Patent ID: 8179611
Filing Date: 2012-05-15
Classification: G02B

Abstract:
1. A zoom lens system that forms an optical image of an object with variable magnification of a factor of 3 or greater, the zoom lens system, in order from an object side to an image side, comprising: a first lens unit having negative optical power; a second lens unit having positive optical power; and a third lens unit having positive optical power, wherein in zooming from a wide-angle limit to a telephoto limit, the lens units move respectively along an optical axis in such a manner that an interval between the first lens unit and the second lens unit should decrease while an interval between the second lens unit and the third lens unit should vary so that the variable magnification is achieved, the first lens unit is composed of one object side lens element and one image side lens element, in the first lens unit, the object side lens element has negative optical power while the image side lens element has positive optical power, and the following conditions are satisfied: ω where, f f ω