Compatible four channel recording and reproducing system
US3940559A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Apr 18, 1974 |
| Grant date | Feb 24, 1976 |
| Priority date | — |
| Expiry date | Apr 18, 1994 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04S3/006
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A compatible four channel sound system for use in conjunction with a recording system for recording four individual audio signals designated L.sub.f, L.sub.b, R.sub.b and R.sub.f on a recording medium having first and second primary information channels and first and second subsidiary information channels, the first and second primary information channels carrying information that is consistent and compatible with existing monophonic and stereophonic standards. In accordance with the preferred embodiment of the invention, means are provided for forming a first composite signal designated L.sub.T which contains, to the extent they are present, L.sub.f in a dominant proportion and L.sub.b and R.sub.b in sub-dominant proportions, L.sub.b and R.sub.b being phase shifted with respect to each other. Means are also provided for forming a second composite signal designated R.sub.T which contains, to the extent they are present, R.sub.f in a dominant proportion and L.sub.b and R.sub.b in sub-dominant proportions, L.sub.b and R.sub.b being phase shifted with respect to each other. Further means are provided for forming a first auxiliary signal by combining all of the individual audio signals…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.