An optical projection device including an illumination system, a
reflective light valve and a projection lens is provided. The adjustable
reflection sheet is disposed behind the adjustable rod integrator along
the light transmission path of the light beam. In addition, the
reflective light valve is disposed behind the adjustable reflection sheet
along the light transmission path of the light beam. The adjustable rod
integrator can shift the light transmission path of the light beam so as
to be incident to the reflective light valve. Moreover, the projection
lens is disposed behind the reflective light valve along the light
transmission path of the light beam. The adjustable reflection sheet can
shift the light transmission path of the light beam so as to pass through
the stopper of the projection lens.