Method and apparatus for tuning data channels in a subscription television system having in-band data transmissions

Claim 1

A subscriber terminal apparatus for use in an in-band television system in which inband information is transmitted within one or more channels, said subscriber terminal apparatus comprising: an apparatus input terminal for receiving a television signal comprising a plurality of channels including said one or more channels containing in-band information; an apparatus output terminal connectable to a television; a tuner for selectively tuning said channels; an on-screen display control circuit having a character memory for storing a character set, a first input terminal coupled to said tuner for receiving a video signal corresponding to a channel tuned by said tuner, a second input terminal for receiving character data for generating character screens using characters in said character set, an output terminal coupled to said apparatus output terminal, and a mode selection input responsive to mode selection data for selectively setting a first mode in which said video signal is output at said output terminal and a second mode in which a character screen on a solid background is output at said output terminal; processing means for determining an occurrence of one of a plurality conditions and for, in response to the occurrence, locating and retrieving character data and final tune data and supplying the character data and mode selection data to said on-screen display control circuit to set the second mode of said on-screen display control circuit and to generate a character screen, corresponding to the occurrence, on a solid background at said output terminal; and tuner control means, responsive to said processing means, for controlling said tuner to tune a final tune channel corresponding to the final tune data while said on-screen display control circuit is in the second mode.