| 摘要 |
PURPOSE:To reduce the damage of an incidence end surface even in case of the use of a high-brightness light source, by forcibly cooling the circumference of the incidence end part of an optical fiber bundle for illumination by the use of a heat pipe. CONSTITUTION:The end surface 31a of an optical fiber bundle 31a for illumination receives the radiant heat from a light source 21, but is cooled through a heat pipe 80. Namely, a working liquid, such as water, sealed in the heat pipe 80 vapors by absorbing the heat from the tip part of a metallic pipe 41, and its steam moves to a cooled radiation part 80b through a conduction part 80c and is condensed there to radiate latent heat. The condensed working liquid is returned to a heating part 80a by the capillarity of the wick in the heat pipe 10. The radiation part 80b is provided with fins 90 cooled by a blower 71. Therefore, even when a high brightness light source is used, the incidence end 31a is never held at high temperature, so its damage is reduced. |
