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:
Dec. 28, 1993
Filed:
Aug. 01, 1990
Applicant:
Inventors:
Assignee:
Sony Corporation, Tokyo, JP;
Attorneys:
Primary Examiner:
Int. Cl.
CPC ...
G11B / ;
U.S. Cl.
CPC ...
369 54 ; 369-2 ; 369-4 ; 369-5 ;
Abstract
An optical recording disc on which an analog audio signal and a digital audio signal are recorded is tested. The analog audio signal results from FM-modulating 2-channel audio signals, and the digital audio signal results from modulating the same 2-channel audio signals in a digital fashion, in order to perform the test, a signal mixed with 2-channel audio signals resulting demodulating an analog audio signal and a signal mixed with 2-channel audio signals resulting from demodulating a digital audio signal are simultaneously reproduced by an electroacoustic transducer and evaluated.