Zoom lens system, imaging device and camera

摘要

A zoom lens system, in order from an object side to an image side, comprising: a first lens unit having positive optical power; a second lens unit having negative optical power; a third lens unit having positive optical power; a fourth lens unit having negative optical power; a fifth lens unit; and a sixth lens unit, wherein in zooming from a wide-angle limit to a telephoto limit at a time of image taking, the first lens unit, the second lens unit, the third lens unit, and the fourth lens unit move along an optical axis so that an interval between the third lens unit and the fourth lens unit at the telephoto limit is larger than that at the wide-angle limit, and wherein focusing from an infinity in-focus condition to a close-object in-focus condition is performed by moving the fourth lens unit along the optical axis.

主权项

1. A zoom lens system, in order from an object side to an image side, comprising:
a first lens unit having positive optical power; a second lens unit having negative optical power; a third lens unit having positive optical power; a fourth lens unit having negative optical power; a fifth lens unit; and a sixth lens unit, wherein in zooming from a wide-angle limit to a telephoto limit at a time of image taking, the first lens unit, the second lens unit, the third lens unit, and the fourth lens unit move along an optical axis so that an interval between the third lens unit and the fourth lens unit at the telephoto limit is larger than that at the wide-angle limit, wherein focusing from an infinity in-focus condition to a close-object in-focus condition is performed by moving the fourth lens unit along the optical axis, and wherein the following conditions (3) and (4) are satisfied:
fT/fW>12.0  (3)FT/FW<1.4  (4) where fT is a focal length of the zoom lens system at the telephoto limit, fW is a focal length of the zoom lens system at the wide-angle limit, FT is an F-number at the telephoto limit, and FW is an F-number at the wide-angle limit.