Patent ID: 8004777

Claim:
An image pickup lens for forming an image of an object on a photoelectrical converter of a solid-state image pickup element, the image pickup lens comprising, in order from an object side thereof: an aperture stop; a first lens having a positive power and comprising a convex surface facing the object side; a second lens having a negative power and comprising a concave surface facing an image side of the image pickup lens; a third lens in a meniscus shape having a positive power and comprising a convex surface facing the image side; and a fourth lens in a meniscus shape having a negative power and comprising a convex surface facing the object side, wherein the image pickup lens satisfies following expressions: 2.0< f 123/ D 6<17.0, and 0.2< r 4/ f< 0.75, where f 123 is a composite focal length of the first lens, the second lens, and the third lens, D 6 is a length of an air space between the third lens and the fourth lens along an optical axis of the image pickup lens, r 4 is a curvature radius of the surface of the second lens facing the image side, and f is a focal length of a total system of the image pickup lens, and wherein the second lens is in a meniscus shape comprising a convex surface facing the object side.