Abstract:
A post print finishing device that incorporates an imaging material binder into the post print handling and finishing functions. In one exemplary embodiment, the finishing device includes a flipper module, an accumulator module and a binder module. The binder module binds sheets together by reactivating imaging material applied to binding regions on the sheets by a printing device. The flipper module receives a sheet leading edge first and discharges the sheet trailing edge first. That is to say, the flipper module flips the sheet before discharging the sheet for further processing. The accumulator module stacks the sheets, presents the sheets to the binder for binding and then discharges the bound stack to the output bin.

Description:
FIELD OF THE INVENTION  
         [0001]    The present invention relates to post print finishing in which printed sheets are bound end to end using imaging material to form a continuous sheet.  
         BACKGROUND OF THE INVENTION  
         [0002]    Current devices and methods for printing and binding media sheets involve printing the desired document on a plurality of media sheets, assembling the media sheets into a stack, and separately stapling, clamping, gluing and/or sewing the stack. In addition to imaging material used to print the document, each of these binding methods require separate binding materials, increasing the cost and complexity of binding. Techniques for binding media sheets using imaging material are known in the art. These techniques generally involve applying imaging material such as toner to defined binding regions on multiple sheets, assembling the media sheets into a stack, and reactivating the imaging material via fusing or other methods, causing the media sheets to adhere to one another.  
           [0003]    Presently, printed banners and other long printed materials are printed on a continuous length of paper or other print media using a plotter or printing press, or by manually assembling and binding together a series of single sheets. In the case of continuous sheet printing, rolls of paper and roll supply devices are necessary. Manually assembling and binding single sheets is, of course, labor intensive and therefore expensive. It would be desirable, as an alternative to conventional continuous sheet printing techniques, to use single sheet printing to automatically produce continuous sheets of printed materials.  
         SUMMARY  
         [0004]    The present invention is directed to the use of imaging material binding techniques to simulate continuous sheet printing with single sheets of print media. Accordingly, in one exemplary embodiment of the invention imaging material is applied to a binding region along the trailing edge of a first sheet. The trailing edge of the first sheet and the leading edge of a following second sheet are overlapped and the imaging material is activated to bind the sheets together. This process may be repeated for successive sheets to form one continuous sheet. The invention may be implemented, for example, in a stand alone appliance used in conjunction with a conventional single sheet printer, as an integrated printing device, or through a computer readable medium used to control operations in one or both of these devices. 
       
    
    
     DESCRIPTION OF THE DRAWINGS  
       [0005]    [0005]FIG. 1 is a schematic view of a laser printer illustrating the major components and operational characteristics of one type of printing device that may be used to implement the present invention.  
         [0006]    FIGS.  2 - 5  are side views of a laser printer such as the one illustrated in FIG. 1 showing the sequence of operation for one embodiment of the invention in which sheets are bound end to end with the printer fuser.  
         [0007]    FIGS.  6 - 9  are side views of a laser printer such as the one illustrated in FIG. 1 showing the sequence of operation for another embodiment of the invention in which sheets are bound end to end with a binding press positioned downstream from the fuser.  
         [0008]    [0008]FIG. 10 is a perspective view of a printer and attached stacker illustrating one type of document printing and finishing system that may be used to implement the invention.  
         [0009]    [0009]FIG. 11 is a side elevation view of a modular stacker that includes flipper, paper path, accumulator and binder modules.  
         [0010]    FIGS.  12 - 13  are more detailed side elevation views of the stacker of FIG. 11 showing the sequence of operation for one embodiment of the invention in which sheets are bound end to end with a fuser positioned in the flipper module.  
         [0011]    [0011]FIG. 14 is a side view of media sheets showing one configuration of end to end binding in which the following sheet is bound to the bottom side of the leading sheet such that the sheets stair step down as they are bound.  
         [0012]    [0012]FIG. 15 is a side view of media sheets showing another configuration of end to end binding in which the following sheet is bound to the top side of the leading sheet such that the sheets stair step up as they are bound.  
         [0013]    [0013]FIG. 16 is a side view of media sheets showing another configuration of end to end binding in which the following sheet is bound alternately to the top and bottom sides of the leading sheet. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0014]    [0014]FIG. 1 is a schematic view of a laser printer illustrating the major components and operational characteristics of one type of printing device that may be used to implement the present invention. FIGS.  2 - 5  and  6 - 9  are side views of a laser printer such as the one illustrated in FIG. 1 showing the sequence of operation for two embodiments of the invention in which sheets are bound end to end with toner. Although these two embodiments of the invention are described with reference to a laser printer, which uses toner as the imaging material, the invention may be implemented with other printing devices using other imaging materials including, for example, inkjet printers. FIGS.  10 - 13  illustrate another embodiment of the invention in which the sheets are bound in a sorter/stacker attached to a printer. In this embodiment, the printer  70  and stacker  72  represent generally any suitable printing device (e.g., printers, copiers, and multi-function peripherals) and associated post print finishing device in which the imaging material can be used to bind a printed documented.  
         [0015]    In as much as the art of electrophotographic laser printing is well known, the basic components of one exemplary laser printer  10  in FIG. 1 are shown schematically and their operation described only briefly. In general, and referring to FIG. 1, document generating software on a personal computer, a scanner or some other input device transmits data representing the desired print image to input  12  on printer  10 . This data is analyzed in formatter  14 . Formatter  14  typically consists of a microprocessor and related programmable memory. The binding region on which toner will be applied to bind sheets together may be selected by the input device and sent on to the printer along with or as part of the print image data. Alternatively, the binding region may be selected by formatter  14  or by programming for a stand alone document processing and finishing device such as the stacker shown in FIGS.  10 - 13 . Formatter  14  formulates and stores an electronic representation of each page to be printed, including the print image and the binding region.  
         [0016]    Once a page has been formatted, the data representing each page is sent to a printer controller  16 . Controller  16 , which also includes a microprocessor and related programmable memory, directs and manages the operation of print engine  18 . Formatter  14  and controller  16  are often integrated together as a single processor/memory component of printer  10 . The page data is used by controller  16  to modulate the light beam produced by laser  20  such that the beam of light  21  “carries” the data. The light beam  21  is reflected off a multifaceted spinning mirror  22 . As each facet of mirror  22  spins through light beam  21 , it reflects or “scans” the beam across the surface of photoconductive drum  24  to reproduce the page on the drum.  
         [0017]    Charging roller  26  charges photoconductive drum  24  to a relatively high substantially uniform polarity at its surface. The areas of drum  24  exposed to light beam  21  are discharged. The unexposed background areas of drum  24  remain fully charged. This process creates a latent electrostatic image on conductive drum  24 . Toner is electrostatically transferred from developing roller  28  onto photoconductive drum  24  according to the data previously recorded on the drum. The toner is thereafter transferred from photoconductive drum  24  onto paper or other media sheet  30  as sheet  30  passes between drum  24  and transfer roller  32 . The toner is fused to the sheet at fuser  33 . Fuser  33  includes fuser rollers  34  and  35  that apply heat and pressure to each sheet as it passes between the rollers. Drum  24  is cleaned of excess toner with cleaning blade  36 , completely discharged by discharge lamp  38  and then recharged by charging roller  26 .  
         [0018]    The marking assembly in an electrophotographic printer, such as a laser printer, includes a photoconductor like drum  24  and the other components necessary to apply toner to a sheet  30 . The term “marking assembly” as used herein also refers generally to the components in any printing device that apply imaging material to the media. The print head in an inkjet printer or the print head in a direct projection electrostatic toner printer are also examples of a marking assembly.  
         [0019]    Referring now also to FIG. 2, each media sheet  30  is pulled into the pick/feed area  40  by feed roller  42  from a paper tray  44 . As the leading edge of sheet  30  moves through pick/feed area  40 , it is engaged by transport rollers  45  which advance to sheet  30  to registration rollers  46 . Registration rollers  46  advance sheet  30  to image area  48  until it is engaged by drum  24  and transfer roller  32  and toner is applied as described above. Media sheet  30  advances to fuser  33  and on to output rollers  50 .  
         [0020]    The continuous sheet binding according a one embodiment of the invention will now be described with reference to FIGS.  2 - 5 . In FIG. 2, a first media sheet  30  has cleared image area  48  and is passing through fuser  33 . Toner has been applied to trailing edge  52  of first sheet  30  along with the desired print image, if any, as first sheet  30  passed through image area  48 . A second sheet  54  is approaching image area  48 . Toner will also be applied to trailing edge  56  of second sheet  54  along with the desired print image, if any, as second sheet  31  passes through image area  48 . Toner need not be applied to the trailing edge of the final page since no binding will occur on that edge.  
         [0021]    Referring to FIG. 3, as the leading edge  58  of second sheet  54  passes through image area  48  and approaches fuser  33 , it overlaps trailing edge  52  of first sheet  30 . This overlap is designated by reference number  59  in FIGS.  2 - 9 . In the preferred embodiment, this overlap is achieved by varying the speed of fuser rollers  34 ,  35  and output rollers  50 . For example, when leading edge  58  of second sheet  54  is detected by a sensor  60  positioned between image area  48  and fuser  33 , the speed of fuser rollers  34 , 35  and output rollers  50  is slowed temporarily to allow leading edge  58  of second sheet  54  to overtake trailing edge  52  of first sheet  30 . Once the desired overlap is achieved, the speed of fuser rollers  34 ,  35  and output rollers  50  is resumed to again match the speed of the two sheets  30  and  54 . Sensor  60  represents generally a conventional electromechanical or photo-optic sensor or any other sensor suitable to detect the presence of the leading edge of each sheet as it passes from image area  48  to fuser  33 . The overlapping edges of sheets  30  and  54  are fused together as they pass through fuser  33  to form a fused joint  61 . This process is repeated for successive sheets  62  to form a continuous sheet  64  as shown in FIGS. 4 and 5.  
         [0022]    FIGS.  6 - 9  illustrate another embodiment of the invention in which sheets are bound end to end with a binding press  66  positioned downstream from fuser  33 . The sequence of operation is the same as that described above for FIGS.  2 - 5 , except that sheets  30  and  54  do not overlap until they approach a binding press  66  downstream of fuser  33  and the toner applied to the binding region is fused at fuser  33  and then refused at binding press  66 .  
         [0023]    In FIG. 6, first media sheet  30  has cleared image area  48  and is passing through fuser  33 . Toner has been applied to trailing edge  52  of first sheet  30  along with the desired print image, if any, as first sheet  30  passed through image area  48 . A second sheet  54  is approaching image area  48 . Toner will also be applied to trailing edge  56  of second sheet  54  along with the desired print image, if any, as second sheet  31  passes through image area  48 . Again, toner need not be applied to the trailing edge of the final page since no binding will occur on that edge  
         [0024]    Referring to FIG. 7, first sheet  30  has cleared fuser  33  to fuse both the print image and the binder toner applied to trailing edge  52  and is moving through output rollers  50 . As the leading edge  58  of second sheet  54  passes through fuser  33  and approaches output rollers  50 , it overlaps trailing edge  52  of first sheet  30  at joint  59 . In the preferred embodiment, this overlap is achieved by varying the speed of output rollers  50 . For example, when leading edge  58  of second sheet  54  is detected by a sensor  60  positioned between fuser  33  and output rollers  50 , the speed of output rollers  50  is slowed temporarily to allow leading edge  58  of second sheet  54  to overtake trailing edge  52  of first sheet  30 . Once the desired overlap is achieved, the speed of output rollers  50  is resumed to again match the speed of the two sheets  30  and  54 .  
         [0025]    Referring to FIG. 8, press  66  closes on the overlapping edges of sheets  30  and  54  to reactivate the toner and fuse the edges together as they pass through press  60  to form a fused joint  61 . This process is repeated for successive sheets  62  to form a continuous sheet  64  as shown in FIG. 9. A suitable press that utilizes a pair of heated platens is described in U.S. patent application Ser. No. [HP PD No. 10008400] filed ______ and titled Post Print Finishing Device With Imaging Material Binder which is incorporated herein by reference in its entirety.  
         [0026]    FIGS.  10 - 13  illustrate another embodiment in which the sheets are bound end to end in a stacker attached to the printer. FIG. 10 is a perspective view of a printer  70  and attached stacker  72  illustrating one type of document printing and finishing system that may be used to implement the invention. Referring to FIG. 10, printer  70  and stacker  72  together make up a document production system designated generally by reference number  74 . Printed sheets are output by printer  70  to stacker  72  where they are routed to an upper output bin  76  or to a lower output bin  78 . Unbound sheets and continuous bound sheets are routed face up to loose sheet bin  76 . Bound documents are collected face down in lower output bin  78 .  
         [0027]    Stacker  72  will now be described with reference to FIGS.  11 - 13 . FIG. 13 is a side elevation view looking into stacker  72  showing the modular design. Stacker  72  includes a continuous sheet binding and flipper module  80 , a paper path module  82 , an accumulator module  84  and a stacked sheet binder module  86 . Each module is mounted to a frame  88 . A power supply  90  and controller  92  are mounted to the lower portion of frame  88 . Power supply  90  and controller  92  are electrically connected to the operative components of modules  80 ,  82 ,  84  and  86 . Controller  92  contains the electronic circuitry and programming necessary to control and coordinate various functions of the components in stacker  72 . The details of the circuitry and programming of controller  92  are not particularly important to the invention as long as the controller design is sufficient to direct the desired functions as described below.  
         [0028]    The modular design of stacker  72  shown in FIG. 11 is adapted from the Hewlett-Packard Company model C8085A stapler/stacker. Each module  80 ,  82 ,  84  and  86  is operatively coupled to but otherwise independent of the adjacent module. In the stacker of the present invention, the flipper module used in the C8085A stapler/stacker is modified to include continuous sheet binding, the stapler module is replaced with stack binder module  86  and controller  92  is modified accordingly to control the operation of the binder rather than a stapler.  
         [0029]    For sheets that will be stacked, bound and output to lower bin  78 , flipper  80  makes the leading edge of each sheet output by printer  70  the trailing edge for routing to paper path  82  and accumulator  84 . Flipping the sheets in this manner from face up to face down is necessary to properly stack the sheets in accumulator  84  prior to stack binding. Paper path  82  moves each sheet face down to accumulator  84  where the sheets are collected, registered, moved to stack binder  86  (when stack binding is desired) and then output to lower bin  78  (bound or unbound). Stack binder  86  reactivates the imaging material applied to select binding regions on sheets collected in accumulator  84  to bind the sheets together. The stack binding aspect of the operation of stacker  72  is described in detail in the Application noted above.  
         [0030]    The continuous sheet binding aspect of the operation of stacker  72  will now be described with reference to FIGS. 12 and 13. First and second media sheets  94  and  95  are output by printer  70  to stacker  72  through printer output rollers  96 . As an entry sensor  98  detect a sheet entering continuous sheet binder and flipper  80 , entry rollers  100  and discharge/fuser rollers  102  are driven forward to move the sheet s toward bin  76 . As the leading edge  104  of second sheet  95  passes through entry rollers  100  and approaches fuser rollers  102 , it overlaps trailing edge  106  of first sheet  94 . This overlap is designated by reference number  108  in FIGS. 12 and 13. Preferably, this overlap is achieved by varying the speed of fuser rollers  102 . For example, when leading edge  104  of second sheet  95  is detected by a sensor  110  positioned between entry rollers  100  and fuser rollers  102 , the speed of fuser rollers  102  is slowed temporarily to allow leading edge  104  of second sheet  95  to overtake trailing edge  106  of first sheet  94 . Once the desired overlap is achieved, the speed of fuser rollers  102  is resumed to again match the speed of the two sheets  94  and  95 . The overlapping edges of sheets  94  and  95  are fused together at joint  112  as they pass through fuser rollers  102  and the imaging material applied to trailing edge  106  is reactivated. This process is repeated for successive sheets to form a continuous sheet  114  as shown in FIG. 13  
         [0031]    FIGS.  14 - 16  show three different configurations for overlapping the first and second sheets. Imaging material is applied to each sheet  122 ,  124  and  126  in the desired print image  128 , if any. In the configuration of FIG. 14, imaging material is also applied for binding to the leading edge  130  of each following sheet  124 ,  122  which is lapped under the trailing edge  132  of each leading sheet  126 ,  124 . In the configuration of FIG. 15, imaging material is applied for binding to the trailing edge  132  of each leading sheet  126 ,  124  which is lapped under the leading edge  130  of each following sheet  124 ,  122 . In the configuration of FIG. 16, imaging material is applied for binding to the leading and trailing edges  130  and  132  of the middle sheet  124  which is lapped under the trailing edge of the leading sheet  126  and the leading edge of the following sheet  122 .  
         [0032]    The binding methods of the present invention can be implemented through computer readable media that contain instructions for performing the desired acts, the memory in controllers  16  and  92  or a printer driver on a remote/host computer for example, for use by or in connection with an instruction execution system, such as the processors in controllers  16  and  92  or the host computer. A “computer-readable medium” includes any of the many physical media such as electronic, magnetic, optical, electromagnetic, infrared, or semiconductor media. More specific examples of a suitable computer-readable medium would include, but are not limited to, a magnetic computer diskette such as floppy diskettes or hard drives, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory, or a compact disc.  
         [0033]    The present invention has been shown and described with reference to the foregoing embodiments by way of example only. Other embodiments are possible. For example, implementing the invention in an attached stacker or a stand alone appliance is not limited to a multi-function modular stacker like the stacker  72  described above. A more simple unit that provides only continuous sheet binding may be used. It is to be understood, therefore, that various embodiments, forms and details may be made without departing from the spirit and scope of the invention which is defined in the following claims.