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:
Sep. 02, 2008
Filed:
Feb. 08, 2007
Takeo Inoue, Hirakata, JP;
Hideki Ohashi, Kyoto, JP;
Takeo Inoue, Hirakata, JP;
Hideki Ohashi, Kyoto, JP;
Sanyo Electric Co., Ltd., Osaka, JP;
Abstract
Echo preventing circuit includes first and second FIR filters. The outputs of the first and second FIR filters are converted into first and second analog signals. An input/output terminal outputs the first analog signal or receives a third analog signal. An AD converter converts an analog signal obtained by subtracting the second analog signal from a signal formed by combining the first analog signal and the third analog signal. A response signal acquiring unit acquires a first response signal from an output of the first FIR filter to an output of the AD converter. A filter coefficient setting unit sets the filter coefficients of the second FIR filter based on the first response signal and sets the filter coefficients of the first FIR filter based on second response signal of a section from and output of the second FIR filter to an output of the AD converter.