Plural belt document feeder with optimum optical properties
US4903074A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 12, 1989 |
| Grant date | Feb 20, 1990 |
| Priority date | — |
| Expiry date | Apr 12, 2009 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03G2215/00185
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A document feeder is provided for presenting documents to the platen of a copier for copying with a vacuum belt platen transport system having document transporting belts movable under a substantially planar vaccum plenum backing. Also included is a vacuum system for applying a partial vacuum to a document sheet being transported by the movable belts over the platen. Show-through and show-around problems are reduced by optically mtching the belts and the plenum backing. In the preferred embodiment, the background surface is slightly roughend and made to be approximately 92% reflective to light during image exposure. The belts are composed of a urethane material which is approximately 16% transmissive but provides a 91% reflectance when moving along the plenum surface.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.