Patent Number: 6,297,914

Title: Zoom lens system

Abstract: A two-lens-group zoom lens system includes a positive first lens group and a negative second lens group in this order from the object, and zooming is performed by varying the distance between the first and the second lens groups. The positive first lens group includes a negative first lens element, a plastic-made second lens element having at least one aspherical surface, and a positive third lens element in this order from the object. The zoom lens system satisfies the following conditions: wherein f.sub.T designates the focal length of the entire zoom lens system at the long focal length extremity; f.sub.1G designates the focal length of the positive first lens group; f.sub.2G designates the focal length of the negative second lens group; and .nu..sub.dL3 designates the Abbe number with respect to the positive third lens element in the positive first lens group.

Inventors: Enomoto; Takashi (Chiba, JP)

Assignee: Asahi Kogaku Kogyo Kabushiki Kaisha

International Classification: G02B 15/16 (20060101); G02B 015/14 (); G02B 013/18 ()

Expiration Date: 10/02/2018