Inkjet printing media handling system with advancing guide shim
AssigneeHewlett-Packard Development Company, L.P.
InventorsSteve O. Rasmussen, Steven B. Elgee
Life of this patent
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Abstract
Accurate advance of a media sheet is achieved by carrying the media sheet on a belt loop. An upstream pinch roller holds the media sheet to the belt upstream of the print zone. A downstream pinch roller holds the media sheet to the belt downstream of the print zone. A guide shim extends along the media path from a position upstream of the upstream pinch roller, passed the upstream pinch roller toward the print zone. The guide shim advances with the bottom edge of the media sheet into the print zone to stabilize the trailing edge so as to allow for a smaller minimum bottom margin.
Claims16
An inkjet printing apparatus which moves a media sheet along a media path and marks the media sheet with ink, comprising:
- an inkjet printhead having a plurality of inkjet nozzles which eject ink onto a portion of the media sheet located within a print zone, the print zone located adjacent to the plurality of nozzles;
- a support which supports the media sheet as the media sheet passes along the media path through the print zone;
- a roller located upstream along the media path prior to the print zone, the roller stabilizing the media sheet relative to a first surface during printing onto at least a first portion of the media sheet;
- a guide shim located along the media path, the guide shim having a guide surface extending at least from the roller, beyond the roller toward the print zone during printing, the guide shim acting upon a portion of the media sheet between the roller and the print zone to keep the media sheet out of contact with the printhead;
- and
- means for advancing the guide shim along the media path into the print zone during printing to at least a third portion of the media sheet.
The inkjet printing apparatus of claim 6, in which the support is an endless belt, and wherein the endless belt comprises an outer surface upon which the media sheet rests, the outer surface being said first surface and said second surface.
The inkjet apparatus of claim 6, in which the support moves along a path between the first roller and second roller while supporting a trailing portion of the media sheet.
A method for advancing a media sheet along a media path through a print zone of an inkjet printing apparatus, the apparatus including an inkjet printhead having a plurality of inkjet nozzles which eject ink, the print zone located adjacent to the plurality of nozzles, the method comprising the steps of:
- receiving the media sheet at a roller which stabilizes the media sheet along the media path relative to a first surface, the roller located upstream along the media path prior to the print zone;
- moving the media sheet under a guide shim toward the print zone, the guide shim acting upon a portion of the media sheet to maintain flatness and advance accuracy of the media sheet as a trailing edge of the media sheet travels beyond the roller toward the print zone;
- ejecting ink onto a portion of the media sheet located within the print zone;
- and
- advancing the guide shim along the media path into the print zone while a trailing portion of the media sheet moves into the print zone.
Dependencies are inferred from the claim text.