Optical system, image pickup apparatus and information code reading device

摘要

An image pickup apparatus including an optical system having an optical element including an optical wavefront modulation function; and a detector at a focal position of the optical system, capturing an object image having passed through the optical system, wherein the optical element including the optical wavefront modulation function has a capability of decreasing an alteration of an optical transfer function in an entire screen due to a difference of object distances, and wherein an absolute value of a focal length of the optical element including the optical wavefront modulation function is greater than an absolute value of a focal length of the entire optical system.