IMAGE PICKUP LENS, IMAGE PICKUP DEVICE USING SAME, AND PORTABLE DEVICE EQUIPPED WITH THE IMAGE PICKUP DEVICE

摘要

The present invention provides an image pickup lens capable of adequately suppressing flare caused by unnecessary diffraction order light. An image pickup lens 7 includes, in order from an object side to an image surface side: an aperture stop 5, a first lens 1 having positive power; a second lens 2 that is a meniscus lens having negative power and whose lens surface facing the image surface side is concave; a third lens 3 that is a meniscus lens having positive power and whose lens surface facing the image surface side is convex; and a fourth lens 4 that has negative power, whose lens surfaces are both aspherical and whose lens surface facing the image surface side is concave near the optical axis. A diffractive optical element is formed on the lens surface of the first lens 1 facing the image surface side. The lens surface provided with the diffractive optical element has 3 or fewer diffraction zones within its effective diameter, and the image pickup lens satisfies the following conditional expression (1): fDOE/f30  (1) where f is a focal distance of an overall optical system, and fDOE is a focal distance of the diffractive optical element alone.