Inventors:
Michael Lee - San Jose CA, US
International Classification:
G03G015/16
Abstract:
This disclosure relates to a modified transfer-roll system and method for electrophotographic printing or the like. A photoconductor, e.g., a photoconductive roller or belt, is provided for collecting a first photostatic charge in a selected form corresponding to an image to be printed, and for retaining toner in the form of the image on a first surface of printing media. Using a first selected voltage from a first power source, a photostatic charging device, such as a charge roller and/or corona, is used to apply the first photostatic charge to the photoconductor. A laser write device activates selected portions of the charge applied to the photoconductor, such portions being in the form of the image. A development roller then transfers toner to the photoconductor, the toner photostatically adhering to the photoconductor in the form of the image. A transfer roller, in contact with the photoconductor at a selected transfer point, transfers the toner image from the photoconductor to the first surface of the printing media. At least one end of the transfer roller is sized and configured for accommodating overhanging edges of printing media as a setback from the paper edges and for clearance from toner on the photoconductor. A second power source applies a second selected voltage to the transfer roller, thereby attracting toner thereto, so as to effect transfer of the toner image from the photoconductor to the printing media first surface. Alternatively, a second surface of the printing media has a second photostatic charge to attract the toner retained by the photoconductor for transfer of the toner image.