| 摘要 |
PROBLEM TO BE SOLVED: To enable to use a slowly rotational cooling fan even under a wide ambient temp. condition and to facilitate a layout and the design of a casing and a circuit by providing a vent in a housing in the lower or upper part of a liquid crystal light valve and separately arranging the liquid crystal light valve and a pair of polarizers. SOLUTION: A cooling fan 15 is provided so that the flow passage of wind for cooling the liquid crystal light valve 7 is made in common with the flow passage for cooling a light source. An intake 16 is provided in the casing of the liquid crystal light valve 7. Consequently, air sucked through the intake 16 passes on the surfaces of polarizers 13, 14 and the liquid crystal light valve 7 and sucked in the cooling fan 15. Air sucked through a sole air intake 16 cools the polarizers 13, 14 and the liquid crystal light valve 7, robs heat of the light source 1 and a polarizing beam splitter and goes through the cooling fan 15. Thus, sufficient cooling is enabled by a single cooling fan 15. |
