Variable-power optical system

Abstract

A variable-power optical system includes, in order from an object, an objective optical system (O), a relay optical system (R), and an eyepiece optical system (E), wherein the relay optical system is provided with, in order from the object, a first lens group (G1) having positive refractive power, a second lens group (G2) having positive refractive power, and a third lens group (G3) having positive refractive power, and is an optical system in which an image formed by the objective optical system with variable optical power, and the variable-power optical system is configured so as to satisfy expressions: 0.7<|β|min<1.4, and 12 (mm)<fmin<15 (mm), where |β|min denotes a minimum of absolute value of imaging magnification of the relay optical system, and fmin denotes a shortest focal length.

Dependencies are inferred from the claim text.