Closed circuit television system having seamless interactive television programming and expandable user participation

摘要

A closed circuit interactive television system (10) provides a multichannel television signal from a localized head end (12) which is used for individualized interactive selections by a plurality of users (22, 24, 26). Each user station contains a conventional television receiver (32a, 32b, 32c) and a smart box or interface and selection device (30a, 30b, 30c). The smart box or interface and selection device (30) is disposed between the television receiver (32) and the RF distribution amplifier (36). The number of user stations (22, 24, 26) on the system (10) is virtually unlimited. The system (10) provides the audio/video television signals (14, 16, 18, 20) in at least frame accurate synchronization to enable seamless video switching between channels, which seamlessness is enhanced through the view of a pair of tuners in the interface selection box (30a, 30b, 30c) which are alternately commanded to pretune to the channel of the next actual choice made prior to the changeover under control of a microprocessor in response to command signals embedded in the television signals being received.