Pay television system
US4688248A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Mar 20, 1985 |
| Grant date | Aug 18, 1987 |
| Priority date | — |
| Expiry date | Mar 20, 2005 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N21/8352
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A pay television system generally comprises a signal generating center, signal distributers and subscriber devices. The center produces and combines a television signal and a control signal and supplies the combined signal to a common cable, and each distributer includes subscriber units which receive the television signal through a first filter and control units which receive the control signal through a second filter. Each control unit which receives a tuning signal from a subscriber controls a corresponding one of the subscriber units to supply the subscriber with the television signal responsively to the control signal and according to the corresponding subscription, and each subscriber device includes at least one tuner which transmits the tuning signal indicating a requested channel to the signal distributer and a television receiver which is supplied with the requested television signal via the tuner when it coincides with the television signal supplied from the signal distributer in reply to the tuning signal.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.