| 摘要 |
PURPOSE:To form a color burst signal with simple circuit constitution by forming a color burst signal having subcarriers every other 1H. CONSTITUTION:Burst flag signals BF are made into signals V1 every other 1H at AND gate 102 by LINESW signals that inverts at every 1H, and these signals V1 are added with color difference linearly sequential signals by an adder 101, and thus a signal BF is eliminated from a signal (B-Y). The residual components of an offset signal at the time of eliminating the signal BF is reduced by a clamping circuit 103 by a pulse CP, and the signal is supplied to a balanced modulator 104. A subcarrier input SC is generated by changing over every other 1H by an input SC-R and an input SC-B whose phase difference is 90 degrees at a gate circuit 105. A balanced modulated signal OH and a signal '1H' which is generated by delaying the former signal OH by 1H are added with each other by adder 107, thus an NTSC chroma signal is formed, and added with an illuminance signal Y and a synchronizing signal by an adder 109 through a BPF 108 to form an NTSC signal.
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