| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a light-shielding device having no variation of load during contraction and elongation and capable of shielding a region against light where a laser beam is guided. <P>SOLUTION: The light-shielding device comprises: a plurality of light-shielding cylinders disposed to block an optical path between a first optical system which is configured to be movable on an object and to guide a laser beam to the object, and a second optical system for guiding a laser beam to the first optical system; a supporting member supporting the light-shielding cylinders; and a bearing disposed on the supporting member. Each of the plurality of light-shielding cylinders has an inner diameter and an outer diameter different from those of other cylinders so as to overlap one another to form a nest. A bearing provided in the first optical system and the bearing provided in the supporting member are slidably fitted to the same guide shaft. <P>COPYRIGHT: (C)2012,JPO&INPIT |
