Patent ID: 7982977

Claim:
An imaging lens, comprising: an iris, a first lens, a second lens, a third lens, and fourth lens sequentially arranged in a direction from an object side, wherein the first lens is a positive lens having positive refractive power, wherein the second lens is a negative lens having negative refractive power, wherein the third lens is a positive lens, which has at least one surface formed in an aspherical shape and has positive refractive power, and wherein the fourth lens is a negative lens, which has an image side surface formed in an aspherical shape and an object side surface formed in a spherical shape, and has negative refractive power, and wherein the imaging lens is configured to satisfy the following conditional expressions: ( r 3 +r 4)/( r 3 −r 4)>−0.7 [1] v 1 −v 2>15.0 [2] v 3 −v 2>15.0 [3] 0>R 3R >R 4F [4] where r 3 is a radius of curvature of an object side surface of the second lens, r 4 is a radius of curvature of an image side surface of the second lens, v 1 , v 2 and v 3 are Abbe constants of the first, second and third lenses, respectively, R 3R is a radius of curvature at a center of an image side surface of the third lens, and R 4F is a radius of curvature at a center of an object side surface of the fourth lens.