Grooved vacuum belt document handling system

摘要

A document handling system in which an air permeable belt advances documents to an imaging station of a copying machine. The belt reflects light rays transmitted thereto except in grooved areas which have been rendered at least partially transmissive to light. These grooved areas contain vacuum apertures in the belt. Semi-circular air channels in the vacuum plenum in concert with the belt apertures provide a means to hold the document to the belt. Light rays transmitted through the partially transmissive grooved areas are reflected from the air channel to back-illuminate the aperture/groove area thereby reducing background shadows associated with these aperture areas. A vacuum system is in communication with the belt for retaining the documents thereon. The vacuum system is arranged to receive the light rays transmitted through the belt and diffusely reflect the light rays incident thereon back through the belt.