PURPOSE: To prevent disturbance of a picture at switching by shifting relatively a phase difference between a synchronizing signal sent to a 1st video equipment and a synchronizing signal sent to a 2nd video equipment while taking a delay time of a television signal in a picture division means into account the delay time.

CONSTITUTION: A signal from a High Vision equipment 1 is delayed by one field or over by a scan converter 5, then a picture of the High Vision equipment 1 displayed on a display device 8 and a picture of an NTSC equipment 2 are displayed while the phase is shifted relatively in the horizontal direction. Thus, a synchronizing signal generator 3 controls a phase difference between synchronizing signals Hsync and Nsync. When the phase difference is set to be equal to a delay in the scan converter 5, the High Vision picture and the NTSC picture displayed on the display device 8 are synchronized.