Abstract:
A media roll positioning assembly for positioning a roll of media includes a guiding device, a retainer and a media roll supporting device. The media roll supporting device includes an elongated element for supporting the roll of media and a support configured to support the media roll supporting device on the guiding device. The guiding device is configured to movably support the support to guide the support in a main displacement direction from an input position to a reference position, the reference position being defined by a reference element. The retainer is configured to retain the support in the reference position, the support being removable from the reference position by application of a force on the media roll supporting device, the force exceeding a predetermined threshold force.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims priority under 35 U.S.C. § 119(e) to U.S. Provisional Application No. 60/960,956 filed on Oct. 22, 2007, the entirety of which is expressly incorporated herein by reference. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    1. Field of the Invention 
         [0003]    The present invention relates to a media roll positioning assembly and to a method for positioning a media roll in such assembly. In particular, the media roll positioning assembly is configured for use in a printing device. 
         [0004]    2. Description of Background Art 
         [0005]    In a printer device according to the background art, a print medium on which an image or text is printed may be supplied on a roll. Such a media roll is to be input in the printing device with a predetermined positional accuracy. The accuracy is not only required with respect to the actual position of the media roll, but with respect to its orientation as well. If the media roll is positioned askew with respect to a predetermined media path through the printer device, the media may get stuck in the printer device, for example. 
         [0006]    A printer device according to the background art comprises a relatively flat surface on which a print medium is to be positioned. Such a printer may be used for printing on relatively inflexible and/or large media. To print on a medium like paper, for example, it is known to use a roll-to-roll assembly, which may be arranged such that the medium may be printed on while the medium is being transported from an input roll to an output roll. The roll-to-roll assembly may be an optional add-on device. 
         [0007]    The roll-to-roll assembly according to the background art comprises an input assembly for supplying a roll of medium. An input assembly according to the background art comprises a locking device for retaining the media roll. When placing the media roll in the input assembly, the media roll needs to be correctly positioned and the locking device requires operation from an operator. Hence, considering that such a media roll is heavy and difficult to handle, introducing and positioning the media roll is difficult and/or requires a relatively large number of method steps. 
         [0008]    Moreover, the input assembly according to the background art is originally configured to be used in combination with a printing press machine. Such a machine requires a heavy duty input assembly, usually provided with a pneumatically operated media retaining shaft. Such an input assembly is thus overkill for a media roll for use with a printing device of the above-described kind and is accordingly relatively expensive. 
       SUMMARY OF THE INVENTION 
       [0009]    It is an object of the present invention to provide a media roll positioning assembly and corresponding method that is user-friendly. 
         [0010]    The object is achieved in a media roll positioning assembly for positioning a roll of media that comprises a guiding device, a retainer and a media roll supporting device and in a method for positioning a media roll in a printing device. 
         [0011]    The media roll positioning assembly according to the present invention comprises a media roll supporting device, which comprises an elongated element for supporting the roll of media and a support configured to support the media roll supporting device on a guiding device. The media roll supporting device is configured such that a media roll may be positioned around the elongated element, when the media roll supporting device is not connected to or arranged in any other device or assembly. Hence, an operator or user may easily position the media roll around the elongated element. The support is configured and arranged such that the support may support the media roll arranged around the elongated element. In particular, the support is configured to support the media roll supporting device, including a media roll, on the guiding device. 
         [0012]    The guiding device is arranged and configured to receive the media roll supporting device at an input position thereof. Then, the media roll supporting device may be moved from the input position to a reference position. The movement is guided by the guiding device such that the media roll supporting device has a predetermined position relative to the printing device when positioned at the reference position. 
         [0013]    At the reference position, the media roll supporting device is retainable by the retainer. In particular, the retainer is configured to retain the support in the reference position and, hence, a media roll arranged around the elongated element may rotate without obstruction from the retainer. The media roll supporting device may be easily removed from the reference position by application of a force—in an embodiment substantially directed in the main displacement direction—which force should exceed a predetermined threshold force. Thus, the media roll is retained in the reference position, when the printing device is in operation and the medium is pulled from the media roll. 
         [0014]    In an embodiment, the reference element comprises a reference surface, wherein the reference surface extends substantially perpendicular with respect to the main displacement direction. The reference surface is configured for engaging the support for, thereby, radially positioning the media roll supporting device. Similarly, the reference element may comprise a reference surface for engaging the support and extending substantially parallel to the main displacement direction for, thereby, axially positioning the media roll supporting device. It is noted that, in an embodiment, a single reference element may comprise multiple reference surfaces. Further, in an embodiment, multiple reference elements may each provide a reference surface, cooperating for accurately positioning the media roll supporting device in multiple directions. 
         [0015]    In an embodiment, the guiding device comprises at least one guiding groove substantially extending in the main displacement direction and the support is configured to be received in said guiding groove such that the media roll supporting device is guidably movable in said main displacement direction by moving the support through said guiding groove. The guiding groove may guide the support not only in the main displacement direction, but also in a direction perpendicular to the main displacement direction. For example, in an embodiment, the guiding groove may comprise a tapered portion. In particular, a side wall of the guiding groove may be employed as a reference surface for positioning the support guided by the guiding device. 
         [0016]    In an embodiment, the elongated element extends substantially perpendicular to the main displacement direction. In such embodiment, the side wall of the guiding groove may provide a reference surface for axially positioning the support and thereby axially positioning a media roll arranged around the elongated element. 
         [0017]    In an embodiment, radial positioning may be performed by providing a reference surface at an end of the guiding groove. For example, a recess in a bottom wall of the guiding groove may be configured to at least partly receive the support. It is noted that in such an embodiment, the recess may be considered a retainer, while a wall of the recess may be considered a reference surface of a reference element. 
         [0018]    In an embodiment, the retainer may comprise a lever. The lever may comprise a retaining element. The lever is configured to have a first position in which it is configured to engage with the support positioned in the reference position such that the support is retained in the reference position. Further, the lever is configured to have a second position in which it is configured not to retain the support positioned in the reference position. In particular, the lever is configured to move from the first position to the second position for releasing the support, when a force exceeding the predetermined threshold force is applied to the media roll supporting device. 
         [0019]    In an embodiment, the lever is spring loaded for pressing the retaining element against the support, when positioned in the reference position, such that the support is pressed against the reference element. 
         [0020]    In an embodiment, the support is rotatably connectable to the elongated element. Thus, the elongated element may rotate, while the support remain stationary, supported by the guiding device and retained by the retainer. 
         [0021]    In an embodiment, the elongated element comprises a fixation device configured to fixate a media roll around the elongated element, and the fixation device is configured to co-axially position the media roll with respect to an axis of the elongated element. Thus, the media roll is fixed on the media roll supporting device. Consequently, when the media roll supporting device is arranged at the reference position, thereby having a predetermined position, the media roll is arranged in a predetermined position. Preferably, a ruler is provided on the elongated element such that the media roll may be positioned relative to the elongated element in an axial direction. Thereby, the media roll is also provided with a predetermined position in the axial direction, when the media roll supporting device is provided with a predetermined axial position, when arranged in the reference position. 
         [0022]    In an embodiment, the support is a substantially circularly shaped element, which may roll over the guiding device. In particular, the substantially circularly shaped element is formed as a disc such that it may roll through a guiding groove. 
         [0023]    In an aspect, the present invention further provides a printing device comprising the media roll positioning device according to any embodiment of the present invention. 
         [0024]    In the method according to the present invention a media roll is positioned in a printing device. The media roll is arranged on a media roll supporting device. The supporting device comprises a support. The support is configured to be positioned at an input position on a guiding device. Then, the media roll supporting device is moved in a main displacement direction from the input position to a reference position as defined by a reference element. In the reference position, the media roll supporting device is retained by a retainer. 
         [0025]    Further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0026]    The present invention will become more fully understood from the detailed description given hereinbelow and the accompanying drawings which are given by way of illustration only, and thus are not limitative of the present invention, and wherein: 
           [0027]      FIG. 1  is a perspective view of an embodiment of a printing device; 
           [0028]      FIG. 2A  is a first perspective view of an embodiment of a media roll positioning assembly according to the present invention for use with the printing device of  FIG. 1 ; 
           [0029]      FIG. 2B  is a second perspective view of the embodiment of the media roll positioning assembly of  FIG. 2A ; 
           [0030]      FIG. 3A  is a perspective view of an embodiment of a media roll supporting device according to the present invention for use in the media roll positioning assembly of  FIG. 2 ; 
           [0031]      FIG. 3B  is a perspective view of a part of the embodiment of the media roll supporting device of  FIG. 3A ; 
           [0032]      FIG. 3C  is a side view of the embodiment of the media roll supporting device of  FIG. 3A ; 
           [0033]      FIG. 4A  is a perspective view of an embodiment of a guiding device and an embodiment of a retainer for use in an assembly of  FIG. 2 ; and 
           [0034]      FIG. 4B  is a perspective view of an embodiment of the media roll positioning device comprising the media roll supporting device of  FIG. 3A  and the guiding device and the retainer of  FIG. 4A . 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0035]    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. 
         [0036]      FIG. 1  shows a printing device  10  for printing an image or text on a relatively large object, in particular on a relatively large and flat object. Such a printing device  10  is well known in the background art. The printing device  10  comprises a support assembly  12  on which a printing surface  14  is arranged. As illustrated, the printing surface  14  may be provided with suction holes for pulling the object onto the printing surface  14  and thereby holding the object flat on the printing surface  14 . A guiding assembly  16  is provided for supporting and guiding a carriage  18 . The carriage  18  is movably supported by the guiding assembly  16  such that the carriage  18  may be moved over the printing surface  14 . For example, the guiding assembly  16  may be movably supported on the support assembly  12  such that the guiding assembly may be moved in a y-direction (as indicated in  FIG. 1 ) and the carriage  18  may be moveably supported by the guiding assembly  16  such that the carriage may be moved in a x-direction guided by the guiding assembly  16 . The carriage  18  is provided with a printing element such as an inkjet printhead for printing the image or the text on the object arranged on the printing surface  14  by ejecting ink drops at predetermined positions. It is noted that the guiding assembly  16  and/or the carriage  18  may be supported such that they may be moved in a z-direction, thereby enabling printing on different media (i.e. objects) having a different dimension in the z-direction (when positioned on the printing surface  14 ). 
         [0037]    The printing device  10  further comprises an interface assembly  20 . The interface assembly  20  is configured for connecting a media roll supporting assembly to the printing device  10  such that the printing device  10  is enabled to print on a media that is supplied from a roll instead of a medium that is positioned on the printing surface  14 , although it is noted that in an embodiment the medium that is supplied from a roll may be moveably supported by, guided over and positioned on the printing surface  14 . In such an embodiment, the medium may be transported from a supply roll arranged at a first side of the printing surface  14  to a media receiving roll arranged at a second side of the printing surface  14 . Hereinafter, an embodiment, which is illustrated in the drawings, is elucidated, in which embodiment a media supply roll and a media receiving roll are arranged at one side of the printing surface  14 . 
         [0038]      FIGS. 2A and 2B  show a media roll supporting assembly  22  configured for being coupled to the printing device  10  of  FIG. 1 . The media roll supporting assembly  22  comprises a first media roll slot  24  and a second media roll slot  26  for supporting two media rolls. In particular, in the illustrated embodiment, a first media roll may supply a medium, while a second media roll may receive the medium after it has been printed. For supporting the media rolls, each slot  24 ,  26  is configured for receiving a media roll supporting device  28 . The media roll supporting device  28  is configured to receive and support the media roll. The media roll supporting device  28  comprises an elongated element around which the media roll may be arranged. The elongated element may be a bar or axle having a cylindrical cross-section, for example. Also other suitable shapes may be employed. The media roll supporting device  28  further comprises a support and may her comprise an assembly of a number of parts, possibly providing additional functionality. In any case, the media roll supporting device  28  is removeably supported in at least one slot  24 ,  26 . Preferably, the media roll supporting device  28  is supported in a suitable slot  24 ,  26  at each end of the media roll supporting device  28 . 
         [0039]    For printing, the medium supplied from a roll arranged in the media roll supporting assembly  22  is guided through the media roll supporting assembly  22  such that the media is moveably supported by and positioned on a media printing surface  30 , possibly provided with a device for holding the medium substantially flat on the media printing surface  30 . Such device may include, but is not limited to, a suction device. For guiding, one or more medium guiding rolls may be provided. For example, a first guiding roll  32 A and a second guiding roll  32 B may be provided. 
         [0040]    One or both media rolls may be driven by a motor  36 , for example through the media roll supporting device  28  supporting the media roll. In  FIGS. 2A   2 B, the motor  36  is arranged at one side of the media roll supporting assembly  22 . Hence, each media roll supporting device  28  is driven at one end thereof. In an embodiment, the motor  36  may be provided at both ends of the media roll supporting device  28 . As shown in  FIG. 2B , a drive coupling  38  is provided for operatively coupling the motor  36  and the media roll supporting device  28 . 
         [0041]      FIG. 3A  shows an embodiment of a media roll supporting device  28  for use in the media roll positioning assembly  22  illustrated in  FIGS. 2A-2B .  FIGS. 3B and 3C  show the embodiment of the media roll supporting device  28  in more detail. Now referring to  FIGS. 3A-3C , the media roll supporting device  28  comprises a base frame element  280 . A substantially cylindrical outer casing  281  surrounds the base frame element  280 . A first positioning rib  282 A and a second positioning rib  282 B protrude from the outer casing  281 . Further, a media roll locking pin  283  is also configured to protrude from the outer casing  281  in order to hold a media roll in a predetermined position relative to the media roll supporting device  28  by bringing the media roll in engagement with the first and second positioning ribs  282 A,  282 B. 
         [0042]    The locking pin  283  is operatively coupled to a locking interface  284 , enabling an operator to actuate the locking pin  283 . As illustrated, the locking interface  284  may be a threaded pin or bolt, or the like, which may be coupled through a cam assembly to a locking mechanism. The locking mechanism may comprise an elongated coupling element  289 A, provided with a guiding recess  289 B which may slide over a guide pin or bolt  289 C, for example. The elongated coupling element  289 A may be operatively coupled to the locking pin  283 . The locking pin  283  may be pre-tensioned by a tensioning mechanism such as a spring  287 . For illustrative purpose, the spring  287  is shown disjointed from a coupling element  288  of the locking pin  283 . However, in practice, the spring  287  can be hooked to the coupling element  288  for driving the locking pin  283  outward relative to the outer casing  281  and for thereby engaging a media roll. Thus, operating the locking interface  284  results in driving the locking pin  283  inward against the spring force. Consequently, since the media roll is engaged with a force corresponding the spring force, there will be virtually no influence of an operator on the force applied to the media roll. 
         [0043]    The media roll supporting device  28  is further provided with a supporting device  285 . In the illustrated embodiment, the supporting device  285  comprises a track roller, which may be received in and be guideably moveable in a main displacement direction through a guiding device. Such guiding device is comprised in the slots  24 ,  26  ( FIGS. 2A ,  2 B). Further, the media roll supporting device  28  comprises an engaging device  286  for engaging the drive coupling  38  ( FIG. 2B ). In the illustrated embodiment, the drive coupling is achieved using a Oldham drive feature, which is well known in the background art. 
         [0044]    In operation, when loading a media roll, the media roll supporting device  28  is removed from the media roll supporting assembly  22  ( FIG. 2A ,  2 B). The locking pin  283  is driven inwardly by operating the locking interface  284 . The media roll, usually having a substantially cylindrical cardboard core with a through hole, is arranged around the media roll supporting device  28  such that one or both ends of the media roll supporting device  28  protrudes from the media roll, thereby enabling the positioning of one or both ends in a corresponding slot  24 ,  26  of the media roll supporting assembly  22 . In particular, the media roll may be axially centered with respect to the media roll supporting device  28 . 
         [0045]    Then, the operator again operates the locking interface  284 . Thus, the locking pin  283  is driven outward due to the spring force applied to the locking pin  283  by the spring  287 . If the media indeed comprises a cardboard core, it may be desirable to provide the locking pin  283  with a sharp edge or sharp tip, which is configured to be at least partially driven into the cardboard of the core, thereby fixing the cardboard core and media roll in an axial direction of the media roll supporting device  28 . Further, the locking pin  283 , by being driven outward, pushes the media roll core such that the core is brought into engagement with the first and the second positioning rib  282 A,  282 B. As a result, the media roll is provided with a predetermined position relative to the media roll supporting device  28 . Once the media roll has obtained a substantially fixed position on the media roll supporting device  28 , the media roll supporting device  28  may be replaced in the media roll supporting assembly  22 . By ensuring that the media roll supporting device  28  is provided with a predetermined position relative to the media roll supporting assembly  22 , the media roll thus obtains a predetermined position relative to the media roll supporting assembly  22 . 
         [0046]    Removing an empty core of a supply roll or removing a full receiving roll may be performed by a method similar to the above method, in which the media roll is removed from the media roll supporting device  28  instead of arranging the media roll around the media roll supporting device  28 . 
         [0047]      FIG. 4A  shows an embodiment of guiding device  40  and retainer  42  according to the present invention. The guiding device  40  and the retainer  42  are provided on a frame element F. The frame element F is a part of a frame of the media roll supporting assembly  22 . In the illustrated embodiment, the guiding device  40  comprises a guiding groove  44 A arranged in a support element  46 . The support element  46  is configured to support (a weight of) a media roll including the media roll supporting device  28 . In an embodiment, the guiding groove  44   a  comprises a tapered portion  44 B. 
         [0048]    The guiding groove  44 A substantially extends in a main displacement direction. At the point where the tapered portion  44 B of the guiding groove  44 A has a relatively large width, an operator may relatively easily position the support  285  in the guiding groove  44 A. By moving the support  285  through the guiding groove  44 A in the main displacement direction, in which direction the width of the guiding groove  44 A becomes smaller, the media roll supporting device  28  obtains a predetermined axial position relative to the media roll supporting assembly  22 . Thus, a vertically extending side wall of the guiding groove  44 A may be considered to be a first reference surface  48 A for axially positioning the media roll supporting device  28  and a media roll supported by said media roll supporting device  28 . 
         [0049]    At an end of the guiding groove  44 A, a second reference surface  48 B may be provided by a reference element extending substantially perpendicular with respect to the main displacement direction provided by the guiding groove  44 A. Thus, the media roll may be loaded into the media roll supporting assembly  22  by moving the media roll supporting device  28  through the guiding groove  44 A in the main displacement direction towards the second reference surface  48 B and engaging the support  285  with said second reference surface  48 B, thereby positioning the media roll supporting device  28  and the corresponding media roll in the main displacement direction. 
         [0050]    The retainer  42  is configured to hold the media roll supporting device  28  in a predetermined reference position defined by the engagement of the support  285  of the media roll supporting device  28  with the first reference surface  48 A and the second reference surface  48 B. In the illustrated embodiment, the retainer  42  comprises a retaining element  50  coupled to a lever  52 . The lever  52  is rotatably coupled to the frame F at a rotation point  54 A. Further, a spring  54 B is arranged between an end portion of the lever  52  and the frame F. Thus, the retaining element  50  is configured to enable positioning of the support  285  in the predetermined reference position, since the retaining element  50  is arranged such that the retaining element  50  may be moved, when the support  285  is moved towards the predetermined reference position. Further, due to the spring  54 B, the retaining element  50  may be engaged with the support  285  such that the support  285  is engaged with the first and the second reference surfaces  48 A,  48 B. 
         [0051]      FIGS. 5A and 5B  show another embodiment of a support element  46  for use in the retainer  42 . The illustrated support element  46  comprises a recess  56  at the predetermined reference position. The recess  56  may define the predetermined reference position, since a bottom wall of the recess  56  may provide the first reference surface  48 A, a first side wall of the recess  56  may provide the second reference surface  48 B and/or a second side wall of the recess  56  may provide a third reference surface  48 C. As above described, for axially positioning the media roll supporting device  28 , a side wall of the guiding groove  44 A may be employed. In the embodiment illustrated in  FIGS. 5A ,  5 B, said second side wall may be employed as the reference surface for axial positioning. It is noted that the recess  56  obviates the use of a retaining element  50  as illustrated in  FIG. 4A . However, it is contemplated that both a recess  56  and the retaining element  50  are comprised in the retainer  42 . Further, although not explicitly shown in  FIGS. 5A ,  5 B, the guiding groove  44 A comprising the recess  56  may be provided with a tapered portion  44 B. 
         [0052]    Now referring to  FIG. 4B , the media roll supporting device  28  is shown, when positioned in the media roll supporting assembly  22 . In  FIG. 4B , the media roll supporting device  28  is provided with a ruler  58 . The ruler  58  is provided for positioning a roll of media axially centered on the media roll supporting device  28 . 
         [0053]    In operation, the media roll supporting assembly  22  ( FIGS. 2A-5B ) is coupled to the printing device  10  ( FIG. 1 ). The embodiment as illustrated in the drawings is such that the guiding assembly  16  may be positioned over the media roll supporting assembly  22 , when the media roll supporting assembly  22  is coupled to the printing device  10  and the carriage  18  may move over the media printing surface  30  of the media roll supporting assembly  22 . However, as described above, the medium provided on a roll may be guided over the printing surface  14  of the printing device  10 . In such an embodiment, the guiding assembly  16  is not required to be enabled to be positioned over (a part of) the media roll support assembly. 
         [0054]    Detailed embodiments of the present invention are disclosed herein; however, it is to be understood that the disclosed embodiments are merely exemplary of the invention, which can be embodied in various forms. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a basis for the claims and as a representative basis for teaching one skilled in the art to variously employ the present invention in virtually any appropriately detailed structure. Further, the terms and phrases used herein are not intended to be limiting; but rather, to provide an understandable description of the invention. 
         [0055]    The terms “a” or “an,” as used herein, are defined as one or more than one. The term plurality, as used herein, is defined as two or more than two. The term another, as used herein, is defined as at least a second or more. The terms including and/or, as used herein, are defined as comprising (i.e., open language). The term coupled, as used herein, is defined as connected, although not necessarily directly. 
         [0056]    The 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 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.