Patent ID: 7688523
Filing Date: 2010-03-30
Classification: G02B

Abstract:
1. 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 refractive power; a second lens having a negative refractive power and comprising a concave surface facing an image side of the image pickup lens; a third lens comprising an aspheric surface; and a fourth lens comprising an aspheric surface, wherein the image pickup lens satisfies following expressions: where f1 is a focal length of the first lens, r4 is a curvature radius of the surface of the second lens facing the image side, f is a focal length of a total system of the image pickup lens, P3 is a refractive power of the third lens, and P is a refractive power of the total system of the image pickup lens.