Matrix four-channel decoding system
US3934086A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Aug 16, 1974 |
| Grant date | Jan 20, 1976 |
| Priority date | — |
| Expiry date | Aug 16, 1994 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04S3/02
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
To the output side of a matrix four-channel decoder for producing four outputs while controlling the mixing coefficients of left and right composite signals in accordance with the level or instantaneous amplitude relationship between directional audio input signals contained in the composite signals are connected first and second low frequency mixers respectively receiving front pair outputs and back pair outputs. The mixers respectively mix two input signals supplied thereto with each other when they fall within a low frequency range, thereby developing mixed outputs thereof at its two output terminals, and, when they fall within the high frequency range, develop the two input signals at its two output terminals respectively. Each of mixed outputs of the first mixer is a sum of the composite signals while each of the mixed outputs of the second mixer is a difference signal thereof.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.