Patent ID: 9250425
Filing Date: 2016-02-02
CPC Classification: G02B

Claim Text:
1. A zoom lens comprising, sequentially from an object side: a first lens group having a negative refractive power; a second lens group having a positive refractive power; a third lens group having a negative refractive power; and a fourth lens group having a positive refractive power, wherein, when zoom is varied from a wide angle end to a telephoto end, positions of the first lens group and the fourth lens group are fixed with respect to an optical axis, wherein the second lens group comprises, sequentially from the object side, a second A lens group having a positive refractive power and a second B lens group having a positive refractive power, and the second B lens group is moved along the optical axis to perform a focusing function from an object that is disposed in a close range to an object that is disposed at infinity, wherein the third lens group is shifted in a direction perpendicular to the optical axis to correct image blur, wherein the first lens group comprises, sequentially from the object side: wherein “fl” denotes a focal length of the first lens group, and “ft” denotes a focal length of the zoom lens at the telephoto end.