| 摘要 |
PURPOSE:To protect the eyes of a person in charge of examination and to improve the efficiency of the observation by automatically inserting a dimming member into an optical path of lighting in cooperation with switching from dark visual field lighting to light visual field lighting. CONSTITUTION:During dark visual field lighting, an optical path changeover knob 10 is pressed in and a filter frame 12 abuts on a stopper 15 by being pressed by a permanent magnet 19 to interpose in an optical path of light visual field lighting. Then when the knob 10 is drawn out to perform switching to the light visual field lighting, the filter frame 12 is swiveled clockwise while attracted and held by the permanent magnet 19 fixed on an optical path switching frame 4, thus constituting the optical system for the light visual field lighting. During the light visual field lighting, an arm 17a is operated to rotate a springing-away ring 17 against a spring 18, and a pawl 17b presses a projection 12a of the frame 12 to rotate the frame 12, which is sprung out of the optical path of light visual field lighting. |
