| 摘要 |
A digital color encoder for producing color TV signal comprises primary color image signal sources, a sampling signal generator, coefficient memories, multipliers and an adder. The primary color image signal sources provide digitized color image signals respectively of red, green and blue. The sampling signal generator generates a sampling clock having a frequency three times as high as that of the chrominence subcarrier and provide three phase sampling signals for 0 DEG , 120 DEG and 240 DEG having a frequency as same as that of the chrominence subcarrier. The coefficient memories provide coefficients for 0 DEG , 120 DEG and 240 DEG for the respective color of red, green and blue according to the formula of NTSC color picture signal. The respective color image signals are sampled at the sampling clock frequency and respectively multipled with the respective coefficients in the multipliers, and then added together in the adder. This a composite color video signal is synthesized without use of ordinary subcarrier modulators for B-Y and R-Y.
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