| 摘要 |
PROBLEM TO BE SOLVED: To provide a portable optical instrument in which the whitening of lens is suppressed. SOLUTION: The portable optical instrument and the optical instrument for vehicle comprise a lens barrel 1 whose inner part is filled with a dry first gas and is intercepted from the outer part and a glass lens group 30 of one sheet or more sheets which are included in the lens barrel 1. By using such a constitution, the portable optical instrument in which water, water vapor and hydrogen inside the lens barrel 1 are removed, the penetration of water, water vapor, hydrogen or the like into the lens barrel 1 is prevented, and the whitening of lens is suppressed, is provided. COPYRIGHT: (C)2006,JPO&NCIPI
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