| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an illumination optical system capable of reducing degradation of a polarization converter due to excessive light from a light source. <P>SOLUTION: The illumination optical system is provided with a polarization separation film and a wavelength plate, and contains the polarization converter 4, which converts non-polarized light from the light source 1 to a prescribed polarized light. The illumination optical system comprises a first filter 15 of reflecting ultraviolet region light and a second filter 16 of absorbing ultraviolet region light, on the light source side rather than the polarization converter 4. Therein, the illumination optical system satisfies the conditions: λ<SB>L</SB><λ<SB>B</SB><440nm, λ<SB>O</SB><λ<SB>C</SB><λ<SB>B</SB><440nm. Where λ<SB>O</SB>is luminescent peak wavelength of the light source existing in the range of 400 nm to 420 nm, λ<SB>L</SB>is a wavelength between λ<SB>O</SB>and 440 nm and is closer to λ<SB>O</SB>than to 440 nm, and λ<SB>B</SB>, λ<SB>C</SB>are respectively cut wavelengths of the first and second filters. <P>COPYRIGHT: (C)2007,JPO&INPIT |
