| 摘要 |
PURPOSE:To obtain a highly reliable filter operable without mutual interference between two types of filters with a simple construction by mounting the two types of filters on a single blade. CONSTITUTION:When an operation irradiation command is issued during an aiming irradiation, an opposite voltage is applied to one desired drive motor 4a to rotate a drive arm 5a clock-wise. Here, a filter blade 3 is rotated with the drive arm 5a counterclockwise through a guide groove 15a. In this case, a tip bending part of the other drive arm 5b gets outside the outer circumference of the filter blade 3 to abut a waiting position stopper 8b and hence, the filter blade 3 stops at a position where the tip bending part of the drive arm 5a abuts an operating position stopper 9. A first filter zone 11 covers an opening 7 at the stoppage position while a light reflecting part 14a of the filter blade 3 overlaps a photoelectric sensor 6 thereby accomplishing an operation irradiation. |
