To provide a device which converts the dynamic image film source TV signals and displays these signals at a high frame rate and with no discontinuation of motions by using a scan converter to output the sequential scanning video signals of a specific frequency which maintain a 3-2 pull-down pattern.

A scan converter outputs the sequential scanning video signals of 60 Hz for maintaining a 3-2 pull-down pattern. If a signal having a converted nominal 60 Hz scanning format or an original nominal 60 Hz input video signal is originally equal to a sequential format signal, the signal is applied to a 60 Hz-120 Hz frame rate doubler. Then the doubler outputs the nominal 120 Hz video signals to maintain a 3-2 pull-down pattern as a 6-4 pattern, and these signals delete the first or the last frame in each of six frame sequences and repeats one or both frames adjacent to each other, in each of four frame sequences adjacent to each other to replace this frame with the first or final frame.