Patent ID: 6249380
Filing Date: 2001-06-19
Classification: G02B

Abstract:
An image-blur correcting optical system comprising an objective optical system, an image-erecting optical system, and an eyepiece optical system, in this order from an object;wherein said objective optical system comprises a front lens group and a rear lens group, in this order from the object; and said front lens group being immoveable;wherein said image-blur correcting optical system comprises a positive blur-correcting lens group constituted by said rear lens group which is arranged to move in a direction perpendicular to an optical axis, in accordance with a magnitude of a shake imposed on said optical system; andwherein said image-blur correcting optical system satisfies the following conditions:0.04<A/fO<0.20.35<B/fO<0.5TL/fO>1.1whereinA designates a distance between said blur-correcting lens group and an optical element which is positioned on the object-side of said blur-correcting lens group;B designates a distance between said blur-correcting lens group and an optical element which is positioned on the eyepiece-side of said blur-correcting lens group;fO designates a focal length of the objective optical system; andTL designates a distance between the object-side surface of the most object-side lens element in said objective optical system and an image plane of said objective optical system.