| 摘要 |
PURPOSE:To expand the ranges of two color difference signals without expanding a composite color television signal and dropping the frequency of a chrominance subcarrier and to transmit said signals by providing an encoder at a transmission side with high and low band LPFs, switching them in the prescribed manner and processing two sets of color difference signals. CONSTITUTION:A switching signal generator 6, responding to a synchronizing signal, switches the switches 2 and 5 of the encoder at the transmission side. Out of the color difference signals C1 and C2 from a matrix circuit 1, the one passes through a high pass LPF 3 through the switch 5 switched similar to the switch 2 while the other passes through a low pass LPF 4, and they turn out to be signals alternately switched from a wide band to a narrow one, and vice versa. An adder circuit 10 synthesizes said signals with a luminance signal through modulators 7 and 8 with orthogonally intersecting phases, to which subcarriers apply. The synthesized signal ends up a composite color signal and transmitted. The bands of two color difference signals are expanded without expanding the band of the composite color signal and dropping the frequency of the subcarrier, and said signals can be transmitted.
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