PURPOSE: To perform the excitation of retrieval of a targeted video by an operator by providing a display signal holder which holds the signals of first to fourth rader signal processing parts, and a display signal controller which takes out a time division rader display arbitrarily from the holder.

CONSTITUTION: First to fourth digital rader video signals 6a-6d output from the first to fourth rader signal processing parts 1a-1d are held sequentially with first to fourth display signal holders 2a-2d, respectively. The display signal controller 5 outputs a display control signal 7 which displays a display video signal 9 on a CRT 4 for display with a prescribed display procedure, and the holders 2a-2d control the timing to output first to fourth time division rader display signals 8a-8d. The signals 8a-8d are taken out of the holders 2a-2d which hold the signals 6a-6d by the signal 7 output from the controller 5, and are converted to the display video signal 9 with frequency for CRT display with a display signal converter 3, then, the targeted video can be displayed on the CRT 4 for display.