WEB MEDIUM ORIENTATION DETECTION

Abstract

In a method for high speed printing of web-based media, a medium is pulled along a media transport path to a pulling transport mechanism. The orientation of the medium with respect to the media transport path is sensed and this orientation is compared to a reference orientation to detect an orientation error. If an orientation error is detected, one or more of the following steps is performed: adjusting a print job for an image to be printed on the web medium; adjusting the transport speed; emitting a communication signal; and stopping the pulling transport mechanism and the image forming unit. It is the insight of the inventor that productivity may be increased by allowing a “tight winding” printing system to start printing at relatively high speed and reduce this speed only when significantly large deviations in the orientation of the web are detected.

Claims

1. Printing system for printing web media, comprising: a take-out roller; a take-up roller for pulling a web medium along a media transport path from the take-out roller to the take-up roller; an image forming unit positioned along the media transport path, characterized by: an orientation sensor for sensing an orientation of the web medium, the orientation sensor comprising: a curved medium support surface defining a turn in the media transport path, which curved medium support surface is tiltable around a tilting axis, which tilting axis extends in a transport direction substantially tangentially to the curved medium support surface in a reference orientation; a tilting sensor for determining tilting data proportional to a tilting angle by which the curved medium support surface is tilted from its reference orientation around the tilting axis; a controller configured to: receive the tilting data from the orientation sensor; compare the tilting data to the reference orientation to determine an orientation error; and compare the orientation error to a deviation threshold.

2. Printing system according to claim 1, wherein: the tilting sensor comprises a displacement sensor attached to the curved medium support surface for detecting a displacement of a section of the curved medium support surface in a direction substantially perpendicular to the curved medium support surface; and the controller is configured to compare the detected displacement to the reference orientation to determine the tilting data.

3. Printing system according to claim 2, wherein: the tilting sensor comprises a pair of displacement sensors attached to opposing lateral sides of the curved medium support surface, each displacement sensor configured for detecting a displacement of a respective side of the curved medium support surface in a direction substantially perpendicular to the curved medium support surface; and the controller is configured to compare the detected displacements to one another to determine the tilting data.

4. Printing system according to claim 1, wherein the controller is further configured to emit an error signal for initiating an appropriate action of the printing system if the orientation error exceeds the deviation threshold.

5. Printing system according to claim 1, wherein the curved medium support surface is positioned upstream of the image forming unit.

6. Printing system according to claim 1, wherein the error signal is configured for reducing the transport speed of the web medium on the transport path.

7. Printing system according to claim 1, wherein the error signal is configured for initiating at least one of the following: controlling the image forming unit to adjust a print job for an image to be printed on the web medium; and emitting a communication signal prompt to an operator.

8. Printing system according to claim 1, wherein the controller is arranged for: classifying the orientation error into an error level by comparing the orientation error to an error level reference; and selecting one of the following steps determined by the error level: controlling the image forming unit to adjust a print job for an image to be printed on the web medium; reducing the transport speed; emitting an communication signal prompt to an operator; and stopping the image forming unit, take-out roller, and the take-up roller.

9. Printing system according to claim 1, further comprising a buffer plate defining the curved medium support surface and urging elements for urging the buffer plate against the web medium, wherein the orientation sensor comprises a tilting angle sensor for determining an tilting angle around the tilting axis between the buffer plate and a buffer plate reference orientation.

10. Method for printing of web-based media, the method comprising the steps of: pulling a web medium at a predefined transport speed over a media transport path, which media transport path extends along an orientation sensor comprising a curved medium support surface defining a turn in the media transport path and along an image forming unit to a pulling transport mechanism; sensing the tilting of the curved medium support surface around a tilting axis, which tilting axis extends in a transport direction substantially tangential to the curved medium support surface in a reference orientation; comparing the sensed tilting to the reference orientation to determine an orientation error; and comparing the orientation error to a deviation threshold.

11. Method according to claim 10, further comprising the step of: sensing a displacement of a section of the curved medium support surface in a direction substantially perpendicular to the curved medium support surface; and determining the tilting of the curved medium support surface around a tilting axis from said displacement.

12. Method according to claim 10, further comprising the step of: sensing a displacement of a two opposing lateral sides of the curved medium support surface in a direction substantially perpendicular to the curved medium support surface; and determining the tilting of the curved medium support surface around a tilting axis from said displacements.

13. Method according to claim 10, further comprising the step of emitting an error signal if orientation error exceeds the deviation threshold.

14. Method according to claim 13, further comprising at least one of the following steps: adjusting a print job for an image to be printed on the web medium; adjusting the transport speed; emitting a communication signal; and stopping transport of the web medium.

15. Method according to claim 10, wherein the step of comparing the orientation data to a reference orientation further comprises determining a rotation angle parameter, which rotation angle parameter corresponds to an angle between a longitudinal direction of the web medium and a transport direction of the media transport path.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0095] The present invention will become more fully understood from the detailed description given herein below and the accompanying drawings which are given by way of illustration only, and thus are not limitative of the present invention, and wherein:

[0096] FIG. 1A is a schematic perspective view of a printing system according to the present invention;

[0097] FIG. 1B is a schematic perspective view of an inkjet printing assembly of the printing system in FIG. 1A;

[0098] FIG. 2 is a schematic side view of a printing system according to the present invention;

[0099] FIG. 3 is a schematic top view of a web between the inkjet printing assembly and the take-up roller in a printing system 1 according to the present invention;

[0100] FIG. 4A-B are schematic perspective views of a buffer plate of a printing system according to the present invention in an aligned state (FIG. 4A) and a misaligned state of the web (FIG. 4B);

[0101] FIG. 4C is a schematic cross-sectional view of a buffer plate of a printing system according to the present invention; and

[0102] FIG. 5 is a diagram illustrating the method according to the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0103] The present invention will now be described with reference to the accompanying drawings, wherein the same reference numerals have been used to identify the same or similar elements throughout the several views.

[0104] FIG. 1A shows a printing system 1, wherein printing is achieved using a wide format inkjet printer. The wide-format printing system 1 comprises a housing 2, wherein the printing assembly, for example the ink jet printing assembly shown in FIG. 1B is placed. The printing system 1 also comprises a storage means for storing image receiving member 3, 4, a delivery station to collect the image receiving member 3, 4 after printing and storage means 5 for marking material. In FIG. 1A, the delivery station is embodied as a delivery tray 6. Optionally, the delivery station may comprise processing means for processing the image receiving member 3, 4 after printing, e.g. a folder or a puncher. The wide-format printing system 1 furthermore comprises means for receiving print jobs and optionally means for manipulating print jobs. These means may include a user interface unit 8 and/or a control unit 7, for example a computer.

[0105] Images are printed on an image receiving member, for example paper, supplied by a roll 3, 4. The roll 3 is supported on the roll support R1, while the roll 4 is supported on the roll support R2. Alternatively, cut sheet image receiving members may be used instead of rolls 3, 4 of image receiving member. Printed sheets of the image receiving member, cut off from the roll 3, 4, are deposited in the delivery tray 6.

[0106] Each one of the marking materials for use in the printing assembly are stored in four containers 5 arranged in fluid connection with the respective print heads for supplying marking material to said print heads.

[0107] The local user interface unit 8 is integrated to the print engine and may comprise a display unit and a control panel. Alternatively, the control panel may be integrated in the display unit, for example in the form of a touch-screen control panel. The local user interface unit 8 is connected to a control unit 7 placed inside the printing apparatus 1. The control unit 7, for example a computer, comprises a processor adapted to issue commands to the print engine, for example for controlling the print process. The printing system 1 may optionally be connected to a network N. The connection to the network N is diagrammatically shown in the form of a cable 9, but nevertheless, the connection could be wireless. The printing system 1 may receive printing jobs via the network. Further, optionally, the controller of the printer may be provided with a USB port, so printing jobs may be sent to the printer via this USB port.

[0108] FIG. 1B shows an ink jet printing assembly 10. The ink jet printing assembly 10 comprises supporting means for supporting an image receiving member 3. The supporting means 11 are shown in FIG. 1B as a platen 11, but alternatively, the supporting means 11 may be a flat surface. The platen 11, as depicted in FIG. 1B, is a rotatable drum 11, which is rotatable about its axis as indicated by arrow A. The supporting means 11 may be optionally provided with suction holes for holding the image receiving member 3 in a fixed position with respect to the supporting means 11. The ink jet printing assembly 10 comprises print heads 12a-12d, mounted on a scanning print carriage 13. The scanning print carriage 13 is guided by suitable guiding means 14, 15 to move in reciprocation in the main scanning direction B. Each print head 12a-12d comprises an orifice surface 16, which orifice surface 16 is provided with at least one orifice 17. The print heads 12a-12d are configured to eject droplets of marking material onto the image receiving member 3. The platen 11, the carriage 13 and the print heads 12a-12d are controlled by suitable controlling means 18a, 18b and 18c, respectively.

[0109] The image receiving member 3 may be a medium in web or in sheet form and may be composed of e.g. paper, cardboard, label stock, coated paper, plastic or textile. Alternatively, the image receiving member 3 may also be an intermediate member, endless or not. Examples of endless members, which may be moved cyclically, are a belt or a drum. The image receiving member 3 is moved in the sub-scanning direction A by the platen 11 along four print heads 12a-12d provided with a fluid marking material.

[0110] A scanning print carriage 13 carries the four print heads 12a-12d and may be moved in reciprocation in the main scanning direction B parallel to the platen 11, such as to enable scanning of the image receiving member 3 in the main scanning direction B. Only four print heads 12a-12d are depicted for demonstrating the invention. In practice an arbitrary number of print heads may be employed. In any case, at least one print head 12a-12d per color of marking material is placed on the scanning print carriage 13. For example, for a black-and-white printer, at least one print head 12a-12d, usually containing black marking material is present. Alternatively, a black-and-white printer may comprise a white marking material, which is to be applied on a black image-receiving member 3. For a full-color printer, containing multiple colors, at least one print head 12a-12d for each of the colors, usually black, cyan, magenta and yellow is present. Often, in a full-color printer, black marking material is used more frequently in comparison to differently colored marking material. Therefore, more print heads 12a-12d containing black marking material may be provided on the scanning print carriage 13 compared to print heads 12a-12d containing marking material in any of the other colors. Alternatively, the print head 12a-12d containing black marking material may be larger than any of the print heads 12a-12d, containing a differently colored marking material.

[0111] The carriage 13 is guided by guiding means 14, 15. These guiding means 14, 15 may be rods as depicted in FIG. 1B. The rods may be driven by suitable driving means (not shown). Alternatively, the carriage 13 may be guided by other guiding means, such as an arm being able to move the carriage 13. Another alternative is to move the image receiving material 3 in the main scanning direction B.

[0112] Each print head 12a-12d comprises an orifice surface 16 having at least one orifice 17, in fluid communication with a pressure chamber containing fluid marking material provided in the print head 12a-12d. On the orifice surface 16, a number of orifices 17 is arranged in a single linear array parallel to the sub-scanning direction A. Eight orifices 17 per print head 12a-12d are depicted in FIG. 1B, however obviously in a practical embodiment several hundreds of orifices 17 may be provided per print head 12a-12d, optionally arranged in multiple arrays. As depicted in FIG. 1B, the respective print heads 12a-12d are placed parallel to each other such that corresponding orifices 17 of the respective print heads 12a-12d are positioned in-line in the main scanning direction B. This means that a line of image dots in the main scanning direction B may be formed by selectively activating up to four orifices 17, each of them being part of a different print head 12a-12d. This parallel positioning of the print heads 12a-12d with corresponding in-line placement of the orifices 17 is advantageous to increase productivity and/or improve print quality. Alternatively multiple print heads 12a-12d may be placed on the print carriage adjacent to each other such that the orifices 17 of the respective print heads 12a-12d are positioned in a staggered configuration instead of in-line. For instance, this may be done to increase the print resolution or to enlarge the effective print area, which may be addressed in a single scan in the main scanning direction. The image dots are formed by ejecting droplets of marking material from the orifices 17.

[0113] Upon ejection of the marking material, some marking material may be spilled and stay on the orifice surface 16 of the print head 12a-12d. The ink present on the orifice surface 16, may negatively influence the ejection of droplets and the placement of these droplets on the image receiving member 3. Therefore, it may be advantageous to remove excess of ink from the orifice surface 16. The excess of ink may be removed for example by wiping with a wiper and/or by application of a suitable anti-wetting property of the surface, e.g. provided by a coating.

[0114] FIG. 2 shows a schematic side view of a printing system 1 according to the present invention. A web medium 3 is provided from a medium roll R1 supported on a take-out roller which may be provided with an actuator for rotating the roll R1. From the media roll R1, the transport path P extends via a moveable buffer plate 30 to the inkjet printing assembly 10, where the web 3 is supported by the platen 11′ or print surface 11′. The curved buffer plate 31 is tiltable around the titling axis TA, which extends tangentially to top surface of the buffer plate 31 in the transport direction D. On the carriage 13 of the inkjet printing assembly an optical sensor 20 is mounted, which sensor is arranged for sensing the web to determine the print quality or the web's position. Downstream of the print surface 11′, the transport path P extends further to the pulling transport mechanism R3, which in FIG. 2 is a take-up roller R3. The roller R3 comprises an actuator for driving the take-up roller R3. A controller 40 is provided for receiving the print job and controlling the printing system 1 accordingly.

[0115] The web medium 3 provided from the roll R1 has a low plane stiffness, which causes the web 3 to buckle easily. Examples of such media are thin media, textile, or certain types of banner media. When sliding over the print surface 11′, the web 3 experiences a friction force which causes the web 3 to buckle, even though a suction force is applied via vacuum holes in the print surface 11′ to hold the medium 3 against the print surface 11′. The buckled web 3 may come into contact with the print heads 12a-d, resulting in the smearing of ink across the web 3 or damage to the print heads 12a-d. To prevent buckling, the medium 3 requires a pulling force to flatten the web 3 over the print surface 11′. This pulling force or tension is provided by a pulling transport mechanism R3 downstream of the inkjet printing assembly 10. Said pulling transport mechanism R3 may be a transport pinch along the transport path P, but is preferably formed as a take-up roller R3. The take-up roller R3 comprises an actuator for rotating the roll R3 and pulling on the web 3, such that the web 3 is under tension along the entire transport path P, or at least between the inkjet printing assembly 10 and the take-up roller R3.

[0116] Prior to printing the leading edge of the web 3 is attached to the take-up roller R3, as shown in FIG. 3. Attaching may be performed by the operator or an automated attachment unit. The web 3 is in practice never perfectly aligned with the rotation axis of the take-up roller R3. The leading edge of the web 3 is generally at a small angle ε with respect to the axis of the take-up roller R3, which angle ε is strongly exaggerated in FIG. 3 for the sake of illustration. While printing, the take-up roller R3 pulls on the web 3 to move the web 3 in the transport direction D. Due to the misalignment of the web 3 on the roller R3, the roller 3 exerts on the web 3 not only a force FD in the transport direction D but also a lateral force FL pushing the web 3 to a side of the transport path P and of the platen 11′. This interplay of forces FD, FL results in a rotation R of the web 3. This rotation R affects the image Im printed on the web medium 3, which becomes misaligned on the medium 3. Additionally the print quality is reduced, since the consecutive swaths wherein the image Im is printed do not properly overlap. Further, the web 3 may oscillate laterally, moving continuously from left to right in the width direction of the transport path P. Severe shifting or oscillating of the web 3 results in damaged media or a paper jam, as the medium 3 moves outside the transport path P. Rotation R is more likely to occur when applying high transport speeds, since both the speed of the web 3 and the forces FD, FL acting on it then become relatively large.

[0117] The present invention allows for high speed printing without additional effort to the operator by monitoring for the occurrence of the above described rotational effects and automatically taking appropriate action. Thereto, the printing system 1 comprises a sensor 20, 30 for detecting the tilting of the curved surface of the buffer plate 31.

[0118] In a preferred embodiment, the orientation sensor 30 comprises a curved buffer plate 31, as shown in FIG. 2. The buffer plate 31 is urged against the web 3 by one or more urging elements 33, which for example may be spring elements or actuators such as electrical linear motors. The urging elements 33 provide a controllable tension to the web 3, which tension may be adjusted by controlling the force applied by the urging elements 33 or the by controlling the position of the buffer plate 31. The orientation sensor 30 is further provided with a tilting sensor 32 for determining the orientation of the buffer plate 31. The tilting sensor 32 comprises one or more displacement or position sensors 32 to determine the relative position of one or both lateral sides of the buffer plate 31. During operation, the buffer plate 31 tilts around titling axis TA out of its initial or reference orientation OR. From the out-of-plane displacement of the side edges of the buffer plate 31, the tilting of the buffer plate 31 is determined. This provides an effective measure for the lateral tension distribution in the web and the rotation R of the web 3.

[0119] FIG. 4A explains in more details the workings of the tilting sensor 30. The tensioned web 3 runs over the curved buffer plate 31 in the transport direction D. Due to the misalignment of the web 3 on the roller R3, as shown in FIG. 3, the web 3 may rotate around a rotation axis parallel an out-of-plane direction O of the web 3. The out-of-plane direction O of the web 3 on the buffer plate 31 is equal to the out-of-plane orientation O of the buffer plate 31 since the web 3 is pre-tensioned over the buffer plate 31. A rotation R of the web 3 is due to the fact that the tension forces acting on one lateral side of the web 3 do not balance out the forces on the other side of the web 3. This results in a tilting S of the buffer plate 31 around a tilting axis TA parallel to the transport direction D. In FIG. 4B, the forces acting on the right side (when viewed along the transport direction) of the web 3 exceed those on the left side of the web 3. The right side of the buffer plate 31 is then pulled downwards i.e. in the out-of-plane direction of the transport path P. For the sake of illustration, the left side of the buffer plate 31 is shown to move upwards, though in practice both sides may also move downwards by different displacements Δ1, Δ2. The tilting S re-orients the buffer plate 32 from its reference orientation OR to the titled orientation O. In the reference orientation OR the out-of-plane direction O of the buffer plate is parallel to the out-of-plane direction (the normal) of the plane of the transport path P, the transport path P being defined as the path formed by the web 3 when aligned perfectly on the take-up roller R3.

[0120] The tilting of the buffer plate 32 is cross-sectionally shown in FIG. 4C. The buffer plate 31 tilts or rotates around the tilting axis TA locally parallel to the transport direction D and tangential to the support surface of the buffer plate 31. The lateral forces on the web 3 move the right side of the buffer plate 31 downwards by a displacement Δ1, while the left side moves up by a distance Δ2, which displacements Δ1, Δ2 are measured by the displacement sensors 32. From said displacements Δ1, Δ2 the orientation O of the buffer plate 31 with respect to the plane of the “ideal” transport path P may be determined. The tilting S of the buffer plate 31 may be defined by the tilting angle α between the sensed orientation (out-of-plane direction O) and the reference orientation of the buffer plate 31 (out-of-plane reference direction OR). The tilting S provides an accurate measure for the tension in the web 3 and for the rotation R of the web 3 with respect to the transport direction D. The rotation R of the web 3 can thus be derived from the tilting of the buffer plate 31 around the tilting axis TA, which tilting axis TA extends parallel to the transport direction whereas the rotation axis for the rotation R is perpendicular to transport direction (and to the plane of transport path P).

[0121] It will be appreciated that in an alternate embodiment, the tilting sensor 20 may be in the form of an optical camera system 20 to determine the orientation of the buffer plate 31.

[0122] The controller 40 compares the difference between the sensed orientation O and the reference orientation OR to a deviation threshold. Said threshold defines a distinction between errors which do affect image quality (visible artifacts) and invisible ones do not reduce print quality. The threshold is preferably a value for a threshold angle or a lateral shift threshold. Orientation errors below the threshold are so small that these do not show up in the printed image, at least not visible by eye. Since such negligible deviations do not visually affect print quality, these are preferably not corrected. This reduces the amount of operations performed by the printing system 1 and ensures smooth operation. Orientation errors above the threshold require compensating or correcting to prevent the image Im from becoming disturbed. In either case, during operation, the printing system 1 keeps monitoring the orientation O of the web 3.

[0123] Once substantial tilting S and in consequence rotation R of the web 3 above the deviation threshold have been determined, the controller 40 initiates the appropriate corrective action, which is shown in the method diagram in FIG. 5. The method according to the present invention starts by an operator inputting a print job via a user interface 8 to the printing system 1. The print job is received by the controller 40, which configures the printing system 1 to perform the print job according to the parameters provided in the print job. When the controller 40 determines that the print job, or specifically the medium 3 used, requires tight winding, the printing system 1 is configured for tight winding, such that a pulling force or a longitudinal tension is present in the web 3, at least between the print heads 12a-d and the take-up roller R3. The controller 40 then sets the initial transport speed of the web 3 to ‘high speed’. This allows the printing system 1 to start printing at least its normal production speed or even higher to prevent an initial reduction in productivity.

[0124] While printing the sensor 30 determines the orientation of the buffer plate 31. This sensed orientation O is compared to a reference orientation OR of the web 3 or the buffer plate 31, wherefrom a deviation or tilting angle α. Since deviations a may occur which are so small that these do not significantly affect the image quality, the deviation α is compared to a threshold. The threshold may be an upper limit, for example a maximum value for an orientation angle α or a lateral shift. The upper limits defines which deviations a are allowable without requiring correction by the printing system 1. i.e. which do not show up in the printed image. If the detected deviation α in the buffer plate's orientation O is below the threshold, printing is continued at the initially selected high speed and the orientation O of the web 3 is continually monitored by the sensor 30. Further, from this tilting angle α, the rotation of the web 3 with respect to the transport direction D can be derived. Said rotation may be further used to determine the amount of deviation in the web's position.

[0125] In case the controller 40 determines a significantly large deviation α of the web's orientation O with respect to its desired position OR on the transport path P, the controller 40 determines that the deviation α exceeds the predefined threshold. The appropriate error level for the deviation α is then determined by the controller 40. Thereby the controller 40 classifies the deviation α into one of a plurality of error levels, such as minor, medium, and critical deviations. This is done by comparing the deviation, for example the size or magnitude of the deviation angle, or the magnitude and frequency of the oscillations in the web's orientation, to an error level reference stored in the memory of the controller 40. The error level reference comprises criteria for classifying a deviation into an error level, for example by defining bottom and/or upper limits or ranges for matching the determined deviations to one of the error levels.

[0126] When a deviation has been selected or classified by the controller 40 as a specific class of error level, the controller 40 instructs the printing system 1 to perform one or more actions linked to said error level. The memory of the controller 40 stores for each error level instructions for performing corrective actions. The error level determines the corrective action(s) to be taken. For example, for minor deviations, the image to be printed may be repositioned or adjusted, either by adjusting the digital bitmap or by repositioning the print heads 12a-d to correct for the determined deviation of the web 3. When the determined deviations are too large to be corrected by adjusting the image, these deviations are classified into a different class. A different corrective action is also required. When selecting a class of such deviations of the web 3, especially in the case of determined periodic oscillations in the web's orientation O, the controller 40 adjusts the transport speed. The speed may be set to a predefined speed wherein oscillations of the web 3 were known to be minimal or absent. Alternatively the speed may be adjusted stepwise while continuously monitoring the deviation α of the web 3 to stepwise reduce or eliminate the deviations or oscillations in the web's orientation. Very large deviations which may cause damaged media or paper jams are classified as critical deviations. When this latter class is selected the controller 40 instructs the printing system 1 to halt the print operation, stopping both the transport mechanism R1-R3 and the inkjet printing assembly 10. Further, the controller 40 may, when selecting any of the error levels, instruct a communication device to send a signal to an operator. The communication device may be a light on the printer, a user interface for prompting the user, or an emitter for sending a wireless signal to a receiver held by the operator. The communication signal may be used to inform the operator of the status of the printing system 1 or to instruct the operator to attend the printing system 1, for example when an increase in deviations or certain class of deviations has been determined. This allows the operator to leave the system 1 unattended. It will be appreciated that apart from magnitude deviations in the web's positions may be classified by type, such as periodic oscillations, lateral shifts, rotations etc.

[0127] Although specific embodiments of the invention are 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 exist. It should be appreciated that the exemplary embodiment or exemplary embodiments are examples only and are not intended to limit the scope, applicability, or configuration in any way. Rather, the foregoing summary and detailed description will provide those skilled in the art with a convenient road map for implementing at least one exemplary embodiment, it being understood that various changes may be made in the function and arrangement of elements described in an exemplary embodiment without departing from the scope as set forth in the appended claims and their legal equivalents. Generally, this application is intended to cover any adaptations or variations of the specific embodiments discussed herein.

[0128] It will also be appreciated that in this document the terms “comprise”, “comprising”, “include”, “including”, “contain”, “containing”, “have”, “having”, and any variations thereof, are intended to be understood in an inclusive (i.e. non-exclusive) sense, such that the process, method, device, apparatus or system described herein is not limited to those features or parts or elements or steps recited but may include other elements, features, parts or steps not expressly listed or inherent to such process, method, article, or apparatus. Furthermore, the terms “a” and “an” used herein are intended to be understood as meaning one or more unless explicitly stated otherwise. Moreover, the terms “first”, “second”, “third”, etc. are used merely as labels, and are not intended to impose numerical requirements on or to establish a certain ranking of importance of their objects.

[0129] The present invention being thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the present invention, and all such modifications as would be obvious to one skilled in the art are intended to be included within the scope of the following claims.