Abstract:
A flexible media transport system includes a director element having articulating tips that provide access to selected media paths. The director element(s) can be incorporated into a director module. Multiple director modules can then be combined into a highly flexible and reconfigurable media transport system. By implementing the joints between the articulating tips and the body of the director element such that a continuous surface is provided in the path of the flexible media, stubbing of the moving media can be avoided. The continuous-surface joint interface can be provided via flexible skins, monolithic articulating tip-director element structures, and preconfigured resilient plate structures, among others.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     1. Field of the Invention  
         [0002]     The invention relates to the field of flexible media handling, and in particular, to reconfigurable media path elements for use in media handling systems.  
         [0003]     2. Related Art  
         [0004]     Conventional paper transport systems, such as incorporated into printers and copiers, are typically custom-designed units. Each unit includes a heavy frame that defines one or more paper paths, and sets of pinch rollers that move sheets of paper through the paper paths. However, because prior art transport systems are custom designed to meet the differing needs of specific printing systems, field reconfigurability and programmable reconfigurability are generally not readily achievable.  
         [0005]     Furthermore, to enhance paper-handling capabilities, it is desirable for a paper transport system to have redirecting capabilities that allow the paper transport system to transport different sheets of paper along different paper paths. Conventional paper transport systems typically use movable gates to provide this redirection capability.  
         [0006]     For example, U.S. Pat. No. 5,303,017, issued Apr. 12, 1994 to Smith, describes a gate-based redirection mechanism, as shown in  FIGS. 1A and 1B . In  FIGS. 1A and 1B , two horizontal baffles  111  and  112  define a first paper path  114 , while a sheet diversion chute  113  defines a second paper path  115 . Pinch rollers  121 ,  122 , and  123  can then move sheets of paper through paper paths  114  and  115 , based on the orientation of a diverter gate  130 .  
         [0007]     In  FIG. 1A , diverter gate  130  is in a horizontal position, thereby allowing pinch rollers  121  and  122  to pass a sheet of paper through first paper path  114  in a transport direction  101 . In  FIG. 1B , diverter gate is rotated downwards (in a diagonal orientation), thereby blocking paper path  114  and allowing pinch rollers  122  and  123  to pass a sheet of paper through second paper path  115  in a transport direction  102 .  
         [0008]     In this manner, diverter gate  130  controls the paper transport direction in  FIGS. 1A and 1B . However, as the speed and routing requirements placed on paper transport systems increase, elements such as diverter gate  130  can limit paper transport capabilities.  
         [0009]     Specifically, the “joint” of diverter gate  130  (i.e., the region where diverter gate  130  makes a movable interface with the frame (baffle  111 )) creates a surface discontinuity in the paper path. This discontinuity limits the reliability and performance of the transport system by creating a location at which the edges of paper sheets can catch or stub, particularly if the sheets are curled or have flaws such as “dog ears”. This stubbing problem is exacerbated as the speed of the paper transport is increased.  
         [0010]     Note that while diverter gate  130  can sometimes be shaped to reduce the effects of the surface discontinuity in one direction, the joint will typically not be suitable for paper transport in the reverse direction. For example, in  FIG. 1A , the tapered profile of diverter gate  130  presents a relatively non-stubbing paper path  114  in transport direction  101 , attempting to move paper in the opposite direction would result in stubbing at joint A.  
         [0011]     Accordingly, it is desirable to provide a system and method for creating highly configurable and high-performance paper transport systems which eliminate the causes of stubbing and jams.  
       SUMMARY OF THE INVENTION  
       [0012]     The invention provides a highly configurable, high-performance media transport system through the use of director elements having articulating tips. The articulating tips provide a simple means for media direction and re-direction, and can be incorporated into a director module for improved media transport system flexibility and can be implemented with continuous-surface joints for improved media transport system reliability.  
         [0013]     According to an embodiment of the invention, a media director module can incorporate multiple media paths and a director element that includes articulating tips. The articulating tips of the director element control access to the media paths and provide a simple means for controlling the transport direction of media through the media director module. Then, by incorporating multiple media director modules into a media transport system (such as in a high-speed printer or copier), complex media routing paths can be readily provided.  
         [0014]     According to an embodiment of the invention, the articulating tips of the director element can comprise a simple gate-type structure connected to the director element via a rotating joint. According to another embodiment of the invention, the articulating tips can be formed by creating living hinges in the director element body. A flipper mechanism in the articulating tip can then provide the desire rotational movement of the tip relative to the director element body.  
         [0015]     According to another embodiment of the invention, the media-handling performance provided by the articulating tips can be improved by creating a continuous surface across the joints between the articulating tips and the director element body. By eliminating surface discontinuities, the potential for media stubbing is minimized, thereby allowing faster media throughput and presenting the opportunity for bi-directional media transport.  
         [0016]     According to an embodiment of the invention, a director element can include a body portion and an articulating tip, all covered by a flexible skin. The portion of the flexible skin covering the body portion of the director element provides guide surfaces that define the media paths provided by the director module. The flexible skin also maintains a continuous surface across the joint between the articulating tip and the body portion, even as the articulating tip changes position relative to the body portion of the director element.  
         [0017]     According to another embodiment of the invention, the entire director element can be formed from a flexible material, with the tip(s) of the director element being driven by an internal flipper(s). By changing the orientation (and/or position) of the flipper, the orientation of the tip of the director element can be adjusted relative to the body of the director element. By creating the director element to have a continuous surface between its tip(s) and its guide surfaces, surface discontinuities at the articulating tip joint(s) can be prevented.  
         [0018]     According to another embodiment of the invention, an articulating tip can be formed by configuring two resilient plates to have default positions that force the ends of the resilient plates towards one another. A flipper placed between the resilient plates can then adjust the position of the articulating tip formed by the contacting ends of the plates. The non-end portions of the resilient plates form the body of the director element and provide guide surfaces for the media paths defined by the director module. Therefore, the resilient plates provide an articulating tip that maintains a continuous surface with the guide surfaces of the director element. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0019]     These and other features, aspects and advantages of the present invention will become better understood with regard to the following description, appended claims, and accompanying drawings, where:  
         [0020]      FIGS. 1A and 1B  show a conventional media redirection mechanism.  
         [0021]      FIGS. 2A, 2B , and  2 C show a media director module according to an embodiment of the invention.  
         [0022]      FIGS. 2D, 2E , and  2 F show a media director module according to another embodiment of the invention.  
         [0023]      FIGS. 3A and 3B  show a printing system incorporating a media transport system formed from media director modules shown in  FIGS. 2A-2C , according to an embodiment of the invention.  
         [0024]      FIGS. 4A and 4B  show an articulating tip that includes a living hinge, according to an embodiment of the invention.  
         [0025]      FIGS. 5A and 5B  show an articulating tip that includes an exterior skin, according to another embodiment of the invention.  
         [0026]      FIGS. 6A and 6B  show an articulating tip that is formed as a one-piece, flexible element, according to another embodiment of the invention.  
         [0027]      FIGS. 7A and 7B  show an articulating tip that is formed from flexible, resilient plates, according to another embodiment of the invention. 
     
    
     DETAILED DESCRIPTION  
       [0028]      FIG. 2A  is a director module  200  for controlling the transport direction of flexible media, such as sheets of paper or cardboard, according to an embodiment of the invention. A director module beneficially eliminates the need for expensive, custom-designed media transport systems by allowing such media transport systems to be created from standardized subunits, as described in co-owned, co-pending U.S. patent applications [A3012] and [A3013], herein incorporated by reference.  
         [0029]     Director module  200  includes a frame  204 , pinch rollers  221 ,  222 , and  223 , and a director element  230 . Frame  204  can comprise any substantially rigid structure that provides support for the components of director module  200  (e.g., a backplane, a mounting plate, or a device housing, among others). A plurality of optional attachment features  281  and  282  allow director module  200  to be assembled to other director modules (or to other elements in a larger media handling system). Note that while pin (feature  281 ) and socket (feature  282 ) features are depicted for exemplary purposes, a director module in accordance with the invention can include any type of attachment feature(s).  
         [0030]     Frame  204  includes fixed guide elements  201 ,  202 , and  203 . Guide surfaces S 201 , S 202 , and S 203  on fixed guide elements  201 ,  202 , and  203 , respectively, face guide surfaces S 231 , S 232 , and S 233 , respectively, on director element  230  to define media paths  211 ,  212 , and  213 , respectively. Note that while three media paths are shown for exemplary purposes, a director module in accordance with the invention can define any number of media paths.  
         [0031]     Pinch rollers  221 ,  222 , and  223  drive flexible media into and out of media paths  211 ,  212 , and  213 . Note that while pinch rollers are depicted as media driving elements for exemplary purposes, a director module in accordance with the invention can include any other driving means, including spherical nip actuators (as described in U.S. Pat. No. 6,059,284 to Wolf et al.) or piezoelectrically driven brushes (as described in U.S. Pat. No. 5,467,975 to Hadimioglu et al.).  
         [0032]     Director element  230  includes a set of articulating tips  231 ,  232 , and  233 . Articulating tips  231 ,  232 , and  233  move relative to the body of director element  230  at joints J 231 , J 232 , and J 233 , respectively. By controlling the positioning of articulating tips  231 - 233 , access can be provided to (and egress can be provided from) a selected one of media paths  211 ,  212 , and  213 . For example, in  FIG. 2A , articulating tips  231  and  232  are rotated to a substantially horizontal position, thereby allowing pinch rollers  221  and  222  to drive media through media path  211  in a transport direction  291 . Note that the media could also be driven in the opposite direction (i.e., the reverse of transport direction  291 ).  
         [0033]     In  FIG. 2B , articulating tip  231  is rotated towards fixed guide element  201  (in the direction of the arrow), while articulating tip  233  is in a substantially vertical position. Pinch rollers  221  and  223  can then drive media through media path  212  in a transport direction  292 . Note that the media could also be driven in the opposite direction (i.e., the reverse of transport direction  292 ).  
         [0034]     In  FIG. 2C , articulating tip  233  is rotated towards fixed guide element  202  (in the direction of the arrow), while articulating tip  232  is rotated towards fixed guide element  201  (in the direction of the arrow). Pinch rollers  223  and  222  can then drive media through media path  213  in a transport direction  293 . Note that the media could also be driven in the opposite direction (i.e., the reverse of transport direction  293 ).  
         [0035]     In this manner, director module  200  provides a simple means for selectably driving media though various different media paths. Note that just as the number of media paths in director module  200  can vary, so can the number of articulating tips. Furthermore, while articulating tips  231 ,  232 , and  233  are described as having two operating positions for exemplary purposes (e.g., articulating tip  231  can either be rotated towards fixed guide element  202  or  201  to provide access to media paths  211  and  212 , respectively), an articulating tip in accordance with the invention could have any number of operating positions. For example, an articulating tip could switch between three different positions to control access to three different media paths.  
         [0036]     Note further that a director module in accordance with the invention can include any number of director elements. For example,  FIG. 2D  shows a director model  200 A in accordance with another embodiment of the invention. Director module  200 A includes director elements  230 A,  230 B,  230 C, and  230 D. Director element  230 A includes articulating tips  231 A and  232 A, director element  230 B includes articulating tips  231 B and  232 B, director element  230 C includes articulating tips  231 C and  231 D, and director element  230 D includes articulating tips  231 D and  232 D.  
         [0037]     Each adjacent pair of articulating tips (i.e., tips  231 A and  231 C, tips  232 A and  232 B, tips  231 B and  231 D, and tips  232 C and  232 D) works in combination to provide access to one of three media paths. For example, in  FIG. 2D , each tip pair is spread apart, thereby allowing access to media paths  211  and  214 , which run between director elements  230 A,  230 B,  230 C, and  230 D and allow media to travel in transport directions  291 A and  291 B, respectively.  
         [0038]     Next, in  FIG. 2E , articulating tips  231 A and  232 A of director element  230 A are rotated towards articulating tips  231 C and  232 B, respectively, thereby providing access to a media path  212  that defines a transport direction  292 A. Meanwhile, articulating tips  231 D and  232 D of director element  230 D are rotated towards articulating tips  231 B and  232 C, respectively, thereby providing access to a media path  216  that defines a transport direction  292 B.  
         [0039]     Finally, in  FIG. 2F , articulating tips  231 C and  232 C of director element  230 C are rotated towards articulating tips  231 A and  232 D, respectively, thereby providing access to a media path  215  that defines a transport direction  293 A. Meanwhile, articulating tips  232 B and  231 B of director element  230 B are rotated towards articulating tips  232 A and  231 D, respectively, thereby providing access to a media path  213  that defines a transport direction  293 B. Various other transport operations (e.g., path splitting/merging) can be performed by director module  200 A through appropriate positioning of articulating tips  231 A,  232 A,  231 B,  232 B,  231 C,  232 C,  231 D, and  232 D.  
         [0040]     According to an embodiment of the invention, complex media routing requirements can be satisfied by linking multiple director modules  200  in a single media handling system.  FIG. 3A  shows a printing system  300  in accordance with an embodiment of the invention. Printing system  300  includes identical director modules  200 ( 1 ),  200 ( 2 ),  200 ( 3 ), and  200 ( 4 ), each of which is substantially similar to director module  200  shown in  FIGS. 2A-2C . Note that according to an embodiment of the invention, director modules in a media handling system can have different orientations, as shown by director module  200 ( 3 ), which is upside-down relative to director modules  200 ( 1 ),  200 ( 2 ), and  200 ( 4 ).  
         [0041]     Printing system  300  also includes paper supplies  301  and  302 , a print engine  303 , and control logic  310 . Control logic  310  includes software or hardware (e.g., sensors and circuits) logic for controlling the articulating tips of director modules  200 ( 1 )- 200 ( 4 ) to direct media from one of paper supplies  301  and  302  to print engine  303  according to the requirements for a given print job.  
         [0042]     For example, as shown in  FIG. 3A , the articulating tips of director modules  200 ( 1 ),  200 ( 2 ), and  200 ( 3 ) are all oriented in a substantially horizontal manner, thereby defining a “straight through” media transport direction  391  that leads from paper supply  301  to print engine  303 . However, in  FIG. 3B , the articulating tips of director module  200 ( 1 ) are positioned so that director module  200 ( 3 ) blocks its horizontal media path and provides access to a media path originating from director module  200 ( 4 ). Meanwhile, the articulating tips of director module  200 ( 4 ) provide access to a media path that leads from paper source  302  to director module  200 ( a ), thereby defining an overall media transport direction  392  that directs media from paper supply  302  to print engine  302 .  
         [0043]     In this manner, director modules  200 ( 1 )- 200 ( 4 ) provide a simple means for constructing a paper handling system that can selectively provide media from different sources ( 301  and  302 ) to print engine  303 . Note that while media paths between two paper supplies and a print engine are described for exemplary purposes, director modules  200  can be used to provide configurable media paths between any type and arrangement of media stations (e.g., paper supplies, print engines, staging areas, reader systems, and binding systems, among others).  
         [0044]     Returning to  FIG. 2A , note that while articulating tips  231 ,  232 , and  233  shown in  FIG. 2A  are depicted as having substantially wedge-shaped cross sections for exemplary purposes, articulating tips in accordance with the invention can comprise any cross sectional shape (e.g., rectangular, oblong, or curved). In addition, a single director module  200  could include articulating tips having a variety of different shapes, sizes, and configurations.  
         [0045]     Furthermore, while articulating tips  231 ,  232 , and  233  are depicted as simple gate-type structures for exemplary purposes, articulating tips in accordance with the invention can be implemented using any mechanism that provides the desired tip movement for director element  230 . Furthermore, as noted above, it is desirable that potential stubbing points in the media path be eliminated to optimize media transport system configurability and reliability. Therefore, according to another embodiment of the invention, joints J 231 - 233  of director module  200  shown in  FIG. 2A  are implemented such that a continuous surface is provided between articulating tips  231 - 233  and the guide surfaces of director element  230 .  
         [0046]     For example,  FIG. 4A  shows a detail view of an articulating tip  431  that could be used in place of articulating tip  231  in  FIG. 2A , according to an embodiment of the invention. Articulating tip  431  includes a tip portion T 431  and a flipper F 431  that is embedded within tip portion T 431 . Tip portion T 431  is part of a larger director body B 430  that makes up director element  230 . Director body B 430  includes guide surfaces S 431  and S 432  that converge towards tip portion T 431 . Guide surfaces S 431  and S 432  face guide surfaces S 201  and S 202 , respectively, of fixed guide elements  201  and  202 , respectively, to define media paths  211  and  212 , respectively.  
         [0047]     Director body B 430  is formed from plastic or metal, thereby allowing a joint J 431  connecting tip portion T 431  to director body B 430  to be formed from a pair of living hinges. Living hinges are thin, flexible webs that are often formed by coining or extrusion and are used to provide reliable hinge structures. The length and thickness of a living hinge depends on the amount of flexion required and the material being used. For example, if tip portion T 431  is roughly 2 mm from axis to nearest surface and the total rotation of tip portion T 431  during normal operation is roughly 30°, joint J 431  could be implemented in plastic using living hinges having a rough length of 10 mm and a rough thickness of 0.1-1.0 mm. Note that while a “double living hinge” (i.e., pair of living hinges forming a single joint) is shown for exemplary purposes, joint J 431  can include any number and type of living hinges.  
         [0048]     Meanwhile, flipper F 431  is a lever element that is rotated (or translated) by an external drive mechanism (not shown for clarity) to control the orientation of tip portion T 431 . As flipper F 431  is rotated (or translated), the flexible living hinges at joint J 431  allow the position of tip portion T 431  to be adjusted relative to director body B 430  and provide access to one of media paths  211  and  212 , while maintaining a continuous surface in the selected media path.  
         [0049]     For example, in  FIG. 4A , flipper F 431  rotates tip portion T 431  towards guide surface S 202 , thereby providing access to media path  211  (and blocking media path  212 ). Pinch rollers  221  can then drive media in a media direction  291  through media path  211 . Because the flexible living hinges of joint J 431  eliminate surface discontinuities in the media path at joint J 531 , pinch rollers  221  can also drive media in the opposite direction (as indicated by the two-headed arrow) at high speed without encountering stubbing at joint J 431 .  
         [0050]     In  FIG. 4B , flipper F 431  rotates tip portion T 431  towards guide surface S 201 , thereby providing access to media path  212  (and blocking media path  211 ). Pinch rollers  221  can then drive media in a media direction  292  through media path  212 . Once again, because the living hinges of joint J 431  eliminate surface discontinuities (stubbing points) at joint J 431 , pinch rollers  221  can also drive media in the opposite direction (as indicated by the two-headed arrow) at high speed without encountering stubbing at joint J 431 . In this manner, articulating tip  431  can improve the bi-directional paper transport capabilities of a director module (e.g., director module  200  shown in  FIG. 2A ).  
         [0051]      FIG. 5A  shows a detail view of an articulating tip  531  that could be used in place of articulating tip  231  in  FIG. 2A , according to an embodiment of the invention. Articulating tip  531  includes a flipper F 531  that is attached to a director body B 530  by a rotational joint J 531  to form director element  230 . A flexible skin  539  covers flipper F 531  and director body B 530 . According to an embodiment of the invention, flexible and stretchable skin  539  is form-fit (e.g., heat-shrunk and selectively adhered) to the exterior of flipper F 531  and director body B 530 . According to another embodiment of the invention, flexible skin  539  is vacuum-sealed against the exterior of flipper F 531  and director body B 530  and optionally glued in place at selected places on the director body B 530 .  
         [0052]     Flexible skin  539  provides guide surfaces S 531  and S 532  that converge towards and cover flipper F 531  to ensure that a continuous surface is maintained across joint J 531 . Guide surfaces S 531  and S 532  face guide surfaces S 201  and S 202 , respectively, of fixed guide elements  201  and  202 , respectively, to define media paths  211  and  212 , respectively.  
         [0053]     When flipper F 431  is rotated by an external drive mechanism (not shown for clarity) towards guide surface S 202 , access is provided to media path  211  (and media path  212  is blocked). Pinch rollers  221  can then drive media in a media direction  291  through media path  211 . Because flexible skin  539  eliminates surface discontinuities at joint J 531 , pinch rollers  221  can also drive media in the opposite direction (as indicated by the two-headed arrow) at high speed without encountering stubbing at joint J 531 .  
         [0054]     In  FIG. 5B , flipper F 431  is rotated towards guide surface S 201 , thereby providing access to media path  212  (and blocking media path  211 ). Pinch rollers  221  can then drive media in a media direction  292  through media path  212 . Once again, because flexible skin  539  eliminates surface discontinuities (stubbing points) at joint J 531 , pinch rollers  221  can also drive media in the opposite direction (as indicated by the two-headed arrow) at high speed without encountering stubbing at joint J 531 . In this manner, articulating tip  531  can improve the bi-directional paper transport capabilities of a director module (e.g., director module  200  shown in  FIG. 2A ).  
         [0055]      FIG. 6A  shows a detail view of an articulating tip  631  that could be used in place of articulating tip  231  in  FIG. 2A , according to another embodiment of the invention. Articulating tip  631  includes a tip portion T 631  and a flipper F 631  that is embedded in tip portion T 631 . Tip portion T 631  is part of a larger director body B 630  that makes up director element  230 . Director body B 630  includes guide surfaces S 631  and S 632  that converge towards tip portion T 631 . Guide surfaces S 631  and S 632  face guide surfaces S 201  and S 202 , respectively, of fixed guide elements  201  and  202 , respectively, to define media paths  211  and  212 , respectively.  
         [0056]     Director body B 630  is formed from a flexible material that allows flexion to occur between tip portion T 631  and director body B 630  at a joint J 631 . For example, according to an embodiment of the invention, director body B 630  and tip portion T 631  can be an extruded plastic, rubber, or even thin metal element. Because tip portion T 631  and director body B 630  are actually a single monolithic element, when flipper F 631  is rotated by an external drive mechanism (not shown for clarity) to move tip portion T 631  relative to director body B 630 , surface continuity is maintained across joint J 631  and stubbing points are eliminated. Director body B 630  and tip portion T 631  can be a composite structure with, for example, a low friction, flexible skin layer bonded to the inner core material.  
         [0057]     Thus, when flipper F 631  rotates tip portion T 631  towards guide surface S 202 , as shown in  FIG. 6A , access is provided to media path  211  (and media path  212  is blocked). Pinch rollers  221  can then drive media in a media direction  291  through media path  211 . Because the monolithic design of tip portion T 631  and director body B 630  eliminates surface discontinuities at joint J 631 , pinch rollers  221  can also drive media in the opposite direction (as indicated by the two-headed arrow) at high speed without encountering stubbing at joint J 631 .  
         [0058]     In  FIG. 6B , flipper F 631  is rotated towards guide surface S 201 , thereby providing access to media path  212  (and blocking media path  211 ). Pinch rollers  221  can then drive media in a media direction  292  through media path  212 . Once again, the monolithic design of tip portion T 631  and director body B 630  eliminates surface discontinuities at joint J 631 , pinch rollers  221  can also drive media in the opposite direction (as indicated by the two-headed arrow) at high speed without encountering stubbing at joint J 631 . In this manner, articulating tip  631  can improve the bi-directional paper transport capabilities of a director module (e.g., director module  200  shown in  FIG. 2A ).  
         [0059]     Note that according to another embodiment of the invention, flipper F 631  could be eliminated by forming tip portion T 631  from shape memory material. Tip portion T 631  could then be moved between desired operating positions (such as shown in  FIGS. 6A and 6B ) through the application of appropriate control signals (e.g., thermal, magnetic, or electrical) to tip portion T 631 .  
         [0060]      FIG. 7A  shows a detail view of an articulating tip  731  that could be used in place of articulating tip  231  in  FIG. 2A , according to another embodiment of the invention. Articulating tip  731  and a director body are formed by resilient plates P 731  and P 732 . Resilient plates P 731  and P 732  can be made of plastic, metal or other flexible sheet materials and can be multi-layered or composite in structure. Resilient plates P 731  and P 732  are configured to have ends that tend to spring towards each other and away from guide surfaces S 201  and S 202 , respectively, of fixed guide elements  201  and  202 , respectively. The contacting ends of resilient plates P 731  and P 732  form articulating tip  731 , while the remaining portions of resilient plates P 731  and P 732  provide guide surfaces S 731  and S 732 , respectively. Guide surfaces S 731  and S 732  face guide surfaces S 201  and S 202 , respectively, to define media paths  211  and  212 , respectively. Resilient plates P 731  and P 732  can be affixed to director body B 730  in various ways, e.g. gluing, riveting, etc.  
         [0061]     Meanwhile, a flipper F 731  positioned between resilient plates P 731  and P 732  controls the position of articulating tip  731 . Thus, as shown in  FIG. 7A , when flipper F 731  is rotated towards guide surface S 202  to bend resilient plate P 732  towards guide surface S 202 , resilient plate P 732  also bends towards guide surface S 202 . In this manner, access is provided to media path  211  (and media path  212  is blocked). Pinch rollers  221  can then drive media in a media direction  291  through media path  211 . Because resilient plate P 731  does not present any surface discontinuities at joint J 731  (i.e., at the region where resilient plate P 731  flexes), pinch rollers  221  can also drive media in the opposite direction (as indicated by the two-headed arrow) at high speed without encountering stubbing at joint J 731 .  
         [0062]     In  FIG. 7B , flipper F 731  is rotated towards guide surface S 201 , thereby bending resilient plate P 731  towards guide surface S 201  of fixed guide element  201 . In response, resilient plate P 731  also bends towards guide surface S 201  and away from guide surface  202 , thereby providing access to media path  212  (and blocking media path  211 ). Pinch rollers  221  can then drive media in a media direction  292  through media path  212 . Because resilient plate P 732  does not present any surface discontinuities at joint J 731  (i.e., at the region where resilient plate P 732  flexes), pinch rollers  221  can also drive media in the opposite direction (as indicated by the two-headed arrow) at high speed without encountering stubbing at joint J 731 . In this manner, articulating tip  731  can improve the bi-directional paper transport capabilities of a director module (e.g., director module  200  shown in  FIG. 2A ).  
         [0063]     Although the present invention has been described in connection with several embodiments, it is understood that this invention is not limited to the embodiments disclosed, but is capable of various modifications that would be apparent to one of ordinary skill in the art. For example, articulating tips  531 ,  631 , and  731  shown in  FIGS. 5A, 6A , and  7 A, respectively, could be incorporated into conventional (i.e., non-modular) media handling systems to enhance media transport flexibility (i.e., providing bi-directional transport capability) and improve media transport reliability (i.e., by eliminating joint surface discontinuities to minimize the chances of stubbing). Therefore, the invention is limited only by the following claims.