Television video signal synchronizing apparatus

摘要

A television video signal synchronizing apparatus, which synchronizes an input television video signal to a reference timing mark. The input video signal is digitized and stored in a memory at locations which are provided by a writing address generator. The writing operation is performed in synchronism with the input video signal. A reading address generator produces reading addresses for reading out the stored video signal to deliver an output television signal which is synchronized to the reference timing mark. The reading address generator is controlled to read out an active video portion of the stored video signal after a delay of about one horizontal scanning period (63.5 microseconds in the NTSC system) immediately after the writing operation of the same active video portion. Thereby "lip lag" i.e. a mismatch between the audio and video signals, is avoided.