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:
Feb. 17, 2009
Filed:
Apr. 05, 2007
Hidehiko Kurimoto, Hyogo, JP;
Yasuo Oba, Shiga, JP;
Hidehiko Kurimoto, Hyogo, JP;
Yasuo Oba, Shiga, JP;
Panasonic Corporation, Osaka, JP;
Abstract
A filtering apparatus includes a main filter, a variation detection circuit, and a variation correction circuit. The variation detection circuit includes a reference filter having at least one resistor and at least one capacitor, detects a variation of CR-product based on the resistor and the capacitor of the reference filter in response to each of a plurality of reference signals having different frequencies from each other, and then outputs a variation detection signal indicating a detected result. The variation correction circuit corrects frequency characteristics of the main filter on the basis of the variation detection signal.