Data transmission method for text display - using TV receiver in which standard picture transmission lines are combined into data channels

摘要

The arrangement of data channels in one television channel is intended to make use of the existing picture construction, and be widely compatible with existing video text appts. Binary coded data is transmitted in data channels, each channel comprising 2 to power n lines of a standard half picture, where n is an integer. The proposed arrangement allows the setting up of data channels compatible with existing video text equipment, and also channels with a transmission rate of 64 kbits per second making use of more recent information services. Even higher rates can be accommodated if required in the future. Two lines per half frame gives the present standard rate of 32 kbits per second. The system can be operated simultaneously with data channels using differing numbers of lines.