Patent ID: 6327098
Filing Date: 2001-12-04
Classification: G02B

Abstract:
A wide-angle zoom lens system comprising a negative first lens group, a positive second lens group, a diaphragm, and a positive third lens group, in this order from an object;wherein upon zooming from the short focal length extremity towards the long focal length extremity, each lens group is arranged to move so that the space between said first and second lens groups and the space between said second and third lens groups are narrowed, and said diaphragm moves integrally with said third lens group;wherein at least one negative lens element having a concave surface facing towards an image is provided in said first lens group, and said concave surface is an aspherical surface; andwherein said wide-angle zoom lens system satisfies the following condition;0.8<X1/fS<2.0whereinX1 designates the distance, along the optical axis, between said aspherical surface in said first lens group and said diaphragm at the long focal length extremity; andfS designates the focal length of the entire lens system at the short focal length extremity.