Patent Application
20070182086
The present application is directed to devices and methods for moving a media sheet in an image forming device and, more specifically, to methods and devices to control a leading edge of the media sheet while entering into or moving along a media path.
An input area of an image forming device includes an input tray for holding one or more media sheets and a pick mechanism for moving the sheets through a section of the media path of the image forming device. The input area is designed to support a large variety of media sheets including paper, envelopes, cardstock, labels, signage, and the like. The mechanical properties of such an assortment of media sheets are noticeably distinct. Fiber content and alignment, material type, thickness, orientation, roughness, and other factors influence the ability of the pick mechanism to move the media sheets from the input tray.
One drawback of some previous image forming devices is the pick mechanism causes buckling of the media sheet while it moves within the input area. The buckled sheet may catch on a corner of the input tray or a support rib and fold under as the sheet is moved along the media path. The buckled sheet is also much more likely to find catch points further along the media path. The buckled media sheet may further require significantly higher motor torque on the pick mechanism to move the sheets from the input tray and along the media path.
The present application is directed to devices and methods to move media sheets within an image forming device. In one embodiment, the device includes a support floor to support the media sheet. Wear members may be positioned across a width of the support floor and include a height to extend outward from the floor. Further, support members may be positioned across the floor and have a height to also extend outward from the floor. The wear members and the support members support the media sheet as it moves along the media path. The heights of the wear members and the support members are such to prevent the media sheet from buckling being a certain amount and preventing media jams.
The present application is directed to devices and methods for moving a media sheet within an image forming device. The media path includes one or more supports spaced across the width of the path to reduce and/or eliminate buckles within the media sheet. In one embodiment, the device includes a combination of support members and wear members that are spaced across the width of the media path to support the media sheet.
A multipurpose feeder 20 may be included to move additional media sheets along the media path. The feeder 20 includes a support floor 7 adjacent to a ramp 15. A pick mechanism 19 may include a pivoting arm 8 and a roller 9. Rotation of the roller 9 moves the media sheet along the media path from the support floor 7 and up the ramp 15. The pick mechanism 19 within the multipurpose feeder 20 may be the same or different from the pick mechanism 18 associated with the media tray 13.
The operation of the image forming device 10 is conventionally known. After the media sheet is introduced through input tray 14 or the multipurpose feeder 20, the media sheet is presented at a media alignment mechanism 22. The media alignment mechanism 22 may include a nip formed between a pair of rollers 102, 104. The media alignment mechanism 22 may remove lateral skew from the media sheet and precisely time its passage on to the image forming stations downstream.
After the media sheet passes the media alignment mechanism 22 it contacts a transport belt 24, which carries the media sheet successively past photoconductor units 26. At each photoconductor unit 26, a latent image is formed by an imaging device 30 and optically projected onto a photoconductive member. The latent image is developed by applying toner to the photoconductive member from a toner reservoir. The toner is subsequently deposited on the media sheet as it is conveyed past the photoconductor unit 26 by the transport belt 24.
The toner is then thermally fused to the media sheet by the fuser 32 and the sheet then passes through reversible exit rollers 34, to land facedown in the output stack 35 formed on the exterior of the image forming apparatus body. Alternatively, the exit rollers 34 may reverse motion after the trailing edge of the media sheet has passed the entrance to the duplex path 36, directing the media sheet through the duplex path 36 for the printing of another image on the back side thereof.
In one embodiment, the ramp 15 is constructed of acrylonitrile butadiene styrene that may be susceptible to erosion caused by continuous contact with the leading edge of the media sheets. The erosion may cause the surface of the ramp 15 to become pitted or roughened which may catch the leading edges resulting in media jams. The erosion may also slow the movement of the media sheets resulting in timing issues that cause print defects.
To prevent erosion of the ramp 15, one or more wear members 40 are positioned across a width of the ramp 15. The wear members 40 extend outward from the ramp 15 and are constructed of a wear-resistant material that prevents the ramp 15 from being damaged as the leading edge of the media sheets move along the media path. The wear members 40 have a higher wear resistance than the ramp 15. In some embodiments, the wear members 40 may be constructed from acetal, TEFLON, TEFLON-impregnated nylon, TEFLON-coated steel, and stainless steel. In one embodiment as illustrated in
As illustrated in
The difference in heights between the wear members 40 and the surface of the ramp 15 may cause buckling across the width of the media sheets. Therefore, one or more support members 50 are positioned on the ramp 15. The support members 50 support the media sheets and prevent excessive buckling along the width of the sheet. As illustrated in the embodiment of
In one embodiment, support members 50 are integrally formed with the ramp 15 such as the embodiment illustrated in
In one embodiment as illustrated in
In one embodiment as discussed above, the wear members 40 and support members 50 are positioned on a ramp 15. The ramp 15 may be part of an input feeder, such as the multipurpose feeder 20 or the media tray 13. Ramps may also be positioned at other locations along the media path. In another embodiment, the wear members 40 and support members 50 are positioned along a non-ramped location. Examples of non-ramped locations may include along curves within the duplex path 36, or along a section upstream from the fuser 32.
Spatially relative terms such as “under”, “below”, “lower”, “upper”, “upstream”, “downstream”, and the like, are used for ease of description to explain the positioning of one element relative to a second element. These terms are intended to encompass different orientations of the device in addition to different orientations than those depicted in the figures. Further, terms such as “first”, “second”, and the like, are also used to describe various elements, regions, sections, etc and are also not intended to be limiting. Like terms refer to like elements throughout the description.
As used herein, the terms “having”, “containing”, “including”, “comprising” and the like are open ended terms that indicate the presence of stated elements or features, but do not preclude additional elements or features. The articles “a”, “an” and “the” are intended to include the plural as well as the singular, unless the context clearly indicates otherwise.
The present invention may be carried out in other specific ways than those herein set forth without departing from the scope and essential characteristics of the invention. In one embodiment, the wear members 40 and the support members 50 have elongated shapes and are aligned substantially parallel along the media path. The present embodiments are, therefore, to be considered in all respects as illustrative and not restrictive, and all changes coming within the meaning and equivalency range of the appended claims are intended to be embraced therein.
