Rotatable print cartridge and method of operation for transporting print media within an electrophotographic printer

摘要

A new and improved electrophotographic printer and method of operation wherein a disposable print cartridge is rotatably mounted within the printer housing and is operative to directly drive paper out of a paper stack within a paper cassette in the housing and into the active print area therein between the surface of a photoconductive drum and an adjacent transfer roller. The rotatable disposable print cartridge is constructed to include a plurality of paper pick up strips and idler rollers uniformly spaced at predetermined locations along the surface of the disposable print cartridge and operative to be directly driven into contact with paper during the paper pick transport and print modes of the printer. In the non-print mode and in preparation for picking and printing the next sheet, the disposable print cartridge is rotated clockwise while the stack of paper drops away from the cartridge surface to avoid contact with the print cartridge at this time. In the subsequent paper pick and print mode, the print cartridge is rotated in a counter-clockwise direction down into direct contact with the top sheet of paper in the rising paper stack in the input paper cassette for driving it into the print area. During this later motion, a drive roller operates against the paper surface to drive the paper between the photoconductive drum and an adjacent transfer roller for printing an image on the paper. Advantageously, the above print cartridge rotational motion eliminates the need for dry powder toner stirrers as well as paper pick rollers.