Compressed digital data interactive program system
US5724091A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 18, 1995 |
| Grant date | Mar 3, 1998 |
| Priority date | — |
| Expiry date | May 18, 2015 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N5/44
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An interactive cable television system is disclosed which utilizes a standard cable television distribution network for simultaneously providing a plurality of viewers with an interactive television program comprising a plurality of signals related in time and content. Video signals are transmitted in a digital format, more than one signal being multiplexed onto a data stream on a single channel. The video signals may be compressed for efficiency. A receiver, in conjunction with a signal selector, selects a particular NTSC channel for playback, then selects a particular video signal from the data stream, and decompresses the video signal for playback. Seamless switching between video signals on different channels is provided. An alternative embodiment is disclosed wherein the various signals which comprise the interactive program are switched at the head end rather than at the receiver. The multiple choice control unit selects a desired signal by relaying the multiple choice selections of the user through a relay box back to a remotely located switching station. The switching station routes the correct video signal down the appropriate cable channel for the particular user.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.