Patent ID: 7701645
Filing Date: 2010-04-20
Classification: G02B

Abstract:
1. A 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 negative optical power; a third lens unit having positive optical power; and a fourth lens unit having positive optical power, wherein: the second lens unit includes a cemented lens element, variable magnification is achieved by moving at least three lens units in an optical axis direction, focusing is achieved by moving the fourth lens unit in the optical axis direction, blur of an image is compensated by moving the third lens unit in a direction perpendicular to the optical axis, and at least one of the following conditions (1) and (2) is satisfied: where, ΔL is an amount of change in the overall optical length, ΔL3 is a difference between an interval from an image surface to a most object side surface of the third lens unit at a wide-angle limit and an interval from the image surface to the most object side surface of the third lens unit at a telephoto limit, IM is an image size, f f