ZOOM LENS SYSTEM

摘要

A zoom lens system includes: a first lens group having a negative refractive power; a second lens group having a positive refractive power; and an aperture between the first and second lens groups, wherein the first lens group and the second lens group are sequentially arranged from an object side to an image side, wherein the zoom lens system performs zooming and focusing by moving the second and first lens groups, respectively, along an optical axis, and satisfies a conditional expression below:;2.5<(fw/ft)×(Tw/Y)<4.5, ;where fw denotes an entire focal length at a wide-angle end, ft denotes an entire focal length at a telephoto end, and Tw denotes a distance between an image plane and an object side lens surface of a lens closest to the object side of the first lens group at the wide-angle end, and Y denotes a radical axis image height.

主权项

1. A zoom lens system comprising:
a first lens group having a negative refractive power; a second lens group having a positive refractive power; and an aperture disposed between the first lens group and the second lens group, wherein the first lens group and the second lens group are sequentially arranged from an object side to an image side, wherein the zoom lens system is configured to perform zooming by moving the second lens group along an optical axis, and perform focusing by moving the first lens group along the optical axis, and wherein the zoom lens system satisfies a conditional expression below:
2.5<(fw/f1)×(Tw/Y)<4.5, where fw denotes an entire focal length at a wide-angle end, ft denotes an entire focal length at a telephoto end, and Tw denotes a distance between an image plane and an object side lens surface of a lens that is closest to the object side of the first lens group at the wide-angle end, and Y denotes a radical axis image height.