| 摘要 |
PURPOSE:To change a filter constituted of a glass delay line into a semiconductor, to miniaturize a circuit and to remove a higher harmonic due to sampling by inserting interpolation data into which a chrominance signal is sampling/ demodulated into low frequency band color difference signal data. CONSTITUTION:Since a sampling frequency of color difference signal data i and j are twice as large as a low band carrier-frequency fc, namely, the data are 1/2 as large as a sampling clock c frequency fs of a low band conversion chrominance. When a PI system low band conversion chrominance signal or PS system low band conversion chrominance signal is sampling/demodulated, an output timing of the data i and j is slipped one clock at 1H step and 2H step at the time in correspondence to an adjacent 1H period. Because data do not exist even by trying to add color difference signal data to simply the 1H delayed data, interpolation data are prepared by interpolation filters 11a and 11b. By passing color difference signal data p and q after their passage through the interpolation filters 11a and 11b through a circuit constituted of 1H memories 12a and 12b and adders 13a and 13b to obtain a comb shaped filter effect. |
