US Patent 7467879 Document illuminator with stepped optical element

An apparatus for scanning a document comprises a platen for supporting at least a portion of the document; a light source; and an optical element for directing light from the light source to the platen. The optical element defines a plurality of small planar surfaces, the small planar surfaces being arranged in a linear array. Light emanating from a source is reflected from one of the small planar surfaces and emerges substantially perpendicular to an exit surface.