| 摘要 |
PROBLEM TO BE SOLVED: To easily attach and fix an optical filter to a casing and further to reduce an influence on optical performance caused by the fixed optical filter. SOLUTION: The device is provided with a first frame member 21 and a second frame member 22 which have first and second attaching surface parts 21d, 22d and through holes 40, 41 respectively. The optical filter 30 is interposed between the first and second attaching surface parts 21d, 22d, the upper surface 30a and the rear surface 30b of the optical filter 30 are held by the first and second frame members 21, 22, the first and second frame members 21, 22 are held in the inside of the casing 12 so as to be elastically pressed from the outside, and light is guided at least from the through hole 40 of the first frame member 21 to the through hole 40 of the second frame member 22 via the optical filter 30. |
