Patent ID: 9291803
Filing Date: 2016-03-22
CPC Classification: G02B

Claim Text:
1. A zoom lens comprising, in order from an object side toward an image side: a first lens unit having a positive refractive power; a second lens unit having a negative refractive power; a third lens unit having a positive refractive power; and a fourth lens unit having a positive refractive power, wherein the second lens unit, the third lens unit, and the fourth lens unit are moved during zooming, wherein a position of the third lens unit at a telephoto end is closer to the object side than a position of the third lens unit at a wide-angle end, and wherein the zoom lens satisfies the following conditional expressions: where fw denotes a focal length of the zoom lens at the wide-angle end, m2 denotes a difference with respect to an image plane in positions of the second lens unit on an optical axis between that at the wide-angle end and that at the telephoto end, f2 denotes a focal length of the second lens unit, β3