| 摘要 |
<P>PROBLEM TO BE SOLVED: To maintain drip-proof property of a lens barrel. <P>SOLUTION: An optical instrument includes: a lens barrel that accommodates an optical member; an annular elastic member that covers an outer peripheral surface of the lens barrel; and a non-elastic member that supports the elastic member from an inner side in a radial direction. The non-elastic member includes: an outer peripheral surface that is liquid tightly in contact with an inner surface of the elastic body; a level difference surface that is opposed to an end surface of the elastic member positioned in an optical axis direction of the optical member; a peripheral groove that is depressed from the level difference surface; and at the outer peripheral surface, a penetration portion that opens at one end and communicates with an inside of the lens barrel. The elastic member has a rib that projects from the end surface and is pushed to an inner surface of the peripheral groove in the optical axis direction so as to be elastically deformed and liquid tightly in contact with the non-elastic member. The penetration portion is enclosed by a region where the elastic member and the non-elastic member are liquid tightly in contact with each other. <P>COPYRIGHT: (C)2013,JPO&INPIT |
