Function generators especially for colour television receivers

Claim 1

COLOUR TELEVISION APPARATUS COMPRISING MEANS FOR SETTING UP THREE SIGNAL COMPONENTS WHICH TOGETHER REPRESENT A COLOURED PICTURE, A PLUARALITY OF NETWORKS, EACH HAVING INPUT TERMINALS TO WHICH AT LEAST THE LOWER FREQUENCIES OF RESPECTIVE ONES OF SAID SIGNAL COMPONENTS ARE APPLIED AND EACH NETWORK BEING ARRANGED TO PRODUCE A RESPECTIVE OUTPUT SIGNAL WHICH REPRESENTS A DIFFERENT APPROXIMATION TO A NON-LINEAR FUNCTION OF THE SIGNAL COMPONENTS APPLIED THERETO, A SERIES OF ONE WAY DEVICES EACH CONNECTED FROM THE OUTPUT OF A RESPECTIVE NETWORK TO A COMMON POINT SO AS TO SET UP AT SAID COMMON PONIT THE ONE OF SAID OUTPUT SIGNALS WHICH LIES AT AN EXTREME OF THE RANGE OF VALUES OF SAID OUTPUT SIGNALS AT THE TIME, THE SIGNAL SET UP AT SAID COMMON POINT BEING THE BEST AVAILABLE APPROXIMATION TO SAID NON-LINEAR FUNCTION AMONG SAID OUTPUT SIGNALS AND MEANS FOR UTILISING AT LEAST THE LOWER FREQUENCIES OF THE SIGNAL SET UP AT SAID COMMON POINT TOGETHER WITH AT LEAST TWO OF SAID THREE SIGNAL COMPONENTS WHICH TOGETHER REPRESENT THE COLOURED PICTURE.