Video encription system
US3982062A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jul 26, 1973 |
| Grant date | Sep 21, 1976 |
| Priority date | — |
| Expiry date | Jul 26, 1993 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N7/167
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
Encription apparatus for restricting distribution of private (e.g., premium) video programs propagated by a CATV cable network, radiation or the like employs picture carrier isolating, phase shifting and linear combining structure for rendering the transmitted video information unrecoverable by conventional television receivers. Authorized receiving stations are provided with inversely functioning electronics which reconstitute the prescribed video amplitude modulation format to permit signal reception. Similar audio program modification and correction structure permits encription and selective reception of the sound portion of the distributed programming.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.