Patent ID: 9013804
Filing Date: 2015-04-21
Classification: G02B,H04N

Abstract:
1. A zoom lens, consisting of: a first lens group having a negative refractive power; and a second lens group having a positive refractive power, provided in this order from an object side; the second lens group practically comprising an object side partial second lens group having a positive refractive power and an image side partial second lens group having a positive refractive power; the distance between the first lens group and the second lens group changing when changing magnification; focusing being performed by moving the image side partial second lens group along an optical axis; and the zoom lens satisfying the following conditional formulae: wherein D1g is the distance from the surface of a lens most toward the object side to the surface of a lens most toward the image side within the first lens group, D2g and D2t are the distance from the surface of a lens most toward the object side to the surface of a lens most toward the image side within the second lens group and the distance between the object side partial second lens group and the image side partial second lens group along the optical axis when focused on infinity at a telephoto end, respectively, ft is the focal length of the entire system at the telephoto end, and f1 and f2 are the focal lengths of the first lens group and the second lens group, respectively.