Video signal scrambling and descrambling systems
US4563702A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 27, 1983 |
| Grant date | Jan 7, 1986 |
| Priority date | — |
| Expiry date | May 27, 2003 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N7/169
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
Systems for scrambling and descrambling video information lines. The scrambling system includes a memory; a storage system for sequentially storing groups of four video information lines in the memory; and a retrieval means for forming groups of four scrambled video information lines by retrieving the stored video information from the memory in a sequence different from the sequence within the stored group in which the information was stored. The retrieval system forms the scrambled video information lines by retrieving a portion of a first stored video information line from a first position therein to form a portion of a first scrambled video information line occupying a second position therein; retrieving a portion of the first stored video information line from the corresponding second position therein to form a portion of a second scrambled video information line occupying a position therein other than the corresponding second position; and forming the portion of the first scrambled video information line occupying the corresponding first position therein by retrieving a portion of a stored video information line other than the first stored video information line from a positio…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.