Patent ID: 6118585
Filing Date: 2000-09-12
Classification: G02B

Abstract:
An optical system for an observing apparatus having an image-vibration compensation system, said optical system including an objective optical system comprising:a first lens having positive refractive power;a second lens having negative refractive power; anda third lens having positive refractive power, said lenses being arranged in that order from an object side,wherein said third lens is movable in a direction orthogonal to an optical axis of said objective optical system to compensate for vibration of an image due to a hand-held shake, and wherein the following relationships are satisfied:0.05<d.sub.12 /f.sub.0 <0.200.5<.vertline.tan 1.degree./(.phi..sub.13 -.phi..sub.12).vertline.<5.0 [(unit:mm)]where,d.sub.12 is a distance between said first lens and said second lens,f.sub.0 is a focal length of said objective optical system,.phi..sub.12 is a composite power of said first and second lenses, and.phi..sub.13 is a composite power of said first, second and third lenses.