Patent ID: 8194330

Claim:
An imaging lens comprising: a first lens: a second lens; a third lens; an aperture stop; and a fourth lens, which are sequentially arranged from the object side of the imaging lens, wherein the first lens has negative power, and an object-side surface of the first lens is convex and an image-side surface of the first lens is concave, and wherein an object-side surface and an image-side surface of the second lens are aspheric, and the second lens has negative power in the vicinity of the optical axis of the imaging lens, and the object-side surface of the second lens is concave in the vicinity of the optical axis, and the image-side surface of the second lens is concave in the vicinity of the optical axis, and wherein an object-side surface and an image-side surface of the third lens are aspheric, and the third lens has positive power in the vicinity of the optical axis of the imaging lens, and the object-side surface of the third lens is convex in the vicinity of the optical axis, and the image-side surface of the third lens is convex in the vicinity of the optical axis, and wherein an object-side surface and an image-side surface of the fourth lens are aspheric, and the fourth lens has positive power in the vicinity of the optical axis of the imaging lens, and the object-side surface of the fourth lens is concave in the vicinity of the optical axis, and the image-side surface of the fourth lens is convex in the vicinity of the optical axis, and wherein when the paraxial curvature radius of the image-side surface of the second lens is r 4 , and the paraxial curvature radius of the object-side surface of the third lens is r 5 , the following formula (1) is satisfied: 0.0 <r 5 /r 4<1.0 (1).