Picture-in picture television receiver with step-by-step still picture control

Claim 1

A television receiver comprising: (a) a cathode ray tube having a picture screen which is divisible into a main picture screen and one or more sub-picture screens inset into the main picture screen; (b) a main picture circuit for supplying a first video signal for the main picture screen video signal; (c) a video signal processor circuit having a memory and including means for receiving a second video signal from an external source and means for selecting one video signal from among said first video signal and said second video signal, and for forming from the selected signal a sub-picture video signal for one or more sub-picture screens inset into the main picture screen of said cathode ray tube; (d) a composing circuit connected to the video signal processor circuit and the main picture circuit for composing the first video signal and said sub-picture video signal into a composite signal which is supplied to the cathode ray tube; (e) a system cathode circuit for controlling said main picture circuit, said video signal processor circuit and said composing circuit; and (f) step-by-step picture switch means, connected to the system control circuit, for supplying a step-by-step picture command signal to said system control circuit, wherein when said step-by-step picture switch means is operated, if only said first video signal is supplied to said composing circuit, said system control circuit causes said first video signal to be supplied to said video signal processor circuit to form a plurality of still picture signals taken at different times from said first video signal, and said first video signal and said plurality of still picture signals taken from said first video signal are supplied to said composing circuit, but if when said step-by-step picture switch is operated, said composing circuit is supplied with said first video signal and a subpicture video signal corresponding to said second video signal, said system control circuit causes said second video signal to be supplied to said video signal processor circuit to form a plurality of still picture signals taken at different times from said second video signal, and said first video signal and a sub-picture video signal corresponding to said plurality of still picture signals taken from said second video signal are supplied to said composing circuit.