Patent Application
20120223116
Embodiments herein generally relate to de-curling methods and devices and more particularly to those that utilize concave/convex rollers and that vary the pressure and speed between the rollers to achieve optimal de-curling performance.
Many times it is necessary to impart or remove curl from a material in order to process in the material more easily. For example, devices that transport sheets of media (such as copiers, printers, multifunction machines, etc.) often benefit from very flat de-curled sheets, which reduces the occurrence of jamming and other malfunctions. Similarly, when ribbons or webs of material are unwound from rolls, they may contain a certain amount of curl that needs to be removed.
Common devices that impart or remove curl can generally utilize pairs of rollers (note that sometimes rollers are referred to as rolls). One of the rollers is more elastic (softer) than the other roller. Pressure is applied between the rollers to form what is referred to as a “nip” and the material to be curled or de-curled is fed through the nip to have the curl removed or added.
Some forms of media can contain curl in two different directions, a lengthwise curl and a widthwise curl. This is often caused when laminated strips are stored on rolls. Such materials can have a widthwise curl caused by different coefficients of expansion of the different materials within the laminate structure. In addition, the materials can include a lengthwise curl corresponding to the curvature of the center of the roll. When media contains curls in multiple directions, conventional de-curlers need to perform multiple processes and use multiple structures to remove each of these different curls.
One exemplary method herein controls a de-curling apparatus. A roll of material is fed through a nip formed between a first roller having a concave shape and a second roller contacting the first roller. The second roller has a convex shape mirroring the concave shape. The first roller and the second roller have different coefficients of elasticities.
The method automatically and continually adjusts the amount of pressure applied at the nip between the first roller and the second roller as the material is unrolled from the roll into the nip.
The method can monitor the amount of curl present in the material as the material reaches the nip and control the process of adjusting the pressure according to the amount of curl present in the material. The method can determine the current radius of the roll or the amount of material remaining on the roll as the material is unrolled from the roll into the nip to monitor the amount of curl.
Another exemplary method of controlling a de-curling apparatus also feeds a roll of material through a nip (formed between a first roller having a concave shape and a second roller contacting the first roller). The second roller again has a convex shape mirroring the concave shape. This method automatically and continually adjusts the relative rotational speed of the first roller and the second roller as the material is unrolled from the roll into the nip. By changing the relative speed between the first roller and the second roller, the method changes the lateral location on surfaces of the first roller and the second roller where there is no slippage between the first roller and the second roller.
An additional embodiment herein comprises a de-curling apparatus that includes a first roller having a concave shape, a second roller contacting the first roller (the second roller having a convex shape mirroring the concave shape), an actuator operatively connected to the first roller and/or the second roller, and a controller operatively connected to the actuator. The actuator changes positions of the first roller and the second roller relative to each other.
A nip is formed between the first roller and the second roller. The nip changes the curl characteristic of the material fed from the roll through the nip. The controller automatically and continually adjusts the amount of pressure applied at the nip between the first roller and the second roller using the actuator as the material is unrolled from the roll into the nip. Thus, the controller monitors the amount of curl present in the material as the material reaches the nip and adjusts the pressure being applied to the nip based on the amount of curl present in the material.
Another exemplary de-curling apparatus herein also has a first roller having a concave shape, a second roller contacting the first roller (the second roller again having a convex shape mirroring the concave shape), an actuator operatively connected to the first roller and/or the second roller, and a controller operatively connected to the actuator. Here, the actuator controls rotational speeds of the first roller and/or the second roller.
Again, a nip is formed between the first roller and the second roller, and the nip again changes the curl characteristic of material fed from the roll of the material through the nip. The controller automatically and continually adjusts the relative rotational speeds of the first roller and the second roller using the actuator as the material is unrolled from the roll into the nip.
In this embodiment, the controller monitors the amount of curl present in the material as the material reaches the nip. When the controller changes the relative speed between the first roller and the second roller, this changes the lateral location on the surfaces of the first roller and the second roller where there is no slippage between the first roller and the second roller.
These and other features are described in, or are apparent from, the following detailed description.
Various exemplary embodiments of the systems and methods are described in detail below, with reference to the attached drawing figures, in which:
As mentioned above, some forms of media contains curls in multiple directions. Further, the amount of curl can change as the material is removed from the roll. This variation in curl amount is due to the fact that the material is sometimes stored by wrapping it around a center roll. The material that feeds out initially tends to be flatter than and the material that feeds out later, as this later material was stored with a tighter wrap angle around the center of the roll.
In order to address these situations, the embodiments herein provide a dual de-curling nip that de-curls material as it is unrolled from a roll and that minimizes marks made on the material. For de-curling the strips along the length, the combination of a solid roller, a compliant roller, and pressure removes the lengthwise curl. The higher the pressure applied at the nip, the more the strip will be de-curled along its length. The embodiments herein vary the pressure to increase the de-curling amount as the lengthwise curl increases (because of the spool diameter change in an emptying roll).
Thus, in one example, the pressure between the rollers is increased continuously to correlate with and counteract the ever-tightening curl radius in the roll of material. When a new roll is used, the pressure resets back to its initial de-curling setting and once again begins to increase as more material is removed from the roll.
As shown in
For example, as shown in
Therefore, the embodiments herein provide de-curling that adjusts the pressure and relative roller speed continuously as material is unrolled from the role. This allows the embodiments herein to de-curl the length (via pressure between solid and compliant roll) of the material. Thus, the embodiments herein provide a single device that performs a number of different de-curling operations, which reduces the overall size, weight, and cost of the de-curler device.
One exemplary method shown in
A linear actuator 218 is operatively connected to the first roller 120 and/or the second roller 122. The linear actuator 218 can comprise any form of motor (e.g., any motor or actuator herein can be electrically powered, hydraulically powered, pneumatically powered, etc., screw-type, gear-type, belt-type, magnetic type, etc.) that changes positions of the first roller 120 and the second roller 122 relative to each other (e.g., moves the axis of the rollers toward or away from each other).
A controller 224 is operatively connected to the actuator 218. The controller/processor 224 controls the various actions of the device 200. A non-transitory computer storage medium device 220 (which can be optical, magnetic, capacitor based, etc.) is readable by the processor 224 and stores instructions that the processor 224 executes to allow the device 200 to perform its various functions, such as those described herein.
A nip 230 is formed between the first roller 120 and the second roller 122 wherein the media 212 passes. The media or material 212 can be any item that needs to be de-curled including paper and paper products, transparencies, plastics, metals, alloys, etc. The nip 230 changes the curl characteristic of the material 212 fed from the roll 210 through the nip 230.
The controller 224 automatically and continually adjusts the amount of pressure applied at the nip 230 between the first roller 120 and the second roller 122 using the linear actuator 218 as the material 212 is unrolled from the roll 210 into the nip 230. Thus, the controller 224 monitors the amount of curl present in the material 212 as the material 212 reaches the nip 230 and adjusts the pressure being applied to the nip 230 based on the amount of curl present in the material 212.
Additionally, rotational actuators 214 control the rotational speeds of the first roller 120 and/or the second roller 122. The controller 224 automatically and continually adjusts the relative rotational speeds of the first roller 120 and the second roller 122 using the actuator 214 as the material 212 is unrolled from the roll 210 into the nip 230. The controller 224 monitors the amount of curl present in the material 212 as the material 212 reaches the nip 230. The adjustment to the relative rotational speed is made to minimize any marks that may appear on the material 212. As discussed above, when the controller 224 changes the relative speed between the first roller 120 and the second roller 122, this changes the lateral location (124, 126, 128) on the surfaces of the first roller 120 and the second roller 122 where there is no slippage between the first roller 120 and the second roller 122.
When monitoring the amount of curl present in the material as the material reaches the nip, the processor 224 can use at least one sensor 226 (optical sensor, tactile sensor, ultrasonic sensor, etc.) to measure curl. Additionally, the processor can determine the current radius of the roll or the amount of material remaining on the roll (again using a sensor 226) as the material is unrolled from the roll into the nip to monitor the amount of curl. As mentioned above, the embodiments herein vary the pressure to increase the de-curling amount as the lengthwise curl increases (because of the spool diameter change in an emptying roll).
In item 302 the method can monitor the amount of curl present in the material as the material reaches the nip. The method can determine the current radius of the roll or the amount of material remaining on the roll as the material is unrolled from the roll into the nip to monitor the amount of curl or can use a sensor.
In item 304, the method automatically and continually adjusts the amount of pressure applied at the nip between the first roller and the second roller as the material is unrolled from the roll into the nip according to the amount of curl present in the material. Also, in item 306, the method automatically and continually adjusts the relative rotational speed of the first roller and the second roller as the material is unrolled from the roll into the nip. By changing the relative speed between the first roller and the second roller, the method changes the lateral location on surfaces of the first roller and the second roller where there is no slippage between the first roller and the second roller thereby minimizing any marks that may be made on the material.
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, 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, 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 embodiments described herein. Similarly, 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 by those ordinarily skilled in the art and are discussed in, for example, U.S. Pat. No. 6,032,004, the complete disclosure of which is fully incorporated herein by reference. The embodiments herein can encompass embodiments that print in color, monochrome, or handle color or monochrome image data. All foregoing embodiments 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). Automatic means that a process is performed by a machine without further user input.
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. The claims can encompass embodiments in hardware, software, and/or a combination thereof. Unless specifically defined in a specific claim itself, steps or components of the embodiments herein cannot be implied or imported from any above example as limitations to any particular order, number, position, size, shape, angle, color, or material.
