| 摘要 |
PURPOSE:To enable free selection of the range of hue adjustment by adding two signals that synchronize with color subcarrier to the first and the second differential amplifier circuit, and making gains of the two amplifier circuits different. CONSTITUTION:The first frequency signal V1 that synchronizes with color subcarrier formed in a color subcarrier generating circuit 8 and the second frequency signal V2 formed by phase shifting the signal by 90 deg. are formed by the first differential amplifier circuits Q5, Q6. A pair of output signals of the amplifier circuits Q5, Q6 are combined by a balancing differential circuits Q1-Q4 according to a hue controlling signal T. Common loading device R6 is provided for an output signal of the second differential amplifier circuits Q7, Q8 that receives the first frequency signal V1 and one of output signal of the first differential amplifier circuit that passed corresponding balancing differential circuit. Gains of the first differential amplifier circuits Q5, Q6 and of the second differential amplifier circuits Q7, Q8 are made different. |
