Patent Application
20160116885
Systems and methods herein generally relate to printing devices, and more particularly to utilization of pressurized airflow within such devices.
Printing devices often utilize pressurized airflow to assist many operations, such as cooling. Fixed geometry paper paths lead to a general tendency in terms of paper trajectory, but an outlying paper type may be problematic and clash with the structure of the paper path. Image quality marks on the prints and physical damage to the print cartridge due to poor paper trajectory from transfer nip to fuser nip are some results of media sheets not following the correct path within printing devices. Typically star wheels and guides are employed to re-direct the paper pre fuser, however these may result in other image quality (IQ) defects such as smear.
Printing apparatuses herein include, among other components, a media path transporting sheets of print media in a process direction. A transfer station is located at a first location of the media path, and a fusing station is located at a second location of the media path (the second location is closer to the end of the media path (in the process direction) relative to the first location).
Also, a single blower is located adjacent the fusing and transfer stations, and two outlets receive air from the single blower. More specifically, ducting is connected to the single blower, and a first outlet and a second outlet are openings within the surface of the ducting. The first outlet (of the two outlets) provides air to the transfer station to reduce the temperature of the transfer station, and the second outlet (of the two outlets) is located between the transfer station and the fusing station and directs the sheets of print media toward one side of the media path. The transfer station is heated during printing operations (e.g., by radiant heat from the fuser and other components), and the first outlet cools the transfer station to dissipate such heat, while the second outlet acts as an air knife to properly position the print media within the media path.
Such printing apparatuses can include a valve located between the single blower and the second outlet, and a processor operatively (meaning directly or indirectly) connected to the valve. The processor controls the valve to cause the second outlet to selectively direct only identified types of the sheets of print media toward one side of the media path.
The transfer station and the fusing station are separated by a distance that is less than a length of the sheets of print media, and the transfer station and the fusing station operate at different sheet feeding speeds, which forms a buckle in the sheets of print media. The second outlet directs the sheets of media into a position to properly form such a buckle.
These and other features are described in, or are apparent from, the following detailed description.
Various exemplary systems and methods are described in detail below, with reference to the attached drawing figures, in which the same numbers represent the same or similar components, where:
As mentioned above, image quality marks on the prints and physical damage to the print cartridge due to poor paper trajectory from transfer nip to fuser nip are some results of media sheets not following the correct path within printing devices. Therefore, constrained or tight paper path geometry, specifically between the transfer nip and fusing nip, will lead to necessary compromises where ranges of paper weights and/or paper sizes are used. Creating printing devices that are robust to any type or size of print media is very challenging with a fixed geometry paper path.
With printing devices, the lead edge of the page leaves the transfer nip travelling up in a vertical paper path and naturally tends toward a first side of the media path, and the lead edge then touches the fuser guide first side and tacks to the fuser nip. As the rotational speeds of the transfer and fuser nips differ slightly a small buckle toward the first side (curvature in the page) is formed. The range of paper sizes, weights and beam strengths of print media that are used within printing devices occasionally results in a media type that does not conform to the ideal media type and, given that the paper path is fixed, the page tracks to an undesirable second side of the media path, which causes the print media to strike components, either causing or leading to physical damage to the components or disturbing the image on the page and creating image quality defects.
To keep the print media biased toward the desirable first side of the media path, the devices herein utilize an air jet or blade that targets the lead edge of the sheet as it exits the transfer nip. The air jet guides the leading edge of the print media sheet to the first side in the paper path and away from internal structures, and this naturally forms an ideal buckle toward the first side. More specifically, the devices herein include an air guide over the top of the print cartridge, which takes in air at the top from a cooling duct, and directs jets and blades of air at the incoming paper edge.
Issues with trailing edge flick are also countered by the air knife. Specifically, some air is allowed to flow across the top of the air guide and target the trail edge of the sheet of media just before it enters the fuser nip, again imparting enough force to push the page image side away from the undesirable fuser guide second side.
Additionally, with printing devices that maintain an identification of the type of print media in use, the control system is optimized further to only activate the air knife when problem paper types are being processed, and the air knife can remain off for normal use. Additionally, the flow rates are adjusted through fan speed control to increase the air pressure outputs from the air knife for difficult media requiring an extra force.
For example, the transfer nip 110 is formed between opposing rollers 112, 114, at least one of which is powered by a motor. As is understood by those ordinarily skilled in the art, the transfer nip 110 is formed between pressure roller 112 and a transfer device 114 that contains marking material that is to be transferred to the sheet of media 102. For example, the transfer device 114 can comprise a photoreceptor (PR), an intermediate transfer belt (ITB), or any other surface that contains patterned marking material (e.g., toners, liquid or solid inks, etc.) that is to be transferred to the sheet of media 102. The pressure roller 112 or the transfer device 114 can be powered by one or more motors.
Similarly, the fuser nip 120 is formed between opposing rollers 122, 124, at least one of which is heated, and at least one of which is powered by a motor. As is understood by those ordinarily skilled in the art, the heat and pressure supplied by the opposing rollers 122, 124 at the nip 120 permanently binds the marking material to the print media.
The printing devices herein also include at least one speed control circuit 224 (shown in
Thus, as shown in
Also, a single blower 130 is located adjacent the fusing station 120, and two outlets 134, 136 receive air from the single blower 130. More specifically, ducting 132 is connected to the single blower 130, and a first outlet 136 and a second outlet 134 are openings within the surface of the ducting 132. Block arrows within the ducting 132 represents airflow and, more technically, an area of increased air pressure relative to the air pressure exterior to the ducting 132, resulting in airflow out of the outlets 134, 136.
The first outlet 136 (of the two outlets) provides air to the transfer station 110 to reduce the temperature of the transfer station 110, and the second outlet 134 (of the two outlets) is located between the transfer station 110 and the fusing station 120 and directs the sheets of print media toward one side of the media path. The transfer station 110 is heated during printing operations (e.g., by radiant heat from the fuser and other components), and the first outlet 136 cools the transfer station 110 to dissipate such heat, while the second outlet 134 acts as an air knife to properly position the print media within the media path 236.
Such printing apparatuses can include a valve 138 located between the single blower 130 and the second outlet 134, and a processor operatively (meaning directly or indirectly) connected to the valve 138. The processor controls the valve to cause the second outlet 134 to selectively direct only identified types of the sheets of print media toward one side of the media path. Therefore, print media exceeding previously established limits on paper weight, thickness, stiffness, length, etc., will cause the processor 224 to open the valve 138 so as to cause airflow out of the second outlet 134 to help maintain the print media that exceeds the previously established limits within the proper location of the media path 236. For example, in
Further, different configurations (such as that shown in
Additionally, the processor 224 controls the speed of the blower 130 depending upon a number of conditions including the temperature of the transfer station 110, the amount by which the print media exceeds such previously established limits on paper weight, thickness, stiffness, length, etc. More specifically, the processor 224 can increase the speed of the blower 130 and/or close the valve 138 in order to direct additional cooling to the transfer station 110 depending upon the amount by which the transfer station 110 is outside an acceptable temperature range. Additionally, the processor can increase the speed of the blower 130 and/or change the amount that the valve 138 is open depending upon the amount by which the print media exceeds such previously established limits on paper weight, thickness, stiffness, length, etc. Thus, if the print media greatly exceeds predetermined limits, the valve 138 can be fully opened and the speed of the blower 130 can be increased to a maximum. Similarly, if the temperature of the transfer station 110 needs to be dramatically lowered, the valve 138 can be completely or partially closed and the speed of the blower can be increased to the maximum. Ranges between such extremes can be balanced depending upon the cooling needs of the transfer station 110 and the amount by which the media exceeds such previously established limits. Further, when the print media 102 is within limits, and the temperature of the transfer station 110 is within limits, the valve 138 can be closed and the speed of the blower 130 can be reduced in order to reduce power consumption.
The input/output device 214 is used for communications to and from the printing device 204 and comprises a wired device or wireless device (of any form, whether currently known or developed in the future). A specialized image processor 224 (that is different from a general purpose computer because it is specialized for processing image data and controlling internal components of a printing device) controls the various actions of the computerized device. A non-transitory, tangible, computer storage medium device 210 (which can be optical, magnetic, capacitor based, etc., and is different from a transitory signal) is readable by the tangible processor 224 and stores instructions that the tangible processor 224 executes to allow the computerized device to perform its various functions, such as those described herein. Thus, as shown in
The printing device 204 includes at least one marking device (printing engine(s)) 240 operatively connected to the specialized image processor 224, a media path 236 positioned to supply sheets of media from a sheet supply 230 to the marking device(s) 240, etc. After receiving various markings from the printing engine(s) 240, the sheets of media can optionally pass to a finisher 234 which can fold, staple, sort, etc., the various printed sheets. Also, the printing device 204 can include at least one accessory functional component (such as a scanner/document handler 232 (automatic document feeder (ADF)), etc.) that also operate on the power supplied from the external power source 220 (through the power supply 218).
The one or more printing engines 240 are intended to illustrate any marking device that applies a marking material (toner, inks, etc.) to sheets of media, whether currently known or developed in the future and can include, for example, devices that use a photoreceptor belt 248 (as shown in
More specifically,
The photoreceptor belt 248 is driven (using, for example, driven rollers 252) to move the photoreceptor in the direction indicated by the arrows past the development stations 242, and a transfer station 238. Note that devices herein can include a single development station 242, or can include multiple development stations 242, each of which provides marking material (e.g., charged toner) that is attracted by the patterned charge on the photoreceptor belt 248. The same location on the photoreceptor belt 248 is rotated past the imaging station 246 multiple times to allow different charge patterns to be presented to different development stations 242, and thereby successively apply different patterns of different colors to the same location on the photoreceptor belt 248 to form a multi-color image of marking material (e.g., toner) which is then transferred to print media at the transfer station 238.
As is understood by those ordinarily skilled in the art, the transfer station 238 generally includes rollers and other transfer devices. Further, item 222 represents a fuser device that is generally known by those ordinarily skilled in the art to include heating devices and/or rollers that fuse or dry the marking material to permanently bond the marking material to the print media.
Thus, in the example shown in
Alternatively, printing engine(s) 240 shown in
One exemplary individual electrostatic marking station 250 is shown in
While
Thus, in printing devices herein a latent image can be developed with developing material to form a toner image corresponding to the latent image. Then, a sheet is fed from a selected paper tray supply to a sheet transport for travel to a transfer station. There, the image is transferred to a print media material, to which it may be permanently fixed by a fusing device. The print media is then transported by the sheet output transport 236 to output trays or a multi-function finishing station 234 performing different desired actions, such as stapling, hole-punching and C or Z-folding, a modular booklet maker, etc., although those ordinarily skilled in the art would understand that the finisher/output tray 234 could comprise any functional unit.
As would be understood by those ordinarily skilled in the art, the printing device 204 shown in
While some exemplary structures are illustrated in the attached drawings, where like numbers identify the same or similar items, those ordinarily skilled in the art would understand that the drawings are simplified schematic illustrations and that the claims presented below encompass many more features that are not illustrated (or potentially many less) but that are commonly utilized with such devices and systems. Therefore, Applicants do not intend for the claims presented below to be limited by the attached drawings, but instead the attached drawings are merely provided to illustrate a few ways in which the claimed features can be implemented.
Many computerized devices are discussed above. Computerized devices that include chip-based central processing units (CPU's), input/output devices (including graphic user interfaces (GUI), memories, comparators, tangible processors, etc.) are well-known and readily available devices produced by manufacturers such as Dell Computers, Round Rock Tex., USA and Apple Computer Co., Cupertino Calif., USA. Such computerized devices commonly include input/output devices, power supplies, tangible processors, electronic storage memories, wiring, etc., the details of which are omitted herefrom to allow the reader to focus on the salient aspects of the devices and methods described herein. Similarly, printers, copiers, scanners and other similar peripheral equipment are available from Xerox Corporation, Norwalk, Conn., USA and the details of such devices are not discussed herein for purposes of brevity and reader focus.
The terms printer or printing device as used herein encompasses any apparatus, such as a digital copier, bookmaking machine, facsimile machine, multi-function machine, etc., which performs a print outputting function for any purpose. The details of printers, printing engines, etc., are well-known and are not described in detail herein to keep this disclosure focused on the salient features presented. The devices and methods herein can encompass devices and methods that print in color, monochrome, or handle color or monochrome image data. All foregoing devices and methods are specifically applicable to electrostatographic and/or xerographic machines and/or processes.
In addition, terms such as “right”, “left”, “vertical”, “horizontal”, “top”, “bottom”, “upper”, “lower”, “under”, “below”, “underlying”, “over”, “overlying”, “parallel”, “perpendicular”, etc., used herein are understood to be relative locations as they are oriented and illustrated in the drawings (unless otherwise indicated). Terms such as “touching”, “on”, “in direct contact”, “abutting”, “directly adjacent to”, etc., mean that at least one element physically contacts another element (without other elements separating the described elements). Further, the terms automated or automatically mean that once a process is started (by a machine or a user), one or more machines perform the process without further input from any user.
It will be appreciated that the above-disclosed and other features and functions, or alternatives thereof, may be desirably combined into many other different systems or applications. Various presently unforeseen or unanticipated alternatives, modifications, variations, or improvements therein may be subsequently made by those skilled in the art which are also intended to be encompassed by the following claims. Unless specifically defined in a specific claim itself, steps or components of the devices and methods herein cannot be implied or imported from any above example as limitations to any particular order, number, position, size, shape, angle, color, or material.
