Patent ID: 7961408

Claim:
A five-lens image lens system, along an optical axis from an object plane to an image plane, comprising: first lens group with a negative power having a negative first lens, a negative second lens from the object plane to the image plane; a second lens group with a positive power having a positive third lens, a positive fourth lens and a negative fifth lens from the object plane to the image plane while an image-side lens surface of the positive fourth lens is glued with an object-side lens surface of the negative fifth lens; an IR cut-off filter 5 ; and a image sensing chip; wherein the five-lens image lens system satisfied the conditions: 2R2>R4>R2; 2| f 12|<| f 34|; and Vd1>Vd2, Vd4>Vd5; wherein R 2 , R 4 respectively represent curvature radius of the image-side lens surface of the negative first lens and the negative second lens; f 12 , f 34 respectively represent focal length of the negative first lens and the negative second lens; Vd 1 , Vd 2 , Vd 4 , Vd 5 respectively are Abbe numbers of the first lens, the second lens, the fourth lens, and the fifth lens.