Signal synthesizing system adaptable for discrete four-channel sound reproducing system and matrix four-channel sound reproducing system
US3932706A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 25, 1973 |
| Grant date | Jan 13, 1976 |
| Priority date | — |
| Expiry date | May 25, 1993 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04S3/02
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
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.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.