Patent ID: 6937283

Claim:
An imaging apparatus for generating an image signal from incident light with higher spatial frequencies of said incident light limited to reduce undersampling artifacts, said apparatus comprising: an image sensor for generating the image signal from an array of photosites; an optical section having a spatial filter made of a highly birefringent uniaxial crystal selected from a group consisting of lithium niobate and lithium tantalate interposed in the path of the incident image light so as to produce at least four spots at a detector plane; and wherein said birefringent uniaxial crystal spatial filter is comprised of two double refractors, and said four spots form a rhomboidal pattern wherein a sharp angle of the rhomboid is 45° and wherein the spatial filter is rotated about an optical axis of the imaging apparatus such that a base of the rhomboidal pattern forms an angle with one of two major coordinates of the imaging apparatus of between 20° to 40°.