JP2007168967A - Paper post-processing apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a paper post-processing apparatus capable of reducing stacking collapse or the like when discharging stapled papers. <P>SOLUTION: The paper post-processing apparatus comprises an alignment means including a pair of alignment plates for aligning a plurality of papers conveyed from an image forming device from both sides along the conveying direction, and capable of moving the pair of alignment plates to the regular alignment position and to the position deviated by the predetermined distance in the direction orthogonal to the paper conveying direction from the regular alignment position, a staple means including a stapler movable along edges in the conveying direction of the plurality of aligned papers, and capable of stapling the conveyed papers at the regular alignment position, and a discharging means for alternately deviating the stapled paper bundles in the direction orthogonal to the conveying direction by the pair of alignment plates, and guiding the paper bundles to a paper discharge tray. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a paper post-processing apparatus that performs post-processing of paper discharged from an image forming apparatus such as a copying machine, a printer, or a multifunction peripheral.

  In recent years, in an image forming apparatus, in order to sort sheets after image formation, or to perform sheet post-processing such as stapling, a sheet post-processing apparatus is adjacent to a paper discharge unit of the image forming apparatus main body. There is something that was provided. For example, in a sheet post-processing apparatus that performs stapling processing, a plurality of sheets (sheet bundles) are aligned by an aligning unit and subjected to stapling, and are carried out to a discharge tray and sequentially stacked on the discharge tray. .

  As a staple processing structure, there is an example described in Patent Document 1, for example. In Patent Document 1, a binding unit that binds the recording paper discharged from the image forming apparatus, a moving unit that moves the binding unit along a plurality of binding positions of the recording paper, and a final binding position of the current recording paper is the next recording. Position control means for controlling the position of the moving means so as to be the start binding position of the paper.

In this Patent Document 1, it is possible to reduce the moving distance and moving time of the binding means, but when the stapled recording sheets are discharged sequentially, the binding positions overlap and are discharged. In this case, the recording paper is swelled when stacked, and it is necessary to limit the number of stacked sheets. Further, there is a drawback in that when a subsequent sheet bundle that has been stapled is discharged, the sheet bundle that has already been discharged onto the tray is pushed out.
Japanese Patent No. 2879969

  Some conventional paper post-processing devices are capable of stapling. However, when recording paper is discharged and stacked on the paper output tray, the number of stacked sheets is limited or stapled when the recording paper is stacked. In addition, there is a drawback that the sheet bundle on the paper discharge tray is pushed out and collapsed by the subsequent sheet bundle.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a sheet post-processing apparatus in which stacking collapse or the like when discharging stapled sheets is reduced.

  The present invention according to claim 1 is a post-processing device for aligning a plurality of sheets conveyed from the image forming apparatus and performing a stapling process to discharge the plurality of sheets conveyed from the image forming apparatus. A stackable processing tray; and a pair of alignment plates for aligning a plurality of sheets placed on the processing tray from both sides along the transport direction, the pair of alignment plates being a normal alignment position, and An aligning means capable of moving from a regular aligning position to a position shifted by a predetermined distance in a direction orthogonal to the transport direction; a stapler movable along edges in the transport direction of a plurality of sheets aligned by the aligning means; Stapling means for performing stapling on a plurality of sheets respectively conveyed at the regular alignment position; and the stapling sheet bundle by the alignment means And a discharge unit that guides the sheet bundle to the discharge tray while being alternately shifted in a direction perpendicular to the transport direction, and discharges the staples of the stack of sheets stacked on the discharge tray so that they are shifted from each other in the upper and lower stages. Characterized by

  According to the present invention, it is possible to reduce a stacking collapse or the like when a stapled sheet is discharged, and it is possible to provide a convenient sheet post-processing apparatus.

  Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. In the drawings, the same portions are denoted by the same reference numerals, and redundant description is omitted.

  FIG. 1 is a perspective view showing a main part of a paper post-processing apparatus according to an embodiment of the present invention, FIG. 2 is a top view of the main part of the paper post-processing apparatus according to an embodiment of the present invention, and FIG. It is a figure explaining the schematic structure of the paper post-processing apparatus which concerns on one Embodiment. 4 to 11 are diagrams illustrating the configuration of each unit of the sheet post-processing apparatus.

  The specific configuration and operation of each part in FIGS. 1 and 2 will be clarified sequentially in the description of the drawings from FIG. 4 onward. First, the paper processing in the paper post-processing apparatus of the present invention will be described with reference mainly to FIG. It explains using.

  The paper P on which an image is formed by the image forming apparatus 5 such as a copying machine is discharged from a pair of paper discharge rollers 6 and conveyed to the paper post-processing device 7. As shown in FIG. 3, the sheet post-processing device 7 includes a standby tray 10, a processing tray 12, a stapler 14, a first discharge tray 16, a second discharge tray 18, a fixed tray 19, a gate G, and the like. is doing.

  The paper P discharged from the pair of paper discharge rollers 6 of the image forming apparatus 5 is received by a pair of entrance rollers 22 provided near the carry-in entrance of the paper post-processing device 7. The entrance roller 22 includes an upper roller and a lower roller. The entrance roller 22 is driven by an entrance roller motor 26 (FIG. 1).

  A gate G is provided on the downstream side of the entrance roller 22 to branch the paper P received by the entrance roller 22 into two paths (flows). The gate G has a wedge-shaped cross section, and the wedge-shaped pointed portion faces the vicinity of the rolling surface of the entrance roller 22. The gate G is pivotally supported by a side wall portion in the sheet post-processing device 7 so as to be rotatable. The wedge-shaped pointed portion takes a first position indicating the upper roller of the entrance roller 22 and a second position indicating the lower roller.

  That is, the first position is a case where a path when post-processing is required for the paper P is selected, and the second position is a path when post-processing is not required for the paper P. To choose.

  When the gate G is in the first position, the paper P is supplied to the first paper feed roller 24 and sent from the first paper feed roller 24 to the standby tray 10. A paper path ceiling 36 (FIG. 1) that guides the paper P to the first paper feed roller 24 is provided between the entrance roller 22 and the standby tray 10. The first paper feed roller 24 includes an upper paper feed roller and a lower paper feed roller.

  Below the standby tray 10 is disposed a processing tray 12 on which the sheets P dropped from the standby tray 10 are stacked. The processing tray 12 aligns and supports the stacked paper P while the paper P is stapled by the stapler 14 which is a processing mechanism that performs post-processing.

  When a predetermined number of sheets are accumulated in the standby tray 10, the tray members 10a and 10b are opened in the directions of the arrows n and m by the standby tray motor 34 (FIG. 1), as shown in FIG. As a result, it drops onto the processing tray 12 and is supplied to the stapler 14.

  As shown in FIG. 4, the stapler 14 is positioned by sliding in the u direction by the staple driving unit 49 and performs a stapling process. Although only one stapler 14 is formed, FIG. 4 shows a state before and after sliding. The position processing tray 12 aligns a plurality of sheets P dropped and supplied from the standby tray 10 in the vertical direction, which is the transport direction, so as to align with a pair of upper and lower upper and lower alignment rollers 38a shown in FIGS. And a roller 38b.

  The vertical and vertical alignment rollers 38a and 38b also serve as a bundle conveying roller that sandwiches the sheet bundle T after completion of the stapling process and picks it up from the stapler 14. The upper vertical alignment roller 38a is driven by a vertical alignment upper roller motor 40, and the lower vertical alignment roller 38b is driven by a vertical alignment lower roller motor 42.

  A rotatable paddle for aligning the uppermost sheet P placed on the processing tray 12 in the vertical direction is located at the position where the trailing edge of the sheet P drops when the sheet P is dropped and supplied to the processing tray 12. 44 is arranged.

  As shown in FIG. 6, the paddle 44 aligns the receiving portion 44 a of the paper P that is dropped and supplied onto the processing tray 12, the punching portion 44 b that scrapes off the paper P on the processing tray 12, and the paper P on the processing tray 12. It has a feed portion 44 c and is driven by a paddle motor 46. The paddle 44 is made of a rubber material and has elasticity.

  A stopper 45 is provided at the end of the processing tray 12 on the side of the stapler 14 to abut the rear end of the paper P and regulate the rear end position. Near the center of the processing tray 12, there is a conveying belt 50 that carries the stapled and the sheet bundle T taken out from the stapler 14 by the vertical and vertical alignment rollers 38a and 38b to the first or second discharge trays 16 and 18. Provided. A feed claw 50 a that hooks the rear end of the sheet bundle T is attached to the transport belt 50.

  The standby tray 10 can drop-feed the paper P to the processing tray 12, and can also be used to transport the paper P in the direction of the first or second paper discharge tray 16, 18. The conveyance of the paper P in the 16 and 18 directions is performed by bringing the standby tray roller 28 for aligning the paper P into contact with the paper P on the standby tray 10. The standby tray roller 28 is controlled to move up and down by a standby tray roller drive source 30 and is driven to rotate by a standby tray roller motor 32 (FIG. 2).

  As shown in FIG. 3, the standby tray 10 is disposed at an inclination angle θ1 in order to support the paper P in a state where the leading edge of the paper P is higher than the rear end. The first or second paper discharge tray 16 or 18 is raised or lowered by the paper discharge tray driving unit 52 to select one of them. The first or second paper discharge trays 16 and 18 are raised and lowered to substantially the same height as the standby tray 10 or the processing tray 12 when the paper P is stacked to improve the consistency of the paper P to be discharged. The first or second paper discharge trays 16 and 18 are arranged at an inclination angle θ2 to support the paper P with the leading edge of the paper P being higher than the trailing edge.

  As shown in FIGS. 7 and 8, the standby tray 10 includes a pair of tray members 10 a and 10 b formed so as to protrude from the wall surface, and receives a sheet while sliding to the width of the sheet P, and both sides of the sheet P. Support. The tray members 10a and 10b are provided with standby stoppers 10c and 10d for regulating the rear end of the paper P.

  The standby tray 10 is slid by a standby tray motor 34 (FIG. 2). During the period from the standby tray 10 to the processing tray 12, when the paper P on the standby tray 10 is dropped and supplied to the processing tray 12, the paper P is prevented from being disturbed in the lateral direction perpendicular to the transport direction. Therefore, lateral alignment plates 47a and 47b are provided as shown in FIG. The lateral alignment plates 47a and 47b can be slid in the v direction so as to match the width of the paper P by the lateral alignment motor 48, and the alignment position can be changed.

  As shown in FIG. 3, when the gate G is in the second position, the paper P that does not require post-processing is supplied to the second paper supply roller 60 and further supplied to the third paper supply roller 61. The second paper feed roller 60 and the third paper feed roller 61 are each composed of an upper paper feed roller and a lower paper feed roller. The paper P conveyed from the third paper feed roller 61 is sent to the fixed tray 19 provided on the upper surface of the paper post-processing device 7.

  The motors 26, 34, 40, 42, 46, 48 and the drive units 49, 52 that drive the various mechanisms described above are driven and controlled by a control circuit (not shown).

  Next, the operation of the sheet post-processing device 7 will be described along the sheet flow. When an image is formed by the image forming apparatus 5 and the paper P is supplied from the paper discharge roller 6, the paper post-processing device 7 performs (1) post-processing of the paper P when (1) post-processing of the paper P is not performed. If the preceding paper P has finished post-processing, (3) the post-processing of the paper P, and the preceding paper P is executing post-processing, the operation differs depending on I do.

  First, when the post-processing of (1) is not performed, the wedge-shaped pointed portion of the gate G is substantially at the second position indicating the lower entrance roller 22b. The paper P supplied from the entrance roller 22 is supplied to the second paper supply roller 60 and further supplied to the third paper supply roller 61. The paper P fed out from the third paper feed roller is discharged to the fixed tray 19 on the upper surface.

  Next, a case where (2) post-processing (staple processing) is performed and there is no preceding paper P on the processing tray 12 will be described. At this time, the standby tray 10 slides and moves the tray members 10a and 10b to the positions indicated by the dotted lines in FIG. The horizontal alignment plates 47a and 47b are arranged so that the width between the horizontal alignment plates 47a and 47b is substantially the same as the width of the paper P in order to align the horizontal direction of the paper P dropped from the paper feed roller 24. Thereby, the paper P fed by the paper feed roller 24 is dropped and supplied directly onto the processing tray 12 without being interrupted by the standby tray 10.

  At the time of dropping, the upper vertical alignment roller 38a is retracted upward, and the receiving portion 44a of the paddle 44 receives the rear end of the paper P. Both sides of the paper P fall while contacting the horizontal alignment plates 47a and 47b, and are aligned in the horizontal direction. Next, the paddle 44 rotates in the direction of the arrow o in FIG. 6 to drop the trailing edge of the paper P from the receiving portion 44a, and then knocks it onto the processing tray 12 by the knocking portion 44b.

  Further, the paddle 44 feeds the paper P in the direction of the arrow q by the feeding portion 44c, and the rear end of the paper P is brought into contact with the stopper 45 to complete the vertical alignment of the paper P. The vertical alignment of the paper P on the processing tray 12 may be performed by the upper vertical alignment roller 38a by moving the upper vertical alignment roller 38a up and down each time.

  In this way, the image-formed sheets P are stacked directly on the processing tray 12 from the sheet feed roller 24 while sequentially aligning in the horizontal and vertical directions. When the number of sheets P reaches a predetermined number, the stapler 14 staples the sheets P on the processing tray 12 at a desired position to form a bundle of sheets T. After that, as shown in FIG. 6, the sheet bundle T is sandwiched between the upper vertical alignment roller 38a rotating in the direction of the arrow r and the lower vertical alignment roller 38b rotating in the direction of the arrow s, and then bundled in the direction of the first paper discharge tray 16. Transport.

  When the rear end of the sheet bundle T passes through the vertical and vertical alignment rollers 38a and 38b, it is hooked on the feeding claw 50a of the conveying belt 50 rotated in the direction of arrow t in FIG. Is done.

  Further, the first discharge tray 16 is arranged so that the inclination angle is θ2, and the leading end of the sheet is higher than the trailing end, so that the first discharge tray 16 is bundled on the first discharge tray 16 in advance. The paper P is not pushed out by contact with the tip of the subsequent paper bundle T. Even if the preceding sheet bundle T is slightly misaligned by the succeeding sheet P, the sheet bundle T falls by its own weight on the first paper discharge tray 16 because of the inclination angle θ2. The stapling process of the paper P stacked in a state where the rear ends are aligned is completed.

  In this way, the sheets are sequentially stacked on the first paper discharge tray 16. The first discharge tray 16 is arranged so that the inclination angle is θ2, and the leading end of the sheet is higher than the trailing end. For example, the first discharge tray 16 is in a state where the sheet P is curled in a mountain. Even if the paper is discharged onto the tray 16, the paper P placed on the first paper discharge tray 16 in advance is not pushed out by contact with the leading edge of the subsequent paper P. That is, the discharged paper P is sequentially placed on the first paper discharge tray 16 without being out of order.

  Next, a case in which the stapling process (3) is performed and the sheet P on which the stapling process is being executed prior to the processing tray 12 remains will be described. At this time, in the standby tray 10, the tray members 10 a and 10 b slide from the position indicated by the dotted line in FIG. 11 in the direction opposite to the arrow m direction or the direction opposite to the arrow n direction, respectively. The paper P can be supported at the position shown. The standby tray roller 28 is retracted above the standby tray 10 so as not to interfere with the paper P. The paper P discharged from the image forming apparatus 5 and supplied by the paper supply roller 24 is temporarily placed on the standby tray 10 in order to wait for the processing tray 12 to become empty.

  The paper P placed on the standby tray 10 descends onto the standby tray 10 and is sent in the standby stoppers 10c and 10d directions by the standby tray roller 28 rotated in the direction opposite to the arrow f direction in FIG. The end is brought into contact with the standby stoppers 10c and 10d to be vertically aligned. Further, since the standby tray 10 is arranged so that the inclination angle is θ1, and the leading edge of the sheet is higher than the trailing edge, the sheet P is vertically contacted by the dead weight with the waiting stoppers 10c and 10d by its own weight. Align.

  The supplied sheets P are sequentially placed on the standby tray 10 without being out of order. Even if the preceding paper P is pushed by the succeeding paper P and is slightly misaligned, there is an inclination angle θ1, so that the paper P reaches the position where the trailing edge comes into contact with the standby stoppers 10c and 10d by its own weight. It is dropped and loaded in alignment with the rear end aligned on the standby tray 10.

  During this time, when the preceding paper P on the processing tray 12 is discharged to the first paper discharge tray 16 side and the processing tray 12 becomes empty, the standby tray 10 positions the tray members 10a and 10b as indicated by solid lines in FIG. 11 to the position indicated by the dotted line in FIG. 11 through the position indicated by the one-dot chain line in FIG. 11, respectively, in the direction of arrow m or arrow n.

  As a result, for example, two sheets of paper P that have been waiting on the standby tray 10 are placed on the processing tray 12 from between the tray members 10a and 10b when the tray members 10a and 10b reach the position indicated by the one-dot chain line in FIG. Drop supplied. At this time, the interval between the lateral alignment plates 47a and 47b is arranged to be substantially the same width as the paper P. Accordingly, the sheet P dropped from the standby tray 10 is regulated in the lateral direction by being regulated by the lateral alignment plates 47a and 47b on both sides.

  The lower sheet P of the two sheets P dropped on the processing tray 12 is sent in the arrow q direction by the lower vertical alignment roller 38b rotated in the direction opposite to the arrow s direction in FIG. The end is brought into contact with the stopper 45 to complete the vertical alignment of the paper P. The upper sheet P of the two sheets P dropped on the processing tray 12 is sent in the direction of the arrow q by the upper vertical alignment roller 38a rotated in the direction opposite to the direction of the arrow r, and the trailing end of the sheet P is stopped at the stopper 45. The vertical alignment of the paper P is completed, and then the upper vertical alignment roller 38a is retracted upward.

  The third and subsequent sheets P ejected from the image forming apparatus 5 are directly dropped onto the processing tray 12 from between the tray members 10a and 10b without waiting on the standby tray 10. Thereafter, the third and subsequent sheets P are sequentially aligned on the sheet P loaded on the processing tray 12 by the paddle 44 first.

  When the number of sheets P stacked on the processing tray 12 reaches a predetermined number, the stapler 14 performs a stapling process to form a sheet bundle T. Thereafter, the sheet bundle T is conveyed in the direction of the first sheet discharge tray 16 by the vertical and vertical alignment rollers 38a and 38b, and the rear end of the sheet bundle T is hooked on the feed claw 50a of the conveyance belt 50. Bundled up, the stapling process for the paper P is completed.

  The above is a description of the overall operation of the sheet post-processing apparatus 7. Next, the configuration of the stapling processing unit and the lateral alignment processing unit, which are features of the present invention, will be described.

  In general, the stapling process may be performed when binding a corner portion of a sheet, or when binding a plurality of locations (for example, two locations) along the edge of the sheet. When the sheet bundle is discharged, the sheet bundle T is stacked on the sheet discharge tray 16 as shown in FIG. 12 and the stapling position ST overlaps, so that the subsequent sheet bundle T is discharged. The sheet bundle T that has already been discharged onto the tray 16 may be pushed out and collapse.

  The sheet post-processing apparatus according to the present invention is characterized in that the rising due to the overlapping of the stapling positions is reduced to prevent the stack of sheets from being stacked.

  FIG. 13 is a diagram for explaining the movement of the stapler 14. As shown in FIG. 4, the stapler 14 can be slid in the u direction by the staple driving unit 49. When binding the corner portion of the paper P, the stapler 14 is moved to the position indicated by the solid line or the alternate long and short dash line in FIG. I do. Further, when binding a plurality of locations (for example, two locations) along the edge of the paper P, the staple ST is performed by moving to a position indicated by a dotted line in FIG.

  FIG. 14 is a diagram for explaining how to perform the stapling process according to the present invention, showing a case where two places along the edge of the sheet P are bound, and the movement of the stapler 14 and the lateral alignment plates 47a and 47b. Is.

  FIG. 14A shows a state in which the paper P is aligned at the normal alignment position by the horizontal alignment plates 47a and 47b. The lateral alignment plates 47a and 47b are movable in a first direction (A1 direction) orthogonal to the paper transport direction and in a direction opposite to the first direction (A2 direction), and the lateral alignment plate 47a moves to a position b1. The specified position is set, and the horizontal alignment plate 47b sets the position b2 to the specified position. When in the normal alignment position, the horizontal alignment plates 47a and 47b move from the positions b1 and b2 to the positions indicated by c1 and c2, and the paper P is aligned in the width direction from both sides along the transport direction.

  On the other hand, the stapler 14 is slid in the A1 direction along the edge of the paper P by the staple driving unit 49, stops at the first staple position a1, and performs stapling processing. Next, the stapler 14 is slid along the edge of the paper P by the distance L1 in the direction A1, stops at the second staple position a2, and performs stapling. In this way, the stapler 14 stops at a plurality of positions in the moving process and performs a stapling process.

  When the stapling process at the first and second stapling positions is completed, as shown in FIG. 14B, the lateral alignment plates 47a and 47b move in the A2 direction by a predetermined distance L2, and the lateral alignment plate 47a is positioned at the position d2. The horizontal alignment plate 47b moves to the specified position b1. Thus, the stapled first sheet bundle T is conveyed to a position shifted in the A2 direction by a distance L2 from the normal alignment position, and is carried out to the sheet discharge tray 16 (or 18) by the conveying belt 50. Note that an interval L1 between the first stapling position a1 and the second stapling position a2 is about 120 mm, and ST indicates a state in which stapling is performed.

  When the first sheet bundle T thus stapled is discharged, the lateral alignment plates 47a and 47b are moved again to the normal alignment positions c1 and c2 as shown in FIG. The incoming paper P is aligned in the width direction by the lateral alignment plates 47a and 47b after movement, and aligned at this alignment position.

  The stapler 14 is at the second stapler position a2, and performs the staple process at the staple position a2. Next, the stapler 14 moves by a distance L1 along the edge of the paper P in the A2 direction, stops at the first stapling position a1, and performs stapling processing. In this way, the stapler 14 stops at a plurality of positions even in the reverse movement process and performs the stapling process.

  When the stapling process is thus completed, as shown in FIG. 14D, the lateral alignment plates 47a and 47b move in the A1 direction by a predetermined distance L2, the lateral alignment plate 47a moves to the specified position b2, and the lateral alignment plate 47b. Moves to e1. Thus, the stapled second sheet bundle T is transported to a position shifted in the A1 direction by a distance L2 from the normal alignment position, and is transported to the sheet discharge tray 16 (or 18) by the transport belt 50. Then, the following steps (a) to (d) are repeated to sequentially perform stapling.

  In the movement of the stapler 14 described above, the distance L1 between the first staple position and the second staple position is determined by the sheet binding interval, but the lateral alignment plates 47a and 47b move in a direction away from the normal alignment position. The distance L2 may be moved by a distance that does not overlap the staple ST of the stapled first sheet bundle and the second sheet bundle, for example, a distance shifted by about 15 mm. By setting the movement distance L2 within, for example, L1 / 2, the movement distances of the lateral alignment plates 47a and 47b can be reduced.

  In this manner, the stapler 14 can be stapled in the process of reciprocating from the position a1 to a2 and from the position a2 to a1 at the regular alignment position, and the moving distance of the stapler 14 can be minimized. . Therefore, the time required for moving the stapler 14 can be reduced, and high-speed processing can be performed. Further, after the stapling process, the sheet bundle is alternately shifted in the A1 direction and the A2 direction by the lateral alignment plates 47a and 47b and carried out.

  In the example of FIG. 14, the positions of the lateral alignment plates 47a and 47b are movable in the A1 and A2 directions with the regular alignment position as the center. However, the lateral alignment plates 47a and 47b are moved in any one of the A1 and A2 directions. You may make it let it.

  That is, after the sheet bundle subjected to the stapling process in FIG. 14A is carried out as it is and the next conveyed sheet is stapled at the regular alignment position, the positions of the lateral alignment plates 47a and 47b are set. The sheet moves in one direction of A1 and A2, and is unloaded with respect to the previously unloaded sheet bundle. In this case, it is necessary to make the amount of movement in one direction longer than the distance L2, but the stapling position of the conveyed sheet bundle can be shifted alternately.

  FIG. 15 shows a state in which the stapled paper bundle T is sequentially discharged to the paper discharge tray 16. FIG. 15A shows the stapling position ST of the paper bundle T being alternately shifted between the upper stage and the lower stage. FIG. 4B shows how the staple position ST of the sheet bundle T is overlapped. As shown in FIG. 5B, the height H1 of the overlapping portion is reduced by the stapling position being alternately shifted. Therefore, even if the sheet bundle T is stacked on the paper discharge tray 16, the swell can be reduced. Further, even when the subsequent sheet bundle T is discharged, the phenomenon that the sheet bundle T already discharged onto the tray 16 is pushed out can be reduced.

  FIG. 15C shows the overlapping state of the sheet bundle T by the conventional stapling process. In this case, since the stapling positions are all the same, the height H2 of the overlapping portion is increased (H2> H1), leading to the collapse of the sheet bundle.

  As described above, according to the embodiment of the present invention, it is possible to prevent the paper from collapsing or pushing when the paper discharged after the stapling process is stacked on the paper discharge tray 16 (or 18). Therefore, a sheet post-processing apparatus that is convenient for the user without lowering the efficiency of the image forming apparatus can be obtained.

    The present invention is not limited to the above description, and various modifications can be made without departing from the scope of the claims. For example, the stapler 14 has been described as performing the stapling process at two locations in the moving process, but the stapler 14 can also perform the stapling process at three locations.

FIG. 3 is a perspective view illustrating a main part of the sheet post-processing apparatus according to the embodiment of the present invention. FIG. 3 is a top view showing a main part of the sheet post-processing apparatus according to the embodiment. The schematic block diagram which shows the paper post-processing apparatus which concerns on the same embodiment. FIG. 3 is a perspective view showing a stapler of the sheet post-processing apparatus according to the embodiment. The perspective view which shows the vertical alignment roller of the paper post-processing apparatus which concerns on the same embodiment. Explanatory drawing which shows the paddle of the paper post-processing apparatus which concerns on the embodiment. FIG. 3 is a schematic perspective view illustrating a standby tray and a processing tray of the sheet post-processing apparatus according to the embodiment. FIG. 3 is a top view showing a standby tray and a processing tray of the sheet post-processing apparatus according to the embodiment. FIG. 3 is a schematic perspective view illustrating a lateral alignment plate and a conveyance belt of the sheet post-processing apparatus according to the embodiment. FIG. 4 is an explanatory diagram illustrating a state where a sheet on a standby tray or a sheet discharge tray of the sheet post-processing apparatus according to the embodiment is pushed out. FIG. 3 is an explanatory diagram illustrating movement of a standby tray of the sheet post-processing apparatus according to the embodiment. Explanatory drawing which shows the operation | movement after a staple process by a general paper post-processing apparatus. FIG. 6 is an operation explanatory diagram illustrating a basic operation of a stapler in the sheet post-processing apparatus of the present invention. FIG. 6 is an operation explanatory diagram for explaining stapling processing and paper discharge operation in the paper post-processing apparatus of the present invention. FIG. 6 is an operation explanatory view for explaining a paper discharge operation after a stapling process in the paper post-processing apparatus of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 5 ... Image forming apparatus 7 ... Paper post-processing apparatus 10 ... Standby tray 12 ... Processing tray 14 ... Stapler 16, 18 ... Paper discharge tray 19 ... Fixed tray 22a, 22b ... Entrance roller 24 ... Paper feed roller 45 ... Stopper 47a, 47b ... Horizontal alignment plate 48 ... Horizontal alignment motor 49 ... Staple drive unit 50 ... Conveyor belt P ... Paper

Claims (6)

A post-processing device that aligns a plurality of sheets conveyed from an image forming apparatus, performs a stapling process, and discharges the sheets.
A processing tray on which a plurality of sheets conveyed from the image forming apparatus can be placed;
A pair of alignment plates for aligning a plurality of sheets placed on the processing tray from both sides along the transport direction, and the pair of alignment plates from the normal alignment position and the normal alignment position to the transport direction Alignment means that can be moved to a position shifted by a predetermined distance in a direction orthogonal to
A stapler that includes a stapler that is movable along a conveyance direction edge of a plurality of sheets aligned by the alignment unit, and that performs a stapling process on a plurality of sheets respectively conveyed at the regular alignment position;
The stapled paper bundle is guided to the paper discharge tray while being alternately shifted in the direction perpendicular to the transport direction by the aligning means, and the staple position of the paper bundle stacked on the paper discharge tray is set at each upper and lower stages. A sheet post-processing apparatus comprising: a discharging unit that discharges the sheets so as to be shifted from each other. The alignment means includes a pair of alignment plates, the normal alignment position, a first direction orthogonal to the conveyance direction centered on the normal alignment position, and a second direction opposite to the first direction. Can move by a predetermined distance,
The discharge unit is configured to guide the bundle of sheets stapled at the regular alignment position to the discharge tray while being alternately shifted in the first direction and the second direction by the alignment unit. Item 2. A sheet post-processing apparatus according to item 1. The stapler means moves the stapler in the first direction when the pair of alignment plates are in the regular alignment position, and conveys the stapler at a first position and a second position along the movement direction. Apply stapling to the incoming paper,
Next, the stapler is moved in a direction opposite to the first direction, and a stapling process is performed on the next conveyed sheet at the second position and the first position along the moving direction. The sheet post-processing apparatus according to claim 1.   2. The sheet according to claim 1, wherein L2 <L1 / 2, where L1 is an interval between stapling positions by the stapler and L2 is the predetermined distance by which the aligning unit moves from the normal alignment position. Post-processing device.   The aligning unit aligns a plurality of sheets placed on the processing tray from both sides along the transport direction, and aligns edges of the plurality of sheets in the transport direction. 2. The sheet post-processing apparatus according to claim 1, further comprising two aligning means.   6. The sheet post-processing apparatus according to claim 5, wherein the second aligning unit includes a stopper that is provided on the stapler and receives an edge of the sheet in the conveyance direction.

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