Patent ID: 7609454

Claim:
An imaging lens comprising, in the order from the object side to the image side thereof, a first lens of positive refraction power, a second lens of negative refraction power, a third lens of positive refraction power, and a fourth lens of negative refraction power; the imaging lens satisfying the formulae: 1 <T/F< 1.4; R 3 /F> 4; and S 1 /S 2>3, wherein T is the overall length of the imaging lens, F is the focal length of the imaging lens, R 3 is the radius of curvature of the object-side surface of the second lens, S 1 is the vertical distance from the edge to the center of the image-side surface of the third lens, and S 2 is the horizontal distance from the edge to the center of the image-side surface of the third lens.