Patent ID: 6226123
Filing Date: 2001-05-01
Classification: G02B

Abstract:
An optical system for an observing system of a binocular having an image-vibration compensation system, said optical system including an objective optical system comprising:a first lens group having positive refractive power;a second lens group having negative refractive power; anda third lens group having positive refractive power, said lens groups being arranged in that order from an object side,wherein at least one of said second and third lens groups is movable in a direction perpendicular to an optical axis of said objective optical system to compensate for vibration of an image due to a hand-held shake, andwherein the following relationships are satisfied:0.1<d.sub.12 /f.sub.0 <0.320.7<f.sub.0 /f.sub.1 <3.0where,d.sub.12 is a distance between said first lens group and said second lens group,f.sub.0 is a focal length of said objective optical system, andf.sub.1 is a focal length of said first lens group,said observing system further comprising an eyepiece through which a user observes an image formed by said objective optical system and an erecting system that is located between said objective optical system and said eyepiece,said first lens, group consisting of a positive lens and a negative lens said second lens group consisting of a negative lens and said third lens group consisting of a positive lens.