Abstract: A projection display including first through third light source units to radiate first through third light beams having different colors, respectively, a light path combining unit to combine paths of the first through third light beams, an optical modulator to sequentially modulate the first through third light beams according to image information, and a projection lens unit to magnify and project the modulated light beams onto a screen. The light path combining unit includes first and second prisms. The first prism includes first and second incidence surfaces, through which the first and second light beams are incident, respectively, a first emission surface, and a first selective reflection surface to transmit the second light beam toward the first emission surface.

Abstract: A projection display includes first through third light source units to radiate first through third light beams, respectively, having different colors, an X-cube prism to combine paths of the first through third light beams, an optical modulator to sequentially modulate the first through third light beams according to image information, and a projection lens unit to magnify and project the modulated light beams onto a screen. Each of the first through third light source units includes at least one optical module. The optical module includes a collimator having a first reflective surface in a parabolic shape, and a compact light source located in the vicinity of a focal point of the first reflective surface.

Abstract: An illuminator in which etendue of collected light emitted from a light source can be dynamically controlled. The illuminator includes a light source generating and emitting light, a concave reflector reflecting the light in a predetermined direction, and a retro-reflector placed in the path of the light reflected by the concave reflector. The retro-reflector has an aperture transmitting some of the light and a specular surface reflecting the rest of the light toward the concave reflector.

Abstract: A projection apparatus including a polarization conversion system to convert light have a first polarization component; a color recycling system, which separates the light into first and second color lights, to transmit and reflect the first and second color lights; an image forming system including a first reflective panel and a second reflective panel, which respectively modulate the first and second color lights, and a third reflective panel, which modulates the third color light; and an optical path conversion system, which splits the optical paths of fourth and fifth color lights incident from the color recycling system such that the first color light in the fourth color light is directed to the first reflective panel, the second color light in the fifth color light is directed to the second reflective panel, and the third color light in the fourth and fifth color light is directed to the third reflective panel