| 摘要 |
<p>PURPOSE:To convert the frequency of a chrominance carrier signal by implementing write/read of a color signal data to/from with 1st and 2nd clock signals with different frequency and using the 2nd clock signal for a switching signal of a changeover means. CONSTITUTION:A color signal whose field frequency is fv(H) in the High vision system is written in memories Ma, Mb by using a clock signal CKM having a frequency 4fsc(H) being four times the chrominance subcarrier and read out by using a clock signal CKN having a frequency 4fsc(H) being four times the chrominance subcarrier in the NTSC system. From a changeover means 5, a 1st color signal is fed to an input terminal T1 a 2nd color signal is fed to an input terminal T2 and an inverted color signal being the inverting the 1st color signal is fed to an input terminal T3 and an inverted color signal being the inverting the 2nd color signal is fed to an input terminal T4 respectively and outputted sequentially by using a clock signal CKN. Thus, the color signal is converted into a chrominance carrier signal by the NTSC system.</p> |
