| 摘要 |
PURPOSE:To suppress picture quality deterioration when a color video signal is multiple-recorded on time division bases by providing separately AGC circuits for a luminance signal and for a color difference signal which intend the optimum of the input level at the front stage of a time division multiplexer. CONSTITUTION:When input signals are Y, R, G and B, switches 38 and 39 are connected as shown in the diagram. The Y signal passes through an AGC circuit 40, and a linear sequence color difference signal U/V from a converter 37 is added to a time division multiplexer 43 through an AGC circuit 41. On the other hand, when the input signal is a composite color video signal, the luminance signal from an LPF 35 is added to the AGC circuit 40 and the linear sequence color difference signal U/V from a decoder 36 is added to the AGC circuit 41. A detector 42 detects the amplitude of the luminance signal and controls the gains of the AGC circuits 40 and 41. As a result, the luminance signal Y and the linear sequence color difference signal U/V, which are the optimal amplification levels are obtained from the AGC circuits 40 and 41, and the time division multiple signal is recorded in a magnetic tape 51 through an AGC circuit 45, a processing circuit 47, and a frequency modulator 48.
|
