| 摘要 |
<P>PROBLEM TO BE SOLVED: To improve light utilization efficiency for a polarized illumination device, and a liquid crystal projection device using it. <P>SOLUTION: The direction of the arc gap of a metal halide lamp 11 is inclined with respect to the optical axis AX of a parabolic mirror 12 in a non-polarized illumination device 10B. The direction of the arc gap and the surface including the optical axis AX are parallel to the longitudinal direction of the polarization conversion element of the polarization conversion device 25. The inclination makes the point ahead angle, at which the light-emitting part seen from the point P1 on the parabolic mirror 12 to be smaller than when there is no inclination, thereby making the largest luminescence image formed in the lens array 22 small. Meanwhile, although the point ahead angle at which the light-emitting part, as seen from the point P2 is made larger than when there is no inclination; since the intensity of the light reflected at the P2 is smaller than that at the point P1, there is no problem in the light utilization efficiency, even if the luminescence image formed in the lens array 22 is made slightly larger. <P>COPYRIGHT: (C)2007,JPO&INPIT |
