Patent Grant
9630427
The presently disclosed technologies are directed to apparatus and methods used to handle substrate media in a marking device using solid ink jetted onto the substrate media. The apparatus and methods described herein integrate cooling, spreading and duplex inversion of cut-sheets after ink has been applied thereto.
Ink jet marking devices that use solid ink print processes generally involve melting the solid ink and jetting it onto a substrate media sheet. The sheet carrying the ink must go through a cooling process while the ink is spread and leveled on the sheet as it is fixed thereon. Generally this process is performed by using several separate serial subsystems downstream of the marking station. Additionally, when printing onto substrate media in the form of individual cut-sheets, it is often desirable to flip the sheet over for duplex printing.
Accordingly, it would be desirable to provide an apparatus and/or method that combines the function of cooling, spreading and duplex inversion of cut-sheets in an integrated, compact, modular and scalable arrangement.
According to aspects described herein, there is disclosed an apparatus for processing ink applied to a substrate media sheet, the apparatus including a control cylinder rotatably supported for thermal conduction to a sheet of substrate media. The sheet conveys ink deposited on a first side thereof. The sheet is held against a peripheral arch of the control cylinder as the control cylinder rotates with the first side of the sheet directly engaging and wrapping around the control cylinder along the peripheral arch. The apparatus also includes a thermal control element for at least one of heating and cooling the control cylinder. The apparatus also includes a pressure roll for spreading the ink. The pressure roll together with the control cylinder forms a spreader nip. The spreader nip is selectively changeable between a closed position and an open position. In the closed position the pressure roll is biased toward the control cylinder for applying pressure to the ink on the sheet. The pressure roll is spaced further away from the control cylinder in the open position relative to the closed position.
Additionally, the apparatus further includes an acquisition nip disposed adjacent the spreader nip for holding the sheet after the sheet passes through the spreader nip. The acquisition nip moves the sheet at least partly through the spreader nip in the open position. The pressure roll moves away from the control cylinder after a trailing edge of the substrate media sheet disengages the pressure roll. This allows the substrate media sheet to pass between the pressure roll and the control cylinder without further engaging the pressure roll. A rotational velocity of the control cylinder is adjustable for regulating a dwell time in which the substrate media sheet remains in direct engagement with the control cylinder. The apparatus further includes a sensor for detecting a temperature of at least one of the substrate media sheet and the ink deposited thereon. The thermal control element adjusts the temperature of the control cylinder in response to the temperature detected by the sensor. The control cylinder at least partially levels the ink while the sheet is held against the peripheral arch. The apparatus further includes a sheet process path for conveying the sheet. The acquisition nip holds the sheet along an intermediate portion of the process path on a first side of the acquisition nip. An exit portion of the process path is disposed on an opposed side of the acquisition nip relative to the intermediate portion. The apparatus further includes at least one controller operatively connected to and controlling the control cylinder, the thermal control element and the pressure roll.
According to further aspects described herein, there is disclosed a method of processing ink applied to substrate media sheets. The method including engaging a sheet of substrate media with a control cylinder rotatably supported along a process path of the sheet. The sheet conveys ink deposited on a first side thereof. The method further including rotating the control cylinder with the sheet held against a peripheral arch of the control cylinder as the control cylinder rotates with the first side of the sheet directly engaging and wrapping around the control cylinder along the peripheral arch. The method further including activating a thermal control element to at least one of heat and cool the control cylinder for thermal conduction to the sheet. The method further includes spreading the ink by passing the sheet between a pressure roll and the control cylinder. The pressure roll together with the control cylinder form a spreader nip. The spreader nip presses the ink on the sheet as it passes through the spreader nip and opens the spreader nip into an open position. The spreader nip is selectively changeable between a closed position and the open position. In the closed position the pressure roll is biased toward the control cylinder for applying pressure to the ink on the sheet. The pressure roll is spaced further away from the control cylinder in the open position relative to the closed position.
Additionally, the method including closing an acquisition nip disposed adjacent the spreader nip for holding the sheet after the sheet passes through the spreader nip. The control cylinder at least partially levels the ink while the sheet is held against the peripheral arch. The pressure roll moves out of the closed position after a trailing edge of the substrate media sheet disengages the pressure roll. A rotational velocity of the control cylinder is adjustable for regulating a dwell time in which the substrate media sheet remains in direct engagement with the control cylinder. The sheet is initially engaged by the control cylinder while the sheet is carried on a platen of a media cart.
The method further including returning the sheet to the platen with the first side facing the platen. The method further including passing the sheet through spreader nip a second time while the spreader nip is in the open position. The method further including after passing the sheet through the spreader nip a second time, conveying the sheet further along the process path to a marking station for application of further ink to a second side of the sheet, the same marking station having previously applied the first side ink. The method further including re-engaging the sheet with the control cylinder after the application of the further ink to the second side of the sheet.
According to further aspects described herein, there is disclosed a system for processing ink applied to substrate media sheets. The apparatus includes a sheet transport including a sled having a platen for supporting thereon a sheet. The sled is translatable along a process path to transport the sheet to a control cylinder and to transport the sheet away from the control cylinder along the process path. The control cylinder is rotatably supported for thermal conduction to a sheet of substrate media. The sheet conveying ink is deposited on a first side thereof. The sheet is held against an arched portion of the control cylinder as the control cylinder rotates with the first side of the sheet directly engaging and wrapping around the control cylinder along the arched portion. The system further includes a thermal control element for at least one of heating and cooling the control cylinder. The system further includes a pressure roll for spreading the ink, the pressure roll together with the control cylinder forming a spreader nip. The spreader nip is selectively changeable between a closed position and an open position. In the closed position, the pressure roll is biased toward the control cylinder for applying pressure to the ink on the sheet, the pressure roll spaced further away from the control cylinder in the open position relative to the closed position.
Describing now in further detail exemplary embodiments with reference to the Figures, as briefly described above.
As used herein, a “media handling assembly” refers to one or more devices used for handling and/or transporting substrate media, including feeding, marking, printing, finishing, registration and transport systems.
As used herein, a “marking device,” “printer,” “printing assembly” or “printing system” refers to one or more devices used to generate “printouts” or a print outputting function, which refers to the reproduction of information on “substrate media” for any purpose. A “marking device,” “printer,” “printing assembly” or “printing system” as used herein encompasses any apparatus, such as a digital copier, bookmaking machine, facsimile machine, multi-function machine, and the like, which performs a print outputting function for any purpose.
Particular marking devices include printers, printing assemblies or printing systems, which can use an “electrostatographic process” to generate printouts, which refers to forming an image on a substrate by using electrostatic charged patterns to record and reproduce information, a “xerographic process”, which refers to the use of a resinous powder on an electrically charged plate record and reproduce information, or other suitable processes for generating printouts, such as an ink jet process, a liquid ink process, a solid ink process, and the like. Also, a printing system can print and/or handle either monochrome or color image data.
As used herein, “substrate media” refers to, for example, paper, transparencies, parchment, film, fabric, plastic, photo-finishing papers or other coated or non-coated substrates on which information can be reproduced, preferably in the form of a sheet or web. While specific reference herein is made to a sheet or paper, it should be understood that any substrate media in the form of a sheet amounts to a reasonable equivalent thereto. Also, the “leading edge” of a substrate media refers to an edge of the sheet that is furthest downstream in the process direction. Additionally, the “trailing edge” of a substrate media refers to an edge of the sheet that is furthest upstream in the process direction.
As used herein, “ink” refers to material for marking or creating an image on substrate media. Ink may be in liquid, gel, or solid form. The ink may change form during the printing process, e.g., solid to liquid. Solid ink may be in the form of colored sticks that can be melted for application to the substrate media.
As used herein, a “nip assembly”, “nip assemblies” or simply a “nip” refers to an assembly of elements that include at least two adjacent revolving or recirculating elements and supporting structure, where the two adjacent revolving or recirculating elements are adapted to matingly engage opposed sides of a transfer belt or substrate media. A typical nip assembly includes two wheels or cylindrical rolls that cooperate to drive or handle a substrate therebetween. One or two of the opposing cylinders can include a driven cylinder, one or two of the opposing cylinders can be a freely rotating idler cylinder or the opposed cylinders can be a combination thereof. Together the two cylinders guide or convey the transfer belt or other substrate within a media handling assembly. More than two sets of mating cylinders can be provided in a laterally spaced configuration to form a nip assembly. It should be further understood that such cylinders are also referred to interchangeably herein as rolls or rolls. Once a substrate is engaged between the opposed revolving or recirculating elements, the space or gap between them is referred to as the “nip gap”.
As used herein, “spreader nip” refers to assembly of elements that include at least two adjacent revolving or recirculating elements and supporting structure that apply pressure to substrate media to spread out ink deposited thereon.
As used herein, the terms “process” and “process direction” refer to a process of moving, transporting and/or handling an image or substrate media conveyed by a transfer belt. The process direction substantially coincides with a direction of a flow path P along which the image or substrate media is primarily moved within the media handling assembly. Such a flow path P is said to flow from upstream to downstream.
As used herein, “module” refers to each of a series of standardized units or subassemblies from which a printing system can be assembled. It should be understood that different modules can perform the same and/or different functions in the printing system, but are standardized to be selectively interconnected and operate together. A “transport module” is capable of moving substrate media through its own subassembly.
As used herein, “control cylinder” refers to a cylindrical to which substrate media is attached and which can regulate a property of the substrate media such as its temperature. The control cylinder may be in the form of a cylindrical drum or roller.
As used herein, “pressure roll” refers to a roller which forms part of a nip and which exerts a force on the substrate media.
As used herein, “thermal control element” refers to a device for regulating the temperature of another device, including one or more heating and or cooling elements that are disposed in or adjacent to the control cylinder. Heating elements may be in the form of electrical resistance coils, or tubing that permits heated fluid to flow there through in a controlled manner. Cooling elements may include tubing which allows cool fluid to flow there through in a controlled manner.
The disclosed technologies employ a solid ink print process which utilizes a wax-like solid ink. The ink is generally supplied in a solid form and melted into tiny droplets that are jetted onto a media through one or more piezo-electric ink jet head. As the ink droplets are deposited onto the substrate media sheet, they coalesce slightly but not necessarily uniformly. Thus, in order to achieve acceptable image quality, several more steps are required in order to achieve a desired uniformity. One initial step involves reducing the temperature of the droplets, as well as that of the substrate media, to a uniform temperature. This is often referred to as the cooling phase. It should be noted that the cooling phase requires a sufficient dwell time that the paper must remain in contact with the cooling roll. Dwell time generally refers to the amount of time the substrate media sheet remains in a region or in contact with a particular surface. After this initial cooling, the next step is often to bring both the substrate media sheet and the deposited ink back to a uniform temperature which often can involve heating and is thus referred to as a heating phase. As with the cooling phase, the heating phase requires a specific dwell time in order to ensure that the substrate media and the ink reach a uniform temperature. Thereafter, once the desired temperature is reached, the ink is ready for spreading which effectively evens out the distribution of the ink droplets for better image quality.
While all these steps are generally done in series, having to provide separate apparatus for each of these phases can be expensive and require significant maintenance. In accordance with aspects of the disclosed technologies, these functions can be combined into an integrated modular architecture. Doing so not only will reduce the cost by having fewer elements in a more compact design, but also means a more compact modular system can be distributed through different types of system architectures. For example, scaling problems generally occur when applying traditional marking methods to large cut-sheets of substrate media that are greater than 40×60 inches in size. However, aspects of the disclosed technologies can be scaled to work with such large cut-sheets which are more cumbersome and difficult to handle than smaller letter-size sheets of paper.
In accordance with aspects of the disclosed technologies, a set of cylinders or rolls acquire the substrate media sheet, used conduction heating or cooling to control the temperature of the sheet and ink deposited thereon and apply pressure as the sheet wraps around the main cylinder as well as further pressure when it passes through a nip assembly to spread the ink. Thereafter, the sheet motion is reversed and re-circulated in a process direction to enable a duplex function that is combined with the temperature and pressure applications all in one compact apparatus.
The acquisition of the sheet 5 by the control cylinder 20 can be accomplished through a sheet acquisition apparatus 24 which may include the use of vacuum, additional nip rollers, paper edge grippers, air pressure, electrostatic retention methods or other known means. Depending on what means are used to maintain the sheet in contact with the control cylinder, such contact is desirable in order for thermal conduction to be affected from the control cylinder to the sheet 5 and the ink 6 carried thereon. Once acquired, the sheet 5 is held against the control cylinder 20 long enough to actively sense the temperature of the sheet 5 and possibly the ink 6 thereon, as well as heat and/or cool the cylinder as needed. The duration that the sheet or portions thereof are in contact with the control cylinder is referred to herein as the “dwell time” of any particular portion of the sheet. During the time that segments of the sheet 5 are in direct contact with the control cylinder 5, the temperature of the cylinder will transfer by conduction to the sheet and the ink thereon. In this way, if the control cylinder is hotter than the sheet 5 and/or the ink 6, such heat will be transferred to those elements. Similarly, the control cylinder can be cooled to thereby draw heat from the sheet 5 or the ink 6 thereon. This system avoids the need for convective or radiant heating which is less efficient and can require more space. Also, by combining the functions of thermal control as well as leveling and spreading of the ink on the substrate media sheet, the dwell time needed for the sheet can be reduced and the size of the heating cooling spreading device is minimized. Further, power requirements for this system can be reduced by this more efficient design. Also, the dwell time of the sheet or portions thereof can be tightly controlled and optimized by correctly choosing the size and velocity of the control cylinder 20.
A thermal control element 21 (
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Often media handling assembly, and particularly printing systems, include more than one module or station. Accordingly, more than one post-application ink processing apparatus as disclosed herein can be included in an overall media handling assembly. Further, it should be understood that in a modular system or a system that includes more than one post-application ink processing apparatus, in accordance with the disclosed technologies herein, could detect sheet position or other sheet characteristics and relay that information to a central processor for controlling registration or speed, including dwell time on the control cylinder. Thus, if additional leveling and spreading is needed or simply further sheet inversion, the apparatus and methods described herein could be employed to achieved the desired sheet handling, for example in another module or station.
It will be appreciated that various of the above-disclosed and other features and functions, or alternatives thereof, may be desirably combined into many other different systems or applications. It will also be appreciated that 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 disclosed embodiments and the following claims.
This Application is a divisional of U.S. patent application Ser. No. 13/677,045, filed on Nov. 14, 2012, currently allowed. The entirety of this application is incorporated by reference herein.
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| 8248640 | Tanaka et al. | Aug 2012 | B2 |
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| Number | Date | Country | |
|---|---|---|---|
| 20160279969 A1 | Sep 2016 | US |
| Number | Date | Country | |
|---|---|---|---|
| Parent | 13677045 | Nov 2012 | US |
| Child | 15172488 | US |
