| 摘要 |
<p>PURPOSE:To attain wide aspect reproduction with broad band and high picture quality without giving effect onto NTSC reproducing screen by applying scanning line conversion to a low frequency luminance signal and a chrominance signal, moving the result to a middle area of the NTSC scanning line, and converting a high frequency luminance signal to both upper and lower regions of the NTSC scanning line. CONSTITUTION:A scanning line introduced from a signal source 1 is separated into a vertical low frequency luminance signal YL in the vertical direction, low frequency chrominance signals I, Q and a high frequency luminance signal YH and the signals YL, I, Q are converted into the number of scanning lines corresponding to the middle region of the NTSC effective scanning line by a scanning line number converter 3 and subjected to loopback multiplexing at a prescribed rate of sampling. Moreover, the signal YH is converted into a value corresponding to both upper and lower scanning line of the NTSC valid scanning line by a scanning line number converter 7 and subjected to loopback multiplexing. Then a vertical high frequency luminance signal Y'H frequency-shifted 9 at a color subcarrier circuit is subjected to position conversion 10 and added 6 to an output from an encoder 5 to be an NTSC signal whose aspect ratio is 4/3, and it is superimposed on the output of a signal generating circuit 12 and the result is outputted.</p> |
