| 摘要 |
<p>A digital TV receiver includes an A/D converter circuit for converting an analog video signal to a digital video signal, a signal separator circuit for separating a digital chroma signal and a digital Y signal from the digital video signal, a colour killer circuit for gating the digital chroma signal to generate a gated C signal when burst components are containing in the digital chroma signal, and a processor circuit for digitally composing RGB signals from the digital Y signal and the gated C signal. The RGB signals are used as tricolour signals for a colour CRT. The colour killer circuit also performs colour control, and includes a burst amplitude detector providing a burst amplitude signal, which compared with an external colour control signal to provide an amplitude control signal which is multiplied with the digital chroma signal to provide an amplitude controlled digital chroma signal. The amplitude control signal is also compared with the colour control signal, and if a predetermined relationship does not exist, a killer signal is produced which gates the digital chroma signal and prevents the generation of a gated C signal when burst components are not present.</p> |
