Cable television with controlled signal substitution
US4331974A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 21, 1980 |
| Grant date | May 25, 1982 |
| Priority date | — |
| Expiry date | Oct 21, 2000 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N2007/17372
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A signal substitution system for cable television applies substitute television program signals in at least one substitute channel to the transmission cable along with singal substitution control signals. The signal substitution control signals include a plurality of different terminal command signals and a plurality of different event command signals, each of the terminal command signals including a respective panelist address signal for identifying a respective panelist receiving station, and each of the event command signals including a normal channel identification signal for identifying a normal channel into which a substitute television program is to be switched. A controller at each panelist receiving station responds to the signal substitution control signals by selectively switching a substitute television program into a normal channel. The controller includes a generator of a local panelist address signal and a substitute channel selector for producing a substitute channel select signal corresponding to a substitute channel. A first comparator compares the received panelist address signal of each terminal command signal with the local panelist address signal and produces …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.