AUTOMATIC HUE CONTROL FOR A TELEVISION RECEIVER

摘要

A color television receiver providing for the direct demodulation of the red, blue and green color representative signals includes an additional pair of hue control demodulators for demodulating color difference signals on opposite sides of the I-axis by equal amounts. The outputs of the hue control demodulators are inverted with respect to one another and are supplied to an adder, which provides a DC control voltage indicative of the relative difference in the amplitudes of the signals obtained from the hue control demodulators. This control voltage then is supplied to a DC controlled variable hue control circuit which shifts the relative phase between the color sync oscillator output and the subcarrier to the demodulators by an amount sufficient to maintain the average outputs of the two hue control demodulators equal in amplitude.