| 摘要 |
A document handler 20 for presenting documents to the platen 23 of a copier 10 for copying with a vacuum belt platen transport system 23 having plural unapertured, thin, low-frictional, document transporting belts 35 with substantial exposed spaces 35a between the edges of the belts, the belts being movable under a substantially planar vacuum plenum backing and imaging background surface 33a overlying the platen, and a vacuum system 33 for applying a partial vacuum to a document sheet being transported by the movable belts; wherein the vacuum plenum surface 33a has multiple vacuum apertures 53 located under and overlaid by the edges of the belts 35, the belts extending in rows under the belt edges across the surface, but not extending into the exposed spaces between the belts. The belts are opaque and white and optically conceal the overlaid vacuum apertures 53. The surface also has multiple vacuum grooves 54 extending transversely in closely spaced parallel rows across the exposed spaces between the edges of adjacent belts but not passing under the belts. The vacuum grooves connect with the vacuum apertures for applying a partial vacuum to a document on the belts in the exposed spaces between the belts, but not applying a partial vacuum under the belts except at the outer edges, so that the belts are substantially riding on ungrooved and unapertured and non-vacuum areas of the vacuum plenum surface to substantially reduce frictional drag between said belts and this surface. Additional vacuum channeling 58 may be provided along a registration edge for additional vacuum holding force together with a vacuum edge seal 72 overlayed by the document edge. |
