A display device is disclosed. The display device includes a condenser unit, an illumination lens system, a plurality of diffractive light modulators, a mirror for separating illumination light from diffracted light, a polarized beam separator, a filter unit and a projection unit. The condenser unit converges polarized light, and outputs the converged polarized light. The illumination lens system converts the polarized light into linear parallel light. The diffractive light modulators produce diffracted light beams. The mirror passes the polarized light therethrough using slits, and reflects the diffracted light beams toward the filter system. The polarized beam separator separates the polarized light on a wavelength basis and then allows the separated beams to be incident on the diffractive light modulators, and converges the diffracted light beams and then outputs the converged light to the mirror. The filter system selects the diffracted light beams having desired diffraction orders from among diffracted light beams using a dichroic filter. The projection system focuses the diffracted light beams, and projects the focused light beams onto a screen.