COMPATIBLE COLOR PICTURE COLOR DIFFERENCE SIGNAL MULTIPLEX TRANSMISSION SYSTEM

摘要

PURPOSE:To attain the reproduction such that a conventional receiver whose aspect ratio is 4:3 reproduces an effective pattern of 16:9 of aspect ratio while upper and lower parts of screen are black and a receiver whose aspect ratio is 16:9 reproduces a broad band color signal with 0-3.0MHz of I signal and 0-2.0MHz of Q signal by multiplexing a high frequency component of a color signal to blank parts formed at upper and lower parts of the screen. CONSTITUTION:A carrier (f) for multiplex to upper and lower space parts is modulated by a modulator 14, the component with higher frequency is eliminated and the lower frequency component is multiplexed to the upper and lower blank parts and sent. A switch S2 is thrown to the output position of an adder 12 when the signal is in effective pattern and thrown to the output position of a multiplier 14 when the signal is in upper and lower blank parts. Thus, an NTSC receiver reproduces the video image whose aspect ratio is 16:9 while the upper and lower parts are at black level and a High Vision receiver demodulates a signal multiplexed to the upper and lower blanks to reproduce the High Vision video image with high definition as the compatibility.