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:
Aug. 12, 2025
Filed:
Sep. 15, 2022
Yamaha Corporation, Hamamatsu, JP;
Yohei Ohtani, Iwata, JP;
Masao Noro, Hamamatsu, JP;
Yamaha Corporation, Hamamatsu, JP;
Abstract
An acoustic apparatus includes a class-D amplifier including a current feedback circuit, and a speaker system including a voice coil driven by the class-D amplifier. The speaker system is configured such that, in a case where the speaker system is driven by an ordinary amplifier having a first output resistance lower than a second output impedance of the class-D amplifier, a Q factor of the speaker system falls below a predetermined lower limit of an ordinary Q factor range of an ordinary speaker system. The current feedback circuit is configured to increase the second output impedance of the class-D amplifier by feeding a current flowing to the voice coil back to an input of the class-D amplifier so as to increase a Q factor as the acoustic apparatus higher than the predetermined lower limit of the ordinary Q factor range and within the ordinary Q factor range.