| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an image projection device effective to color tint and irregular color of black, and restraining the lowering of light quantity. <P>SOLUTION: In a color separation and composing system, white light from an illumination system is separated to RGB and guided to light valves, so that respective image light beams are composed. When the angle of a light beam made incident on the light valve is defined as θ, and the refractive index of a polarizing beam splitter prism of an optical path G is defined as n, a light beam incident angle β on the film surface of the prism is expressed as β=45°+sin<SP>-1</SP>(1/n×sinθ). In a wavelength region W meeting W<Wa when wavelength that transmittance on a long wavelength side is 5% is defined as Wa in an incident angle on a dichroic mirror α=45°-θ, light made incident on the film surface of the polarizing beam splitter of the optical path G at the angle of β is shown as follows. In a rate in which the light is guided to the light valve G, a rate that light whose plane of polarization is rotated by 90° is made incident on the light valve is ≤5% when light whose predetermined plane of polarization is made incident on the light valve is 100%. <P>COPYRIGHT: (C)2008,JPO&INPIT |
