| 摘要 |
PURPOSE:To effectively compress noise while an excessive modulation is prevented by providing a broadcasting, unit with preemphasis circuits for a high frequency component included in a luminance signal and providing a receiver with deemphasis circuits. CONSTITUTION:A matrix circuit 1 separates a luminance signal component Y and a chrominance component C from an image pickup signal incoming to the broadcasting unit. The component Y puts into an LPF 2 and an HPF 3. The preemphasis circuits 4 and 5 process the high frequency component in the luminance signal passing through the HPF 3. The emphasis rate of the circuit 6 is maximum where an input amplitude is minimal, and as the amplitude increases, the rate decreases steadily. Where the input amplitude is maximum, no emphasis takes place. An adder 6 links the high frequency component that the circuit 5 has processed to a low frequency component to attain a luminance signal component Ye. A color encoder 8 links the component Ye to the chrominance component C to attain a broadcasting color television signal. On the other hand the receiver is provided with the deemphasis circuits 14 and 15.
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