| 摘要 |
<p>An automatic hue control system is provided for a color television receiver. The system uses a single sampling of a vertical interval reference (VIR) signal to establish the hue setting of the receiver. The VIR signal periodically appears during a pre-selected line in the vertical blanking interval of a broadcast video signal. The VIR signal includes a chrominance reference portion of such phase that one color difference signal is zero, and also includes another portion having no chroma content. Sampling of the VIR signal during at least part of the chrominance reference portion and AC coupling in a control loop enable the loop to respond to any transition in the one color difference signal between chroma reference times and no chroma times. Any such transition is used to correct The hue setting of the receiver.</p> |
