ROTARY SCANNER

摘要

A high quality, relatively inexpensive rotary scanner provides both transmission and reflection scanning of documents mounted on a rotary drum. The drum translates with respect to an imaging lens located adjacent the drum and on the exterior thereof. A first illuminating (92) element surrounding the imaging lens illuminates the document on the drum for reflection scanning; a second illuminating element (162) mounted on a cantilevered arm extending along the axis of the drum illuminates the document for transmission scanning. Focusing of the image is performed either automatically or under the control of the user. A high resolution and wide dynamic range is provided by a set of photomultiplier tubes which receive light from the imaging lens by way of an aperture wheel which provides apertures of selectable size in accordance with the desired resolution. User replaceable lamp modules allow the precise positioning of high intensity replacement lamps without need for a technician.