| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To prevent the characteristic deterioration of an optical element due to the heat ray of a light source with a simple configuration. <P>SOLUTION: A color wheel 3 is arranged on an optical path L between the light source 1 and a light tunnel 4 as the optical element. The color wheel 3 is constituted by forming color light transmissive dielectric multi-layer films on a heat absorption glass. The heat ray of the light emitted from the light source 1 is absorbed by the heat absorption glass, and the heat is discharged with the rotation of the color wheel 3. The light emitted from the light source 1 does not always enter the same position of the color wheel 3, the light enters only a part of the color wheel 3, then, the heat can be discharged when the light does not enter in the midst of rotation. Thus, the heat discharging efficiency is enhanced. Besides, it is unnecessary to separately install a heat absorption filter on the optical path L, then, the number of components is reduced. <P>COPYRIGHT: (C)2004,JPO&NCIPI</p> |
