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. 11, 2001
Filed:
Dec. 05, 1997
Minoru Kasama, Nakai-machi, JP;
Fuji Xerox Co., Ltd., Tokyo, JP;
Abstract
Pseudo space transmitting signal processing means of the signal processing means simulates the frequency response of the space up to the silencing point from a noise source, while pseudo inverse filter signal processing means simulates an inverse filter characteristic 1/(K×Sp×G,) for canceling the characteristic of the combined frequency response (K×Sp×G,) of K of noise input means, Sp of a secondary sound source speaker, and G,up to a silencing point from a secondary sound source speaker. The pseudo space transmitting signal processing means and pseudo inverse filter signal processing means set a gain characteristic equal to an original space transmitting characteristic and inverse filter characteristic, respectively. Moreover, the pseudo space transmitting signal processing means is structured to provide a delay of phase for an amplitude characteristic, while the pseudo space transmitting signal processing means is structured to lead the phase as much as a delay of the pseudo inverse filter signal processing means. Thereby, the present invention can provide an active silencer comprising signal processing means for generating signal for canceling noise and having a stable filter characteristic.