Abstract:
A media transport array for forming sequential media streams feeding a media processing system in which serial flows, parallel flows, or both are desired are structured from standard, batch fabricatable media path modules. Each media path module includes a frame unit, intermodule latching means, media control electronics, and media state sensing electronics. Within each media path module, at least one media transport nip receives media and passes it to an independently actuated media director. Media guides support media as it moves into and out of the media director.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
   The following copending applications, U.S. application Ser. No. 10/357,761 filed Feb. 4, 2003, titled “Frameless 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 
   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 
   This invention relates generally to media transport systems, and more particularly to sheet direction modules within such a transport system. 
   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. 
   It is an object of this invention to provide standard, mass produced, batch fabricatable modules consisting of standard subunits, which can be linked physically, electrically and electronically, from which any path for transporting flexible media could be constructed. 
   SUMMARY OF THE INVENTION 
   Briefly stated, and in accordance with one aspect of the present invention, there is provided a media transport array for forming sequential media streams feeding a media processing system in which serial flows, parallel flows, or both are desired. The media transport array is structured from standard, batch fabricatable media path modules. Each media path module includes a frame unit, intermodule latching means, media control electronics, and media state sensing electronics. Within each media path module, at least one media transport nip receives media and passes it to an independently actuated media director. Media guides support media as it moves into and out of the media director. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     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: 
       FIG. 1  illustrates a media director system module according to one embodiment of the subject invention positioned to guide media through a ninety degree turn; 
       FIG. 2  illustrates the media director system module according to the embodiment of  FIG. 1 , positioned to guide media horizontally; 
       FIG. 3  illustrates a media director system module according to another embodiment of the subject invention positioned to guide media horizontally; 
       FIG. 4  illustrates a media director system module according to the embodiment of  FIG. 3 , positioned to guide media through a ninety degree turn; 
       FIG. 5  illustrates an array of media director modules in the embodiment of  FIG. 1  configured as a print engine media path; 
       FIG. 6  is a perspective view of the media director system module according to the embodiment of  FIG. 1 ; 
       FIG. 7  illustrates a media director system module according to another embodiment of the subject invention; 
       FIG. 8  illustrates an array of media director modules in the embodiment of  FIG. 7  configured as a print engine media path; and 
       FIG. 9  illustrates an array of media director modules including an embodiment of an extensible transport module according to the subject invention. 
   

   DETAILED DESCRIPTION OF THE INVENTION 
   Although custom designed media transport systems are utilized extensively in industry, standard media path modules from which any media 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 are exemplary modules, themselves incorporating standard subunits, which can be linked physically, electrically and electronically to provide these benefits. The media path modules consist of a linkable frame, motor driven drive nip units, media convergence guide units, switchable director units, media edge and/or relative motion detection units, and power/computation/communication units. The modules link mechanically to form an integrated system which is physically strong and electrically bussed. 
     FIG. 1  illustrates a side view of an exemplary embodiment of the media path modules for linearly translating media or turning media. At any instant, such modules can be used to split media streams, merge media streams or pass media along, forward or backward, in one of two orthogonal directions. The modules  100  consist of standard frame  110  with interlocking mechanisms  120  and media state sensors, such as, for example, edge detectors or relative motion detectors (not shown). Interlocking mechanisms  120  may be selected from many alternative means known to the art. Four driven transport nips  130 ,  132 ,  134 , and  136  and media inlet guides  140  move media into and out from rotary media director  160 . Illustrated in this embodiment are cylindrical nips, which 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. 
   Rotary media director  160  consists of a rotary housing holding in-line and deflector units  150 . Cylindrical nips  130 ,  132 ,  134 , and  136  can be driven using separate motors (not shown), or can be chain driven by a single motor (e.g. for a module in which media only enter from a fixed side). All drive and control electronics as well as communication bus drivers are mounted within the frame. All intermodule electrical signals (power and communication) are passed through by connectors, which mate as part of the module joining operation. In this figure, rotary media director  160  is positioned to guide media  180  into a cylindrical nip  132  on the right side of module  100  and out through a cylindrical nip  136  at the lop side of module  100  in a ninety degree path, guided by deflector unit  150 . Of course by reversing the motor rotation, media transport direction is reversed. Frame units  110  and rotary media director  160  may be constructed from various known plastics and/or metals. 
     FIG. 2  illustrates the module  200  having standard frame  210  with interlocking mechanisms  220  and media state sensors, such as, for example, edge detectors or relative motion detectors (not shown). Interlocking mechanisms  220  may be selected from many alternative means known to the art. Four driven cylindrical nips  230 ,  232 ,  234 , and  236  and media inlet guides  240  move media into and out from rotary media director  260 . Frame units  210  and rotary media director  260  may be constructed from various known plastics and/or metals. Media director  260  consists of a rotary housing holding in-line and deflector units  270 . Here rotary media director  260  is positioned to guide media  250  into cylindrical nip  234  on the left side of module  200  and out through opposing cylindrical nip  232  on the right side of module  22  along a horizontal path. Of course by reversing the motor rotation media transport direction is reversed. Cylindrical nips  230 ,  232 ,  234 , and  236  can be driven using separate motors (not shown), or can be chain driven by a single motor. All drive and control electronics as well as communication bus drivers are mounted within the frame. All intermodule electrical signals (power and communication) are passed through by connectors which mate as part of the module joining operation. 
   Turning now to  FIG. 3 , there is illustrated another exemplary embodiment of media path module  300 . Module  300  includes frame  310  with interlocking mechanisms  320  and media state sensors, such as, for example, edge detectors or relative motion detectors (not shown). Interlocking mechanisms  320  may be selected from many alternative means known to the art. Four driven cylindrical nips  330 ,  332 ,  334 , and  336  and media inlet guides  340  move media into and out from media director  360 . Frame units  310  and media director  360  may be constructed from various known plastics and/or metals. Media director  360  consists of laterally shifted deflector vanes with pass-through centers  370 . Here media director  360  is positioned in a first orientation to guide media  350  into cylindrical nip  334  on the left side of module  300  in a horizontal path through opposing cylindrical nip  332  on the right side of module  300 . Of course by reversing the motor rotation media transport direction is reversed. Media director  360  is translated at 45 degrees to the horizontal and vertical axes in milliseconds by one of various possible drive mechanisms (not shown), such as, for example, linear motors with simple hinged connections to the media director or a rack and pinion coupling. Alternatively, multiposition solenoids can be used, as well as other drive mechanisms known in the art. Detents may be utilized to achieve director positioning, or an LED/photodiode pair could be used to add precision to director positioning. Cylindrical nips  330 ,  332 ,  334 , and  336  can be driven using separate motors (not shown), or can be chain driven by a single motor (e.g. for a module in which media only enter from a fixed side). All drive and control electronics as well as communication bus drivers are mounted within the frame. All intermodule electrical signals (power and communication) are passed through by connectors, which mate as part of the module joining operation. 
   Referring now to  FIG. 4 , there is illustrated another exemplary embodiment of media path module  400 . Module  400  includes frame  410  with interlocking mechanisms  420  and media state sensors, such as, for example, edge detectors or relative motion detectors (not shown). Interlocking mechanisms  420  may be selected from many alternative means known to the art. Four driven cylindrical nips  430 ,  432 ,  434 , and  436  and media inlet guides  440  move media into and out from media director  460 . Frame units  410  and media director  460  may be constructed from various known plastics and/or metals. Media director  460  consists of translated deflector vanes with pass-through centers  470 . Here media director  460  is translated up and to the right to guide media  450  into cylindrical nip  434  on the left side of module  400  and out through cylindrical nip  430  at the bottom of module  400  in a ninety-degree path. Of course by reversing the motor rotation media transport direction is reversed. Media director  460  is translated in milliseconds by one of various possible drive mechanisms (not shown), such as, for example, linear motors with simple hinged connections to the media director or a rack and pinion coupling. Alternatively, multiposition solenoids can be used, as well as other drive mechanisms known in the art. Detents may be utilized to achieve director positioning, or an LED/photodiode pair could be used to add precision to director positioning. All drive and control electronics as well as communication bus drivers are mounted within the frame. All intermodule electrical signals (power and communication) are passed through by connectors, which mate as part of the module joining operation. 
   Turning now to  FIG. 5 , an array of modules  500  illustrates an example of a reconfigurable media path configured around units such as a print engine  530  (xerographic, ink jet, or other), finishers, input sources, etc. In array  500  media paths can be retrograde as well as forward transporting and parallel flows can be enabled. The size of media modules  510  is determined by several aspects of the media to be transported. The spacing between nips  520  must be less than the shortest media length in the process direction. Nips  520  are beneficially, but not necessarily, placed within a module such that the spacing between nips  520  is uniform throughout the media path after module connection. Another constraint is directed to the radius of curvature in turns, which cannot be too small to accommodate the stiffest media that may move through the array. A typical radius in xerographic printers is approximately five centimeters. With the constraints typical of current xerographic use, modules as shown here and used in such an application would be approximately twenty centimeters on a side and have a five-centimeter radius of curvature in turning operations. 
   The media path module embodiments of  FIGS. 1 and 2  are shown in a perspective view in FIG.  6 . In this embodiment cylindrical nip drives  640  continue the length of the module, although their individual parts are indicated only at the end of module  600  for the purposes of clarity. As described in more detail hereinabove, media is received from media inlet guides  620 , proceeds through cylindrical nip  640 , and into rotary media director  610 , which directs media either forward or backward, in one of two directions. Intermodule connectors  630  provide the capability for connecting individual modules and also for intermodule connections for communication and control electronics. 
   Another exemplary embodiment of the media path modules for linearly translating media or turning media is illustrated in FIG.  7 . In this embodiment, module  700  consists of standard frame  740  with interlocking mechanisms  750  and media state sensors, such as, for example, edge detectors or relative motion detectors (not shown). Interlocking mechanisms  750  may be selected from many alternative means known to the art. A single driven transport nip  710  and media inlet/outlet guides  730  move media into rotary media director  720 . At any instant, such modules, with a single allowed input, can be used to direct media output in any of three directions  760 . Illustrated in this embodiment are cylindrical nips, described in more detail hereinabove. However, it should be noted that other actuation means to provide tangential media forces can be used instead. Examples of alternate means of actuation include a spherical nip actuator and a piezo pusher means, as described hereinabove with reference to the embodiment illustrated in FIG.  1 . 
   Rotary media director  720  consists of a rotary housing holding in-line and deflector units  770 . Cylindrical nips  710  can be driven using separate motors (not shown), or can be chain driven by a single motor (e.g. for a module in which media only enter from a fixed side). All drive and control electronics as well as communication bus drivers are mounted within the frame. All intermodule electrical signals (power and communication) are passed through by connectors, which mate as part of the module joining operation. In this figure, rotary media director  720  is positioned to guide media (not shown) into a cylindrical nip  710  on the left side of module  700  and out through media inlet/outlet guides  730  at the right side of module  700  in a flow-through path, guided by deflector unit  720 . Frame units  740  and rotary media director  720  may be constructed from various known plastics and/or metals. Although this embodiment has been described with the media director in the form of a rotary housing, it will be appreciated that media director  720  could also take the form of translated deflector vanes with pass-through centers as described with reference to FIG.  3 . 
     FIG. 8  illustrates an example embodiment of a media path utilizing the single inlet/multiple outlet media path module embodiment described with respect to FIG.  7 . In this embodiment, a reconfigurable media path is structured from a plurality of single inlet/multiple outlet media path modules  850  around units such as a print engine  860  (xerographic, ink jet, or other), or finishers, input sources, etc. In array  800  media paths are forward transporting and parallel flows can be enabled, as shown by media paths  810  and  870 . Media flow may also be diverted to various alternate destinations, as illustrated by the exit directions of media paths  810  and  840 . In this embodiment the function of the media director is shown schematically, for clarity; it will be appreciated that the media director could take the form of any of the media director embodiments described herein. 
   The size of media modules  850  is determined by several aspects of the media to be transported. The spacing between nips  820  must be less than the shortest media length in the process direction. Nips  820  are placed within a module such that the spacing between nips  820  is beneficially uniform throughout the media path after module connection. Another constraint is directed to the radius of curvature in turns, which cannot be too small to accommodate the stiffest media that may move through the array. A typical radius in xerographic printers is approximately five centimeters. With the constraints typical of current xerographic use, modules as shown here and used in such an application would be approximately twenty centimeters on a side and have a five centimeter radius of curvature in turning operations. In those cases in which pass-through flow only is desired, extraneous module elements may be removed from the individual modules, such as in modules  880 , in which the media director and extraneous media guides have been removed. 
   In the embodiments described hereinabove, the media path modules are essentially uniform along their length with the motor drives mounted at the two ends, Optionally, in those systems where certain degrees of freedom are fixed (not programmably reconfigurable) the media director may be replaced with a fixed guide unit and related motor drives may be omitted or removed. Furthermore, extensible straight transport modules (having no director) shorter than the active modules can be interposed to allow for arbitrary length runs between connected engines (such as print engines or finishers or paper sources, etc.) to be achieved. Turning now to  FIG. 9 , media path modules are configured in an example system  900  in which and example embodiment of an extensible straight transport module  920  is included to provide a shortened connection run to print engine  970 . Extensible straight transport module  920  includes frame  930  and frame extensions  940  in the form of parallel plates upon which frame  930  may be telescoped. Module  920  also includes in this example embodiment two transport nips  950  and  960 , but it is understood that such a module would operate beneficially with one nip only. 
   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, media path modules can use separately driven nips and the nips can have independently driven segments in the cross-process direction as well, which would permit de-skewing and other operations requiring more than one degree of freedom. Furthermore, the directors can be driven in time-dependent motions. For example, the translational director can be over-retracted to facilitate entry of the sheet leading edge into the curved surface of the director, and then returned to the sheet turning position. Additionally the in-line/deflector units and the deflector vanes of the example embodiments of the media directors described herein may take various alternate forms, as will be appreciated by one knowledgeable in the art. 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.