Patent Application
20190210383
A printer may include a media tray to hold a quantity of print media, a print media path to move and/or route print media through the printer, and a pick assembly to pick a sheet of print media from the media tray and feed the sheet to the media path. Improper or ineffective pick and/or feed of print media may result in media damage or jams and/or may result in unintended multi-sheet pick and/or feed of print media.
As illustrated in the example of
Input tray or trays 110 supply a bulk quantity of print media 102 or supply a single quantity of print media 102 to print engine 140 for printing on print media 102 by print engine 140. In one implementation, input trays 110 include a media tray 112 and a multi-purpose media tray 114.
In one implementation, media tray 112 is a tandem media tray set including media trays 112a and 112b. Media trays 112a and 112b are positioned side-by-side or laterally of each other, and each hold a separate quantity of print media 102. Although illustrated and described as a tandem media tray set, media tray 112 may include a single media tray.
In one implementation, multi-purpose media tray 114 is a manual or bypass media tray and receives manual input of print media 102 from externally of printer 100 such that print media 102 is directed to print engine 140 for printing. Print media 102 may include, for example, envelopes, letterhead, checks, fabric, or other print media suited for single or manual input including sheet material, such as paper, card stock, transparencies, Mylar, and the like. Multi-purpose media tray 114 may also support quantities of print media such as multi-sheet stacks of print media for input to printer 100.
Print engine 140 can be a laser print engine, an inkjet print engine, or any other type of print engine. In one implementation, a print area or print zone 142 is defined in which printing on print media 102 by print engine 140 occurs. In one example, printer 100 is implemented as an inkjet printing system, and print engine 140 includes, for example, a printhead assembly.
In one example, output bin 150 is provided at an end of print media path 120 through printer 100. In one example, output bin 150 is excluded such that a media transport path to a separate output device is provided.
Print media path 120 routes print media 102 through printer 100 for printing on print media 102 by print engine 140. More specifically, print media path 120 routes print media 102 from one or more of input trays 110, to and through print zone 142 of print engine 140, and to output bin 150 (or other output device). To achieve the handling and routing of print media 102, print media path 120 may include a variety of guides, rollers, wheels, etc.
In one implementation, print media path 120 includes input path portions 122a and 122b, an input path portion 124, and a print path portion or portions 126. In one example, input path portions 122a and 122b communicate with and receive input of print media 102 from respective media trays 112a and 112b, input path portion 124 communicates with and receives input of print media 102 from multi-purpose media tray 114, and print path portion or portions 126 direct print media 102 through print zone 142 for printing on print media 102 by print engine 140.
As noted above, pick assembly 130 picks print media 102 from input tray or trays 110 and feeds print media 102 to print media path 120. For example, pick assembly 130 picks print media 102 from multi-purpose media tray 114 and feeds print media 102 to input path portion 124 of print media path 120. As such, input path portion 124 directs print media 102 to print path portion 126 of print media path 120.
As illustrated in the example of
In one example, print media path 120 includes a series of opposing rollers and/or wheels, including, for example, a pinch roller 162 and an opposing starwheel 164, to guide and/or route print media 102 along print media path 120 including, for example, print path portion 126 of print media path 120. Although one pinch roller 162 and one starwheel 164 are illustrated and described, multiple pinch rollers 162 and/or multiple starwheels 164, including multiple pinch roller and starwheel pairs, may be provided along print media path 120.
In one implementation, a motor 138 rotates pick roller 132 to pick print media 102 from media tray 114 and feed print media 102 into media path 120, as described below. Motor 138 imparts rotation to pick roller 132 via, for example, a gear, shaft or other coupling.
In one example, a media path sensor 104 senses print media 102 in media path 120. In one implementation, media path sensor 104 provides feedback or input for operating pick assembly 130 and, more specifically, pick roller 132 of pick assembly 130, as described below.
In one example, a controller 170, including a processor and memory, communicates with pick assembly 130 to control operation of pick assembly 130. More specifically, in one implementation, controller 170 communicates with motor 138 and media path sensor 104. As such, controller 170 provides output to motor 138 for operation of pick roller 132 in picking of print media 102 from media tray 114. In addition, controller 170 receives feedback or input from media path sensor 104 regarding a position of print media 102 in media path 120, and provides output to motor 138 for operation of pick roller 132 in feeding of print media 102 to media path 120.
In one embodiment, with input of media path sensor 104, controller 170 determines a position of a leading edge of print media 102 in media path 120. As such, based on the position of the leading edge of print media 102 in media path 120, controller 170 provides output to motor 138 for operation of pick roller 132 in picking of print media 102 from media tray 114 and feeding of print media 102 to media path 120, as described below.
As illustrated in the example of
In one example, separation roller 134 is separately driven and rotated or subjected to a resistive torque in a direction opposite the direction of media feed (counterclockwise in the illustrated example). In one implementation, a torque limiter (or torque clutch) allows pick roller 132 to overdrive separation roller 134 and rotate separation roller 134 in the direction of media feed (clockwise in the illustrated example). More specifically, in instances, friction between pick roller 132 and separation roller 134, or between pick roller 132 and print media, is enough to overcome the resistive torque and rotate separation roller 134 in the direction of media feed (clockwise in the illustrated example).
For example, when only one sheet of print media is picked and in nip 136, pick roller 132 overcomes the resistive torque of separation roller 134 such that pick roller 132 overdrives separation roller 134 and rotates separation roller 134 in the direction of media feed (clockwise in the illustrated example). More specifically, friction between pick roller 132 and the one sheet of print media is enough to overcome the resistive torque such that the torque limiter allows separation roller 134 to be overdriven and rotated in the direction of media feed (clockwise in the illustrated example). Thus, the one sheet of print media is transported.
However, when multiple sheets of print media are picked and in nip 136, pick roller 132 does not overcome the resistive torque of separation roller 134 such that pick roller 132 does not overdrive separation roller 134 and separation roller 134 does not rotate in the direction of media feed (clockwise in the illustrated example). More specifically, friction between the top sheet of print media and the other sheets of print media below is not high enough to overcome the resistive torque and overdrive separation roller 134. As such, the resistive torque of separation roller 134 rotates separation roller 134 in the direction opposite the direction of media feed (counterclockwise in the illustrated example). Thus, separation roller 134 holds and separates the other sheets of print media, such that only the top sheet of print media is transported.
In one implementation, in picking print media 102 from media tray 114, pick roller 132 is rotated at a substantially constant velocity by motor 138. In one example, the substantially constant velocity of pick roller 132 is maintained using a closed loop control. For example, a speed of motor 138 is monitored and controlled, for example, by controller 170, to maintain a substantially constant velocity of pick roller 132. More specifically, a servo control may be used to control motor 138 and produce a substantially constant velocity of pick roller 132.
As illustrated in the example of
In one implementation, in feeding print media 102 into media path 120, pick roller 132 is rotated with a substantially constant torque by motor 138. In one example, the substantially constant torque of pick roller 132 is maintained using an open loop control. For example, a substantially constant current may be applied to motor 138, for example, by controller 170, to rotate pick roller 132 with a substantially constant torque. More specifically, a substantially constant pulse width modulation (PWM) may be used to control motor 138 and produce a substantially constant torque at pick roller 132. In one implementation, the substantially constant torque is defined to overcome, fully, mostly or at least partially, a drag force of nip 136 between pick roller 132 and separation roller 134 (including the resistive torque applied to separation roller 134 in a direction opposite the direction of media feed). Furthermore, in one implementation, the substantially constant torque is defined to avoid picking a next print media from media tray 114, if present.
In one example, rotation of pick roller 132 switches from rotation at a substantially constant velocity to rotation with a substantially constant torque based on a position of print media 102. More specifically, in one implementation, control of motor 138 switches from closed loop control for the substantially constant velocity to open loop control for the substantially constant torque when print media 102 including, more specifically, leading edge 102a of print media 102 is at (or beyond) pinch roller 162 of media path 120. In one example, leading edge 102a of print media 102 is sensed by media path sensor 104 and provided as input to controller 170.
As illustrated in the example of
In one implementation, after print media 102 leaves pick roller 132, operation of pick assembly 130 is paused or discontinued. More specifically, in one example, after trailing edge 102b of print media 102 leaves nip 136 between pick roller 132 and separation roller 134, pick roller 132 stops rotating and is idle.
More specifically, in one implementation, in operating pick assembly 130 in the first mode or manner, voltage is applied to motor 138 to rotate pick roller 132 at a substantially constant velocity, as described above. In addition, in one implementation, in operating pick assembly 130 in the second mode or manner, only enough voltage is applied to motor 138 to overcome the drag force of nip 136 between pick roller 132 and separation roller 134 (including the resistive torque applied to separation roller 134 in a direction opposite the direction of media feed), as described above. Thus, with no print media in nip 136, pick roller 132 is in a balanced state or equilibrium state with no velocity such that pick roller 132 is idle. However, as print media is pulled from nip 136, pick roller 132 rotates with a substantially constant torque.
In one example, with print media 102 fully within media path 120, operation of motor 138 returns to closed loop control. As such, operation of pick assembly 130, as described above, may be repeated for a next or another print media 102.
At 202, method 200 includes contacting the print media with a pick roller, such as pick roller 132, and picking the print media from the media tray, such as print media 102 from media tray 114, as illustrated, for example, in
At 204, after picking the print media, method 200 includes maintaining the contacting of the print media with the pick roller and feeding the print media to the media path, such as pick roller 132 contacting print media 102 and feeding print media 102 to media path 120, as illustrated, for example, in
In one example, rotating the pick roller in a second manner different than the first manner, for example, at 204, includes switching from the first manner to the second manner when a leading edge of the print media is at a pinch roller of the media path, such as leading edge 102a of print media 102 at pinch roller 162 of media path 120, as illustrated, for example, in
Operating a pick assembly, such as pick assembly 130, as illustrated and described herein, results in handling or moving print media in a first manner for a first portion of a pick and feed operation and handling or moving print media in a second manner for a second portion of a pick and feed operation. More specifically, rotating pick roller 132 in a first mode or manner with a substantially constant velocity facilitates picking of print media from an input tray, such as media tray 114, and feeding the print media into a media path, such as media path 120, and rotating pick roller 132 in a second mode or manner with a substantially constant torque facilitates continued feeding of the print media into the media path. As such, picking print media from an input tray and feeding print media into a media path, as illustrated and described herein, provides for picking and feeding of print media without knowing a location or position of a trailing edge of the print media. In addition, by picking and feeding print media, as illustrated and described herein, media damage and/or media jams, as well as unintended multi-sheet pick and/or feed of print media may be minimized or avoided. For example, if a location or position of a trailing edge of a print media is unknown, rotating pick roller 132 for a length longer than a length of the print media may result in additional sheets of print media being picked and fed. Rotating pick roller 132 for a length shorter than a length of the print media, however, may tear the print media and/or result in a media jam, as rollers and/or wheels of the media path, such as pinch roller 162 and starwheel 164, may not be able to pull the print media out of the nip of pick roller 132 and separation roller 134 due to the drag force created by the nip. Thus, rotating pick roller 132 in a second mode or manner with a substantially constant torque, as illustrated and described herein, allows or makes it easier for rollers and/or wheels of the media path, such as pinch roller 162 and starwheel 164, to “pull” the print media out of the nip of pick roller 132 and separation roller 134 for continued feeding of the print media into the media path without knowing a location or position of a trailing edge of the print media and without damaging the print media and/or creating a media jam. Although specific examples have been illustrated and described herein, a variety of alternate and/or equivalent implementations may be substituted for the specific examples shown and described without departing from the scope of the present disclosure. This application is intended to cover any adaptations or variations of the specific examples discussed herein.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/US2016/050757 | 9/8/2016 | WO | 00 |
