| 摘要 |
PURPOSE:To obtain a field memory device which can manage a memory capacity with the same extent as an NTSC system color video signal even when a PAL and SECAM system color video signal is stored to a field memory by converting a chrominance components by converting the frequency and synthesizing the signal with a luminance signal. CONSTITUTION:A luminance signal separated and demodulated from a terminal 11 by a PAL system reproducing video signal is inputted, an to a terminal 12, the chrominance components having the frequency of 4.43MHz+ or -0.5MHz, in which the frequency is reversely converted, are inputted. The chrominance components are frequency-converted to the 2/3-fold frequency (central frequency 2.96MHz) of a color sub-carrier frequency fSC by a balance modulator 14, inputted through a BPF15 to and adder 16 and added with a luminance signal band- limited to 2.5MHz at a LPF13. A composite video signal is inputted into an A/D converter 17, A/D converted by 2fSC, and the signal for three obtained samples is parallelly converted by a serial/parallel converter 18 and written into a memory 19 by the 2/3 fSC cycle time. The capacity of the memory 19 goes to be the same as the memory constitution in case of an NTSC system.
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