Patent ID: 6859315

Claim:
An image display unit, comprising: an illumination optical system for illuminating an image display element with light from a light source; and a projection optical system for projecting light from the image display element onto a projection surface onto which the light is to be projected, wherein said illumination optical system includes a polarization converting element for transforming non-polarized light into linearly polarized light, said polarization converting element comprising: a polarization beam splitter having an array-like planar shape, comprising a transparent base material having a polarization separation film, made of a dielectric multilayered film, cemented at a cemented surface between arrays, wherein an incidence angle θg of a principal direction from which light is incident upon the polarization separation film satisfies a relation θg>45 deg., and wherein an angle formed by a normal to a light incidence surface of said polarization beam splitter and an optical axis of the light incidence angle of said polarization beam splitter is not less than 0 deg. and not more than 20 deg.; and a waveplate for registering a polarization direction of one of two polarized lights, being separated by said polarization separation film of said polarization beam splitter, with a polarization direction of the other polarized light, wherein a normal to a light entrance surface of a polarization beam splitter provided in said polarization converting element is inclined with respect to an optical axis of said illumination optical system.