Patent Publication Number: US-6705603-B1

Title: Binding apparatus

Description:
TECHNICAL FIELD 
     The present invention relates to a binding apparatus, and more particularly, it relates to a binding apparatus for binding papers formed with images in and discharged from an image forming apparatus. 
     BACKGROUND TECHNIQUE 
     Binding apparatuses for binding bundles of a plurality of papers discharged from an image forming apparatus such as a copying machine, a printer or a facsimile include an apparatus having a plurality of trays for successively loading bundles of papers to be staled on the trays and stapling the bundles and an apparatus successively storing sheets in a single tray, stapling the sheets and thereafter feeding bundles of the stapled sheets for successively storing the bundles in another tray. 
     Japanese Patent Publication No. 8-9451 (Japanese Patent Laying-Open No. 1-313261) discloses an apparatus discharging papers to extend over two trays, registering and stapling the papers and thereafter extruding bundles of the stapled papers into the upstream tray for successively storing the same. 
     The apparatus having a plurality of trays for successively loading bundles of papers to be stapled in the trays and stapling the bundles is complicated in structure and increased in cost due to the large number of trays, and the number of the bundles of sheets processible by this apparatus is disadvantageously restricted to the number of the trays. 
     The apparatus successively storing sheets in a single tray, stapling the sheets and thereafter feeding bundles of the stapled sheets for successively storing the bundles in another tray requires a mechanism for feeding the bundles of the stapled sheets in addition to the tray for stapling the sheets and the tray for storing the bundles of the sheets, and hence this apparatus is extremely increased in size to require a remarkably high cost. 
     While the apparatus discharging papers to extend over two trays, registering and stapling the papers and thereafter extruding bundles of the stapled papers into the upstream tray for successively storing the same can be relatively miniaturized, a complicated mechanism is required for extruding the bundles of sheets into the upstream tray. 
     The present invention has been proposed in consideration of the aforementioned circumstances, and an object thereof is to provide a miniature binding apparatus which can staple a bundle of papers with a simple structure. 
     DISCLOSURE OF THE INVENTION 
     The binding apparatus according to the present invention comprises first discharge means for discharging a single or plurality of first papers, positioning means for stopping the single or plurality of first papers and a second paper on a specified position and positioning the single or plurality of first papers and the second paper, binding means for binding the single or plurality of first papers and the second paper as positioned, second discharge means located under the first discharge means for discharging the second paper and thereafter pressing the second paper against the positioning means while pressing the single or plurality of first papers discharged by the first discharge means against the positioning means and discharging the single or plurality of first papers and the second paper after the single or plurality of first papers and the second paper are bound by the binding means, and switching means for switching a path for feeding the single or plurality of first papers or the second paper toward either the first discharge means or the second discharge means. 
     In the binding apparatus according to the present invention, the first discharge means discharges a single or plurality of first papers, the positioning means stops the single or plurality of first papers and a second paper on a specified position and positions the single or plurality of first papers and the second paper, the binding means binds the single or plurality of first papers and the second paper as positioned, the second discharge means is located under the first discharge means for discharging the second paper and thereafter pressing the second paper against the positioning means while pressing the single or plurality of first papers discharged by the first discharge means against the positioning means and discharging the single or plurality of first papers and the second paper after the single or plurality of first papers and the second paper are bound by the binding means, and the switching means switches a path for feeding the single or plurality of first papers or the second paper toward either the first discharge means or the second discharge means. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 illustrates the appearance of a binding apparatus  1  according to the present invention. 
     FIG. 2 illustrates the structure of an embodiment of the binding apparatus  1  according to the present invention. 
     FIG. 3 illustrates the structure of discharge rollers  12 . 
     FIG. 4 illustrates operation of the discharge rollers  12 . 
     FIG. 5 illustrates the operation of the discharge rollers  12 . 
     FIG. 6 illustrates the operation of the discharge rollers  12 . 
     FIG. 7 illustrates the operation of the discharge rollers  12 . 
     FIG. 8 illustrates the structure of a shutter  13 . 
     FIG. 9 is a diagram illustrating operation of the shutter  13 . 
     FIG. 10 is a diagram illustrating the operation of the shutter  13 . 
     FIG. 11 is a front elevational view illustrating a mechanism for vertically moving a tray  11 . 
     FIG. 12 is a top plan view illustrating the mechanism for vertically moving the tray  11 . 
     FIG. 13 is a diagram illustrating operation of the binding apparatus  1 . 
     FIG. 14 is a diagram illustrating the operation of the binding apparatus  1 . 
     FIG. 15 is a diagram illustrating the operation of the binding apparatus  1 . 
     FIG. 16 is a diagram illustrating the operation of the binding apparatus  1 . 
     FIG. 17 illustrates the structure of another embodiment of the binding apparatus  1  according to the present invention. 
     FIG. 18 illustrates another structure of the discharge rollers  12 . 
     FIG. 19 illustrates operation of the discharge rollers  12 . 
     FIG. 20 illustrates the operation of the discharge rollers  12 . 
     FIG. 21 illustrates the structure of a discharge mechanism of the binding apparatus  1  discharging a bundle of papers  3  with a hook; 
     FIG. 22 illustrates operation of the discharge mechanism of the binding apparatus  1  discharging the bundle of the papers  3  with the hook; 
     FIG. 23 illustrates the structure of still another embodiment of the binding apparatus  1  according to the present invention. 
     FIG. 24 is a flow chart illustrating processing of the binding apparatus  1  for binding the bundle of the papers  3 . 
    
    
     BEST MODES FOR CARRYING OUT THE INVENTION 
     While embodiments of the present invention are now described, the features of the present invention are described as follows with the corresponding embodiment (only one) in parenthesis succeeding each means, in order to clarify the correspondence between each means of the invention described in the scope of claim for patent and the embodiments described below. However, this description is of course not intended to restrict each means to the described one. 
     The binding apparatus according to the present invention comprises a first discharge unit (for example, discharge rollers  20  shown in FIG. 2) discharging a single or plurality of first papers, a positioner (for example, a shutter  13  shown in FIG. 2) stopping the single or plurality of first papers and a second paper on a specified position and positioning the single or plurality of first papers and the second paper, a binder (for example, a staple  14  shown in FIG. 2) binding the single or plurality of first papers and the second paper as positioned, a second discharge unit (for example, discharge rollers  12  shown in FIG. 2) located under the first discharge unit for discharging the second paper and thereafter pressing the second paper against the positioner while pressing the single or plurality of first papers discharged by the first discharge unit against the positioner and discharging the single or plurality of first papers and the second paper after the single or plurality of first papers and the second paper are bound by the binder, and a switcher (for example, a switching flapper  15  shown in FIG. 2) switching a path for feeding the single or plurality of first papers or the second paper toward either the first discharge unit or the second discharge unit. 
     Referring to FIG. 1, the binding apparatus  1  according to the present invention is mounted on a discharge port of a printing apparatus  2  discharging printed papers  3  for stapling a prescribed bundle of the papers  3 . 
     Referring to FIG. 2, a tray  11  vertically moves in FIG. 2 so that the bundle of the papers  3  stapled by the binding apparatus  1  is loaded thereon. 
     Discharge rollers  12  normally rotate (the upper one of the discharge rollers  12  rotates clockwise in FIG. 2) for discharging a paper  3  shown in FIG. 9 fed through a feed path on the lower side in FIG. 2 from a lower discharge port up to an intermediate portion of the paper  3 , reversely rotate as shown in FIG. 10 (the upper one of the discharge rollers  12  rotates counterclockwise in FIG. 2) after a shutter  13  returns to a specified position for drawing the paper  3  into the binding apparatus  1 , and presses the paper  3  against the shutter  13 . When reversely rotating, the discharge rollers  12  draw a paper  3  discharged from an upper discharge port into the binding apparatus  1  while sliding this paper  3  on the paper  3  held between the discharge rollers  12 , and press the same against the shutter  13  for registering the papers  3 . After a bundle of the papers  3  is stapled, the discharge rollers  12  normally rotate for discharging the bundle of the stapled papers  3  onto the tray  11 . 
     As described later with reference to FIG. 8, the shutter  13  is urged counterclockwise in FIG. 2 about a shaft  53  provided on an upper portion of the shutter  13 , to be pressed against a specified position of the body of the stapler  14  and stop when no paper  3  is fed through the feed path on the lower side in FIG.  2  and passed through the shutter  13 . When the discharge rollers  12  reversely rotate for registering the bundle of the papers  3 , the bundle of the papers  3  is pressed against the shutter  13 . When a paper  3  is fed through the feed path on the lower side in FIG. 2, this paper  3  rotates the shutter  13  about the shaft provided on the upper portion thereof clockwise in FIG. 2 at a prescribed angle against the urging force of a spring (not shown), and is discharged from the lower discharge port. 
     The stapler  14  staples and binds a bundle of a prescribed number of papers  3  pressed against the shutter  13  and registered due to the reverse rotation of the discharge rollers  12 . A switching flapper  15  switches the feed path to feed a paper  3  fed by feed rollers  16  to either feed rollers  17  or feed rollers  18 . The feed rollers  16 , the feed rollers  17 , the feed rollers  18  and feed rollers  19  hold the paper  3  and rotate for feeding the paper  3  to be discharged from the upper discharge port or the lower discharge port. An upper one of discharge rollers  20  rotates clockwise in FIG. 2 for discharging the paper  3  (second or subsequent paper  3  to be stapled) fed by the feed rollers  19  from the upper discharge port. 
     The structure of the discharge rollers  12  is now described with reference to FIG. 3. A roller  31  made of sponge is provided on its surface with projections for adjusting frictional force between the roller  31  and the paper  3  to be capable of holding a warped paper  3 . The roller  31  transmits torque not exceeding a prescribed value to the paper  3  as feeding force. As described later with reference to FIG. 6, the roller  31  is formed to be deformed when rollers  32   a  and  32   b  come into contact with the paper  3 , not to inhibit this contact. The rollers  32   a  and  32   b  (the rollers  32   a  and  32   b  are hereinafter simply referred to as rollers  32  when the same may not be distinctively described independently of each other) are smaller in outer diameter than the roller  31 . 
     When a shaft of a motor  33  rotates, a pulley  34  mounted on the shaft of the motor  33  rotates to transmit the torque of the shaft of the motor  33  to a pulley  36  through a belt  35 . The pulley  36  is fixed to an end of a shaft  37 , while a pulley  38  is fixed to another end of the shaft  37 . The shaft  37  is rotatably fixed to a frame  44  and an arm  42 . Therefore, the torque transmitted to the pulley  36  rotates the pulley  38 . 
     A pulley  40  is fixed to a shaft  41 , which is rotatably mounted on the arm  42  and the frame  44 . The torque transmitted to the pulley  38  is transmitted to the pulley  40  through a belt  39 , to rotate the roller  31  as well as the rollers  32   a  and  32   b  through the shaft  41 . 
     A solenoid  43  rotates the arm  42  about the shaft  37  within a prescribed angle range. 
     Operation of the discharge rollers  12  driven by the solenoid  43  is now described. FIGS. 4 and 5 are diagrams for illustrating the operation of the discharge rollers  12  reversely rotating for registering the bundle of the papers  3 . The solenoid  43  is turned off to free a plunger  43   a . The arm  42  freely rotates about the shaft  37  within the specified angle range so that the surface of the roller  31  comes into contact with the uppermost paper  3 . At this time, the rollers  32  are not in contact with the paper  3 . The roller  31  rotates counterclockwise in FIG. 4, for moving the paper  3  rightward in FIG.  4  and pressing the same against the shutter  13 . After the paper  3  is pressed against the shutter  13 , the rotating roller  31  slides on the paper  3 . 
     FIGS. 6 and 7 are diagrams for illustrating the operation of the discharge rollers  12  normally rotating for discharging the bundle of the stapled papers  3 . The solenoid  43  is turned on to move the plunger  43   a  toward the body of the solenoid  43 . The arm  42  rotates about the shaft  37  clockwise in FIG. 6, so that the surfaces of the rollers  32  come into contact with the uppermost paper  3 . At this time, the roller  31  is so deformed that the rollers  32  can be in contact with the paper  3 . The rollers  32  rotate clockwise in FIG. 6, for moving the bundle of the stapled papers  3  leftward in FIG.  6  and discharging the same. 
     The shutter  13  is now described with reference to FIG. 8. A shutter frame  51  (corresponding to the shutter  13  shown in FIG. 2) rotates about the shaft  53  fixed to the body of the binding apparatus  1 . The shutter frame  51  is urged by a spring  54  to be pressed against part of the body of the stapler  14  and stop on the specified position. A bundle (not shown) of the papers  3  held by a feed guide  52  and pressed against the shutter frame  51  stops on a specified position with respect to the stapler  14  (not shown). 
     FIG. 9 is a diagram for illustrating operation of the shutter  13  carried out when the feed rollers  17  and the discharge rollers  12  discharge the first paper  3  for the bundle of the papers  3  to be stapled from the lower discharge port. The paper  3  fed by the feed rollers  17  rotates the shutter frame  51  about the shaft  53  clockwise in FIG. 9 against the urging force of the spring  54  with the force (feeding force) transmitted from the feed rollers  17 . The paper  3  reaches the discharge rollers  12  while rotating the shutter frame  51 , to be fed by the discharge rollers  12  and discharged from the lower discharge port. 
     FIG. 10 is a diagram for illustrating the operation of the shutter  13  carried out when the bundle of the papers  3  is registered. The shutter frame  51  is urged by the spring  54  to be pressed against part of the body of the stapler  14  and stop on the specified position. The discharge rollers  12  reversely rotate (the roller  31  rotates counterclockwise in FIG. 10) for pressing a paper  3   a  held between the discharge rollers  12  against the shutter  13 . When the discharge rollers  12  reversely rotate to press the paper  3   a  against the shutter  13 , the force applied to the shutter  13  acts in the same direction (for rotating the shutter  13  counterclockwise in FIG. 10) as the urging force of the spring  54 , not to further rotate the shutter  13 . A paper  3   b  discharged from the upper discharge port slides on the paper  3   a  on the tray  11 , and is drawn into the binding apparatus  1  by the discharge rollers  12 , pressed against the shutter  13  and registered with the paper  3   a.    
     FIG. 11 is a front elevational view for illustrating a mechanism for vertically moving the tray  11 . FIG. 12 is a top plan view for illustrating the mechanism for vertically moving the tray  11 . When a shaft of a motor  61  rotates, a pulley  62  fixed to the shaft of the motor  61  rotates for transmitting the torque of the motor  61  to a gear  66  through a belt  63 , a gear  64  and a gear  65 . A pulley  67  is fixed to an end of a shaft  71  along with the gear  66 , while the shaft  71  is rotatably fixed to the binding apparatus  1 . A pulley  69  is rotatably fixed to the binding apparatus  1 . A belt  68  extended along the pulley  67  and the pulley  69  is partially fixed to the tray  11 . A pulley is fixed to another end of the shaft  71 , and a belt  72  is extended along this pulley. The belt  72  is partially fixed to a specified portion of the tray  11 . The tray  11  is fixed to a rail (not shown) to be only vertically movable in FIG.  11 . When the shaft  71  and the pulley  67  rotate due to the rotation of the shaft of the motor  61 , the belt  68  and the belt  72  so rotate that the tray  11  vertically moves in FIG. 11 following the rotation of the belt  68  and the belt  72 . 
     Photoelectric switches  70   a  and  70   b  are shielding type switches, which output prescribed signals when the bundle of the papers  3  intercepts the optical axis connecting the photoelectric switches  70   a  and  70   b . On the basis of these signals, the binding apparatus  1  can vertically move the tray  11  and control the same so that the upper surface of the bundle of the papers  3  loaded on the tray  11  is located on the uppermost position not intercepting the optical axis connecting the photoelectric switches  70   a  and  70   b , i.e., a specified position with respect to the discharge rollers  12 . 
     The operation of the binding apparatus  1  is now described with reference to FIGS. 13 to  16 . When discharging the first paper  3  to be stapled as shown in FIG. 13, the binding apparatus  1  rotates the switching flapper  15  counterclockwise in FIG. 13 for feeding the first paper  3  fed by the feed rollers  16  to the feed rollers  17 . The first paper  3  held between the feed rollers  17  rotates the shutter frame  51  clockwise in FIG. 13, and reaches the discharge rollers  12 . The discharge rollers  12  discharge the first paper  3  to a position enabling the shutter frame  51  of the shutter  13  to return to the original position while partially holding the first paper  3 , and the binding apparatus  1  thereafter reversely rotates the discharge rollers  12  while keeping the solenoid  43  off as shown in FIG. 4, for pressing the held paper  3  against the shutter frame  51  of the shutter  13  returning to the original position. After the paper  3  is pressed against the shutter frame  51 , the rotating roller  31  of the discharge rollers  12  slides on the paper  3 , so that the paper  3  stops on the position where the same is pressed against the shutter frame  51 . 
     Then, the binding apparatus  1  rotates the switching flapper  15  clockwise in FIGS. 14 and 15 for feeding a second or subsequent paper  3   b  with the feed rollers  16 , the feed rollers  18 , the feed rollers  19  and the discharge rollers  20 , discharging the paper  3   b  from the upper discharge port and loading the same on the paper  3   a  on the tray  11 , as shown in FIGS. 14 and 15. The paper  3   b  loaded on the paper  3   a  slides on the paper  3   a , and is moved rightward in FIGS. 14 and 15, drawn into the binding apparatus  1  again and pressed against the shutter frame  51  of the shutter  13  by the reversely rotating discharge rollers  12 . After the paper  3   b  is pressed against the shutter frame  51 , the rotating roller  31  of the discharge rollers  12  slides on the paper  3   b  similarly to the case shown in FIG. 13, so that the paper  3   b  stops on the position where the same is pressed against the shutter frame  51  and is registered with the paper  3   a.    
     When the registered papers  3  reach a prescribed number, the binding apparatus  1  staples the bundle of the papers  3  with the stapler  14 . Thereafter the binding apparatus  1  turns on the solenoid  43 , presses the rollers  32  against the papers  3  and normally rotates the discharge rollers  12  as shown in FIG. 6, for discharging the bundle of the stapled papers  3  onto the tray  1  as shown in FIG.  16 . The binding apparatus  1  moves the tray  11  downward in FIG. 16 so that the bundle of the papers  3  discharged onto the tray  11  does not intercept the optical axis between the photoelectric switches  70 . The upper surface of the bundle of the papers  3  discharged onto the tray  11  moves down to a specified position with respect to the discharge rollers  12 , so that a next paper is discharged from the lower discharge port with no interception by the bundle of the papers  3  loaded on the tray  11 . 
     As hereinabove described, the binding apparatus  1  staples the bundle of the papers  3  and discharges the same onto the tray  11 . 
     FIG. 17 illustrates another embodiment of the binding apparatus  1 . Parts similar to those shown in FIG. 2 are denoted by the same reference numerals, and redundant description is not repeated. A switching flapper  81  is located between feed rollers  19  and discharge rollers  20 . When the switching flapper  81  rotates counterclockwise in FIG. 17, a paper  3   a  fed by the feed rollers  19  is fed to discharge rollers  12  without passing through a shutter  82 . The shutter  82  remains unrotating. When the switching flapper  81  rotates clockwise in FIG. 17, a paper  3   b  fed by the feed rollers  19  is fed to the discharge rollers  20 . 
     According to the structure shown in FIG. 17, the feed rollers  17  can be omitted and the shutter  82  may not be formed to rotate so that the binding apparatus  1  can be more simplified in structure as compared with that shown in FIG.  2 . 
     FIG. 18 is a bottom plan view of discharge rollers  12  more improved in force for registering papers  3 , and FIG. 19 is a side elevational view of the discharge rollers  12 . Parts similar to those shown in FIG. 3 are denoted by the same reference numerals, and redundant description is not repeated. Each of rollers  91   a  and  91   b  is provided with four paddles and fixed to a shaft  92 , as shown in FIGS. 18 and 19. The shaft  92  is rotatably fixed to an arm  96 . The torque of a shaft  41  is transmitted to the shaft  92  through a pulley  93  fixed to the shaft  41 , a belt  94  and a pulley  95 . Therefore, the rollers  91   a  and  91   b  rotate in the same direction as a roller  31 . 
     The rollers  91   a  and  91   b  having the puddles can reliably draw a paper  3  into the binding apparatus  1  also when the paper  3  is warped, as shown in FIG.  19 . 
     FIG. 20 is a perspective view of the discharge rollers  12  more improved in the force for registering the papers  3 . Ends of the paper  3  drawn by the rollers  91   a  and  91   b  are pressed downward in FIG. 20, so that the paper  3  is reliably held by the roller  31  and registered with other papers  3 . 
     Therefore, the binding apparatus  1  having the discharge rollers  12  shown in FIGS. 18 and 19 more reliably registers the papers  3 . 
     FIG. 21 illustrates the structure of a discharge mechanism of the binding apparatus  1  for discharging a bundle of papers  3  as stapled with a hook. FIG. 22 illustrates a state in an intermediate stage of the discharge operation of the binding apparatus  1  discharging the bundle of the papers  3  with the hook. Discharge rollers  12  of the binding apparatus  1  shown in FIG. 21, having a roller  31  of sponge and rollers  91  provided with paddles, has neither rollers  32  of rubber nor a mechanism such as the solenoid  43  pressing the rollers  32  against papers. 
     When the binding apparatus  1  rotates the roller  31  of sponge and the rollers  91  provided with paddles for registering the bundle of the papers  3 , the hook  101  is located rightward beyond the shutter  13  as shown in FIG. 21, and not in contact with the bundle of the registered papers  3 . After the bundle of the registered papers  3  is stapled, a shaft of a motor  102  rotates clockwise, as shown in FIG.  22 . Following the rotation of the shaft o the motor  102 , the hook  101  moves leftward in FIG. 22 for pressing an end of the bundle of the papers  3  and discharging the bundle of the papers  3 . After the bundle of the papers  3  is discharged onto the tray  11 , the shaft of the motor  102  is rotated counterclockwise in FIG. 22, for returning the hook  101  to the position shown in FIG.  21 . 
     Thus, the binding apparatus  1  shown in FIGS. 21 and 22 more reliably discharges the bundle of the papers  3 . 
     FIG. 23 is a diagram for illustrating a structure of the binding apparatus  1  having a punching mechanism. Parts similar to those shown in FIG. 2 are denoted by the same reference numerals, and redundant description is not repeated. A punch unit  111  is fixed to a position not hindering the operation of the shutter  13  and the stapler  14 , for punching specified positions of a bundle of stapled or only registered papers  3  in a prescribed case. When the punch unit  111  punches the bundle of only registered papers  3 , the binding apparatus  1  discharges the bundle of the papers  3  through the discharge mechanism shown in FIGS. 21 and 22. 
     Processing of the binding apparatus  1  for binding the bundle of the papers  3  is now described with reference to a flow chart shown in FIG.  24 . At a step S 11 , the binding apparatus  1  rotates the switching flapper  15  counterclockwise in FIG. 2, for switching the path for feeding the paper  3  to that leading to the lower discharge port. At a step S 12 , the discharge rollers  17  of the binding apparatus  1  feed the paper  3  until the paper  3  rotates the shutter  13  clockwise in FIG.  2  and thereafter reaches the discharge rollers  12 . The discharge rollers  12  feed the paper  3  leftward in FIG. 2 until an end of the paper  3  separates from the shutter  13  and the shutter  13  rotates counterclockwise and returns to the original position (the position shown in FIG. 2) due to the urging force of the spring  54 . At a step S 13 , the binding apparatus  1  reversely rotates the discharge rollers  12  while keeping the solenoid  43  off, for pressing the paper  13  against the shutter  13 . 
     At a step S 14 , the binding apparatus  1  rotates the switching flapper clockwise in FIG. 2, for switching the path for feeding the paper  3  to that leading to the upper discharge port. The step S 14  may be carried out in advance of the step S 13 . At a step S 15 , the binding apparatus  1  rotates the feed rollers  18 , the feed rollers  19  and the discharge rollers  20 , for discharging the next paper  3  from the upper discharge port. The paper  3  discharged from the upper discharge port is drawn by the reversely rotating discharge rollers  12  while sliding on the paper  3  already loaded on the tray  11 , to be pressed against the shutter  13  and registered with the paper  3  already loaded on the tray  11 . 
     At a step S 16 , the binding apparatus  1  determines whether or not the discharged papers  3  have reached a prescribed number, to return to the step S 15  and continuously discharge the paper  3  when determining that the discharge papers  3  have not yet reached the prescribed number. 
     When the binding apparatus  1  determines that the discharged papers  3  have reached the prescribed number at the step S 16 , the process advances to a step S 17  so that the stapler  14  of the binding apparatus  1  staples the bundle of the registered papers  3 . At a step S 18 , the binding apparatus  1  normally rotates the discharge rollers  12 . At a step S 19 , the binding apparatus  1  turns on the solenoid  43  for pressing the rollers  32  against the bundle of the papers  3  as shown in FIG. 6, and discharging the bundle of the papers  3 . At a step S 20 , the binding apparatus  1  discharges the bundle of the papers  3  onto the tray  11 , thereafter turns off the solenoid  43 , moves up the rollers  32  as shown in FIG. 4, and stops rotating the discharge rollers  12 . At a step S 21 , the binding apparatus  1  moves down the tray  11  to the position where the bundle of the papers  3  loaded on the tray  11  does not intercept the optical axis between the photoelectric switches  70 , and terminates the processing. 
     As hereinabove described, the binding apparatus  1  binds the bundle of the prescribed number of papers  3  and loads the bundle of the papers  3  on the tray  11 . 
     INDUSTRIAL AVAILABILITY 
     the binding apparatus according to the present invention, which can staple a bundle of papers with a simple structure and a small size, is suitably applied to a stapling apparatus serving as a post-processor for various types of papers.