Patent ID: 7420746
Filing Date: 2008-09-02
Classification: G02B

Abstract:
1. A zoom lens system comprising, in order from an object side to an image side: a first lens unit having a positive optical power; a second lens unit having a negative optical power; a third lens unit having a positive optical power; and a fourth lens unit having a positive optical power, wherein the first lens unit consists of, in order from the object side to the image side, a first lens element having a negative optical power, a second lens element having a positive optical power, and a third lens element having a positive optical power; wherein the second lens unit consists of, in order from the object side to the image side, a fourth lens element having a negative optical power, a fifth lens element having a negative optical power, and a sixth lens element having a positive optical power, wherein an absolute value of an optical power of a surface on the image side of the fourth lens element is larger than an absolute value of an optical power of a surface on the object side of the fourth lens element, wherein the fifth lens element has a concave surface facing the object side, wherein an absolute value of an optical power of a surface on the object side of the sixth lens element is larger than an absolute value of an optical power of a surface on the image side of the sixth lens element, wherein a surface on the image side of the fifth lens element and a surface on the object side of the sixth lens element are located away from each other along an optical axis; wherein the second lens unit and the fourth lens unit move during zooming, and wherein a focal length of the second lens element (f