| 摘要 |
PURPOSE:To obtain a normal hue on an index tube by detecting the hue of color signals on the basis of the fact that the extent of a hue error depends mainly upon the hue of reproduced colors and by adjusting the phase of a chrominance subcarrier signal according to the result of the detection. CONSTITUTION:A color signal applied to a terminal 11 is supplied to a 360 deg. phase detector 19, which detects its hue and sends its output to a phase adjusting circuit 20. The phase adjusting circuit 20 further advances or delays the phase of a signal, obtained by shifting a chrominance subcarrier signal applied to a terminal 8 in phase by phase shifting circuits 17 and 18, according to the output of the detector 19 and outputs the resulting signal to the 1st frequency mixer 7. An index signal applied to a terminal 5 is mixed by the mixer 7 with the phase-adjusted chrominance subcarrier and the mixture is mixed with the color signal by the 2nd frequency mixer 9, whose output is added by an adder 14 to a monochrome signal applied to a terminal 15, thereby outputting the resulting signal to an index tube 16. |
