Hue control circuits for color television receivers

Claim 1

IN A COLOR TELEVISION RECEIVER FOR REPRODUCING A COLOR IMAGE IN RESPONSE TO A RECEIVED COMPOSITE COLOR TELEVISION SIGNAL, WHICH SIGNAL INCLUDES A CHROMA SIGNAL HAVING COLOR SUBCARRIER SIDEBAND COMPONENTS AND A COLOR BURST REFERENCE SIGNAL, SAID RECEIVER INCLUDING A COLOR DEMODULATOR AND A COLOR BURST SEPARATOR FOR DERIVING A COLOR BURST SIGNAL FROM SAID CHROMA SIGNAL, SAID COLOR BURST SEPARATOR INCLUDING SIGNAL TRANSLATING CIRCUIT MEANS HAVING A RESONANT CIRCUIT TUNED TO THE FREQUENCY OF SAID COLOR BURST REFERENCE SIGNAL FOR SUPPLYING SAME TO SAID COLOR DEMODULATOR, THE COMBINATION INCLUDING, A PHASE SHIFTING NETWORK FOR SHIFTING THE PHASE OF THE COLOR BURST REFERENCE SIGNAL APPEARING ACROSS SAID RESONANT CIRCUIT, SAID PHASE SHIFTING NETWORK INCLUDING A DIODE AND A CAPACITOR CONNECTED IN SERIES AND COUPLED ACROSS SAID RESONANT CIRCUIT, MEANS FOR APPLYING A FIXED BIAS VOLTAGE TO ONE SIDE OF SAID DIODE, AND MEANS FOR APPLYING A VARIABLE BIAS VOLTAGE TO THE OTHER SIDE OF SAID DIODE, SAID DIODE PRESENTING A VARIABLE RESISTANCE IN SERIES WITH SAID CAPACITOR TO SHIFT THE PHASE OF SAID COLOR BURST REFERENCE SIGNAL, SAID PHASE SHIFT BEING DETERMINED BY THE CONDUCTION OF SAID DIODE AS ESTABLISHED BY THE DIFFERENCE BETWEEN SAID FIXED BIAS VOLTAGE AND SAID VARIABLE BIAS VOLTAGE, WHEREBY SAID VARIABLE BIAS VOLTAGE PROVIDES HUE CONTROL FOR SAID REPRODUCED IMAGE.