System for digitally transmitting and displaying texts on television screen
USRE32187E · kind E · reissue
Assignee
Inventors
Key dates
| Filing date | Jun 3, 1981 |
| Grant date | Jun 17, 1986 |
| Priority date | — |
| Expiry date | Jun 3, 2001 |
Classification
- Technology area (CPC —)General
Abstract
In the disclosed teletext system, the transmitter station broadcasts data cks data from several channels, the data packs being time multiplexed. Each data pack comprises a prefix signal for causing a teletext receiver either to accept the data packs of a selected channel or to reject data packs from other channels. In addition to the prefix, and possibly page flags followed by page numbers and row flags followed by row numbers, the sequence of eight-bit words, transmitted in a pack, may comprise escape eight-bit words followed by type identity eight-bit words, which are themselves followed by a sequence of characters to be displayed in the same type the identity of which is determined by the preceding type identity eight-bit words. Each teletext receiver comprises, a first conventional random access memory storing the coded characters, a second random access memory storing the type identity eight-bit words at the same address as those of the characters belonging to the sequence in the first random access memory. A read operation from the first random access memory, for display purpose, is performed at the same time as the read operation from the second random access memory. The out…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.