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:
Jun. 01, 1999
Filed:
Oct. 27, 1997
Applicant:
Inventors:
Assignee:
Sony Corporation, Tokyo, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H04R / ;
U.S. Cl.
CPC ...
381111 ; 381117 ; 381401 ;
Abstract
A speaker apparatus which drives an electromagnetic-coupling-type speaker in accordance with a digital signal is provided with a speaker unit, and a plurality of amplifiers corresponding to the number of quantization bits of a digital audio signal. The output terminals of the amplifiers are connected to the respective primary coils, respectively, and the output impedances of the plurality of the amplifiers are made equal to those of the respective primary coils to which the amplifiers are connected. Each bit of each sample of the digital audio signal is amplified by the plurality of the amplifiers and supplied to the respective primary coils, respectively.