Patent ID: 9726866
Date: 2017-08-08
CPC Classifications: G02B

Claim:
1. A zoom lens comprising, in order from an object side to an image side: a first lens unit having positive refractive power; a second lens unit having negative refractive power; a third lens unit having positive refractive power; and a fourth lens unit having positive refractive power, wherein during zooming, the first lens unit is not moved, and the second lens unit, the third lens unit, and the fourth lens unit are moved to change an interval between adjacent lens units, wherein the following conditional expressions are satisfied: where m2 is a moving amount of the second lens unit during zooming, which is a difference of a position of the second lens unit on an optical axis of the zoom lens at a wide angle end and at a telephoto end, m3 is a moving amount of the third lens unit during zooming, which is a difference of a position of the third lens unit on the optical axis of the zoom lens at the wide angle end and at the telephoto end, f2 is a focal length of the second lens unit, and fw is a focal length of the zoom lens at the wide angle end.