| 摘要 |
<p>In a color television receiving circuit, a colordemodulating subcarrier signal produced by an oscillator is applied through a first variable phase shifter and further through only a second variable phase shifter to a second color demodulator circuit. The subcarrier signal, after passing through the first variable phase shifter, is applied to a color demodulator circuit provided particularly for hue error detection, When a received composite color television signal includes a vertical interval reference (VIR) signal, the detected output from the hue-error demodulator circuit is used to control the amount of phase shift of the first variable phase shifter, thereby automatically correcting the color hue. On the contrary, when the received signal does not include the VIR signal, the amount of phase shift of the first variable phase shifter is constant. The amount of phase shift of the second variable phase shifter can be changed by a common adjusting variable resistor irrespective of whether the VIR signal is present or not and hence the color hue can be preferentially adjusted.</p> |
