NTSC interference detector

摘要

An NTSC interference detector is disclosed which includes an NTSC extracting filter for extracting an NTSC signal component from a received I-channel signal; a comparing portion for integrating the NTSC signal output from the NTSC extracting filter for a predetermined period and deciding whether the NTSC signal component is above a first reference value or not; and a control signal generator for adding the signal output from the comparing portion for every horizontal sync, deciding the presence or absence of NTSC interference according to a second reference value, and outputting a control signal according to the presence or absence of NTSC interference, thereby accomplishing a precise detection of NTSC interference.