Patent attributes
A reflecting prism (PR1) and a reflecting prism (PR2) each adapted to bend an incident ray at a predetermined angle for reflection are arranged in such a manner that an incident surface of the reflecting prism disposed on a side of a subject on an optical path and the exit surface of the other reflecting prism are aligned substantially parallel to each other. The incident surface or the exit surface of at least one of the reflecting prisms has an optical power. At least one lens group including one or more lens element is arranged between the two reflecting prisms in such a manner that the optical axis of the lens group is coincident with the axis of the optical path between the two reflecting prisms. At least one lens group is moved in the direction of the optical axis thereof. Thus, provided are a thin and superfine zoom optical system, an imaging lens device incorporated with the zoom optical system, and a digital apparatus loaded with the imaging lens device.
