Patent Application
20090051099
In a printing system for printing on print media, it is desirable for the print media to be aligned as accurately as possible to register the print media for feeding through the printing system. Deviations from aligned or straight feeding of the print media can result in image skew. More specifically, misalignment of the print media can result in an image that is printed on the print media as being tilted or angled relative to the print media. Accordingly, registering the print media to align or deskew the print media before printing of the image on the print media is desirable.
For these and other reasons, a need exists for the present invention.
In the following detailed description, reference is made to the accompanying drawings which form a part hereof, and in which is shown by way of illustration specific embodiments in which the invention may be practiced. In this regard, directional terminology, such as “top,” “bottom,” “front,” “back,” “leading,” “trailing,” etc., is used with reference to the orientation of the Figure(s) being described. Because components of embodiments of the present invention can be positioned in a number of different orientations, the directional terminology is used for purposes of illustration and is in no way limiting. It is to be understood that other embodiments may be utilized and structural or logical changes may be made without departing from the scope of the present invention. The following detailed description, therefore, is not to be taken in a limiting sense, and the scope of the present invention is defined by the appended claims.
In one embodiment, printing system 10 includes a media tray 20, a pick assembly 30, a registration assembly 40, and a controller 50. As described below, media tray 20, pick assembly 30, and registration assembly 40 are arranged and configured to supply print media 12 to a media path 14 of printing system 10 for printing on print media 12. More specifically, media tray 20 holds print media 12 and pick assembly 30 picks a sheet of print media 12 and routes print media 12 to media path 14. Registration assembly 40 is positioned in media path 14 after pick assembly 30 and senses print media 12 in media path 14. As such, registration assembly 40 registers print media 12 in media path 14, and then advances print media 12 along media path 14, as described below.
In one embodiment, media tray 20 supports or holds a plurality of sheets of print media 12 in a stacked arrangement or configuration. The stacked arrangement or configuration of print media 12 results in a stack height of print media 12. Accordingly, the stack height of print media 12 varies based on a quantity or amount of print media 12 held by media tray 20. In one exemplary embodiment, media tray 20 holds between 1 and 100 sheets of print media 12.
In one embodiment, media tray 20 includes a backing plate 22 and a transition plate 24. Backing plate 22 and transition plate 24 are arranged such that backing plate 22 supports a surface of print media 12 and transition plate 24 supports an edge of print media 12. In one exemplary embodiment, transition plate 24 extends from backing plate 22 in a horizontal manner and guides print media 12 to media path 14.
In one embodiment, backing plate 22 is oriented at an angle to horizontal. In one exemplary embodiment, the angle of backing plate 22 is an obtuse angle. As such, in the exemplary embodiment, print media 12 supported by media tray 20 is oriented in a vertical manner at an angle corresponding to the angle of backing plate 22.
In one embodiment, pick assembly 30 includes a pick arm 32 and a pick roller 34. Pick roller 34 is supported by pick arm 32 and contacts a top sheet 121 of the stack of print media 12 to pick top sheet 121 of print media 12 from the stack. In one embodiment, pick arm 32 is an articulating arm and is biased toward backing plate 22 of media tray 20 such that pick arm 32 moves toward backing plate 22 as print media 12 is removed from media tray 20.
In one embodiment, pick assembly 30 also includes a spacer wheel 36. Spacer wheel 36 is supported by pick arm 32 and maintains contact with a top sheet of the stack of print media 12 as print media 12 is removed from media tray 20. As such, spacer wheel 36 and, therefore, pick arm 32 follow the stack height of print media 12. Thus, in one embodiment, a stack height and/or a quantity or amount of print media 12 held in or supported by media tray 20 is determined from the position of pick arm 32. Although only one pick roller 34 and one spacer wheel 36 are illustrated and described, it is within the scope of the present invention for pick assembly 30 to include one or more pick rollers 34 and/or one or more spacer wheels 36.
In another embodiment, printing system 10 includes a media tray sensor 26. Media tray sensor 26 senses print media 12 in media tray 20 and provides feedback and/or input regarding a stack height and/or a quantity or amount of print media 12 held in or supported by media tray 20. In one embodiment, media tray sensor 26 includes a low media sensor of printing system 10.
In one embodiment, the position of pick arm 32 and/or input from media tray sensor 26 is used to determine a stack height and/or a quantity or amount of print media 12 held in or supported by media tray 20. As such, the stack height and/or quantity or amount of print media 12 held in or supported by media tray 20 is used to control operation of registration assembly 40, as described below.
In one embodiment, registration assembly 40 includes a feed roller 42 and a pinch roller 44. Pinch roller 44 is positioned opposite feed roller 42 such that feed roller 42 and pinch roller 44 form a nip 46 therebetween. As described below, pick assembly 30 routes print media 12 to nip 46 such that registration assembly 40 registers print media 12 in media path 14. Thereafter, registration assembly 40 advances print media 12 along media path 14. Although only one feed roller 42 and one pinch roller 44 are illustrated and described, it is within the scope of the present invention for registration assembly 40 to include one or more feed rollers 42 and/or one or more pinch rollers 44.
In one embodiment, registration assembly 40 also includes a media path sensor 48. Media path sensor 48 senses print media 12 in media path 14 and provides feedback or input for operating registration assembly 40 and, more specifically, feed roller 42 of registration assembly 40, as described below.
In one embodiment, controller 50 communicates with pick assembly 30 and registration assembly 40 to control operation of pick assembly 30 and registration assembly 40, as described below. More specifically, in one embodiment, controller 50 communicates with pick arm 32 and pick roller 34 of pick assembly 30, and communicates with feed roller 42 and media path sensor 48 of registration assembly 40. As such, controller 50 receives feedback or input from pick arm 32 regarding a position of pick arm 32, and provides output to pick roller 34 for operation of pick roller 34 and picking of print media 12 from media tray 20. In addition, controller 50 receives feedback or input from media path sensor 48 regarding a position of print media 12 in media path 14, and provides output to feed roller 42 for operation of feed roller 42 and registering of print media 12 in media path 14.
In one embodiment, with input of the position of pick arm 32 or input from media tray sensor 26, controller 50 determines a stack height and/or a quantity or amount of print media 12 held in or supported by media tray 20. In addition, with input of media path sensor 48, controller 50 determines a position of print media 12 in media path 14. As such, based on the stack height and/or quantity or amount of print media 12 held in or supported by media tray 20 and the position of print media 12 in media path 14, controller 50 provides output to feed roller 42 for registering print media 12 in media path 14, as described below.
In one embodiment, after media path sensor 48 senses a leading edge 121a of top sheet 121 in media path 14, feed roller 42 of registration assembly 40 is operated to register top sheet 121 in media path 14. More specifically, in the illustrated embodiment, feed roller 42 is rotated counterclockwise in a second direction opposite the first direction. As such, nip 46 between feed roller 42 and pinch roller 44 is driven opposite to the direction in which top sheet 121 is fed to nip 46. Thus, feed roller 42 and pinch roller 44 register top sheet 121 in media path 14. In registering top sheet 121 in media path 14, feed roller 42 and pinch roller 44 deskew or align top sheet 121 in media path 14.
In one embodiment, registration assembly 40 is operated for a predetermined time based on the quantity or amount of print media 12 in media tray 20 to register print media 12 in media path 14. More specifically, as the quantity or amount of print media 12 in media tray 20 decreases, the predetermined time that registration assembly 40 is operated to register print media 12 in media path 14 increases, as described below.
As illustrated in the embodiment of
As illustrated in the embodiment of
In one embodiment, after media path sensor 48 senses a leading edge 122a of top sheet 122 in media path 14, feed roller 42 of registration assembly 40 is operated to register top sheet 122 in media path 14. More specifically, in the illustrated embodiment, feed roller 42 is rotated counterclockwise in a second direction opposite the first direction. As such, nip 46 between feed roller 42 and pinch roller 44 is driven opposite to the direction in which top sheet 122 is fed to nip 46. Thus, feed roller 42 and pinch roller 44 register top sheet 122 in media path 14. In registering top sheet 122 in media path 14, feed roller 42 and pinch roller 44 deskew or align top sheet 122 in media path 14.
As described above, registration assembly 40 is operated for a predetermined time based on the quantity or amount of print media 12 in media tray 20 to register print media 12 in media path 14. More specifically, as the quantity or amount of print media 12 in media tray 20 decreases, the predetermined time that registration assembly 40 is operated to register print media 12 in media path 14 increases, as described below.
In one embodiment, as described above, pick arm 32 is an articulating arm and is biased toward backing plate 22 of media tray 20 such that spacer wheel 36 maintains contact with a top sheet of print media 12. As such, with a reduced stack height of print media 12, pick arm 32 moves closer to backing plate 22. Thus, compared to the higher stack height of print media 12 in the embodiment of
Accordingly, with the lower stack height of print media 12 in the embodiment of
As illustrated in the embodiment of
Although specific embodiments have been illustrated and described herein, it will be appreciated by those of ordinary skill in the art that a variety of alternate and/or equivalent implementations may be substituted for the specific embodiments shown and described without departing from the scope of the present invention. This application is intended to cover any adaptations or variations of the specific embodiments discussed herein. Therefore, it is intended that this invention be limited only by the claims and the equivalents thereof.
