| 摘要 |
PROBLEM TO BE SOLVED: To provide more compact illumination optical system and an image forming apparatus using the same.SOLUTION: An illumination optical system includes a fly-eye lens 3 that divides a light beam from a light source 1 into a plurality of light beams, a mirror 5 that causes the light beams emitted from the fly-eye lens 3 to enter the fly-eye lens 3 again, and a 1/4 wavelength plate 4 that is arranged between the fly-eye lens 3 and mirror 5. The illumination optical system further includes a PBS 2 that is arranged between a liquid crystal panel 7 and the fly-eye lens 3, introduces S-polarized light from the light source 1 to the fly-eye lens 3, and introduces P-polarized light from the fly-eye lens 3 to the liquid crystal panel 7. |
