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:
Jul. 15, 2008
Filed:
Mar. 02, 2007
Takeo Inoue, Hirakata, JP;
Hideki Ohashi, Kyoto, JP;
Yoshitaka Onaya, Ota, JP;
Sanyo Electric Co., Ltd., Osaka, JP;
Abstract
An echo prevention circuit includes a filter that receives a first digital signal and outputs second and third digital signals; first and second DA converter that convert the second and third digital signals into first and second analog signals respectively; a circuit to subtract the second analog signal from a signal generated by combining the first analog signal and a third analog signal, a circuit to amplify the signal from the subtracting circuit; an AD converter that converts the amplified signal into a digital signal; a responsive signal acquiring unit to acquire a first response signal from the input of the first DA converter to the output of the AD converter and to acquire a second response signal from the input of the second DA converter to the output of the AD converter; and a unit to set filter coefficients based on the first and second response signals.