Scanners

Claim 1

A scanner for providing electronic signals descriptive of information in a document, including: a platen having a convex, circular cylindrical surface, said cylindrical surface having an axis; means for moving a document over said platen in contact with said cylindrical surface in a direction parallel to said axis; said platen having a slot open at said cylindrical surface and elongate in a plane perpendicular to said axis; an opaque enclosure bounding an enclosed integrating space and having a diffusely reflecting internal surface, said enclosure being at the side of said platen remote from said cylindrical surface, said slot being open to said enclosed space, said axis being at the exterior of said enclosure remote from said platen; a window providing access for light between the exterior and the interior of said enclosure, said window being located across said plane perpendicular to said axis and so disposed and of such size that all parts of said slot may be seen from said axis through said window; means for directing a beam of light from the exterior of the enclosure through said window and said slot to form a spot on that portion of a document in contact with said platen which overlies said slot, the line of the axis of the portion of said beam within said enclosure intersecting said axis of said cylindrical surface; means for imparting a scanning motion to said beam so that said spot scans said document and whereby said line of said axis of said beam remains intersecting said axis of said cylindrical surface during said scanning motion; and detector means for sensing the intensity of light diffusely reflected into the enclosed space by the portion of said document illuminated by said spot and for providing an electronic signal related to the intensity of the reflected light and thereby descriptive of the information in the portion of the document on which the spot is incident.