Variable focal length lens , optical device , method of adjusting the variable focal length lens

摘要

PROBLEM TO BE SOLVED: To provide a low-cost variable focal length lens capable of achieving superior optical performance, to provide an optical device having the variable focal length lens, and to provide a method for adjusting the variable focal length lens.;SOLUTION: The variable focal length lens includes: a front lens group GF having negative refractive power; a center lens group GM having positive refractive power; and a rear lens group GR having positive refractive power in order from the object side. The lens changes a focal distance by changing at least one air interval inside the front lens group GF, air intervals of the front lens group GF and the center lens group GM, and the air intervals of the center lens group GM and the rear lens group GR. The lens also includes an adjustment mechanism by which, after assembling the front lens group GF, the center lens group GM and the rear lens group GR, a lens group of a part of the front lens group GF is eccentrically tilted and the lens group of a part or the whole of the rear lens group GR is eccentrically shifted to perform position adjustment.;COPYRIGHT: (C)2012,JPO&INPIT