Patent Publication Number: US-11027567-B2

Title: Sheet processing apparatus and image forming system comprising the same

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates to a sheet processing apparatus for performing a post-processing on sheets each having an image formed on it, and relates to an image forming system comprising the sheet processing apparatus. 
     2. Description of the Related Arts 
     Hitherto used is a sheet processing apparatus that is configured to bind sheets each having an image formed by an image forming apparatus such as a printer or a copier. Generally, sheet processing apparatuses of this type are configured to lay a plurality of sheets ejected from an image forming apparatus, one upon another, on the processing tray provided downstream the sheet ejecting passage, to staple-bind the sheets at one part or some parts, and to store the sheets in the accumulating tray arranged still downstream the sheet ejecting passage. 
     With regard to the binding process mentioned above, a sheet processing apparatus is available, in which not only the binding process using staples, but also a non-stable binding process using no staples can be selected. Such a sheet processing apparatus is configured to select the staple binding or non-staple binding, in order to bind the sheets transported from the sheet ejecting passage onto the processing tray and aligned with one another on the processing tray. 
     The sheet processing apparatus described above can perform various binding operations on the sheets accumulated on the processing tray, such as one-part binding of binding sheets at the left corner or right corner and two-part binding of binding sheets at one long side or one short side of each sheet. In the non-stable binding process, the sheets are bound at one part, either the left corner or the right corner, because the number of sheets that can be bound together is limited. That is, only a few sheets can be bound together. 
     In the non-stable binding process, no staples are used. The number of sheets that can be bound together is therefore limited as described above. Further, the non-stable binding process is performed less frequently than the staple binding process. In order to perform the non-stable binding process automatically as the stable binding mechanism is performed, the apparatus must be massive and disadvantageous in terms of cost and performance. 
     Further, in the conventional sheet processing apparatus, either the staple binding process or the non-staple binding process is selected for the sheets accumulated on the tray for the post-processing. Therefore, the non-needle binding may be performed in some cases even if the number of sheets exceeds the prescribed value. If the non-staple binding is performed on more sheets than the prescribed number, it will result in an undesirable sheet binding. 
     SUMMARY OF THE INVENTION 
     This invention relates to a sheet-binding apparatus for binding sheets together. The apparatus comprises: a first insertion section having a slit through which sheets may be manually inserted from outside; a staple-binding mechanism for staple-binding the sheets inserted into the first insertion section; a second insertion section having a slit through which sheets may be manually inserted from outside; and a non-staple binding mechanism for binding the sheets inserted into the second insertion section, without using staples. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic diagram of an image forming system which comprises a sheet processing apparatus according to the present invention; 
         FIG. 2  is a sectional view of the main section of the sheet processing apparatus; 
         FIG. 3  is a sectional view of a sheet processing apparatus according to a first embodiment, which comprises first and second manual binding sections provided at the front side; 
         FIG. 4  is a plan view of the sheet processing apparatus according to the first embodiment; 
         FIG. 5  is a sectional view of a sheet processing apparatus according to a second embodiment, which comprises a first manual binding process section at the front side and a second manual binding section at the rear side; 
         FIG. 6  is a plan view of the sheet processing apparatus according to the second embodiment; and 
         FIG. 7  is a plan view of a sheet processing apparatus according to a third embodiment. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     The embodiments of this invention will be described below in detail, with reference to the accompanying drawings.  FIG. 1  is a sectional view of an image forming system  1 , as viewed at the operating front side, which incorporates a sheet processing apparatus  2  which is a post-processing unit. The image forming system  1  comprises a housing  4 , a sheet supplying section  5 , an image forming section  6 , and an original reading section  7 , and the like. The sheet supplying section  5 , image forming section  6  and the original reading section  7  are incorporated in the housing  4 . The sheet processing apparatus  2  is arranged in a space  3 , into which sheets each having an image formed in the image forming section  6  are ejected. 
     The image forming system  1  comprises various mechanisms for forming images. The original reading section  7  reads the original laid on the platen  30 , and the image forming section  6  prints the image on the sheets sequentially transported from the sheet supplying section  5 . The sheets, each having an image printed on it, are transported into the space  3 . The sheets are then bound together in one of various ways in the sheet processing apparatus  2  arranged in the space  3 . 
     The sheet supplying section  5  comprises at least one cassette  5   a  for holding sheets. A plurality of sheets is held in the cassette  5   a . The sheet supplying section  5  may have, by option, two or more cassettes. Therefore, sheets of one size can be held in one cassette, and sheets of another size can be held in another cassette. The cassette  5   a  incorporates sheet feeding rollers  32  for feeding sheets and a sheet separating unit (not shown) for separating one sheet from another. 
     The image forming section  6  comprises an image forming mechanism  33  of, for example, electrostatic type. The image forming mechanism  33  has a plurality of drums for the color components, respectively, each composed of photosensitive material (photoconductor). For each drum, there are arranged a light-emitting device (e.g., laser head), a developing device, and the like. On each drum, a latent image (electrostatic image) is formed by the light-emitting device. In the developing device, toner ink is applied to each drum, forming an ink image. The ink images are transferred from the drums onto transfer belts and are synthesized on the sheet. 
     The original reading section  7  comprises a platen  30  and a reading carriage  34  which moves back and forth along the platen  30 . The platen  30  is made of transparent glass. The reading carriage  34  has a light-source lamp  35 , a reflection mirror  36  for guiding the light reflected from the original, and a photoelectric transducer element  37 . The photoelectric transducer element  37  is constituted by a line sensor which is arranged in the widthwise direction (i.e., main scanning direction) of the original mounted on the platen  30 . As the reading carriage  34  moves back and forth in the sub-scanning direction, namely the direction at right angles to the widthwise direction (i.e., main scanning direction) of the platen  30 , the photoelectric transducer element  37  reads the image formed on the original. Above the platen  30 , an original pushing plate  31  is arranged, covering the original. 
     The image forming section  6  transfers the image read by the original reading section  7 , to the sheet transported from the sheet supplying section  5 . The sheet to which the image has been transferred is ejected into a first transport path  8   a  or into a second transport path  8   b  which is provided in the sheet processing apparatus  2  shown in  FIG. 2 . The first transport path  8   a  is selected so that the sheets may be subjected to various binding processes by the sheet processing apparatus. The second transport path  8   b  is selected so that the sheets may be ejected onto an ejected-sheet tray  20 . The image-formed sheets transported along the first transport path  8   a  are transported into the sheet processing apparatus  2 , are aligned with one another, and are subjected to a specific process. The sheets processed are accumulated on an accumulating tray  12  arranged downstream. 
     As shown in  FIG. 2 , the sheet processing apparatus  2  comprises a housing  10  small enough to be incorporated in the space  3  provided in the image forming system  1 . The sheet processing apparatus  2  further comprises a punching process section  9  arranged upstream the housing  10 , a binding section  11  arranged downstream the punching process section  9 , and an accumulating tray  12  located downstream the binding section  11 . The punching process section  9  comprises the above-mentioned first transport path  8   a , a punching mechanism  9   a  configured to punch any sheet transported along the first transport path  8   a , a trash bin  9   b  for storing the chips made as the punching mechanism  9   a  punches each sheet, and a second transport path  8   b  for guiding sheets onto the ejected-sheet tray  20  provided on the upper surface of the binding section  11 . The punching mechanism  9   a  comprises a drive motor (not shown) and a drive cam  9   c  coupled to the drive motor. The drive cum  9   c  shown in  FIG. 2  is an eccentric cam. 
     The binding section  11  comprises a transporting unit (third transport passage)  13 , a passage exit port  14 , an ejecting unit (pair of ejecting rollers)  60 , a processing tray  15 , a paddle rotary member  16   a , an aligning plate  17   a , a pair of side-aligning plates  17   b  and  17   c , a stapler  18 , and a sheet ejecting belt  61 . The transporting unit  13  transports any sheet coming from the punching process section  9 . The passage exit port  14  is provided downstream the transporting unit  13 . The ejecting unit  60  ejects any sheet from the passage exit port  14 . The processing tray  15  is arranged downstream the passage exit port  14  and configured to hold the sheets ejected by the ejecting rollers  60 . The paddle rotary member  16   a  takes sheets from the processing tray  15  and moves them in a take-up direction different from the sheet transporting direction. The aligning plate  17   a  aligns the sheets, at the leading end, in the sheet-taking direction (at the trailing end, in the sheet transporting direction). The side-aligning plates  17   b  and  17   c  align the sheets on the processing tray  15 , at both sides in the widthwise direction at right angles to the sheet transporting direction. The stapler  18  binds together the sheets aligned on the processing tray  15 . The sheet ejecting belt  61  ejects the sheets bound together by the stapler  18 , onto the accumulating tray  12 . 
     The paddle rotary member  16   a  has a band-shaped elastic member, and is secured to the distal end of a lifting/lowering arm  16   c . The lifting/lowering arm  16   c  has a support axle  16   b  at the base part. The lifting/lowering arm  16   c  rotates around the support axle  16   b  functioning as fulcrum, and moves the paddle rotary member  16   a  up and down between the sheet take-in position where it contacts the sheet placed on the processing tray  15  and the sheet releasing position where it releases the sheet placed on the processing tray  15 . 
     The binding section  11  has a binding mechanism  19 . The binding mechanism  19  has the function of staple-binding the sheets aligned by the aligning plate  17   a  and pair of side-aligning plates  17   b  and  17   c , by using the stapler  18 . That is, the stapler  18  automatically performs staple-binding on the sheets which are aligned on the processing tray  15 . In the staple binding, one stapler  18  can move to the corner of each sheet aligned with any other, and bind the sheets at one part, and can move to along the long side of the sheets and bind the sheets at two parts. 
     As shown in  FIG. 1 , the sheet processing apparatus  2  according to this invention comprises, in addition to the binding section  11 , a first binding unit (first manual binding section)  21  and a second binding unit (second manual binding section)  22 , which binds the sheets set from outside by, for example, manual feeding. The first manual binding section  21  is arranged adjacent to the binding section  11  located in the space  3  that is provided in the image forming system  1 . As shown in  FIG. 1  and  FIG. 2 , the second manual binding section  22  is arranged adjacent to the accumulating tray  12  that protrudes outside from the space  3 . In this embodiment, the accumulating tray  12  of the sheet processing apparatus  2  is configured to protrude outside from the space  3  provided in the image forming system  1 . Therefore, the second manual binding section  22  is also positioned outside the space  3 . However, at least one part of the second manual binding section  22  can also be configured to be located in the space  3  in the image forming system  1  in which at least one part of the accumulating tray  12  is provided in the space  3 . 
       FIG. 3  and  FIG. 4  illustrate the configuration of a sheet processing apparatus  2   a  according to the first embodiment. In this embodiment, the first manual binding section  21  is arranged adjacent to one end of the front (F) of the binding section  11 , as viewed in the sheet-widthwise direction of the binding section  11 . With respect to the accumulating tray  12 , the second manual binding section  22  is arranged adjacent to one end of the front (F) of the accumulating tray  12 , as is viewed in the sheet-widthwise direction of the accumulating tray  12 . 
     The binding section  11  and the first manual binding section  21  are formed integral with each other, constituting a staple-binding unit. As shown in  FIG. 4 , the first manual binding section  21  is formed by extending a part of the front (F) of the binding section  11  which intersects, at right angles, with the direction of transporting sheets in the binding section  11 . The first manual binding section  21  has a first insertion port  25  shaped like a slit and comprises a first support member  63 , first and second control plates  40   a  and  40   b , a first sheet-detecting sensor S 2 , a stapler-detecting sensor S 1 , and an operation button  41 . Through the first insertion port  25 , a sheet can be manually inserted into the first manual binding section  21 . The first support member  63  supports the sheet A inserted through the first insertion port  25 . The first and second control plates  40   a  and  40   b  hold the two edges of each sheet A inserted, defining a corner of each sheet A at such a position as to bind the sheets A together. The first sheet-detecting sensor S 2  detects that the sheets A are positioned and can be bound together at the corner. The stapler-detecting sensor S 1  detects whether the stapler  18  has moved to the manual-stapling position of the first manual binding section  21 . The operation button  41  may be pushed to make the stapler  18  bind the sheets together. The operation button  41  has an LED lamp  65  that emits light if the first sheet-detecting sensor S 2  detects a sheet A. 
     The stapler  18  has its home position at the manual stapling position in the first manual binding section  21 . That is, the stapler  18  usually stays at the manual stapling position, i.e., home position. The stapler  18  moves in the widthwise direction of the sheet, stops at the sheet binding position, and binds the sheets together on the processing tray  15 . 
     The first manual binding section  21  operates in a specific sequence. The first manual binding section  21  starts operating when sheets A aligned at one end are inserted through the first insertion port  25 . When each sheet A has its corner abut on the first and second control plates  40   a  and  40   b , the first sheet-detecting sensor S 2  detects one end of each sheet A, and the LED lamp  65  is turned on. The user can therefore recognize that the sheets A are at the position where they can be bound together. The user then pushes the operation button  41 . The stapler  18  therefore starts binding the sheets A. The first insertion port  25  has such a width that more than  30  sheets of ordinary type cannot be inserted at a time, because the stapler  18  cannot bind more than  30  sheets. 
     As shown in  FIG. 4 , the second manual binding section  22  comprises a non-staple mechanism  28 , a second insertion port  26  shaped like a slit, a second support member  64 , first and second control plates  42   a  and  42   b  and a second sheet-detecting sensor S 3 . The non-staple mechanism  28  is configured to perform non-staple binding. Through the second insertion port  26 , sheets may be inserted. The second support member  64  supports the sheets inserted through the second insertion port  26 . The first and second control plates  42   a  and  42   b  respectively hold the two edges of each sheet B inserted, which define a corner. The second sheet-detecting sensor S 3  detects whether the sheets B have abut on the first and second control plates  42   a  and  42   b  and thereby positioned to be bound. 
     As shown in  FIG. 2 , the non-staple mechanism  28  comprises a pair of teeth members (i.e., upper teeth member  28   a  and lower teeth member  28   b ). These teeth members bite sheets, deforming each sheet under pressure, crushing sheet fibers and entangling them, thereby binding the sheets together. Thus, the non-staple mechanism  28  performs so-called pressure-bond binding. Besides the pressure-bond binding, various binding methods, such as half-blank binding and lance binding, are available. Still another binding method is available, in which the sheets are bent and then passed through a hole. In this embodiment, the non-staple mechanism  28  is arranged at a rear (R) corner of the second support member  64 . The lower teeth member  28   a  is secured, with its upper surface flush with the mounting surface of the second support member  64 . The upper teeth member  28   b  is configured to be moved by a drive unit (not shown) to the position where it meshes with the lower teeth member  28   a  and to a position where it is away from the lower teeth member  28   a.    
     As shown in  FIG. 3 , the second manual binding section  22  is arranged in front (F) of the accumulating tray  12 , side-by-side with the first manual binding section  21  as viewed from the front. Further, the upper surface of the second manual binding section  22  functions as a support surface  27  that supports a part of the sheet A inserted into the first insertion port  25  of the first manual binding section  21 . The second insertion port  26  is positioned below the support surface  27 , and is inclined by an angle substantially equal to the angle by which the first insertion port  25  is inclined. The non-staple mechanism  28  has been secured at a position where it obliquely presses the sheets B inserted through the second insertion port  26 . The number of sheets B that can be processed in the non-staple mechanism  28  is limited to about five (5). Therefore, the second insertion port  26  has a width smaller than the width of the first insertion port  25 , so that less sheets may be inserted through it than through the first insertion port  25 . 
     The second manual binding section  22  has an operation button  41  and an LED lamp  66 . The operation button  41  may be pushed to make the non-staple mechanism  28  bind sheets. The LED lamp  66  is turned on when the first sheet-detecting sensor S 2  detects a sheet. The second manual binding unit  22  starts a sequence of operations when the sheets B aligned at one end are inserted into the second insertion port  26 . When the sheets B so inserted abut, at a corner, on the first and second control plates  42   a  and  42   b , the second sheet-detecting sensor S 3  detects one end of each sheet B, and the LED lamp  66  is turned on. Seeing the LED lamp  66  turned on, the user recognizes that the sheets B are at the position where they can be bound together. Then, the user may push the second operation button  43 . When the second operation button  43  is pushed, the non-staple mechanism  28  is driven, binding the sheets B together. 
     The second manual binding section  22  used in this embodiment is a non-staple binding unit formed integral and comprising, as shown in  FIG. 2 , a non-staple mechanism  28 , a drive unit for driving the non-staple mechanism  28 , a second insertion port  26 , a second support member  64 , first and second control plates  42   a  and  42   b , and a second sheet-detecting sensor S 3 . This non-staple binding unit is secured, by fastening members  68  such as screws, to a side surface  67  at the front of the stapling unit that comprises the binding section  11  and the first manual binding section. Hence, the non-staple binding unit is coupled to the stapling unit with the fastening members  68 , and can be decoupled from the stapling unit by removing the fastening members  68 . 
     In the sheet processing apparatus  2   a  according to this embodiment, the second manual binding section  22  is arranged in front (F) of the accumulating tray  12  and at the side of the first manual binding section  21  in left-to-right direction. Therefore, the front surfaces of the first manual binding section  21  and second manual binding section  22  can be substantially flush with each other, preventing the apparatus from becoming large. Further, since the first insertion port  25  is located higher than the second insertion port  26  and the upper surface  27  of the second manual binding section  22  is arranged, supporting the sheet inserted through the first insertion port  25  of the first manual binding section  21 , the sheets can be stabilized as they are bound by the first manual binding section  21 . Moreover, the binding failure can be reduced, because the first and second manual binding sections  21  and  22  have the first and second insertion ports  25  and  26 , respectively, and because the first and second insertion ports  25  and  26  have a width for passing sheets in number appropriate for the binding method. 
       FIG. 5  and  FIG. 6  show the configuration of a sheet processing apparatus  2   b  according to the second embodiment. In this embodiment, the second manual binding section  22  is arranged on the rear (R) side in the widthwise direction of the sheet, namely on the side facing away from the accumulating tray  12 . In this embodiment, the upper surface of the accumulating tray  12  can be used as support surface  12   a  to support a part of the sheet B inserted into the second insertion port  26  of the second manual binding section  22 . Therefore, as shown in  FIG. 5 , the second manual binding section  22  can be located higher than otherwise, and the height and inclination of the second insertion port  26  can be matched with the upper surface of the accumulating tray  12 . As a result, the accumulating tray  12  supports the sheet B, except that part existing in the second insertion port  26 , and the sheet B can be stabilized and well-bound to another sheet. The second embodiment is different from the first embodiment, only in that the second manual binding section  22  is arranged differently. The first and second manual binding sections  21  and  22  are similar in structure and function to those of the sheet processing apparatus  2   b , and will not be described here. 
     In the embodiments described above, the stapler  18  is provided in the first manual binding section  21 , and the non-staple mechanism  28  is provided in the second manual binding section  22 . In a third embodiment, the non-staple mechanism  28  may be provided in the first manual binding section  21 , and the stapler  18  may be provided in the second manual binding section  22 . In the third embodiment, the non-staple mechanism  28  is configured to move between the binding section  11  and the second manual binding section  22  as is illustrated in  FIG. 7 . The non-staple mechanism  28  moves in the widthwise direction of the sheets on the processing tray  15 , along the long side of each sheet, and binds the sheets together at one part or two parts. 
     In the sheet processing apparatuses  2   a  and  2   b  according to the first and second embodiments, respectively, the first manual binding section  21  and the second manual binding section  22  can be arranged in the space at one side of the binding section  11  and one side of the accumulating tray  12 , each protruding a little therefrom. The sheet processing apparatuses can therefore be made compact, and can be easily incorporated into a small image forming system having a small space  3 . Further, the second manual binding section  22  may be arranged in front of the first manual binding section  21  or the punching process section  9 , though the section  22  is arranged adjacent to the front or rear of the accumulating tray  12  in the first and second embodiments. Still further, sheets can be easily hand-fed, because the first manual binding section  21  and the second manual binding section  22  are arranged in an open space provided at the operation side (i.e., front) of the image forming system  1 . Furthermore, the second manual binding section  22  is a mechanism independent of the binding mechanism  19  provided in the binding section  11 , and can therefore be arranged in front of the accumulating section  12  or at the rear thereof, and can be used, if necessary, as an optional component. 
     This application is based upon and claims the benefit of priority from the prior Japanese Patent Application No. 2018-075555, filed Apr. 10, 2018, the entire contents of which are incorporated herein by reference.