1. A projection system having multiple screens for image display, comprising: at least two screens arranged to form a polygon, with a front side of each of said screens having a substantially flat surface; a multi-projector including at least two sub-projector units for projecting an image to a rear side of each of said screens; and a plurality of light blocking curtains which prevent interference between images projected from each of said sub-projector units to a corresponding one of said screens and which are installed between edges of said screens and said multi-projector.