Television channel selection apparatus employing multi-picture display

Claim 1

In a channel selection apparatus manually operable for selecting one of a plurality of television channel signals to derive a video signal to be supplied to television picture display means having a display screen, the apparatus including television signal receiving circuit means coupled to receive said plurality of television channel signals for selecting and demodulating one of said channel signals to produce a first video signal, memory means capable of storing data representing at least one field of said first video signal, and control circuit means for controlling receiving circuit means and said memory means, operable to selectively establish a normal operating mode of said apparatus in which one of said channel signals is fixedly selected by said television signal receiving circuit means and said first video signal is directly transferred to said display means and a multi-picture display operating mode in which data stored in said memory means are continuously read out and converted to a second video signal which is transferred to said display means, the improvement whereby said control circuit means controls said receiving circuit means during said multi-picture display mode operation to sequentially select said plurality of television channel signals during respective time intervals of fixed duration, and controls said memory means during each of said time intervals such that data derived from said first video signal representing a television picture in compressed form are repetitively written into said memory means during a plurality of successive fields of said first video signal, said data being written concurrently with said continuous read-out operation, whereby a miniature display picture corresponding to a currently selected one of said channels is displayed by said display means in the form of a moving picture, while miniature display pictures corresponding to the remainder of said channels are displayed in the form of respective static pictures, and whereby said control circuit means executes control upon a transition from said multi-picture display mode to said normal operating mode such that one of said channel signals that is currently selected at the time of said transition is thereafter held continuously selected by said receiver circuit means.