an additional sound wave in accordance with the drive signal for cancellation of the noise. In the electric noise attenuation method, there are provided in a given region for noise attenuation, first and second error sensor groups for detecting an interference sound wave produced between the noise and additional sound wave, at a sampling time, a filter coefficient is calculated based on the information relating to the first error sensor group, at the next sampling time, another filter coefficient is calculated based on the information relating to the second error sensor group, and these operations are repeatedly executed sequentially for each error sensor to thereby update the filter coefficient of the adaptive digital filter.