Apparatus and method for transporting print media through a printzone of a printing device

#The present invention relates to printing devices. More particularly, the present invention relates to an apparatus and method enabling dual-loading of print media through a printzone of a printing device.

#Printing devices, such as inkjet printers and laser printers, use printing composition (e.g., ink or toner) to print images (text, graphics, etc.) onto a print medium in a printzone of the printing device. Inkjet printers may use print cartridges, also known as “pens”, which deposit printing composition, referred to generally herein as “ink”, onto a print medium such as paper, labels, forms, transparencies, or fabric. Each pen has a printhead that includes a plurality of nozzles. Each nozzle has an orifice through which the printing composition is ejected. To print an image, the printhead is propelled back and forth across the print medium by, for example, a carriage while ejecting printing composition in a desired pattern as the printhead moves. The particular ink ejection mechanism within the printhead may take on a variety of different forms known to those skilled in the art, such as thermal printhead technology. For thermal printheads, the ink may be a liquid, with dissolved colorants or pigments dispersed in a solvent.

#Printing devices typically include an input tray which houses a supply of print media. Some printing devices have multiple input trays that allow different types (e.g., size, color, weight, composition, etc.) of print media to be used in a printing device. Multiple input trays also allow back-up supplies of print media to be available so a user doesn't have to load print media into a printing device as often. During operation of a printing device, a print medium is selected from an input tray. Once a print medium has been acquired from the input tray, it is transported to the printzone for printing. Subsequent to printing in the printzone, the print medium is ejected from the printing device.

#FIG. 1 is a diagrammatic view of a printing device that includes an embodiment of the present invention.

#FIG. 1 is a diagrammatic view of an inkjet printing device 20 that includes an embodiment of the present invention and which may be used for printing business reports, correspondence, desktop publishing, and the like. A variety of printing devices are commercially available. For instance, some of the printing devices that may embody the present invention include printers, plotters, copiers, and facsimile machines, to name a few, as well as various combination devices, such as combination facsimiles and printers. In addition, the present invention may be used in a variety of types of printing devices such as inkjet printers and laser printers.

#Some of the major elements of printing device 20 are shown in FIG. 1, including print engine 22, print medium transport mechanism 24 in accordance with the present invention, and vacuum platen 26. Print engine 22 may comprise any type of apparatus by which an image is recorded on print medium 28, including inkjet printing mechanisms and laser mechanisms. A processing device 30 is used to control formation of images on print medium 28 by print engine 22, as generally indicated by arrow 32. Processing device 30 often receives instructions from a host device, typically a computer, such as a personal computer (not shown). Many of the functions of processing device 30 may be performed by a host computer (not shown), including any printing device 20 drivers resident on the host computer, by electronics (also not shown) in printing device 20, or by interactions between the host computer and the electronics. As used herein, the term “processing device 30” encompass these functions, whether performed by a host device, printing device 20, an intermediary device between the host device and printing device 20, or by combined interaction of such elements.

#Print medium transport mechanism 24 also includes a porous belt 34 that is disposed around a pair of driven rollers 36 and 38. Rollers 36 and 38 may be selectively driven by processing device 30 of printing device 20 and one or more motors and drive gears (which are not shown) so as to rotate about points 40 and 42 in either a clockwise or counter-clockwise direction which allows porous belt 34 to selectively move in either of the directions indicated by arrows 44 and 46. Porous belt 34 is in fluid communication with vacuum platen 26 by, for example, a plurality of apertures (not shown) formed though porous belt 34. In this manner, print medium 28 is held against porous belt 34 for the span of the length of vacuum platen 26 and can be moved to and from printzone 48 any number of times. This span may be changed by resizing the dimensions of vacuum platen 26.