Patent ID: 8379309
Filing Date: 2013-02-19
Classification: G02B

Abstract:
1. A zoom lens system having a plurality of lens units, each lens unit being composed of at least one lens element, the zoom lens system, in order from an object side to an image side, comprising: a first lens unit having positive optical power; a second lens unit having positive optical power; and at least two subsequent lens units, wherein the first lens unit moves along an optical axis at the time of zooming from a wide-angle limit to a telephoto limit, an interval between the second lens unit and a lens unit which is one of the at least two subsequent lens units varies at the time of zooming or at the time of focusing from an infinity in-focus condition to a close-object in-focus condition, the first lens unit is composed of at least three lens elements, each of the first lens unit and the second lens unit includes at least one lens element having negative optical power, and the following conditions (1) and (2) are satisfied: where vd vd m is the maximum value among the amounts of movement of each subsequent lens unit at the time of zooming from a wide-angle limit to a telephoto limit, f f