Abstract: A projector includes a lighting optical system for emitting a lighting beam, a color separation/light guiding optical system for separating the lighting beam from the lighting optical system into optical paths for three colored light beams, a light modulation device provided for each of the colored light beams and for modulating the light beam, which is separated and guided to the optical path for each of the colored light beams by the color separation/light guiding optical system, in accordance with image information, a light beam combining optical system for combining the colored light beams each modulated by the light modulation device for each of the colored light beams, and a projection optical system for projecting the light beams output via the light beam combining optical system.

Abstract: An auxiliary reflecting mirror is manufactured by heating the central portion of a quartz glass tube and compressing the central portion by pushing two end portions of the quartz glass tube so that the wall thickness of the central portion thickens, accommodating the quartz glass tube after thickening the wall thickness of the central portion in a mold having inner surfaces formed to the reflecting surface shape, which is to be formed in an auxiliary reflecting mirror, and forming an expanded portion by expanding the central portion, of which the wall thickness was thickened, by introducing a gas from the two ends of the quartz glass tube, cutting the quartz glass tube in at least the central portion of the expanded portion, evaporating a reflecting film on the outer surface of the expanded portion and forming a reflecting surface.

Abstract: An integrator type illumination optical system has a first lens array and a second lens array. The first lens array includes left, center, and right column groups. The thickness of the lens cells of the center column group is thinner than that of the lens cells in other column groups, and the thickness of the lens cells in the left and right column groups increases from the inner column outward gradually. The lens cells in the left and right column groups are shaped to converge incident light away from the optical axis of the integrator type illumination optical system, and the lens cells in the center column group are shaped to converge incident light toward the optical axis of the integrator type illumination optical system.