Technique for generating semi-compatible high definition television signals for transmission over two cable TV channels
US4535352A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Apr 16, 1984 |
| Grant date | Aug 13, 1985 |
| Priority date | — |
| Expiry date | Apr 16, 2004 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N11/26
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
The present invention relates to a technique for generating a Semi-Compatible High Definition Television (SC-HDTV) signal which can be sent over two present-day Cable Television (CATV) channels. In accordance with the present invention, a HDTV signal is formed comprising a line scan rate which is a multiple of the line scan rate of a current conventional TV signal. The SC-HDTV signal is formed therefrom by transmitting a first HDTV line as is and a second HDTV line as a field differential signal transmitted via QAM on the IF or RF carrier of the first line signal at a line scan rate of a current conventional TV signal. Arrangements are also disclosed frDconverting the SC-HDTV signal back into either a HDTV or conventional TV signal.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.