Patent Publication Number: US-2010119332-A1

Title: Sheet finishing device

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application is based upon and claims the benefit of priority from provisional U.S. Applications 61/112,640 filed on Nov. 7, 2008, the entire contents of which are incorporated herein by reference. 
    
    
     TECHNICAL FIELD 
     The present invention relates to a sheet finishing device which finishes a sheet on which an image is formed by an image forming apparatus of a copy machine, printer or MFP (multi-functional peripheral). 
     BACKGROUND 
     A sheet finishing device binds a sheet on which an image is formed by an image forming apparatus. As a sheet binding technique, stapling may be used in which plural sheets are bound with metal staples. However, stapling with metal staples may impair safety of the user. Moreover, metal staples must be removed from stapled sheets at the time of recycling the sheets. 
     Meanwhile, recently, for example, JP-A-8-39959, JP-A-10-871 and JP-A-10-872 disclose devices that bind sheets with a dedicated adhesive tape. However, in the conventional devices, a dedicated adhesive tape having adhesiveness needs to be loaded. 
     It is desirable to develop a sheet finishing device which does not require separate preparation of a dedicated binding tape to bind sheets on which an image is formed, and which enables reduction in running costs, improved easiness of maintenance, elimination of the need to remove staples at the time of recycling, and more effective utilization of sheets. 
     SUMMARY 
     According to an embodiment, a sheet finishing device includes a processing tray which supports sheets having an image formed thereon by an image forming unit, a binding unit which binds a plurality of the sheets on the processing tray by using a paper tape, and a stacker which stacks a sheet bundle bound by the binding unit. 
    
    
     
       DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic view of configuration showing a sheet finishing device according to a first embodiment; 
         FIG. 2A ,  FIG. 2B ,  FIG. 2C  and  FIG. 2D  are schematic perspective views showing procedures for cutting used sheets by a tape producing unit according to the first embodiment; 
         FIG. 3  is a schematic perspective view showing the cutting by a lower cutter edge and an upper cutter edge of the tape producing unit according to the first embodiment; 
         FIG. 4A ,  FIG. 4B  and  FIG. 4C  are schematic explanatory views showing procedures for accumulating, in a tape supply unit, paper tapes cut by the tape producing unit according to the first embodiment; 
         FIG. 5  is a schematic perspective view showing the tape supply unit according to the first embodiment; 
         FIG. 6  is a schematic view of configuration showing a stapling unit according to the first embodiment; 
         FIG. 7A ,  FIG. 7B ,  FIG. 7C ,  FIG. 7D ,  FIG. 7E ,  FIG. 7F  and  FIG. 7G  are schematic explanatory views showing sheet binding procedures using the stapling unit according to the first embodiment; 
         FIG. 8  is a flowchart showing the production of paper tapes according to the first embodiment; 
         FIG. 9  is a flowchart showing the stapling with a paper tape according to the first embodiment; 
         FIG. 10A ,  FIG. 10B  and  FIG. 10C  are schematic explanatory views showing procedures for bending a paper tape according to the first embodiment; 
         FIG. 11  is a partial perspective view showing a sheet bundle stapled with a paper tape according to the first embodiment; 
         FIG. 12  is a schematic view of configuration showing a sheet finishing device according to a second embodiment; 
         FIG. 13  is a schematic perspective view showing a tape supply unit according to the second embodiment; 
         FIG. 14  is a schematic view of configuration showing a stapling unit according to the second embodiment; 
         FIG. 15A ,  FIG. 15B ,  FIG. 15C ,  FIG. 15D  and  FIG. 15E  are schematic explanatory views showing sheet binding procedures using the stapling unit according to the second embodiment; and 
         FIG. 16  is a schematic perspective view showing a tape forming unit and a tape supply unit according to a modification. 
     
    
    
     DETAILED DESCRIPTION 
     Hereinafter, a first embodiment will be described with reference to the attached drawings.  FIG. 1  is a schematic view of configuration showing a sheet finishing device  10  according to the first embodiment. The sheet finishing device  10  discharges a sheet P discharged from an image forming apparatus  90  such as an MFP having an image forming unit to form an image on a sheet, to a fixed tray  12  or a placing tray  13  as a stacker. CPU 50  controls the sheet finishing device  10 . The CPU 50  includes a determining unit  50   a  and a memory  50   b.    
     The sheet finishing device  10  has a punch unit  15  as a punching unit which punches a hole in the sheet P discharged after image formation by the image forming apparatus  90 . The punch unit  15  has a first roller  15   a  and a punch section  15   b.  The sheet finishing device  10  has a second roller  11  which carries the sheet P passed through the punch unit  15 , and a first gate  17  which allocates the sheet P to the direction of a first exit roller  14  or to the direction of a second exit roller  16 . 
     The sheet finishing device  10  has a processing tray  18  which finishes the sheet P allocated to the second exit roller  16  by the first gate  17 , and a stapling unit  21  as a binding unit which binds plural sheets on the processing tray  18  with a paper tape T. The sheet finishing device  10  has a lateral alignment board  20  which laterally aligns the sheets P on the processing tray  18 , a paddle  26  which longitudinally aligns the sheets P on the processing tray  18 , an ejector  24  which discharges the bundled sheets P from the stapling unit  21  after the sheets P on the processing tray  18  are bound, and a bundle pawl belt  30  having a bundle pawl  31  which discharges the bundled sheets P to the placing tray  13 . 
     A standby tray  22  which stands by for supply of sheets to the processing tray  18  is arranged above the processing tray  18 . A standby tray roller  28  which discharges sheets directly to the placing tray from the standby tray  22  is arranged above the standby tray  22 . 
     The sheet finishing device  10  has a tape producing unit  36  as a tape forming unit which produces a paper tape T to be used by the stapling unit  21 , and a tape supply unit  37  as a tape supply portion which supplies the produced paper tape to the stapling unit  21 . 
     The sheet finishing device  10  has a sheet supply unit  38  as a sheet supply portion which supplies a used sheet S to the direction of the image forming apparatus  90 . The sheet supply unit  38  supplies the used sheet S to a paper supply tray  91  of the image forming apparatus  90  if the used sheet S is reusable. The sheet supply unit  38  supplies the used sheet S to the tape producing unit  36  if the used sheet S is not reusable. 
     The sheet supply unit  38  has a used sheet tray  40  on which the used sheet S is to be placed, a sheet detection switch  40   a  which detects the presence or absence of the used sheet S on the used sheet tray  40 , a sheet pickup roller  41  which picks up the used sheet S, a scanner  42  which scans creases and scratches on the used sheet S, a second gate  46  which allocates the used sheet S to the direction of the image forming apparatus  90  or to the direction of the tape producing unit  36 , a first carrying path  47  which leads the used sheet S to the paper supply tray  91 , and a second carrying path  48  which leads the used sheet S to the tape producing unit  36 . 
     Scanned data from the scanner  42  is inputted into the determining unit  50   a  of the CPU  50 . The memory  50   b  of the CPU  50  stores a threshold value of damage. The determining unit  50   a  compares the scanned data with the threshold value of damage. The determining unit  50   a  determines that the used sheet s is reusable when the scanned data is less than a threshold value of damage. In case that the used sheet S records used times in advance, the scanner  42  scans the number of used times of the used sheet S. The determining unit  50   a  compares the scanned data with the threshold value of used times which stored in the memory  50   b.  The determining unit  50   a  determines that the used sheet s is reusable when scanned data is smaller than a threshold value of used times. The tape producing unit  36  is shown in  FIG. 2A  to  FIG. 2D ,  FIG. 3 , and  FIG. 4A  to  FIG. 4C . The tape producing unit  36  has a plate-like lower cutter edge  51  having an edge with a saw-toothed cross section on the surface, and an upper cutter edge  52  which the edge part of the lower cutter edge  51  rubs against to cut the used sheet S into paper tapes T. The upper cutter edge  52  moves up and down above the lower cutter edge  51 . 
     The lower cutter edge  51  rotates about a shaft  54 . The end on the rotating side of the lower cutter edge  51  has a rack  56 . The rack  56  meshes with a pinion  57 . As the pinion  57  rotates, the rack  56  and the lower cutter edge  51  rotate in a reciprocating manner. 
     The tape supply unit  37  is shown in  FIG. 5 . The tape supply unit  37  has a tape tray  58  on which the paper tapes T produced by the tape producing unit  36  are accumulated, a tape pickup roller  60  which takes out a paper tape T from the tape tray  58 , a tape cutter  61  which cuts the paper tape T, and a carrying guide  62  and a carrying roller  63  which carry the paper tape T to the stapling unit  21 . The tape cutter  61  has a fixed lower edge  61   a,  and an upper edge  61   b  which moves up and down. 
     In the tape supply unit  37 , the tape pickup roller  60 , the tape cutter  61  which cuts the paper tape T, and the carrying guide  62  and the carrying roller  63  which carry the paper tape T to the stapling unit  21  are arranged on the rear side and the front side of the sheet finishing device  10 . The tape supply unit  37  can move the tape tray  58  on which the paper tapes T produced by the tape producing unit  36  are accumulated, together with the stapling unit  21 , to the rear side and the front side of the sheet finishing device  10 . 
     The stapling unit  21  is shown in  FIG. 6  and  FIG. 7A  to  FIG. 7G . In the sheet finishing device  10 , the stapling unit  21  can slide to the front or rear side and can select stapling one part or two parts in a sheet bundle B. The stapling unit  21  has a slit  71  for inserting the paper tape T therein on a bundle supporting unit  70  which supports the sheet bundle B, and a bending member  72  for winding the paper tape T on the sheet bundle B. The bending member  72  is made to slide by the rotation of a first cam  72   a  and by a first spring  72   b.  Above the bundle supporting unit  70 , a stamp  73  which pastes glue to the paper tape T wound on the sheet bundle D, and a bundle carrying guide  74  for the sheet bundle B are provided. The stamp  73  is made to slide by the rotation of a second cam  73   a  and by a second spring  73   b.    
     The production of the paper tape T will be described with reference to the flowchart of  FIG. 8 . At the time of producing the paper tape T, the used sheet S is placed on the used sheet tray  40 . As the sheet detection switch  40   a  detects the used sheet S (Yes in ACT  100 ), the sheet pickup roller  41  carries the used sheet S to the scanner  42  (ACT  101 ). In case that the used sheet S is reusable from the scanned data of the scanner  42  (Yes in ACT  102 ), the sheet supply unit  38  carries the used sheet S to the paper supply tray  91  of the image forming apparatus  90  (ACT  103 ). 
     In case that the used sheet S is not reusable from the scanned data of the scanner  42  (No in ACT  102 ), the sheet supply unit  38  carries the used sheet to the tape producing unit  36  (ACT  106 ). The tape producing unit  36  cuts the used sheet S (ACT  107 ). The cut paper tapes T are accumulated on the tape tray (ACT  108 ). 
     At the time of producing the paper tapes T, in the tape producing unit  36 , (1) the used sheet S carried from the second carrying path  48  is placed on the lower cutter edge  51  in the state where the lower cutter edge  51  is kept horizontal ( FIG. 2B ). The position on the lower cutter edge  51  where the used sheet S is placed is regulated by a stopper  53 . (2) The upper cutter edge  52  is lowered in the direction of arrow n ( FIG. 2C ). As shown in  FIG. 3 , the upper cutter edge  52  rubs against the lower cutter edge  51  and thus cuts the used sheet S in the shape of paper tapes T ( FIG. 2D ). 
     After the paper tapes T are formed, (3) the pinion  57  is rotated in the direction of arrow q, thereby rotating the rack  56  and the lower cutter edge  51  in the direction of arrow r. The lower cutter edge  51  becomes inclined and the paper tapes T on the lower cutter edge  51  falls and accumulates on the tape tray  58  of the tape supply unit ( FIG. 4B ). (4) As the pinion  57  is rotated in the direction of arrow u, the rack  56  and the lower cutter edge  51  are rotated in the direction of arrow v and the lower cutter edge  51  becomes horizontal again ( FIG. 4C ). 
     The stapling with the paper tape T will be described with reference to the flowchart of  FIG. 9 . The punch unit  15  forms a punch hole H at a stapling position on the sheets P on which an image is formed by the image forming apparatus in staple process (ACT  120 ). The sheets P are carried to the second roller  11 . The sheets P are allocated toward the second exit roller  16  from the second roller  11  and then accumulated and aligned on the processing tray  18  (ACT  121 ). 
     The sheet bundle B on the processing tray  18  is slid in the direction of arrow h, then abutted on a sidewall  70   a  of the bundle supporting unit  70 , and set at a stapling start position on the bundle supporting unit  70  (ACT  122 ). The position of the punch hole H in the sheet bundle B set at the stapling start position coincides with the position of the slit  71  of the bundle supporting unit  70  ( FIG. 7A ). As stapling starts, the paper tape T on the tape tray  58  is carried to the stapling unit  21  (ACT  123 ). The tape supply unit  37  takes out the paper tape T on the tape tray  58  by the tape pickup roller  60 . The paper tape T thus taken out is cut to a required length by the tape cutter  61  and is carried to the stapling unit  21  along the carrying guide  62  by the carrying roller  63  ( FIG. 7B ). 
     The paper tape T is passed through the punch hole H in the sheet bundle B and then inserted in the slit  71  of the supporting unit  70  (ACT  124 ,  FIG. 7C ). The sheet bundle B is slid in the direction of arrow j and front edge position of the sheet bundle B is made to coincide with the position of the bending member  72  (ACT  126 ). Front edge of the paper tape T is regulated by the bundle carrying guide  74  and bent along the surface of the sheet bundle B ( FIG. 7D ,  FIG. 10A ). The first cam  72   a  is rotated to raise the bending member  72 , and the paper tape T is bent along the front edge of the sheet bundle B (ACT  127 ,  FIG. 7E ,  FIG. 10B ). 
     The first cam  72   a  is rotated and the bending member  72  is lowered by the first spring  72   b.  The sheet bundle B is thus slid in the direction of arrow h and set at a gluing position. The second cam  73   a  is rotated to lower the stamp  73  and glue is pasted to the paper tape T bent along the surface of the sheet bundle B (ACT  128 ,  FIG. 7F ,  FIG. 10C ). 
     The second cam  73   a  is rotated and the stamp  73  is raised by the second spring  73   b.  The sheet bundle B is slid in the direction of arrow h (ACT  130 ). The rear edge of the paper tape T is regulated and bent by the bundle carrying guide  74  and bonded to the gluing position of the paper tape T ( FIG. 7G ). As shown in  FIG. 11 , the paper tape T is wound between the punch hole H and the edge of the sheet bundle B and the sheet bundle B is thus stapled with the paper tape T. The sheet bundle B with its stapling completed with the paper tape T is taken out of the stapling unit  21  by the ejector  24 . The sheet bundle B is carried on the processing tray  18  by the bundle pawl  31  interlocked with the turn of the bundle pawl belt  30  and is stacked in the placing tray  13  (ACT  131 ). 
     According to the first embodiment, the paper tape T is wound between the punch hole H in the sheet bundle B and the edge of the sheet bundle B, thus binding the sheet bundle B. Compared with the stapling with metal staples, there is no risk of injuring the handler&#39;s hand and user safety is provided. In the case of recycling the sheets P, the need to remove metal staples is eliminated. According to the first embodiment, the paper tape T used to bind the sheet bundle is made of the used sheet S. A sheet that is not reusable for image formation is cut to produce the paper tape T. More effective utilization of the used sheet S is realized. 
     Next, a second embodiment will be described. The second embodiment differs from the first embodiment in the mechanism of the binding unit and the tape supply unit. In the second embodiment, the same parts of the configuration as those of the first embodiment are denoted by the same reference numerals and will not be described further in detail. In the second embodiment, a stapling unit  80  which is already known in JP-A-8-39959, JP-A-10-871 and JP-A-10-872 is used as a binding unit. As shown in  FIG. 12 , a tape supply unit  77  as a tape supply portion of a sheet finishing device  76  has a gluing unit  78  which pastes glue on the paper tape T used in the stapling unit  80 . In the second embodiment, a third carrying path  79  is provided which leads the used sheet S to the tape producing unit  36 . 
     The tape supply unit  77  is shown in  FIG. 13 . The tape supply unit  77  has the tape tray  58 , the tape pickup roller  60  and the tape cutter  61 , and has a gluing unit  78  which pastes the glue on the paper tape T, at a position close to the tape cutter  61 . The gluing unit  78  supplies glue  78   b  stored in a glue tank  78   a  to a gluing roller  78   d  via an intermediate roller  78   c.  In the tape supply unit  77 , the tape pickup roller  60 , the tape cutter  61  and the gluing unit  78  are arranged to the rear side and the front side of the sheet finishing device  10 . In the tape supply unit  77 , the tape tray  58  on which the paper tapes T produced by the tape producing unit  36  are accumulated is movable to the rear side and the front side of the sheet finishing device  10 , together with the stapling unit  80 . 
     The stapling unit  80  is shown in  FIG. 14  and  FIG. 15A  to  FIG. 15E . The stapling unit  80  has an endless plastic film  81  which carries the paper tape T pasted the glue by the tape supply unit  77 . The plastic film  81  is laid over a driving roller  82 , a separation roller  83   a , and first and second tension rollers  83   b  and  83   c,  and turns in the direction of arrow w. The plastic film  81  has the glued paper tape T pasted thereto and carries the paper tape T in the direction of arrow w. The plastic film  81  separates the pasted paper tape T at the position of the separation roller  83   a.    
     A guide pin  84  which guides the paper tape T along the plastic film  81  is pressed in contact with the outer circumference of the plastic film  81 . A separation guide  84   a  which separates the front edge of the paper tape T from the plastic film  81  is brought close to the outer circumference of the plastic film  81 . 
     The stapling unit  80  has a stopper  85   a  which regulates the stapling position of the sheet bundle B, in a bundle supporting unit  85 . The stapling unit  80  has a holding plate  86  for binding the paper tape T on the sheet bundle B, a tape guide pin  87  which moves up and down at the position of the punch hole H formed in the sheet bundle B, an attachment piece  88 , and a holding roller  89 , above the bundle supporting unit  85 . The holding plate  86  is attached to a press-down member  86   b  which is moved up and down by the rotation of a cam  86   a.  When the tape guide pin  87  is moved down, the paper tape T is pasted to the tape guide pin  87  and a pasting part  87   a  which passes through the punch hole His formed. A stamp  92  which abuts the rear end of the paper tape T to the tape guide pin  87  is brought close to the outer circumference of the plastic film  81 . The stamp  92  is slid by the rotation of a third cam  92   a  and by a third spring  92   b.    
     A restoration spring  97   a  and a holding spring  97   b  act between the press-down member  86   b,  and a fixed bracket  95  and a supporting bracket  96  of the tape guide pin  87 . When the cam  86   a  rotates to press down the press-down member  86   b  to the direction of arrow x, the holding plate  86  is lowered. As the press-down member  86   b  is pressed down to the direction of arrow x, the tape guide pin  87  is lowered by the restoration spring  97   a  and the holding spring  97   b.  The holding roller  89  is lightly energized to the direction of the sheet P by a spring  89   a.  The holding roller  89  moves up and down according to the thickness of plural sheets P. 
     As the stapling starts, the tape supply unit  77  takes out the paper tape T on the tape tray  58  with the tape pickup roller  60  and causes the paper tape T to pass the gluing roller  78   d  so that paper tape T is pasted the glue. The paper tape T is cut to a required length by the tape cutter  61  and supplied to the stapling unit  80 . 
     On the processing tray  18 , the aligned sheet bundle B is slid to the direction of arrow h to a tape winding start position on the bundle supporting unit  76 , and the stapling with the paper tape T is started then. When the sheet bundle B reaches the winding start position, the front edge of the sheet bundle B pushes up the holding roller  89  against the spring  89   a.  As the stapling is started, the plastic film  81  turns in the direction of arrow w. The stapling unit  80  glues a pasted paper tape T on the endless plastic film  81  and carries the paper tape T. The guide pin  84  guides the paper tape T on the plastic film  81 . The paper tape T reaches the separation roller  83   a.  The paper tape T is separated from the plastic film  81  by the separation guide  84   a  provided at the position of the separation roller  83   a.  The front edge of the paper tape T sequentially separated from the plastic film  81  is glued to the attachment piece  88  situated above ( FIG. 15A ). 
     The sheet bundle B further slides to the direction of arrow h to the position where the sheet bundle is abutted against the stopper  85   a.  The punch hole H in the sheet bundle B is situated right below the tape guide pin  87 . The front edge of the paper tape T separates from the attachment piece  88  and adheres to the surface of the sheet bundle B. The cam  86   a  is rotated and the press-down member  86   b  is pressed down to the direction of arrow x. The distal end side of the paper tape T is thus made to adhere to the sheet bundle B by the holding plate  86  ( FIG. 15B ). As the press-down member  86   b  is pressed down to the direction of arrow x, the tape guide pint  87  is pressed down by the restoration spring  97   a  and the holding spring  97   b.  The tape guide pin  87  passes through the punch hole H of the sheet bundle B and falls between the separation roller  83   a  and the rear end of the paper tape T. The third cam  92   a  is rotated and the stamp  92  is slid in the direction of arrow i. The rear end of the paper tape T is thus pressed to contact the tape guide pin  87  ( FIG. 15C ). The third cam  92   a  is rotated and the stamp  92  is moved away from the paper tape T by the third spring  92   b.    
     The cam  86   a  is rotated and the press-down member  86   b  is returned to the direction opposite to arrow x by the restoration spring  97   a.  The holding plate  86  moves away from the sheet bundle B. The tape guide pin  87  rises and moves out of the punch hole H. The rear end of the paper tape T adheres to the pasting part  87   a  and passes through the punch hole H ( FIG. 15D ). 
     The ejector  24  pushes out the sheet bundle B to the direction of arrow j. The rear end of the paper tape T is stripped off the pasting part  87   a.  The rear end of the paper tape T passes the holding roller  89 , and adheres to the sheet bundle B. The stapling unit  80  finishes Bindings of the sheet bundle B with the paper tape T ( FIG. 15E ). The sheet bundle B with the stapling completed with the paper tape T is slid on the processing tray  18  by the bundle pawl  31  interlocked with the turn of the bundle pawl belt  30  and is stacked in the placing tray  13 . 
     According to the second embodiment, compared with the stapling with metal staples, there is no risk of injuring the handler&#39;s hand and user safety is provided. In the case of recycling the sheets P, the need to remove metal staples is eliminated. The paper tape T is produced using the used sheet S which is not reusable, and more effective utilization of the used sheet S is realized. 
     The invention is not limited to the embodiments and various changes and modifications can be made without departing from the scope of the invention. For example, the structure and arrangement position of the binding unit and the tape forming unit are arbitrary. For example, in the second embodiment, the tape forming unit may be changed to a modification  1  shown in  FIG. 16 . In the modification  1 , a lower cutter edge of a tape forming unit  136  is formed as a front-side lower edge  152   a  and a rear-side lower edge  152   b  which are separated at the center. After the paper tape T is formed, the front-side lower edge  152   a  and the rear-side lower edge  152   b  are inclined toward the front side and the rear side, respectively. Tape supply units  177   a  and  177   b  are arranged the front side and the rear side of the lower cutter edges  152 , respectively. The paper tapes T formed by the front-side lower edge  152   a  and the rear-side lower edge  152   b  are accumulated on a front-side tape tray  158   a  and a rear-side tape tray  158   b  respectively. The tape winding position, the tape winding width and so on by the binding unit are not limited, either.