Two-channel compatible HDTV system
US4907069A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jun 1, 1988 |
| Grant date | Mar 6, 1990 |
| Priority date | — |
| Expiry date | Jun 1, 2008 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N11/26
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A video signal is produced as a 37.8 MHz bandwidth high resolution signal. The system then derives a compatible NTSC signal from that signal and transmits the NTSC signal on one channel and an enhancement signal is transmitted on a second channel. The enhancement signal is produced by storing the 37.8 MHz signal, scanning it at a lower frame rate, and folding it so that the original information is retained within a normal channel width. In an HDTV receiver, the two channels are received and the signals are decoded separately then, using dot interlace techniques, combined to produce the HDTV signal having three times the horizontal and vertical resolution of a standard NTSC signal.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.