Patent ID: 6985307

Claim:
An imaging lens comprising a first lens L 1 , an aperture diaphragm S 1 , a second lens L 2 , and a third lens L 3 , and constituted such that said first lens L 1 , said aperture diaphragm S 1 , said second lens L 2 , and said third lens L 3 are arranged in succession from the object side to the image side, wherein said first lens L 1 is a resin lens having a positive refractive power and a meniscus shape in which the convex surface faces the object side, said second lens L 2 is a resin lens having a positive refractive power and a meniscus shape in which the convex surface faces the image side, and said third lens L 3 is a resin lens having a negative refractivity, both surfaces of said first lens L 1 being aspheric, both surfaces of said second lens L 2 being aspheric, and both surfaces of said third lens L 3 being aspheric, and said imaging lens satisfying the following conditions, 0.24< r 1 / r 2 <0.34 (1) 0.08 <D 2 / f< 0.1 (2) 0.24 <D 3 / f< 0.29 (3) 1.0 <d/f< 1.5 (4) where f is the focal length of the entire lens system, r 1 is the radius of curvature (axial curvature radius) of the object side surface of the first lens L 1 in the vicinity of the optical axis, r 2 is the radius of curvature (axial curvature radius) of the image side surface of the first lens Li in the vicinity of the optical axis, D 2 is the distance between the first lens Li and second lens L 2 , D 3 is the thickness at the center of the second lens L 2 , and d is the distance(in air) from the object side surface of the first lens LI to the image surface.