Abstract: This specification discloses an image projector for projecting a tri-color composite optical image on a screen as a magnified optical image. A reading light beam emitted from a light source is separated into three color beams, e.g., Red, Green and Blue color beams through a tri-color separation and composition optical system. The separated color beams are irradiated on image forming devices provided correspondingly with Red, Green and Blue color images to read out color images respectively therefrom. Each of the reflected light beams from the image forming device carrying color image information impinges again on the tri-color separation and composition optical system to compose a composite image beam. The composite image beam is projected on the screen through an optical lens system comprising a first lens group, a second lens group and a third lens group disposed along an optical axis in order.