To solve a problem that the formation of one high definition image over all the multi-screen is not tried in a conventional system for synthesizing the pictures of respective display units or displaying these pictures while expanding them when displaying a multi-picture by using the display unit of a large screen.

Concerning an optical image, with which one optical subject of one image pickup area 36 is divided into three, an image pickup signal overlapping boundary parts is outputted by each of cameras 23d, 24d and 26d. This image pickup signal is inputted through a transmission part 40 to each of projectors 51b, 51c and 51a inside a projection part 50. In each of projectors 51a, 51b and 51c, the image pickup signal is converted from electric to optic and projected on a plane screen 52 and the image of a divided image pickup area corresponding to the input image pickup signal is displayed. On the screen 52, the image of one consecutive optical subject in an image pickup area 36 as a whole is displayed, This image is a high definition image having the number of pixels almost triple as many as that of HDTV image and is displayed on the screen 52 as a large picture.