Patent ID: 7068440

Claim:
A variable magnification optical system for forming an optical image of an object on a light-receiving surface of an image sensor with a variable magnification, the variable magnification optical system including an optical construction comprising, from an object side, a first reflective surface, a first movable unit, a second reflective surface, and a second movable unit, wherein an optical axis is bent at substantially ninety degrees by the first reflective surface and is further bent by the second reflective surface, wherein, during magnification variation from a wide-angle end to a telephoto end, the first and second reflective surfaces are kept in fixed positions with respect to an image surface, and the first and second movable units move along the optical axis, and wherein conditional formula (1) below is fulfilled: 1.0 <TR 12 /y ′max<12.5 (1) where TR12 represents a distance along the optical axis between the first and second reflective surfaces, and y′max represents a maximum image height.