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:
Jan. 16, 1996
Filed:
Mar. 16, 1993
Manpei Tamamura, Oota, JP;
Hiroshi Iidaka, Koganei, JP;
Kazuyuki Kondo, Oota, JP;
Keitaro Yokota, Hoya, JP;
Fuji Jukogyo Kabushiki Kaisha, Tokyo, JP;
Pioneer Electronic Corporation, Tokyo, JP;
Abstract
In an automobile compartment noise reduction system, an ignition signal transforming circuit processes an ignition pulse signal to obtain a vibration noise source signal with a frequency spectrum composed of 0.5.times.n (integers) order components of the engine r.p.m. as the primary source signal. The signal is applied to an adaptive filter and an LMS calculating circuit via a speaker-microphone transmission characteristic correcting circuit. The primary source signal is synthesized by the filter into a cancel signal and then outputted through a speaker as canceling sound. The canceling sound is received by at least one error microphone at a noise receiving point as an error signal. The error signal is applied to the LMS calculating circuit. The LMS circuit updates the filter coefficients of the adaptive filter on the basis of the primary source signal and the error signal so that the error signal can be minimized. The noise reduction system has high reliability with low cost, and is easy to mount.