| 摘要 |
PURPOSE:To attain the transmission of a high definition signal with a present NTSC system and to prevent the interference to a present television due to the high definition signal by frequency-interleaving, multiplexing and transmitting the high definition signal to the high frequency area side of a luminance signal. CONSTITUTION:A luminance signal including the high definition signal inputted to an input terminal 1 is band-limited by a two-dimensional LPF 2, impressed through an interlace converting device 3 to an LPF 4 and a band limited luminance signal YL is obtained. The output of the LPF 4 is subtracted from a signal through a delaying circuit 16 and a high frequency area component (high definition component) YH of the luminance signal is obtained. On the other hand, a horizontal synchronizing frequency fH inputted from a terminal 8 is (n)-multiplied by a multiplier 9, and a phase modulation is executed by a phase modulator 11 to invert a phase at every even number field. By the phase modulating signal, the above-mentioned high definition signal YH is frequency-converted, a BPF is passed through and the high definition signal YH is frequency-shifted to the high frequency area part of the above-mentioned luminance signal YH. By adding the frequency-shifted definition signal YH to an adder 13, the frequency interleaving is executed to the high frequency area part of the luminance signal YH to be transmitted.
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