Patent ID: 7131730
Filing Date: 2006-11-07
Classification: G02B,G03B,H04N

Abstract:
1. A projection display optical system comprising: an illumination optical system which illuminates an illumination surface with a generally telecentric illumination luminous flux, the illumination optical system comprising at least one optical element, wherein light intensity distribution of the illumination luminous flux on the illumination surface changes depending on a deviation angle of an incident ray with respect to a normal to the illumination surface, and wherein the optical element optically operates the illumination luminous flux such that a ratio of angle widths at which light intensity reaches half of a peak value in each of two axis directions orthogonal to each other on the illumination surface is an aspect ratio of 2:1 or higher; a spatial light modulation element which modulates a luminous flux emerging from the illumination optical system by a group of pixels arranged two-dimensionally; a projection lens which projects the luminous flux modulated by the spatial light modulation element onto a projection surface; a plurality of transmission type liquid crystal modulation elements as the spatial light modulation element; and one of a wavelength selective deviating element and a polarization direction selective deviating element which combines luminous fluxes modulated by the respective transmission type liquid crystal modulation elements and is disposed in an optical path from the plurality of transmission type liquid crystal modulation elements to the projection lens, wherein a direction perpendicular to a direction in a deviating surface by the deviating element matches a direction in which an angle width at which light intensity reaches half of a peak value in the light intensity distribution is larger, of two axis directions orthogonal to each other on the illumination surface.