| 摘要 |
PURPOSE:To obtain a filter which is stable and capable of continuously varying the transmittivity extending over a wide range, by inserting two transparent plates into the optical path so as to be a surface symmetry, and varying an angle to the optical axis. CONSTITUTION:Worm wheels 9a, 9b are installed to glass plates 3a, 3b, and the angle is varied by a worm gear 10 so as to be a surface symmetry against an optical axis 11. In this way, it is possible to obtain a filter which is stable and capable of continuously varying the transmittivity extending over a wide range. |
