Abstract:
A frameless media path module is provided for a media processing system feeding media streams through a media path structured for serial or parallel flows. The frameless media path module includes a plurality of media guides and not less than two media transport nips operated by at least one actuator. Means is included for attaching the frameless media path module to a supporting structure. Media state sensing electronics detect media edge or relative motion and intermodule electrical communication capability is provided.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS  
       [0001]    The following copending applications, Attorney Docket Number D/A3012, U.S. application Ser. No. ______, filed Feb. 4, 2003, titled “Media Path Modules”, is assigned to the same assignee of the present application. The entire disclosure of this copending application is totally incorporated herein by reference in its entirety. 
     
    
     
       INCORPORATION BY REFERENCE  
         [0002]    The following U.S. patents are fully incorporated herein by reference: U.S. Pat. No. 5,467,975 to Hadimioglu et al. (“Apparatus and Method for Moving a Substrate”); and U.S. Pat. No. 6,059,284 to Wolf et al. (“Process, Lateral and Skew Sheet Positioning Apparatus and Method”).  
         BACKGROUND OF THE INVENTION  
         [0003]    This invention relates generally to media transport systems, and more particularly to modular, reconfigurable media path modules within such a transport system.  
           [0004]    Paper transport systems within printing systems are generally constructed from custom designed units, usually consisting of heavy frames supporting pinch rollers driven by one or a few motors. One such system is shown in U.S. Pat. No. 6,322,069 to Krucinski et al., which utilizes a plurality of copy sheet drives, pinch rollers, and belts to transport paper through the printer system. Another approach is taught by U.S. Pat. No. 5,303,017 to Smith, which is directed to a system for avoiding inter-set printing delays with on-line job set compiling or finishing. Smith accomplishes this through the use of sheet feeders and diverter chutes with reversible sheet feeders, also utilizing pinch rollers driven by motors. However, because prior art transport systems are custom designed to meet the differing needs of specific printing systems, field reconfigurability and programmable reconfigurability are not possible.  
           [0005]    It is an object of this invention to provide frameless standard modules, consisting of standard subunits, which can be linked physically, electrically and electronically by attachment to an external frame, and from which any path for transporting flexible media could be constructed.  
         SUMMARY OF THE INVENTION  
         [0006]    Briefly stated, and in accordance with one aspect of the present invention, a frameless media path module is provided for a media processing system feeding media streams through a media path structured for serial or parallel flows. The frameless media path module includes a plurality of media guides and not less than two media transport nips operated by at least one actuator. Means is included for attaching the frameless media path module to a supporting structure. Media state sensing electronics detect media edge or relative motion and intermodule electrical communication capability is provided.  
           [0007]    In accordance with another aspect of the invention, a reconfigurable media path assembly is provided for a media processing system feeding media streams through a media path structured for serial or parallel flows. The reconfigurable media path assembly includes not less than one frameless media path module having a plurality of media guides, not less than two media transport nips, module attachment means, at least one actuator, intermodule electrical communication means, and media state sensing electronics. The frameless media path modules are attached to a support assembly.  
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0008]    The foregoing and other features of the instant invention will be apparent and easily understood from a further reading of the specification, claims and by reference to the accompanying drawings in which:  
         [0009]    [0009]FIG. 1 illustrates transport module configurations formed from components according to the subject invention;  
         [0010]    [0010]FIG. 2 is a perspective view of one embodiment of a transport module assembled on a support panel according to the subject invention;  
         [0011]    [0011]FIG. 3 illustrates an configuration of modules to form a reconfigurable media path;  
         [0012]    [0012]FIG. 4 illustrates a plan view of a configuration of modules within a double-wide framework;  
         [0013]    [0013]FIG. 5 is an oblique view of the embodiment according to FIG. 5;  
         [0014]    [0014]FIG. 6 is a perspective view of the embodiment of FIG. 5 showing transport modules assembled on support panels according to the subject invention;  
         [0015]    [0015]FIG. 7 is an oblique view of the embodiment according to FIG. 5, in which media is directed into or out of the media plane. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0016]    Paper transport systems, constructed from custom designed units generally consisting of heavy frames supporting pinch rollers driven by one or a few motors, are utilized extensively in industry, but have limitations in regard to part reusability and reconfigurability. Standard paper path modules from which any paper path could be constructed would enable shorter time-to-market, lower cost through economies of scale, high part reusability, field reconfigurability, and programmable reconfigurability. The media path modules disclosed herein consist of an integrated, flexible sheet transport and guide assembly with motor driven drive nip units, paper convergence guide units, sheet edge and/or relative motion detection units, and power/computation/communication units. The modules are fixed in place to an external frame to form a modular system which is physically strong and electrically bussed.  
         [0017]    Turning to FIG. 1, there is illustrated exemplary embodiments  100 ,  140 , and  180  of generic transport modules for linearly translating or turning media. Such units can be used to merge paper streams or pass media along forward or backward in the process directions. Module  100  consists of flexible media guides  120  with integrated media transport nips  110 , media inlet guides  125 , and drive motors  150  (shown oversized) configured to transport media in a desired path, in this example generally horizontal in direction. The modules are essentially uniform along their length with the motor drives mounted at the two ends of the module. Various types of sheet guides are contemplated by the disclosure herein, for example solid, perforated, or others known in the art. The motors may be much smaller than shown in FIG. 1, and thus modules can be more closely configured than would appear from the figure. Additionally, the modules can be driven using separate motors or, in less general applications, can be chain driven by a single motor (e.g. for a module in which media only enter from a fixed side).  
         [0018]    For the purposes of clarity, a cylindrical nip is illustrated as the transport mechanism for this embodiment. Cylindrical nips are pinch rollers which contact the media from both sides along a line. One of the cylinders is driven rotationally about its axis and the other is an idler which supports or provides the normal pinching force. It should be noted that other actuation means to provide tangential media forces can be used instead. An example of one such alternate means of actuation is a spherical nip actuator, which contacts the media in only a small area and is in principle capable of driving the media tangentially in an arbitrary direction, as is described in U.S. Pat. No. 6,059,284 to Wolf et al. (“Process, Lateral and Skew Sheet Positioning Apparatus and Method”) incorporated herein by reference in its entirety. Another example of an alternate means of actuation is a piezoelectrically driven brush or brushes to move the media in a desired direction, as taught by U.S. Pat. No. 5,467,975 to Hadimioglu et al. (“Apparatus and Method for Moving a Substrate”) incorporated herein by reference in its entirety.  
         [0019]    These basic elements may alternately be configured as shown in configurations  140  and  180 , which also include media inlet guides  165  and media exit guides  170 . In configuration  140  media inlet guides  165 , flexible media guides  160 , and transport nip  145  are configured to impart an angular directional change in the media path. In configuration  180 , flexible media guides  185 , media inlet guides  175 , media outlet guides  170 , and media transport nips  190  and  195  impart dual angular directional changes in the media path. The modules include media edge sensors and driven transport nips with media inlet guides. All drive and control electronics as well as communication bus drivers are mounted onto the guide using any of many methods known in the art, for example flexible printed circuit board technology. All intermodule electrical signals for power and communication are passed to the modules by connectors which connect either with other modules or with the external frame.  
         [0020]    The term module here refers to an assembly of guides, rollers, motors, sensors, and optional computational and communication components. Different module types with different properties may be provided for different purposes, e.g., transport modules, gate modules with additional switch and motor, registration modules, etc. Turning now to FIG. 2, one embodiment of a module assembly does not require a rigid frame for the transport modules themselves, but instead consists of an external frame providing support for individual transport modules. In this example embodiment, the frame is formed from two parallel panels  210  having a predetermined hole pattern. Although in this example embodiment holes  240  in the hole pattern are shown as being circular, it will readily be appreciated that the hole pattern could assume any of numerous geometric shapes or, alternatively, a slot pattern could be utilized. Rods  220  are attached to parallel panels  210  at desired opening locations by any methods known in the art. Although rods  220  are cylindrical in shape as illustrated in this embodiment, they may be fabricated in various geometric shapes, for example they may have square or rectangular cross-sections. The transport module  230  is then attached at either the module top or bottom to rods  220 . By being attached on only one side to rods  220 , the other side of transport module  230  may be hinged to permit opening of the module for clearance of a media blockage. Frame panels  210  and rods  220  may be fabricated from metals and plastics known in the art.  
         [0021]    Alternative means to assemble a frame to hold the media modules are possible. For example, instead of parallel panels, an open structure of beams may be assembled to form a rigid frame as in an open frame bridge. As another alternative, a solid housing of fixed or variable size could serve a similar purpose. In another embodiment, the transport modules may be attached directly to a rigid frame, rather than being supported by rods. This approach, although it may limit field reconfigurability of the transport system, would still provide flexibility in assembly in a manufacturing environment. Interlocking mechanisms to connect modules to the frame may be selected from many alternative means known to the art. All drive and control electronics as well as communication bus drivers are mounted on the modules or within the frame. All intermodule electrical signals (power and communication) are passed through by connectors, either with other modules or via the frame, which mate as part of the operation of connecting modules to the frame and to other modules.  
         [0022]    [0022]FIG. 3 illustrates an example of a reconfigurable media path  300  configured from a plurality of standard modules. In example embodiment  300  the media paths can be retrograde as well as forward transporting and parallel flows can be enabled. Here modules  310 ,  320 ,  330 , and  340  are attached to panel  360  in such a way that media received by module  310  may be transported by module  320  to gate module  350 , which provides the capability for splitting a media path and creating parallel media paths. In this example, media may flow past gate  350  either to module  330  or module  340 . The spacing and size of the modules are determined by several aspects of the sheets to be transported. For example, the spacing between nips  360  and  370  must be less than the shortest media length in the process direction. Similarly, the spacing between nips  380  and  390  also must be less than the shortest media length in the process direction. Media stock stiffness provides another constraint, in that the radius of curvature in turns, such as at the transition from module  310  to module  320 , cannot be too small to accommodate the stiffest media that may move through the media path. A typical radius in xerographic printer applications is approximately five centimeters. For constraints typical of current xerographic usage, the spacing between nips would be approximately ten centimeters, with a five centimeter radius of curvature in turning operations.  
         [0023]    The embodiments described with respect to FIG. 2 hereinabove enable the ability to construct a double-wide frame supporting both large and smaller transport path assemblies side by side on the same rod. This enables provision for two parallel media paths in the same frame, as illustrated in FIG. 4 in a top view to show the arrangement of transport path assemblies. Here single frame  400  supports transport path assemblies  410 ,  420 , and  430 , with media moving in process direction  440 . In this example embodiment, media is being transported from separate parallel paths  420  and  430  to a single output path  410 . Using the xerographic process as an example, paths  420  and  430  may be transporting paper from two different print engines to a single finisher served by path  410 .  
         [0024]    This embodiment is further illustrated in FIG. 5, in an oblique view. Because paths  520  and  530  are parallel and in the same plane, module-supporting rods (not shown in this figure, but as rods  620  in FIG. 6) may extend the entire width of both transport assemblies  520  and  530  to support transport modules mounted internally in those transport path assemblies. In this embodiment media moves along process path direction  540 , with transported media from transport path assemblies  520  and  530  being received by transport path assembly  510 . This embodiment is illustrated in perspective in FIG. 6, in which module support rods  620  extend the entire width of two transport assemblies  680  and  690 . Attachment means  650  secure transport modules  640  to rods  620 . In this example embodiment, the frame is formed from parallel panels  610  having a predetermined hole pattern. Although in this example embodiment the hole pattern is shown as being circular, it will readily be appreciated that the hole pattern could assume any of numerous geometric shapes or, alternatively, a slot pattern could be utilized. Rods  620  are attached to parallel panels  610  at desired opening locations by any methods known in the art. Although rods  620  are cylindrical in shape as illustrated in this embodiment, they may be fabricated in various geometric shapes, for example, they may have square or rectangular cross-sections. The transport modules  640  are attached at either the module top or bottom to rods  620 . By being attached on only one side to rods  620 , the other side of transport modules  640  may be hinged to permit opening of the module for clearance of a media blockage. Frame panels  610  and rods  620  may be fabricated from metals and/or plastics known in the art.  
         [0025]    Alternative means to assemble a double-wide frame to hold the media modules are possible. For example, instead of parallel panels, an open structure of beams may be assembled to form a rigid frame as in an open frame bridge. As another alternative, a solid housing of fixed or variable size could serve a similar purpose. In another embodiment, the transport modules may be attached directly to a rigid double-wide frame, rather than being supported by rods. This approach, although it may limit field reconfigurability of the transport system, would still provide flexibility in assembly in a manufacturing environment. Interlocking mechanisms to connect modules to the frame may be selected from many alternative means known to the art. All drive and control electronics as well as communication bus drivers are mounted on the modules or within the frame. All intermodule electrical signals (power and communication) are passed through by connectors, either with other modules or via the frame, which mate as part of the operation of connecting modules to the frame and to other modules.  
         [0026]    Another possible arrangement of transport path assemblies is illustrated in FIG. 7, in which parallel paths in differing planes provide for the joining of transport paths from transport path assemblies  720  and  730  into transport path assembly  710 , again moving in process direction  740 . This arrangement provides for a gate module at point  750  which is capable of moving media in a lateral direction (left to right or right to left) such that media can be moved along one of two alternate route in process direction  740 . Similarly, by moving in the reverse process direction, two paths can be merged into a single path. This enables the connection of not only transport paths that are stacked on top of one another, but also paths that are laid out side by side in a double-wide frame.  
         [0027]    Various means may be utilized to assemble a double-wide frame to hold the media modules in the double-wide embodiments contemplated in FIG. 7. For example, parallel panels, such as described with reference to FIG. 6, could shape the double-wide frame, or an open structure of beams may be assembled to form a rigid frame as in an open frame bridge. As another alternative, a solid housing of fixed or variable size could serve a similar purpose. In another embodiment, the transport modules may be attached directly to a rigid double-wide frame, rather than being supported by rods. This approach, although it may limit field reconfigurability of the transport system, would still provide flexibility in assembly in a manufacturing environment. Interlocking mechanisms to connect modules to the frame may be selected from many alternative means known to the art. All drive and control electronics as well as communication bus drivers are mounted on the modules or within the frame. All intermodule electrical signals (power and communication) are passed through by connectors, either with other modules or via the frame, which mate as part of the operation of connecting modules to the frame and to other modules.  
         [0028]    While the present invention has been illustrated and described with reference to specific embodiments, further modification and improvements will occur to those skilled in the art. For example, the modules may utilize separately driven nips and the nips can be independent in the cross-process direction as well, to permit deskewing and other operations requiring more than one degree of freedom. Additionally, other types of sheet state sensors, such as relative motion detectors, can be used in place of or in addition to sheet edge detectors. It is to be understood, therefore, that this invention is not limited to the particular forms illustrated and that it is intended in the appended claims to embrace all alternatives, modifications, and variations which do not depart from the spirit and scope of this invention.