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:
Sep. 06, 1994
Filed:
Feb. 19, 1993
Shinya Okabe, Shimizu, JP;
Shinichi Shimode, Minori, JP;
Ryouji Sato, Shimizu, JP;
Masamichi Hanada, Shimizu, JP;
Takao Senshu, Shizuoka, JP;
Hirokiyo Terada, Shizuoka, JP;
Minetoshi Izushi, Shimizu, JP;
Hiroshi Takenaka, Shimizu, JP;
Masahiro Ito, Shimizu, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
An active noise control system for a three-dimensional space, including noise detecting means, sound generating means, noise control effect detecting means and a control device consisting of a phase of a wave signal fed from the noise detecting means wherein a plurality of noise control effect detecting means and sound generating means are disposed at a distance shorter than a wavelength of the noise to be controlled, and input signals of the respective sound generating means and output signals of the respective noise control effect detecting means are fed through filters, separately, to control the sound for active noise control. In case of an air conditioner, the noise control effect detecting means are disposed at positions where an air stream flowing through the air conditioner is not obstructed thereby.