Patent ID: 7440195
Filing Date: 2008-10-21
Classification: G02B

Abstract:
1. A zoom lens system for directing an optical image on an electric image sensor, said zoom lens system comprising: a first lens unit disposed on a most object side and having a negative optical power; a second lens unit having a positive optical power; and a following lens unit including at least a third lens unit and a fourth lens unit, wherein at least one lens unit included in the following lens unit has at least a positive lens element and a negative lens element, wherein the following condition is satisfied: where fl is a focal length of the most image side lens unit, and fw is a focal length of the zoom lens system in a shortest focal length condition; and wherein the focusing is performed by moving on the optical axis a positive single lens element disposed in a position on the image side of a diaphragm, the positive single lens element not included in the most image side lens unit.