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:
Feb. 17, 2009
Filed:
May. 14, 2004
Tatsumi Nakajima, Inzai, JP;
Kazunori Suzuki, Inzai, JP;
Tatsumi Nakajima, Inzai, JP;
Kazunori Suzuki, Inzai, JP;
Takenaka Corporation, Osaka-Shi, JP;
Abstract
The present invention provides an active control type noise reducing device that is disposed at a sound barrier and with which can be obtained an excellent noise reduction effect with respect to moving sound sources. Linear array of flat loudspeakers are arranged in ascending order from an incoming side of automobiles towards an outgoing side. Delay times of 0, τ, 2τ, . . . , 8τ are respectively given in the arrangement order to the linear array of flat loudspeakers. By delaying signals in correspondence to the arrangement order, the wavefront of a control sound can be slanted in a diagonal direction. Namely, 'line sound sources', where sound sources are linearly arranged, arc pseudo-realized.