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. 19, 2005
Filed:
Sep. 25, 2003
Kouji Nakajima, Tokyo, JP;
Kouji Nakajima, Tokyo, JP;
Denon, Ltd., Tokyo, JP;
Abstract
An object of the present invention is to provide a digital amplifier which is capable of preventing a reproduction of an analogue audio signal from a loud speaker, when an output sound volume from the loud speaker is set to zero and when inputting of a digital audio signal or an input signal is stopped. In order to achieve the object, in the digital amplifier of the present invention, a silent PWM signal output sectionoutputs a PWM signal having a duty ratio of 50%, instead of a PWM signal generated by the PWM signal generating section, in the following cases: the factor detecting sectiondetects that the digital audio signal is multiplied by the factor '0' in the gain regulation section, the silent signal determining sectiondetermines that the signal input from the reproducing unitis stopped, and the silent signal determining sectiondetermines that the digital audio signal is a signal at a silent level.