| 摘要 |
PURPOSE:To obtain an excellent reproduction of color for a wide range color temperature change, by electrically converting color temperature without use of a color temperature conversion filter. CONSTITUTION:A color temperature setting circuit 20 consists of an addition/ subtraction circuit 21, a color temperature error detection circuit 22, a YL control circuit 23, an AGC circuit 24, and a switch 25 and a luminance signal from an input terminal 19 is summed or subtracted so as to make the color difference signal picking up a white objective at each color temperature zero. A color difference output control circuit 27 determines a control voltage of a level setting circuit 26 from an output of the circuit 23 corresponding to the color temperature so that the level of an output color difference signal offers an optimum reproduction of color. Further, at each color temperature, the phase of an inputted color subcarrier is phase-shifted with a phase shifter 29 so that an optimum phase of a color subcarrier can be obtained at each color temperature to input the carrier signal of a balancing modulator 31. In this case, a signal controlling the phase shifter 29 is determined at a phase control circuit 30 from an output signal of the circuit 23 relating to the color temperature so that the optimum reproduction of color can be obtained. |
