05485221 is referenced by 353 patents and cites 4 patents.

A headend of a subscription television system includes a video combiner that combines video signals from four separate programs into a composite video signal. The video signals are formatted to produce the composite video signal such that one of the programs appears in each quadrant of the displayed picture. Text data streams are then inserted into the vertical blanking interval of the composite video signal. The composite video signal is transmitted in a channel of a broadband television signal to a plurality of subscriber terminals. A plurality of virtual channels are defined by combinations of quadrants of the composite video signal and quadrants of text from the text data streams. When the subscriber selects a virtual channel, the composite video signal is tuned from the broadband signal, and the text data stream forming the text display of the virtual channel is extracted. An on-screen display uses the text data stream and the composite video signal to generate a display signal whereby text may be displayed in three quadrants and video corresponding to one of the programs may be displayed in the remaining quadrant.

Title
Subscription television system and terminal for enabling simultaneous display of multiple services
Application Number
73404
Publication Number
5485221
Application Date
April 19, 1994
Publication Date
January 16, 1996
Inventor
Kinney C Bacon
Lawrenceville
GA, US
Michael T Hayashi
Aurora
CO, US
Robert O Banker
Cumming
GA, US
Agent
Banner & Allegretti
Assignee
Scientific Atlanta
GA, US
IPC
H04N 5/445
View Original Source