| CPC G02B 15/144 (2019.08) [G02B 13/0045 (2013.01); G02B 13/009 (2013.01); G02B 15/20 (2013.01); G02B 15/167 (2013.01)] | 16 Claims |

|
1. A zoom optical system, comprising:
a first lens group, a second lens group, a third lens group, and a fourth lens group which are sequentially arranged from an object side to an image side,
wherein each of the first lens group to the fourth lens group includes two lenses,
wherein the second lens group and the third lens group are movable,
wherein the first lens group consists of a first lens and a second lens which are sequentially arranged from the object side to the image side,
wherein the second lens has an object side plane convex to the object side and an image side plane convex to the object side,
wherein the object side plane of the second lens has a larger curvature radius than a curvature radius of the image side plane of the second lens, and
wherein an effective focal length (EFL) in a telephoto is defined by Mathematical Expression below:
![]() where EFLtele refers to the effective focal length of the zoom optical system in the telephoto, and HimageD refers to a value of half a diagonal length of an image sensor pixel area.
|