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:
May. 04, 2010
Filed:
Aug. 21, 2006
Kazutoshi Aida, Osaka, JP;
Kazutoshi Aida, Osaka, JP;
Panasonic Corporation, Osaka, JP;
Abstract
A variable gain amplifier (: VGA) for amplifying an amplitude of a signal extracted by a pickup (), an A/D converter () for converting the amplified signal into digital, and an amplitude detecting circuit () for detecting amplitude information from the digital information, are provided. A gain control circuit () for calculating a control value for the VGA () is calculated from the detected amplitude information, and an envelope generating circuit () for executing an operation of absorbing transfer characteristics of the VGA () from the control value for the VGA () and the amplitude information, are provided to generate an envelope extracted by the pickup (). When the characteristics of the VGA () vary, a degree of the variation is calculated from the amplitude information of the signal extracted by the pickup () and amplitude information obtained by fixing the control value for the VGA (), and characteristic correction is executed.