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. 07, 2004
Filed:
Jan. 12, 2001
Matsushita Electric Industrial Co., Ltd., Osaka, JP;
Abstract
A low-pass filter of over-sampling type oversamples an input digital audio signal T and filters and removes the low frequency components of the produced aliasing noise. A spectrum analyzer circuit calculates the spectrum intensity of a predetermined band of an output signal from the low-pass filter. An expanded signal generating circuit generates an expanded signal having frequency components of the output signal from the low-pass filter. A level control circuit controls the level of the expanded signal according to the spectrum analyzer circuit. An adder adds the level-controlled expanded signal to the output signal from the low-pass filter thereby to generate a digital audio signal T