Abstract:
The present invention relates to media handling devices and media handling methods. One aspect of the invention provides a media handling method including providing a media handling device having an initial media path; selectively moving a guide member using a motor intermediate a first position where the guide member is spaced from media within the initial media path and a second position where the guide member contacts the media within the initial media path; applying a control signal to the motor to control the moving; and modulating the control signal.

Description:
FIELD OF THE INVENTION 
     The present invention relates to media handling devices and media handling methods. 
     BACKGROUND OF THE INVENTION 
     Image forming devices, such as printers and copiers, have become increasingly sophisticated. Some image forming devices provide additional functions other than typical printing or document reproduction functions. Some conventional printers and other image formation systems include a plurality of device attachments or stations configured to handle such additional functions. More specifically, in addition to the provided image formation equipment, assemblies can be included for stapling documents, stacking documents, folding documents, etc. 
     Media handling devices are typically provided to direct media to proper document preparation stations. In some applications, handling functions of media are implemented to provide proper orientation or presentation of media to the various document preparation stations. An exemplary handling function is flipping the orientation of media during passage of the media from one station to another. 
     Accordingly, conventional paper handling systems have been developed to provide flipping and other media handling functions. One exemplary media handling device includes an input device configured to receive media and initially direct media within the media handling device. A set of rollers is typically positioned downstream of such input device. During entry of media within the media handling device, the rollers are provided in a receiving state wherein the rollers are separated by a fixed distance in order to receive the incoming media. Following entry of the media intermediate the separated rollers, a motor is actuated to draw one roller towards the other roller with the inputted media therebetween. 
     The movement of the roller is implemented using a direct current (DC) motor in some designs. In such arrangements, the DC motor operates to move the separated roller towards the other roller to contact the media. Thereafter, the plural rollers control subsequent movement of the media within the media handling device. 
     In conventional configurations, the DC motor drives the movable roller to a hard stop against the other roller. Such is implemented without the use of feedback control to indicate the position of the roller being moved. However, the hard stops have been observed to produce acoustic noise during operation of the media handling device. Such acoustic noise is undesirable in many environments. 
     Therefore, a need exists to provide improved media handling devices and methodologies to handle the movement of media. 
     SUMMARY OF THE INVENTION 
     According to one aspect of the invention, a media handling device comprises: a housing having an initial media path; a moveable guide member positioned to guide media within the initial media path; a motor configured to selectively move the guide member intermediate a first position where the guide member is spaced from the media within the initial media path and a second position where the guide member contacts the media within the initial media path; and a controller configured to apply a control signal to the motor to control the motor and corresponding movement of the guide member, the controller being further configured to modulate the control signal. 
     A second aspect of the invention provides a media handling device comprising: a housing having a first media path and a second media path; an input configured to provide media into the first media path; an output configured to output media from the second media path; a moveable guide member configured to direct the media from the first media path to the second media path to flip the media; a motor configured to move the guide member intermediate a first position where the guide member is spaced from the media within the initial media path and a second position where the guide member contacts the media within the initial media path; and a controller configured to apply a control signal to the motor to control the motor and corresponding movement of the guide member, the controller being further configured to modulate the control signal. 
     Another aspect of the invention provides a media handling method comprising: providing a media handling device having an initial media path; selectively moving a guide member using a motor intermediate a first position where the guide member is spaced from media within the initial media path and a second position where the guide member contacts the media within the initial media path; applying a control signal to the motor to control the moving; and modulating the control signal. 
    
    
     DESCRIPTION OF THE DRAWINGS 
     Preferred embodiments of the invention are described below with reference to the following accompanying drawings. 
     FIG. 1 is a functional block diagram of an exemplary media system according to one aspect of the present invention. 
     FIG. 2 is a functional representation of an exemplary media handling device of the media system. 
     FIG.  3 -FIG. 7 are functional representations of exemplary operations of the media handling device. 
     FIG. 8 is a functional block diagram of components of an exemplary media handling device. 
     FIG. 9 is a flow chart which illustrates exemplary operations of the media handling device. 
     FIG. 10 is a graphical representation of operations of a motor of the media handling device. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     This disclosure of the invention is submitted in furtherance of the constitutional purposes of the U.S. Patent Laws “to promote the progress of science and useful arts” (Article 1, Section 8). 
     Referring to FIG. 1, an exemplary media system  10  is shown. The depicted media system  10  includes a first media device  12 , a media handling device  14  and a second media device  16 . In the illustrated configuration, devices  12 ,  14 ,  16  are implemented as separate units. In other arrangements according to the invention, devices  12 ,  14 ,  16  are implemented within a single housing forming a unitary device. Other configurations of media system  10  are possible. 
     Devices  12 ,  14 ,  16  are configured to provide different functions in the described media system  10 . In one embodiment, media device  12  and media device  16  are configured to provide processing operations of the media. For example, media device  12  may be an image forming device, such as a printer or copier, for providing images upon media. Second media device  16  can be configured to provide downstream processing operations of the printed media, such as stacking, stapling, etc. 
     Media handling device  14  is configured to receive media from first media device  12  and to apply such media to second media device  16  in the depicted arrangement. Media handling device  14  is configured to additionally provide media handling or manipulation operations in the described configuration. As detailed further below, media handling device  14  is configured to flip media received from media device  12  before application of such media to media device  16 . Devices  12 ,  14 ,  16  are configured to provide other operations or functionalities in other configurations. 
     Referring to FIG. 2, details of an exemplary configuration of media handling device  14  are shown. The illustrated media handling device  14  includes an outer housing  18 . Housing  18  includes an input  20  and output  22  as shown. Input  20  and output  22  can comprise orifices within housing  18  operable to respectively permit ingress and egress of media with respect to housing  18 . In the described arrangement, input  20  is positioned to receive media from media device  12  and output  22  is configured to output media to media device  16 . 
     The depicted configuration of housing  18  includes a first media path  24  and a second media path  26  as illustrated. Media received from media device  12  via input  20  is guided to media path  24 . More specifically, input  20  is arranged adjacent media path  24  to provide received media within media path  24 . Output  22  is positioned to receive media from media path  26 . 
     Media handling device  14  additionally includes plural guide assemblies  28 ,  30 ,  32  in the described embodiment. A sensor  34  is also provided within housing  18  of the illustrated media handling device  14 . In the depicted configuration, individual guide assemblies  28 ,  30 ,  32  comprise plural guide members. For example, guide assembly  28  includes guide members  36 ,  38 . Guide assembly  30  includes guide members  40 ,  42 . Guide assembly  32  includes guide members  44 ,  46 . Exemplary guide members include rollers although other configurations of such guide members are possible. Guide members  40 ,  42  of guide assembly  30  may be referred to as flipper switches which implement a flipping function of the media. 
     Guide assemblies  28 ,  30 ,  32  define media paths  24 ,  26  within housing  18 . As depicted, guide assembly  28  defines a portion of media path  24  and guide assembly  32  defines a portion of media path  26 . Sensor  34  is positioned adjacent media path  24  and is sensitive to the presence of media traveling along media path  24  (media is not shown in FIG.  2 ). Sensor  34  is configured to indicate the presence or absence of media at a corresponding location along media path  24 . Although not shown, additional sensors can be provided along media paths  24 ,  26  to provide additional position information of media traveling along such media paths  24 ,  26 . 
     As described in further detail below, guide assembly  30  is configured to receive media from first media path  24  and to guide such media to second media path  26  to flip the media. In the described configuration, guide member  40  is a moveable guide member and guide member  42  is a stationary guide member. 
     In the described configuration, a common motor (not shown) is utilized to drive guide members  36 ,  38 ,  42 . More specifically, guide members  36 ,  38 ,  42  are driven at a speed equal to the speed of media received from media device  12  in one embodiment. Guide member  40  is free to rotate in the described configuration. 
     Another motor (not shown in FIG. 2) is configured to move guide member  40  intermediate a first position (as illustrated in FIG. 2) where guide member  40  is spaced from media within media path  24  and a second position  41  (illustrated in phantom in FIG. 2) where guide member  40  contacts media within media path  24 . 
     Guide member  42  is positioned adjacent the second position  41  of moveable guide member  40  to contact media in media path  24 . More specifically, in such second position  41 , guide member  40  is adjacent guide member  42  with the media sandwiched therebetween. In the illustrated configuration, if no media is present within media paths  24 ,  26 , guide member  40  in second position  41  contacts guide member  42 . 
     Guides  44 ,  46  are driven by a motor (not shown) at a speed which matches a media speed of media device  16  in the described arrangement. Such facilitates transportation of media from media handling device  14  to media device  16 . 
     As described above, guide assembly  28  is an input guide configured to pass media received from input  20  along media path  24  in the described configuration. Guide assembly  32  provides an output guide configured to pass media along media path  26  to output  22 . 
     Guide assembly  30  is configured to direct media within media path  24  to media path  26 . Directing media from media path  24  to media path  26  operates to flip the media. A flap  48  is utilized to assist with the direction of media from media path  24  to media path  26  in the depicted configuration. Operations of flap  48  and guide assembly  30  are described in detail below with reference to FIG.  3 -FIG.  7 . 
     Referring to FIG. 3, media  50  is illustrated traveling along first media path  24  (shown in phantom) responsive to rotation of guide members  36 ,  38 . Media  50  can comprise paper, envelopes, transparencies, etc. The depicted media  50  comprises a sheet of paper having edges  52 ,  54 . During travel along media path  24 , edge  52  is a leading edge and edge  54  is a trailing edge. 
     FIG. 3 illustrates the initial movement of media  50  within media handling device  14 . Sensor  34  initially detects the presence of media  50  following passage of edge  52  of media  50  through input  20  and over sensor  34 . Guide member  40  is provided in the first or initial position as shown during reception of media  50  within media handling device  14 . 
     Referring to FIG. 4, guide member  40  is illustrated being lowered towards guide  42 . Responsive to detection of leading edge  52  by sensor  34 , a motor (shown in FIG. 8) is controlled to lower guide member  40  towards the second position adjacent guide member  42 . The rotational speed of guides  36 ,  38  can be increased following detection of media  50  by sensor  34 . 
     Referring to FIG. 5, guide member  40  is illustrated in the second position (position  41  of FIG. 2) adjacent guide member  42 . Guide assembly  30  defines a nip  56  to receive media  50  during positioning of moveable guide member  40  in position  41 . Following the passage of edge  54  of media  50  out of guide assembly  28 , flap  48  may be driven by a motor (not shown) in a downward direction towards media  50 . Although not shown, a sensor may be provided on a downstream side of guide assembly  28  to monitor the exit of edge  54  from guide assembly  28 . 
     Referring to FIG. 6, such downward movement of flap  48  guides media  50  to media path  26  and guide assembly  32 . Following the appropriate positioning of media  50  using flap  48 , the direction of rotation of guide member  42  is reversed to direct media  50  towards guide assembly  32 . The direction of rotation of guide member  42  is reversed after a sufficient stabilization period of time following the reception of media  50  along media path  24  within nip  56 . Guide member  42  directs media  50  into a nip  58  defined by guide members  44 ,  46  of guide assembly  32 . 
     Referring to FIG. 7, guide members  44 ,  46  are driven to pass media  50  along media path  26  towards output  22 . Media  50  is passed to media device  16  (FIG. 1) following passage through output  22 . The direction of media  50  from input  20  along media paths  24 ,  26  to output  22  flips the orientation of media  50 . 
     Following passage of media to guide assembly  32 , guide member  40  is raised towards the initial position of guide member  40  shown in FIG.  3 . Additionally, flap  48  is raised along with guide member  40  to a position for receiving subsequent media along media path  24 . 
     Referring to FIG. 8, a controller  60  and a motor  62  are illustrated. In particular, controller  60  is coupled with sensor  34  and motor  62 . Motor  62  is additionally coupled with guide member  40 . In the depicted configuration, controller  60  comprises a microcontroller configured to execute firmware for controlling the operations of media handling device  14 . In the depicted configuration, motor  62  comprises a direct current (DC) motor. Motor  62  is driven by current controlled responsive to a control signal received from controller  60 . 
     As described further below, operations of controller  60  are provided for controlling guide member  40  using motor  62 . More specifically, controller  60  receives position information of media  50  from sensor  34 . Responsive to such position information, controller  60  can regulate motor  62  to control the movement of moveable guide member  40  intermediate the first position and the second position. 
     It is desired to reduce the acoustic noise of media handling device  14  during the movement of guide member  40  intermediate such first and second positions. Accordingly, controller  60  is configured to apply a control signal as described below to motor  62  to control the operation thereof and corresponding movement of guide member  40 . 
     In accordance with certain aspects of the invention, controller  60  is configured to modulate the control signal applied to motor  62 . As described further below, controller  60  is configured in one embodiment to selectively pulse width modulate the control signal applied to motor  62 . Controller  60  is configured to modulate the control signal during movement of guide member  40  in the described embodiment. At other times, controller  60  provides a substantially constant or steady state control signal to motor  62 . 
     In one embodiment, the application of the substantially constant control signal to motor  62  is responsive to guide member  40  being in one of the first position and the second position. Controller  60  is configured to detect a hard stop of moveable guide member  40  at one of the first position and the second position. Controller  60  then provides the constant control signal to motor  62  after detection of the hard stop. 
     Motor  62  applies a holding torque to guide member  40  responsive to reception of the constant control signal. Such is utilized to increase a normal force within nip  56  of guide assembly  30  to assist with the movement of media  50  during the positioning of guide member  40  in the second position. Additionally, if the modulated control signal fails to fully move guide member  40  to one of the first position or the second position, the subsequent constant control signal can urge or fully move guide member  40  to the appropriate first position or second position. 
     According to another aspect, controller  60  is configured to time the modulation of the control signal and to provide the substantially constant control signal after timing a predefined length of time. Such length of time is typically chosen to be of sufficient duration for guide member  40  to fully travel the distance intermediate the first position and the second position. Other control schemes utilizing a modulated control signal to control motor  62  are possible. 
     Different modulation schemes were utilized in experiments to tune the control of motor  62 . Table A below illustrates exemplary modulation schemes and corresponding operations of media handling device  14 . 
     
       
         
               
               
               
               
               
             
               
               
               
               
               
             
           
               
                   
                 TABLE 1 
               
               
                   
                   
               
               
                   
                   
                 Downwards 
                   
                 Upwards 
               
               
                   
                 Downwards 
                 speed at 
                 Upwards 
                 max speed 
               
               
                   
                 total time 
                 contact 
                 total time 
                 at contact 
               
               
                   
                   
               
             
             
               
                   
               
             
          
           
               
                 25% duty 
                 125 ms 
                 13.87 Hz 
                   
                   
               
               
                 cycle 
               
               
                 50% duty 
                  90 ms 
                 24.5 Hz 
                 108 ms 
                  9.91 Hz 
               
               
                 cycle 
               
               
                 75% duty 
                  56 ms 
                 31.54 Hz 
                  65.2 ms 
                 17.95 Hz 
               
               
                 cycle 
               
               
                 Full current 
                  49.4 ms 
                 37.16 Hz 
                  52.8 ms 
                 28.12 Hz 
               
               
                   
               
             
          
         
       
     
     Following experimentation, controller  60  is configured in one aspect to provide the following operation for controlling motor  62 . During movement of guide member  40  in a downward direction from the first position to the second position, controller  60  is configured to use a 25% duty cycle (5 ms timing) for approximately 150 ms. Following the timing of the predefined length of time (e.g., 150 ms), controller  60  applies a constant control signal to motor  62  to provide full current within motor  62  for application of the holding torque (increased normal force applied to media) during movement of media  50  out of guide assembly  30  to media path  26 . Such constant control signal also assures movement of guide member  40  into the second position. 
     Following the passage of media  50  to guide assembly  32 , guide member  40  is returned to the first position. During upwards movement from the second position to the first position of moveable guide member  40 , the control signal is modulated by controller  60  using a 50% duty cycle for approximately 150 ms. Following the timing of 150 ms, 100 ms of a constant control signal is applied to motor  62  to implement full current operation thereof. Such is utilized in one aspect to assure proper return of guide member  40  into the first position. 
     Referring to FIG. 9, a flow chart illustrates an exemplary method for controller  60  to control the movement of guide member  40  from the first position to the second position and vice versa. The method is implemented as executable code within the firmware of media handling device  14  according to one aspect. Alternatively, such methodology can be implemented within hardware in another configuration. 
     For movement of guide member  40  from the first position to the second position, controller  60  determines at step S 10  whether an initiate event has occurred. An exemplary initiate event is the detection of media within media handling device  14 . Sensor  34  is utilized to indicate such presence of media in the described embodiment. Controller  60  idles at step S 10  until media is detected. 
     Thereafter, controller  60  proceeds to step S 12  following the detection of the initiate event. At step S 12 , controller  60  issues or outputs a modulated control signal to motor  62 . The control signal may be modulated according to one of the exemplary schemes described above. 
     Controller  60  then proceeds to step S 14  to determine whether an intermediate event has been detected. In one aspect, controller  60  is configured to time a predefined time period comprising the intermediate event. Step S 14  is utilized in such a configuration to apply the modulated control signal to motor  62  for the predefined time period. The intermediate event comprises a hard stop detection of guide member  40  in the second position according to another aspect. Controller  60  proceeds to step S 16  responsive to the detection of an intermediate event. 
     At step S 16 , controller  60  outputs the constant control signal to motor  62 . Application of the constant control signal results in the application of a holding torque of guide member  40  to media  50  and guide member  42 . 
     Thereafter, controller  60  proceeds to step S 18  to monitor for the presence of a termination event. During application of the constant control signal with guide member  40  in the second position, an appropriate detection event can be an indication from a sensor that the media has been moved from guide assembly  30 . Another exemplary termination event is a timer (e.g., controller  60 ) counting a predefined time period. 
     Following detection of the termination event with guide member  40  in the second position, controller  60  proceeds to step S 20  to de-assert the constant control signal to idle motor  62 . 
     Thereafter, controller  60  can re-execute the depicted method of the flow chart of FIG. 9 to control the movement of guide member  40  from the second position back to the first position. The following describes execution of the depicted flow chart during movement of guide member  40  from the second position to the first position. 
     Controller  60  determines at step S 10  whether an initiate event has occurred. The initiate event is the passage of media from guide assembly  30  to guide assembly  32  according to one aspect. Controller  60  idles at step S 10  until the initiate event is detected. 
     Thereafter, controller  60  proceeds to step S 12  following the detection of the initiate event. At step S 12 , controller  60  issues or outputs a modulated control signal to motor  62 . The control signal may be modulated according to one of the exemplary schemes described above for providing upward movement of guide member  40  to return to the first position. 
     Controller  60  then proceeds to step S 14  to determine whether an intermediate event has been detected. In one aspect, controller  60  is configured to time a predefined time period comprising the intermediate event. Step S 14  is utilized in such a configuration to provide the application of the modulated control signal to motor  62  for the predefined time period. The intermediate event comprises a hard stop detection of guide member  40  in the first position according to another aspect. Controller  60  then proceeds to step S 16  responsive to the detection of an intermediate event. 
     At step S 16 , controller  60  outputs the constant control signal to motor  62 . The constant control signal can operate to kick or urge guide member  40  fully into the desired first position. 
     Thereafter, controller  60  proceeds to step S 18  to monitor for the presence of a termination event. During application of the constant control signal with guide member  40  in the first position, an exemplary termination event is the timing of a predefined period of time (e.g., 100 ms). Other termination events are possible. 
     Following detection of the termination event with guide member  40  in the first position, controller  60  proceeds to step S 20  to de-assert the constant control signal to idle motor  62 . 
     Thereafter, controller  60  returns to step S 10  in one configuration to await the detection of another initiate event (e.g., reception of new media) and to execute the depicted flow chart methodology again to provide movement of guide member  40  from the first position to the second position. The depicted flow chart is repeated during operation of media handling device  14  to continuously flip media. 
     Referring to FIG. 10, a timing diagram illustrates various operations of media handling device  14 . Time increases from left to right in the depicted timing diagram. Plural lines are illustrated in FIG.  10 . Line  70  illustrates the movement of motor  62  during the operation of media handling device  14 . Line  72  illustrates current within motor  62  during such operations. Line  74  illustrates an enable control signal issued by controller  60  to control the current within motor  62 . Line  76  illustrates a direction control signal of controller  62  to control motor  62  to control the direction of movement of guide member  40  intermediate the first and second positions. Guide member  40  is moved downward responsive to control signal  76  being asserted. Guide member  40  is moved upward responsive to control signal  76  being de-asserted. 
     The timing diagram is illustrated initially with guide member  40  in the first position. At time t 0 , an initiate event is detected by controller  60  of media handling device  14 . Such results in the application of a modulated control signal from controller  60  to motor  62  as represented by line  74 . At time t 1 , an intermediate event is detected (e.g., a predefined length of time has been timed) and the modulated control signal of line  74  is de-asserted. 
     Thereafter, application of a constant control signal as shown by line  74  provides a full current holding torque of motor  62  applied in a downward direction to urge guide member  40  fully to the second position. 
     At time t 2 , a termination event occurs (e.g., media has left guide assembly  30  for travel along the second media path  26 ). In the described configuration, controller  60  thereafter re-executes the method of the flow chart and operates to again output a modulated control signal corresponding to line  74  to move guide member  40  upward towards the first position. The reader will note that signal  76  is de-asserted at time t 2  to provide upward movement to guide member  40 . 
     The modulated control signal represented by line  74  is outputted for a predefined length of time. Following the timing of the predefined length of time at time t 3 , a constant control signal is issued again by controller  60  as represented by line  74  to urge guide member  40  into the first position. Controller  60  times the application of the second constant control signal as represented by line  74  until a time t 4 . 
     Such timing of the predefined length of time corresponds to a termination event. Thereafter, controller  60  awaits the reception of subsequent media or other appropriate initiate event wherein the control signals may be issued again to motor  62 . 
     In compliance with the statute, the invention has been described in language more or less specific as to structural and methodical features. It is to be understood, however, that the invention is not limited to the specific features shown and described, since the means herein disclosed comprise preferred forms of putting the invention into effect. The invention is, therefore, claimed in any of its forms or modifications within the proper scope of the appended claims appropriately interpreted in accordance with the doctrine of equivalents.