| 摘要 |
PROBLEM TO BE SOLVED: To provide a shutter mechanism of a light irradiation device where a shutter plate is made thin and light in weight, by which high speed opening/ closing is realized, and which is not thermally deformed even when it is used for opening/closing for the beam of light of a discharge lamp having high irradiation intensity for a long time. SOLUTION: In the rotary type shutter plate 61, a fan-shaped notched part is formed and made into a light passing part 63, and a non-notched part plate is made into a lightproof part 64, and the light incident surface of the lightproof part of the plate 61 is made into a mirror surface 65, and an infrared ray radiation film 66 is formed on the back surface of the light incident surface. The light passing part is formed between a pair of lightproof parts only by one, and the plate 61 on an opposite side to the light passing part with respect to the center of the plate 61 is formed so that the center of gravity of the plate 61 may be aligned with the center of the plate 61, then the area of the center part of the plate 61 is made large. |
