Patent ID: 6856467
Filing Date: 2005-02-15
Classification: G02B

Abstract:
1. An image pickup system comprising a zoom lens and an image pickup plane located on an image side of the zoom lens, wherein: said zoom lens comprises, in order from an object side of said zoom lens, a first lens group of negative refracting power comprising a negative lens element having an aspheric surface and a positive lens element, a second lens group comprising, in order from an object side thereof, a positive single lens element L for zooming from a wide-angle end to a telephoto end of said zoom lens focused on an object point at infinity, said second lens group moves only toward the object side, said third lens group moves in a locus different from that of said second lens group, said third lens moves for focusing, and the following conditions (1) and (2) are satisfied: where R 21F is an axial radius of curvature of an object side-surface of the single lens element L 21 in the second lens group, R 21R is an axial radius of curvature of an image side-surface of the single lens element L 21 in the second lens group, and β 2T is a magnification of the second lens group at the telephoto end focused on an object point at infinity.