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:
Jan. 13, 1976
Filed:
May. 25, 1973
Susumu Takahashi, Tokyo, JA;
Ryosuke Ito, Tokyo, JA;
Sansui Electric Co., Ltd., Tokyo, JA;
Abstract
The invention discloses a system for synthesizing first and second recording or transmission signals adaptable for both of a discrete four-channel stereo sound reproducing system and a matrix four-channel stereo sound reproducing system. The first recording or transmission signal includes a first audio main signal and a first carrier signal frequency modulated by a first audio sub-signal, whereas the second recording or transmission signal includes a second audio main signal and a second carrier signal frequency modulated by a second audio sub-signal. Each of the first and second audio main signals is formed by combining four sound signals with a predetermined amplitude ratio and a predetermined phase relationship, whereas each of the first and second sub-signals is formed by combining three of the four sound signals with a predetermined amplitude ratio and a predetermined phase relationship. The first and second main signals are used to effect the matrix four-channel sound reproduction, while a combination of the first and second main signals and the first and second sub-signals is used to effect the discrete four-channel sound reproduction.