Abstract:
An imaging apparatus including an image transfer device, a first motor, a redrive section and a duplexing section. The first motor is drivingly connected to the image transfer device. The reversible redrive section is downstream from the image transfer device, and the reversible redrive section includes a second motor. The duplexing section includes a third motor. The duplexing section is positioned to receive media from the redrive section. The first motor, the second motor and the third motor are each independently controlled.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This is a non-provisional application based upon U.S. provisional patent application Ser. No. 61/017,076 entitled “DUPLEX ARCHITECTURE FOR AN IMAGING FOR AN IMAGING APPARATUS”, filed Dec. 27, 2007 which is incorporated herein by reference. 
     
    
     MICROFICHE APPENDIX 
       [0002]    None. 
       GOVERNMENT RIGHTS IN PATENT 
       [0003]    None. 
       BACKGROUND OF THE INVENTION 
       [0004]    1. Field of the Invention 
         [0005]    The present invention relates to an imaging apparatus, and more particularly to the printing section of an imaging apparatus having a duplex architecture. 
         [0006]    2. Description of the Related Art 
         [0007]    In an image forming apparatus, such as a laser printer, ink jet printer, copy machine or the like, often it is desirable to form an image on both sides of the substrates being printed. Printing on both sides, referred to as duplex printing, can create an impression of a more professionally prepared document, when appropriately bound, while also reducing file storage space requirements, media expense, shipping expenses and other handling expenses, particularly for long documents. 
         [0008]    In a duplex printing operation, after an image is printed on a first side of the substrate, the substrate must be reversed in some fashion to present the opposite side of the substrate for printing. For proper appearance of a duplex printed document, the image on the second side should be positioned on the substrate similarly to the image on the first side of the substrate. That is, the top, bottom and side spacings should be the same on each side of the substrate, and both images should be properly aligned with the edges of the substrate. Numerous types of substrate reversal systems are known, including systems that merely turn the substrate over, as well as systems that reverse the substrate lengthwise and turn the substrate over. The image application procedure and substrate reversal system are selected so that the tops and bottoms of the images on both sides are in the desired relationship. 
         [0009]    In today&#39;s world there is more and more focus on the economy especially in the area of paper usage. One example of this relates to the recent energy star regulations, in which any device has a printing speed of ≧45 pages/minute must ship the duplexer included. The most popular duplex architecture is an internal design. This is effective in keeping the overall size of the device as small as possible. 
         [0010]    There are two areas in which the internal duplex design has problems. First, they are not able to accommodate a wide range of media due to the tight turn radius of a paper path, the motor control design and the overall paper path length. For example, some printers can only support 16 to 28 pound plain paper and only in limited sizes. The second problem is that the performance of the printers drop off significantly in terms of sides/minute duplex which is much lower than pages/minute in the simplexed mode. 
         [0011]    What is needed in the art is an internal duplex design that can support a wide range of media and provide improved performance cost effective manner. 
       SUMMARY OF THE INVENTION 
       [0012]    The present invention relates to a printing assembly showing a duplex paper path. 
         [0013]    The invention in one form is directed to an imaging apparatus including an image transfer device, a first motor, a redrive section and a duplexing section. The first motor is drivingly connected to the image transfer device. The reversible redrive section is downstream from the image transfer device, and the reversible redrive section includes a second motor. The duplexing section includes a third motor. The duplexing section is positioned to receive media from the redrive section. The first motor, the second motor and the third motor are each independently controlled. 
         [0014]    An advantage of the present invention is that the speed of the paper in the three separate sections can be independently controlled. 
         [0015]    Another advantage of the present invention is that the paper in the redrive and duplexing paths be driven at a much higher speed than the base paper path. 
         [0016]    Yet another advantage of the present invention is that a page can be held in the duplex section while another page is being printed in the base paper path. 
         [0017]    Still yet another advantage of the present invention is that multiple pages can be moving independently in the three separate sections that define a paper path. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0018]    The above-mentioned and other features and advantages of this invention, and the manner of attaining them, will become more apparent and the invention will be better understood by reference to the following description of an embodiment of the invention taken in conjunction with the accompanying drawings, wherein: 
           [0019]      FIG. 1  is a perspective view of an imaging apparatus in the form of a printer that incorporate an embodiment of the split drive architecture of the present invention; 
           [0020]      FIG. 2  is a schematical view of paper paths of an embodiment of the split drive system of the present invention utilized in the printer of  FIG. 1 ; 
           [0021]      FIG. 3  is a quasi-schematical sectioned side view of a the printer of  FIGS. 1 and 2 ; 
           [0022]      FIG. 4  is another quasi-schematical sectioned side view of the printer of  FIG. 3  showing an advancement of the paper flow; 
           [0023]      FIG. 5  is another quasi-schematical sectioned side view of the printer of  FIG. 4  showing a further advancement of the paper flow; 
           [0024]      FIG. 6  is another quasi-schematical sectioned side view of the printer of  FIG. 5  showing yet another advancement of the paper flow; 
           [0025]      FIG. 7  is another quasi-schematical sectioned side view of the printer of  FIG. 6  showing an even further advancement of the paper flow; and 
           [0026]      FIG. 8  is a schematical block diagram of the functions of the printers illustrated in  FIGS. 1-7 . 
       
    
    
       [0027]    Corresponding reference characters indicate corresponding parts throughout the several views. The exemplification set out herein illustrates an embodiment of the invention, in one form, and such exemplification is not to be construed as limiting the scope of the invention in any manner. 
       DETAILED DESCRIPTION OF THE INVENTION 
       [0028]    Referring now to the drawings, and more particularly to  FIG. 1 , there is shown a perspective view of an imaging apparatus  10 , which for the ease of illustration is also known as a printer  10  having a paper tray  12  and a finished printed tray  14 . Printer  10  incorporates an internal duplex system herein described as a split drive duplexing architecture. 
         [0029]    Now, additionally referring to  FIG. 2  there is shown a schematic view of a media transport system illustrated as split drive system  16  that is incorporated into printer  10 . Split drive system  16  includes a base engine section  18 , a redrive section  20 , a duplexing section  22 , respectively having paper paths  24 ,  26  and  28 . Sections  18 ,  20  and  22  are independently controlled, each having a defined paper path and an independently driven motor controlling the speed at which media traverses each section. 
         [0030]    Base engine section  18  also known as an imaging section  18  includes a motor  30 , an aligner  32 , an imaging device  34 , which may be a drum  34  for transferring of an image therefrom to the media or a printhead  34  directly placing text and graphics upon the media. Section  18  additionally includes a fuser  36  for the fusing of toner onto the media positioned downstream from drum  34 . 
         [0031]    Redrive section  20  includes a reversible motor  38  and rollers  40  for the transport of the media while the media is in redrive section  20 . Motor  38  is not only reversible but also has a variable speed that drives the media at speeds under the control of a controller  46 . 
         [0032]    Duplexing section  22  includes a motor  42  and rollers  44  for the transport of a media in duplexing section  22 . Motor  42  drives in only one direction and may be a variable speed motor. Rollers illustrated herein are for the purpose of explanation of the invention and are not limited to the number, position or size in the illustrations. The rollers of each section are utilized by that section and if driven are driven by the motor of that particular section. Further, the positioning of the rollers in each section have been selected to allow at least three pages to be separately controlled in the overall paper path of printer  10 . 
         [0033]    Now, additionally referring to  FIGS. 3-7  there is illustrated a movement of pieces of media, hereinafter referred to as paper pages to illustrate the operation of the present invention. Pages  50 - 60  are illustrated at different positions in the flow as they go through sections  18 ,  20  and  22  as appropriate. In  FIG. 3  pages  50  and  52  have been delivered to paper receiving tray  14 . Page  54  is transitioning from section  18  to redrive section  20  as illustrated by the arrow thereon. Meanwhile a new page  56  is entering into a section  18  for the placement of an image thereon. Page  58  is being held in duplexing section  22  and is illustrated in a stopped position. Now in  FIG. 4 , page  54  is traveling through redrive section  20  while page  56  is having an image placed thereon in section  18 . Page  58  remains in duplexing section  22 . Now, in  FIG. 5  page  54  has left redrive section  20  and is now in tray  14 . Page  56  is being driven into redrive section  20  until it completely exits section  18 . Meanwhile page  58  is entering into section  18  from duplexing section  58 . Duplexing section  58  has motor  42  which drives page  58  at a very high rate of speed so that it may then enter section  18  in an expeditious manner. Now, in  FIG. 6 , page  58  has entered into base engine section  18  as it leaves duplexing section  22  and page  56  is entering duplexing section  22  and it may wait or be timed so that the reverse side can be printed thereon in the proper sequence. Now, referring to  FIG. 7  a new page  60  enters section  18  as page  58  leaves section  18  and is entering redrive section  20 . Since page  58  has been printed on each side it will be transported to tray  14  by way of redrive section  20 . The selection of simplex or duplex printing for page  60  will then determine whether page  60  exits redrive section  20  or is rerouted through duplexing section  22 . Perhaps following page  60 , or at some later point, page  56  will then enter into base section  18  for printing on a reverse side thereof. 
         [0034]    Now, additionally referring to  FIG. 8  there is shown a portion of imaging apparatus  10  having a split drive system  16  including a controller  46  that independently controls motors  30 ,  38  and  42 . Motors  30 ,  38  and  42  are shown as being respectively in sections  18 ,  20  and  22 . Controller  46  independently controls the speed of motors  30 ,  38  and  42 . Additionally, motor  38  is reversible to reroute the paper to duplexing section  22 . 
         [0035]    The present invention achieves an internal duplex design, which can support a wide range of media types and media weights and delivers speeds close to simplex performance by the dedicated motor control systems for each of the redrive, the internal duplex path and the base path. The present invention is able to address the power and handoff requirements needed the wide range of media size and type, and the associated timing necessary to deliver faster printing speeds. Paper path turn radiuses are made so that they support a wide range of media weights, for example from 16 pound to 90 pound paper weights. The roller spacing in the paper paths can be advantageously situated to support sizes from A5 up to 33 inch banner media. 
         [0036]    Often during the use of a printer paper is printed in a combination of duplex and simplex jobs. For example, it is not unusual for a duplex job to be followed by a simplex job. The present invention can start the duplex page then pick the simplex page while the duplex pages are reversing into the duplex path. In this sequence the simplex page adds no additional job time to what is needed to just print the duplex page. This advantageously leads to reduce job time for many applications that are sensitive to mixed demands of simplex and duplex jobs. 
         [0037]    Split drive system  16  is able to accommodate multi-sheets in the path and achieve higher throughputs without impacting the base engine speed.  FIG. 2  shows how the paper path is split. Motor  30  drives media through paper path  24  in a forward direction. Motor  38  drives the media in paper path  26  in a forward or reverse direction. Motor  42  in duplexing section  22  drives the media in duplexing section  22  in a forward direction only. The breaking up of the paper paths in the split internal duplex design allows for independent control of the three paper paths  24 ,  26  and  28  to thereby achieve higher throughput in printer  10 . Split drive system  16  allows for the simultaneous control of multiple sheets either at a common paper speed, or different paper speeds or at times even stopping a sheet as needed to support the robust timing of the production of printed jobs. Until the media is handed off to each section each drive has independent control of each sheet. This flexibility provides for more robust paper feed reliability, higher throughput and faster time to first print. 
         [0038]    As previously mentioned split drive system  16  allows for variable return speeds of the media in either redrive section  20  and/or duplexing section  22 . This flexibility is important for several reasons including it provides superior performance over a wide range of media lengths. For example, when feeding more common size letter and A4 media the variable speed return can be optimized to balance performance and acoustics, but for longer media like folio and legal media, the return speed can be increased to provide consistent timing and performance in the transport of larger media sizes. Another advantage of split drive system  16  is that even faster speeds available for unique customer applications. The architecture of split drive system  16  allows for a variable return speed and overall has a flexibility for the printer to print faster than classic duplex methods. Another advantage of the present invention is that there is no need to change the base engine process speed. Another dynamic of the present invention is that it is tolerant of gap variations that occur in the normal fixed/feed sequence by dynamically adjusting timing that occurs within the split drive system  16 . 
         [0039]    A further advantage is that controller  46  can allow the simplex path, which is a combination of paper path  24  and the forward portion of paper path  26  to function in the event there is an issue with duplex path  28 . Controller  46  detects a problem and alerts an operator and allows printer  10  to continue functioning as a simplex printer while deactivating duplexing section  22 . Further, controller  46  may be configured by a user to disable duplex path  28  and use printer  10  as a simplex printer. Printer  10  includes the sensors and an algorithm that utilizes the sensors to determine problems as they occur in printer  10 . The algorithm actively reconfigures printer  10  to continue to function, even if in a less than optimal manner, by deactivating features that have failed to function properly. The algorithm identifies the problems to an administrator or user for user intervention and to remedy the problem. 
         [0040]    While this invention has been described with respect to embodiments of the invention, the present invention may be further modified within the spirit and scope of this disclosure. This application is therefore intended to cover any variations, uses, or adaptations of the invention using its general principles. Further, this application is intended to cover such departures from the present disclosure as come within known or customary practice in the art to which this invention pertains and which fall within the limits of the appended claims.