Small-sized variable magnification optical system

Abstract

A variable magnification optical system includes at least three optical units which are a first moving optical unit, a fixed optical unit and a second moving optical unit. The three optical units are arranged in that order in a propagation direction of light, and a variation of magnification is effected by a relative movement between the first moving optical unit and the second moving optical unit. If a ray which exits from an object and enters the variable magnification optical system, and passes through a center of a stop of the variable magnification optical system and reaches a center of a final image plane is represented as a reference axis ray, the second moving optical unit has a cross-sectional shape which is asymmetrical in a plane which contains the reference axis, and a curved reflecting surface which is inclined with respect to the reference axis, and the direction of the entering reference axis and the direction of the exiting reference axis of the second moving optical unit are parallel to each other and differ from each other by 180°, the variable magnification optical system being arranged in such a manner that a final image is formed after an intermediate image is formed at least twice.

Dependencies are inferred from the claim text.