Interactive home information system
US5412720A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | May 1, 1992 |
| Grant date | May 2, 1995 |
| Priority date | — |
| Expiry date | May 1, 2012 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N2007/1739
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An interactive cable television system having a plurality of feeder servers, a plurality of home interface controllers and a feeder port. Home interface controllers are each equipped with a radio frequency input and a data communications link with a receiver and transmitter in the feeder port. A node control in communication with the feeder port determines whether a home interface controller is active and then assigns a feeder server to it. The feeder server provides one of a plurality of information signals from a headend depending on a selection input. Digitally compressed video signals are provided at the headend. The digitally compressed video signals can be provided by a modulator means at a carrier frequency greater than the upper frequency limit for carrying analog television signals with acceptable quality on the cable system. The cable television system may make use of a scrambler that maintains the chrome subcarrier on a sync-stripped output signal at all times including the period of vertical retrace. The sync-stripped output signal is modulated at a first carrier frequency and the sync-signal is modulated at a second carrier frequency. A corresponding decoder is provide…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.