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. 07, 2004
Filed:
Aug. 27, 2002
Toshihiko Muramatsu, Iwata-gun, JP;
Yamaha Corporation, Hamamatsu, JP;
Abstract
A battery charger is used for charging a battery incorporated in a portable audio device such as a portable telephone, and it comprises a connector and a circuit block for performing charging operation with the battery of the portable audio device via the connector. The circuit block contains a digital power amplifier that ensures digitization of audio signals transmitted thereto from the portable audio device via the connector. The battery charger can be connected with speakers, which produce sounds based on digital audio signals amplified by the digital power amplifier. Since the digital power amplifier has a good efficiency in power consumption and produces a very small amount of heat during operation, the battery charger can be considerably downsized, and it can reliably ensure a high quality reproduction of audio signals during charging operation for the battery of the portable audio device in progress.