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. 04, 2001
Filed:
Jan. 06, 1997
Applicant:
Inventors:
Atsushi Yamaguchi, Kawasaki, JP;
Hiroyuki Furuya, Kawasaki, JP;
Assignee:
Fujitsu Limited, Kawasaki, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
A61F 1/106 ; G10K 1/116 ; H03B 2/900 ;
U.S. Cl.
CPC ...
A61F 1/106 ; G10K 1/116 ; H03B 2/900 ;
Abstract
A configuration of providing a microphone in a duct having an air current therein, for use in an active noise reduction device for reducing noise propagating in the duct by producing sounds counteracting the noise, includes an expanded room formed by enlarging an area of a cross section of part of the duct, wherein the cross section is perpendicular to a direction of the air current, and a microphone provided in the expanded room for picking up the noise in order to produce signals for the sounds.