Patent ID: 7400456

Claim:
A low-pass-filter, anti-aliasing lens, comprising: a first outer lens surface configured to receive light waves incident thereon; a second outer lens surface configured to transmit light waves transmitted through the lens from the first lens surface; and a changeable aperture operably associated with the lens; wherein at least one of the first outer lens surface and the second outer lens surface is defined by a seamless profile comprising a plurality of adjoining concave and convex segments having sag perturbations disposed therealong, the seamless profile and sag perturbations being configured to reduce spatial aliasing in an image produced by the lens along a focal plane associated therewith so as to pass predetermined lower spatial frequencies and reject predetermined higher spatial frequencies; the lens, the first and second outer lens surfaces, and the aperture having an optical axis associated therewith, each of the plurality of adjoining segments being defined by a cubic polynomial function unique thereto and being rotationally symmetric in respect of the optical axis, the first and second outer lens surfaces being symmetric about the optical axis, the sag perturbations being configured to provide a controlled amount of spherical aberration such that the amount of spherical aberration provided by the lens is substantially independent of changes in the aperture.