Patent ID: 8310768

Claim:
An optical imaging lens system comprising five lens elements with refractive power, in order from an object side to an image side: a first lens element with positive refractive power having a convex object-side surface; a second lens element with negative refractive power; a third lens element having a convex object-side surface and a concave image-side surface; a fourth lens element having both surface being aspheric; and a fifth lens element having a concave image-side surface with at least one inflection point formed thereon; wherein the optical imaging lens system further comprises a stop and an electronic sensor on which an object is imaged; wherein a focal length of the optical imaging lens system is f, a focal length of the first lens element is f 1 , a focal length of the fourth lens element is f 4 , a thickness of the fourth lens element on the optical axis is CT 4 , a thickness of the fifth lens element on the optical axis is CT 5 , a distance on the optical axis between the stop and the electronic sensor is SL, a distance on the optical axis between the object-side surface of the first lens element and the electronic sensor is TTL, and they satisfy the relation: 0.28 ≦f/f 1 −f/f 4<1.5; 0.8 <CT 4 /CT 5<1.5; and 0.7 <SL/TTL< 1.1.