| 摘要 |
PURPOSE:To simplify a constitution by placing a revolving shaft of a filter frame for holding two kinds of filters, so that it becomes parallel to a surface direction of its filter and orthogonal to an optical axis direction, rotating this filter frame, and positioning selectively the filter on an optical path. CONSTITUTION:Two kinds of filters 21, 22 having an equal optical path length are held in a direction for making an angle to each other. Also, a filter frame 20 rotating centering around a revolving shaft 26 which is parallel to a surface direction of said filters 21, 22 and orthogonal to an optical axis direction is provided, and a knob 27 being a switching operation mechanism for rotating this filter frame 20 and positioning selectively the filters 21, 22 on an optical path is also incorporated. In this way, a moving space of the frame 20 part containing the filters 21, 22 can be reduced, and the switching mechanism part of the filters 21, 22 can be made compact. |
