| 摘要 |
<p>PURPOSE:To reduce the probability that a DC component is present in a recording signal by inverting the logical level of one of two samples and canceling mutually DC components. CONSTITUTION:A composite color video signal inputted from an input terminal 1 is sampled by an A/D converter 2 at a frequency 4fsc and quantized into an 8-bit signal. This 8-bit natural binary code is converted by a code converter 3 into a specific code, which is divided into four channels by a channel separator 4. It is evident in figure that samples inputted to word inversion control circuits 5a, 5b, 5c and 5d for respective channels are in phase with subcarriers and the correlation between two continuous samples is large. Therefore, outputs of switch circuits 6a, 6b, 6c and 6d are signals containing an extremely small DC component.</p> |
