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:
Jun. 20, 1995
Filed:
Oct. 13, 1993
Keitaro Yokota, Hoya, JP;
Manpei Tamamura, Ohta, JP;
Kazuyuki Kondo, Ohta, JP;
Hiroshi Iitaka, Koganei, JP;
Fuji Jukogyo Kabushiki Kaisha, Tokyo, JP;
Abstract
In an automobile vehicle, fuel injection pulse outputted from an electronic control unit of an engine is transformed into a voltage value as a primary source. The voltage values is transformed by the convolution sum process and synthesized into a sound to cancel the engine noise. The synthesized sound is outputted through the speaker in the passenger compartment. On the other hand, the reduced noise sound is detected as an error signal by the microphone. The error signal is inputted to an LMS circuit where the filter coefficient is updated in accordance with both inputted error signal and the primary source. Since the fuel injection pulse before the combustion stroke is used, the noise sound can be precisely and immediately reduced even in the transient conditions of the vehicle operation.