Frequency converter for a digital chrominance modulator

摘要

A frequency converter circuit for converting the frequency of a Hi-Vision carrier chrominance signal into the frequency of an NTSC signal includes a buffer memory wherein color signal data are written in according to a writing signal derived from the Hi-Vision (source) subcarrier frequency, and color signal data are read out according to a reading signal derived from the NTSC (target) subcarrier frequency. The reading signal may correspond to a delayed writing signal, which is delayed by a time derived from the target subcarrier frequency.