Systems for changing the playback time of recorded image signals

摘要

An image signal playback time changing method which causes a synchronization signal generating device (16) to generate a plurality of synchronization signals which have field frequencies which differ from a predetermined absolute standard synchronization signal based on a playback speed control signal. One of the above mentioned synchronization signals is provided as an outer standard signal to a modification digital video tape player (17) to change the playback speed of an image signal recorded in a video recording medium (13). A field frequency converting device (19) causes the field frequency of the playback image signal from the playback device (17) to equal the frequency of the predetermined absolute standard synchronization signal. As a result, this image signal playback time changing method can change the playback time of the image signal recorded in the video recording medium (13) while preventing the deterioration of the quality of the image signal.