Patent ID: 8614856

Claim:
An imaging lens for solid-state imaging elements, comprising: a first lens directing a convex surface toward an object side near an optical axis and having positive refractive power; a second lens directing concave surfaces toward the object side and an image side near the optical axis and having negative refractive power; a meniscus-shaped third lens directing a convex surface toward the image side near the optical axis and having positive refractive power; and a biconcave-shaped fourth lens directing concave surfaces toward the object side and the image side near the optical axis, wherein the first to fourth lenses are arranged in this order from the object side of the imaging lens, and conditional expressions (1), (2), (3), and (8) are satisfied, the conditional expressions (1), (2), (3), and (8) being −0.95<f2/f<−0.5, −0.95<f4/f<−0.35, −0.025≦r8/r7<0.0, and −0.064≦r4/r3<0.0 respectively, where f represents the composite focal length of the entire imaging lens system; f2 represents the focal length of the second lens; f4 represents the focal length of the fourth lens; r3 represents the curvature radius of the object side surface of the second lens; r4 represents the curvature radius of the image side surface of the second lens; r7 represents the curvature radius of the object side surface of the fourth lens; and r8 represents the curvature radius of the image side surface of the fourth lens.