Image projection apparatus

An image projector has a light source emitting blue, green, and red illumination light, a digital micromirror device forming blue, green, and red images, and a projection system enlarging the images, and fulfills the formula FP 1/(2·sin {sin−1[1/(2·FI)]+ }), where, when mirror surfaces forming pixels are referred to as pixel surfaces, mirror-reflected light on the pixel surface along the illumination axis is referred to as mirror-reflected light, and angles between, of the diffracted light produced as a result of the rays along the illumination axis being diffracted, the part traveling in a direction closest to the mirror-reflected light and the normal line to the image display surface is defined as diffraction angles B, G, and R, then represents the largest of the angles B, G, and R, FI represents f-number of illumination light, and FP represents f-number of projection system.