Patent Number: 7,133,214

Title: Zoom lens system and image-taking apparatus having the same

Abstract: A zoom lens system is disclosed, comprising, in order from an object side to an image side, a first lens unit with a positive refractive power, a second lens unit with a negative refractive power, a third lens unit with a positive refractive power, and a fourth lens unit with a positive refractive power, wherein a distance between the respective lens units is changed during zooming. The third lens unit consists of, in order from the object side to the image side, a first lens sub-unit including a positive lens with an object-side surface which has a convex shape and having a positive refractive power, an aperture stop, a second lens sub-unit including a negative lens and having a negative optical power, and a third lens sub-unit including a positive lens and having a positive optical power.

Inventors: Hoshi; Koji (Tochigi, JP)

Assignee: Canon Kabushiki Kaisha

International Classification: G02B 15/14 (20060101)

Expiration Date: 2019-11-07 0:00:00