Patent ID: 8605365
Filing Date: 2013-12-10
Classification: G02B

Abstract:
1. A zoom lens system comprises a first lens group, having a negative refractive power, a diaphragm, and a second lens group, having a positive refractive power, in that order from an object, wherein the first lens group and the second lens group move in the optical axis direction so that the distance between the first lens group and the second lens group decreases upon zooming from the short focal length extremity to the long focal length extremity; wherein the first lens group includes a negative lens element, a negative lens element, a negative lens element, and a positive lens element, in that order from the object, wherein the second lens group includes a positive lens element, a positive lens element, a negative lens element, and a positive lens element, in that order from the object; and wherein the following conditions (1) and (2) are satisfied: wherein Σ1G designates the distance on the optical axis from the most object-side surface of the first lens group to the most image-side surface thereof, fw designates the focal length of the entire zoom lens system at the short focal length extremity, and ΔX2G designates the traveling distance of the second lens group when zooming between the short focal length extremity and the long focal length extremity is performed.