| 摘要 |
<p>An optical scanning device for scanning a document to produce image signals related to the density of the image on successively scanned document areas includes a platen (10) for supporting a document and a surface (50) of substantially uniform reflectivity extending along the edge of the platen. A bar of light (58) is directed so as to strike the document and the surface (50) of substantially uniform reflectivity and moves across the document in synchronization with optical scanning of the document. Light reflected from the surface of substantially uniform reflectivity is directed to a plurality of reference transducers (52, 54) which sense the position of the bar of light. A servo control loop (60, 64), responsive to the reference transducers, positions a reflector (42) during the scanning operation so that the area on the document being scanned is properly illuminated.</p> |
