Patent ID: 8289624

Claim:
An imaging lens system including, in order from an object side to an image side: a first lens group comprising a first lens element having a convex object-side surface; and a second lens group comprising a second lens element with positive refractive power; wherein the imaging lens system further includes an EDOF coding element, and an object is imaged on an electronic sensor; wherein by moving the first lens group and the second lens group along an optical axis, the zooming operation is performed such that the system switches between a wide-angle mode and a telephoto mode; and wherein a radius of curvature of the object-side surface of the first lens element is R 1 , a radius of curvature of an image-side surface of the first lens element is R 2 , a radius of curvature of an object-side surface of the second lens element is R 3 , a focal length of the imaging lens system in the wide-angle mode is f W , and they satisfy the relations: 1.5< R 1/ R 2; and 0.4< R 3/ f W <0.6.