Post-processing device and image forming device

Abstract

To provide a post-processing device capable of producing high-quality paper bundles in which needle-less crimp binding is performed to have appropriate binding strength.SOLUTION: The post-processing device has first loading means on which conveyed paper is temporarily loaded, crimp binding means that performs crimp binding on a bundle of paper loaded on the first loading means, and a control unit. The crimp binding means binds a bundle of paper without using a needle, and the control unit determines the crimp binding force and crimp binding time of the crimp binding means based on a drive current value according to the following measurement method when the first bundle of paper is bound and the number of sheets of paper to be crimp bound. [Measuring method] The crimp binding means has a crimping member that binds a bundle of paper, and the crimping member is operated by a motor. The drive current value when binding a bundle of paper is obtained by measuring the maximum value of current flowing to the motor during the period from start of rotation of the motor for crimping until stop of rotation.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a post-processing device and an image forming system. [Background technology]

[0002] There is known a post-processing device that performs a binding process by pressing the stack of sheets of paper with upper and lower teeth without using metal staples to bind the stack of sheets of paper. In order to properly bind the stack of sheets of paper, studies have been conducted on such a post-processing device so that the conditions for pressing the stack of sheets of paper are appropriate.

[0003] Patent Document 1 discloses a sheet binding device equipped with a pressure means for pressing and binding a plurality of sheets together, and discloses that the time for pressing the sheets can be adjusted. According to Patent Document 1, it is possible to perform binding processing according to the state of the sheet stack. Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the conventional technology, even if the fiber direction of the paper, the number of sheets, the binding method, etc. are changed, the pressing force and the pressing time are constant, so there is a problem that a satisfactory binding force cannot be obtained when the binding conditions are unfavorable. Therefore, it is not possible to produce a stack of sheets of paper with an appropriate binding force, and the quality of the produced stack of sheets of paper is not satisfactory. In addition, for example, when the number of sheets of paper is small, excessive pressing may be performed, causing the paper to tear, and when the number of sheets of paper is large, there is a problem that the binding force is insufficient.

[0005] SUMMARY OF THE PRESENT DISCLOSURE An object of the present invention is to provide a post-processing device that can produce a high-quality stack of paper sheets by performing stapleless pressure binding with an appropriate binding force. [Means for solving the problem]

[0006] In order to solve the above problems, the post-processing device of the present invention has a first stacking means on which transported paper is temporarily stacked, a crimping binding means for crimping and stapling the stack of paper loaded on the first stacking means, and a control unit, wherein the crimping binding means binds the stack of paper without using staples, and the control unit determines the crimping force and crimping pressurization time of the crimping binding means based on a drive current value measured by the measurement method described below when the first stack of paper is stapled and the number of sheets of paper to be crimped and bound. [Measurement method] The pressure-bonding binding means has a pressure-bonding member that binds the stack of papers, and the pressure-bonding member is operated by a motor, and the drive current value when the stack of papers is bound is determined by measuring the maximum value of the current flowing through the motor from the time the motor starts to rotate for pressure bonding to the time it stops rotating. Effect of the Invention

[0007] According to the present invention, a post-processing device can be provided that can produce a high-quality stack of paper sheets by performing stapleless compression binding with an appropriate binding force. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a schematic diagram illustrating an example of an image forming system. [Diagram 2] FIG. 2 is a schematic diagram for explaining an example of a post-processing device. [Diagram 3] FIG. 2 is a schematic plan view illustrating an example of a binding unit. [Figure 4] FIG. 13 is a schematic perspective view for explaining an example of a pressure binding means, and is a diagram for explaining an example of rear oblique binding. [Diagram 5] FIG. 2 is a schematic perspective view for explaining an example of a pressure binding means, and is a diagram for explaining an example of two-point binding. [Figure 6] 1A to 1D are schematic side views illustrating an example of a pressure binding means. [Figure 7]1A to 1C are schematic side views for explaining an example of a pressure binding means, and are diagrams for explaining an example of adjusting the pressure bonding force. [Figure 8] 1A to 1E are schematic side views for explaining an example of a pressure binding means, and are diagrams for explaining an example of adjusting the pressure application time. [Figure 9A] FIG. 13 is a schematic perspective view for explaining an example of a pressure binding means, and is a diagram for explaining an example when the direction of the bound portion is set along the main scanning direction. [Figure 9B] FIG. 13 is a schematic perspective view for explaining an example of a pressure binding means, and is a diagram for explaining an example when the direction of the bound portion is set along the sub-scanning direction. [Figure 10] 13 is a flow chart illustrating an example of a pressure binding process, and is a flow chart illustrating an example of a case where a grain direction is determined based on a drive current value. [Figure 11] FIG. 13 is a schematic plan view of a main portion for explaining an example of two-point binding. [Figure 12] FIG. 13 is a schematic plan view of a main portion for explaining another example of two-point binding. [Figure 13] 11 is a flow chart for explaining an example of a pressure binding process, and a flow chart for explaining an example of adjustment of a pressure force and a pressure application time. [Figure 14] FIG. 2 is an example of a control block diagram. [Figure 15] 5A and 5B are schematic diagrams for explaining a driving current value. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, a post-processing device and an image forming system according to the present invention will be described with reference to the drawings. Note that the present invention is not limited to the following embodiment, and can be modified within the scope of what a person skilled in the art can imagine, such as other embodiments, additions, modifications, deletions, etc., and any aspect is included in the scope of the present invention as long as it achieves the functions and effects of the present invention.

[0010] The post-processing device of the present invention comprises a first stacking means on which transported paper is temporarily stacked, a pressure binding means for performing pressure binding on the stack of paper loaded on the first stacking means, and a control unit, wherein the pressure binding means binds the stack of paper without using staples, and the control unit determines the pressure force and pressure application time of the pressure binding means based on a drive current value measured by the measurement method described below when the first stack of paper is bound and the number of sheets of paper to be pressure-bound. [Measurement method] The pressure-bonding binding means has a pressure-bonding member that binds the stack of papers, and the pressure-bonding member is operated by a motor, and the drive current value when the stack of papers is bound is determined by measuring the maximum value of the current flowing through the motor from the time the motor starts to rotate for pressure bonding to the time it stops rotating.

[0011] In addition, the image forming system of the present invention has an image forming device that forms an image on paper, and a post-processing device that receives the paper on which an image has been formed by the image forming device, and is characterized in that the post-processing device is the post-processing device of the present invention.

[0012] FIG. 1 is a schematic diagram showing an example of the overall configuration of an image forming system 100 according to the present embodiment. The image forming system 100 includes an image forming apparatus 101 and a post-processing apparatus 1. The post-processing apparatus 1 can be attached to, for example, the side of the image forming apparatus 101. The post-processing apparatus 1 receives paper P on which an image has been formed, from a paper discharge port on the side of the image forming apparatus 101. The paper P conveyed into the post-processing apparatus 1 undergoes a predetermined process.

[0013] The image forming apparatus 101 includes, for example, an image forming means, an operation unit 102, etc. The image forming means is not particularly limited, but includes, for example, an image carrier, a charging means, a developing means, a fixing means, etc. The fixing means includes, for example, a heater that fixes the toner onto the paper.

[0014] The operation unit 102 is capable of setting, for example, a printing method, etc. In addition, the operation unit 102 is capable of setting, for example, a process to be performed when the number of sheets to be bound exceeds the limit, etc.

[0015] The post-processing device 1 has, for example, two types of binding units, a staple-less stapler 2 and a staple-containing stapler 3. The staple-less stapler 2 and the staple-containing stapler 3 will be described later.

[0016] 2 is a schematic diagram for explaining an example of the post-processing device 1. An example of the paper conveying operation will be explained with reference to FIG.

[0017] <Paper receiving section> The post-processing device 1 of this example has an introduction path 4, an upper conveying path 6, a straight conveying path 7, and a lower conveying path 8. The introduction path 4 is a path that receives the paper P discharged from the image forming device 101. The introduction path 4 branches into three paths, the upper conveying path 6, the straight conveying path 7, and the lower conveying path 8.

[0018] The upper conveying path 6 is a path leading to the proof tray 5. The straight conveying path 7 is a path for performing shift processing, end binding, two-point binding, etc. The lower conveying path 8 is a path for performing saddle stitching, folding, etc.

[0019] An entrance roller 9 and an entrance sensor 10 are disposed in the introduction path 4. The entrance sensor 10 detects that the paper P has been carried into the post-processing device 1. A horizontal transport roller 11 is disposed downstream of the entrance roller 9, and the horizontal transport roller 11 transports the carried-in paper P.

[0020] Rotatable branching claws 12 and 13 are disposed at a branching portion at the end of the introduction path 4. The paper P is sorted into the upper conveying path 6, the straight conveying path 7, and the lower conveying path 8 by the rotation of the branching claws 12 and 13.

[0021] <Proof discharge section> The branch claw 12 switches the traveling direction of the paper P from the introduction path 4 to the upper transport path 6. The paper P is transported along the upper transport path 6 and discharged onto the proof tray 5.

[0022] <Shift discharge section and shift operation> Intermediate conveying rollers 14 are disposed upstream of the straight conveying path 7. The paper P is conveyed to the downstream side of the straight conveying path 7 via the intermediate conveying rollers 14. The intermediate conveying rollers 14 can be moved a certain amount in a direction perpendicular to the conveying direction (for example, toward the front and rear of the paper surface) by a driving means. In the shift / sort mode, the intermediate conveying rollers 14 move a certain amount in a direction perpendicular to the conveying direction while the paper P is being conveyed. As a result, the paper P shifts a certain amount in a direction perpendicular to the conveying direction. Shifting the paper P a certain amount in a direction perpendicular to the conveying direction in this manner is also referred to as a shift operation.

[0023] Discharge rollers 15 and a discharge sensor 16 are disposed on the straight transport path 7. Discharge rollers 15 discharge paper P to a paper discharge tray 17. The discharged paper P is stacked in sequence on the paper discharge tray 17. Note that discharge may also be referred to as ejection, and stacking may also be referred to as stacking.

[0024] The paper discharge port to the paper discharge tray 17 is provided with a paper discharge roller 15 and a driven roller 18. The paper P or a bundle of paper P is sandwiched between the paper discharge roller 15 and the driven roller 18 and discharged to the paper discharge tray 17. The driven roller 18 can transition between a closed state in which the paper P or the bundle of paper P is sandwiched and can be discharged, and an open state in which the paper P or the bundle of paper P is not sandwiched. The transition of the driven roller 18 can be performed by, for example, a paper discharge guide plate.

[0025] After the shifting operation is performed (or without the shifting operation), the sheet P or the stack of sheets P is discharged onto the sheet discharge tray 17 by the sheet discharge roller 15 and the driven roller 18.

[0026] <Up and down movement of the shift tray> A filler 19 is provided near the top of the paper discharge outlet. The filler 19 is provided so that its tip contacts the central upper surface of the paper P stacked on the paper discharge tray 17 or the upper surface near the central portion. The filler 19 is arranged so as to be rotatable around its base side as an axis. A top surface detection sensor that detects the height of the tip of the filler 19 is provided near the base of the filler 19. The height of the paper surface of the stacked paper P is detected by the filler 19 and the top surface detection sensor.

[0027] The paper output tray 17 can be raised and lowered. The raising and lowering of the paper output tray 17 is controlled by, for example, a control unit. The control unit controls a drive means for raising and lowering the paper output tray 17. The paper output tray 17 is also called a shift tray, etc. The sheets P stacked on the paper output tray 17 are also collectively called a stack, etc.

[0028] As the number of sheets P stacked on the paper output tray 17 increases, the height of the stacked sheets P (height of the stack) rises. When the height of the stack rises to a predetermined height, the top surface detection sensor turns on. When the top surface detection sensor turns on, the control unit controls the drive means to lower the paper output tray 17. When the paper output tray 17 has lowered and the top surface detection sensor turns off, the control unit stops the lowering of the paper output tray 17.

[0029] By lowering the paper output tray 17, it is possible to ensure the loading capacity of the paper output tray 17. By raising the paper output tray 17, the loading surface of the paper output tray 17 and the paper output outlet are not too far apart, which reduces the disturbance of the loaded items. When the paper output tray 17 repeatedly lowers and rises and reaches a specified tray full height, the post-processing device 1 issues a stop signal to the image forming device 101, and the image forming system 100 stops the image forming operation.

[0030] <Compression binding, staple binding> A staple tray 20 is disposed on the straight transport path 7. The sheet P transported to the staple tray 20 is aligned in the transport direction by an alignment member. The alignment member has, for example, a tapping roller (not shown in FIG. 2) and a return roller 21. The tapping roller performs a pendulum motion to come into contact with the sheet P and guide the sheet P above the staple tray 20. The return roller 21 then comes into contact with the sheet P and butts the rear end of the sheet P against a reference fence 22, thereby aligning the position of the sheet P in the transport direction.

[0031] A jogger fence 23 is provided on the staple tray 20. The jogger fence 23 advances and retreats in a direction perpendicular to the surface of the paper P, for example, in the width direction of the paper P, and aligns the width direction position of the paper P transported to the staple tray 20. The paper P transported to the staple tray 20 is aligned by the hitting roller, the return roller 21, and the jogger fence 23, and is then loaded on the staple tray 20.

[0032] The sheets P loaded on the staple tray 20 are stapled by a binding unit. The binding unit has, for example, a stapleless stapler 2 and a stapler with staples 3. The stapleless stapler 2 performs pressure binding without using staples on the sheets P. The stapler with staples 3 performs staple binding with staples on the sheets P. A stack of sheets P is produced by the binding unit.

[0033] The binding position can be set, for example, by the operation unit 102, and a binding position suitable for the binding type can be set. The bundle of sheets P that has been stapled is discharged in the paper discharge direction by the discharge claw 24, and is sandwiched between the paper discharge roller 15 and the driven roller 18 and discharged to the paper discharge tray 17.

[0034] <Saddle stitching and folding> In the lower conveying path 8, saddle stitching, folding, etc. of the paper P are performed. The paper P is conveyed to the lower conveying path 8 by switching the branching claw 13. The conveyance to the lower conveying path 8 can be selected as appropriate, for example, the timing of switching the branching claw 13 can be selected as appropriate. The paper P conveyed to the straight conveying path 7 is detected by the paper leading edge detection sensor 25, and after the rear end of the paper P passes through the branching part of the straight conveying path 7 and the lower conveying path 8, the branching claw 13 is switched. When the branching claw 13 is switched, the intermediate conveying roller 14 rotates in the reverse direction, and the paper P is switched back and conveyed to the lower conveying path 8.

[0035] The lower conveying path 8 is provided with saddle stitching conveying rollers 26, 27, 28, a saddle stitching stapler 29, etc. When performing saddle stitching, the paper P is conveyed to a saddle stitching position, and the saddle stitching stapler 29 performs stitching in the center of the paper P. The paper P that has been stapled is conveyed by the saddle stitching conveying rollers 27, 28 to a paper folding stopper 30 in the paper folding section. The conveyed paper P is folded in the center by a paper folding blade 31 and a paper folding plate 32, and is discharged to a saddle stitching tray 34 by a center folding paper discharge roller 33.

[0036] <Perforation Processing Unit> A punching unit 35 is disposed downstream of the entrance roller 9 of the introduction path 4. The punching unit 35 includes, for example, a registration detection means and a punching means. The registration detection means detects registration misalignment. When performing punching, the punching unit 35 takes into account the registration misalignment detected by the registration detection means and performs punching at an appropriate position on the received paper P.

[0037] In addition, the means for punching, the means for saddle stitching and folding, and the means for pressure binding are configured to be removable, and the configuration can be changed by attaching and detaching these as appropriate according to the user's needs.

[0038] The post-processing device 1 of this embodiment includes a first stacking unit, a pressure binding unit, and a control unit, and may include other units such as an alignment unit and a second stacking unit, as necessary. The first stacking means is, for example, the staple tray 20 described above, and the transported sheets are temporarily stacked thereon. The alignment means is, for example, the alignment member described above, and aligns the stack of sheets stacked on the first stacking means. The alignment means has, for example, the hitting roller, return roller 21, reference fence 22, jogger fence 23, etc. described above. The pressure binding means is, for example, the stapleless stapler 2, and performs pressure binding on the stack of sheets stacked on the first stacking means.

[0039] The second stacking means is, for example, the above-mentioned discharge tray 17, on which the stack of pressure-stitched sheets is discharged and stacked. However, pressure-stitching is not necessarily required for the stack of sheets, and instead of pressure-stitching, staples may be used to staple the sheets using the stapler 3.

[0040] A detailed example of the post-processing device 1 of this embodiment will be described below. In the following example, the matters described with reference to FIG. 2 may be described again.

[0041] Fig. 3 is a schematic plan view of the main parts for explaining an example of the post-processing device 1, and is another schematic plan view for explaining the binding unit of Fig. 2. In the figure, the scanning direction of the stapleless stapler 2 is the main scanning direction, and the direction perpendicular to the main scanning direction is the sub-scanning direction. The white arrow in the figure indicates the direction in which the paper P is discharged, that is, the direction toward the paper discharge tray 17. The main scanning direction is the same as the width direction of the paper P, and the sub-scanning direction is the same as the direction in which the paper P is discharged.

[0042] The stapler 2 is moved in the main scanning direction based on a guide rod 36. The stapler 3 with staples is moved in the main scanning direction based on a guide rod 37.

[0043] The post-processing device 1 stacks and aligns (aligns) the sheets P output from the image forming device 101 in a staple tray 20 to form a stack of sheets. The post-processing device 1 abuts the rear end of the sheets P against a reference fence 22, which serves as a reference surface, and aligns the sheets P in the width direction using a jogger fence 23.

[0044] The stapler 2 or the stapler 3 with staples performs a stapling process on the aligned (aligned) stack of sheets P. Whether the stapler 2 or the stapler 3 with staples performs the stapling process can be set by the operation unit 102. The stack of sheets P after the stapling process is discharged to the sheet discharge tray 17 by the driven roller 18, the discharge claw 24, etc., and is stacked on the sheet discharge tray 17.

[0045] 4 is a schematic diagram for explaining an example of the movement of the staple-less stapler 2, and is a diagram for explaining an example of performing rear diagonal binding. Whether or not to perform rear diagonal binding can be set by the operation unit 102. In addition, the number of sheets to be bound can be set by the operation unit 102.

[0046] When performing rear diagonal binding, after a designated number of sheets P are transported to the staple tray 20, the staple-less stapler 2 rotates and moves from the initial position to perform the binding process on the corners of the sheets P. The initial position is diagrammatically indicated by the symbol 2', but is not limited to the position shown in the figure.

[0047] In the rear diagonal binding of this example, the bound portion is linear, and the direction of the bound portion line is at an angle with respect to the side of the paper P. In addition, the rear refers to one of the four corners of the paper P.

[0048] 5 is a schematic diagram for explaining an example of two-point stapling by the staple-less stapler 2. Whether or not to perform two-point stapling can be set by the operation unit 102. In addition, the number of sheets to be stapled can be set by the operation unit 102.

[0049] When performing two-point stapling, after a designated number of sheets P are transported to the staple tray 20, the staple-less stapler 2 moves from the initial position and performs stapling processing at multiple points while moving along the side of the sheets P. As shown in the figure, in the two-point stapling of this example, two binding portions are adjacent to each other, and multiple adjacent two binding portions are formed.

[0050] As shown in FIGS. 4 and 5, the binding process by the stapleless stapler 2 is not limited to one, but can be appropriately selected.

[0051] 6 is a schematic side view for explaining a typical example of stapleless binding operation. The figure shows the operation in chronological order of (a) at the top left, (b) at the top right, (c) at the bottom left, and (d) at the bottom right.

[0052] The stapler 2a performs a stapling operation when the paper P is transported to the binding unit and a specified number of sheets are bundled. (a) shows the state in which the specified number of sheets are bundled. As shown in the figure, the stapler 2a of this example has upper crimping teeth 40, lower crimping teeth 41, an arm 42, a first spring support portion 43, a spring 44, a second spring support portion 45, a rotating body 48, and a motor 49.

[0053] 1(b) shows a state in which the arm 42 rotates and the upper crimping teeth 40 come into contact with the stack of paper sheets P. Although not particularly limited, the rotation of the arm 42 rotates the rotor 48, which causes the upper crimping teeth 40 to move in a direction in which they come into contact with the stack of paper sheets P. The upper crimping teeth 40 are movable in a direction in which the upper crimping teeth 40 and the lower crimping teeth 41 mesh with each other. The arrow in the figure shows a schematic representation of the direction of rotation of the rotor 48. A motor 49 rotates the rotor 48.

[0054] (c) shows a state in which the arm 42 has further rotated from the state in (b). When the arm 42 rotates further, the first spring support portion 43 rotates in a direction that pulls the spring 44. The rotation direction of the first spring support portion 43 is shown diagrammatically by an arrow in the figure, which points, for example, to the front side (left side in the figure). When the first spring support portion 43 rotates as shown in (c), the upper and lower crimping teeth are crimped together, and the fibers of the stack of paper P are intertwined to perform crimp binding.

[0055] (d) shows a state in which the arm 42 has rotated further from the state in (c). When the arm 42 rotates further, the first spring support portion 43 rotates to a position returning to the original state in (a). This makes it possible to transport the stack of papers P. In this manner, the stapler 2a performs a staple-less stapling process and creates a stack of papers P.

[0056] In (d), the bound portion formed on the stack of paper P is indicated by the reference symbol 36. The second spring support portion 45 adjusts the pressure force of the spring 44 and is usually fixed. The stapleless staple binding process is also called stapleless operation, pressure binding, or pressure binding process.

[0057] In addition, the binding portion 38 formed by the upper and lower crimping teeth 40 and 41 in FIG. 6 has a linear shape as shown in FIG. 5, for example, when viewed in a plane.

[0058] In conventional technology, stapleless operation is performed with the same pressure, regardless of the grain direction (the direction of the paper fibers). Therefore, in conventional technology, the pressure cannot be adjusted during the stapling operation of a small number of sheets or a large number of sheets, and the pressure cannot be changed depending on the paper fiber direction. Therefore, in conventional technology, there is a problem that the fibers may not be completely entangled when performing stapleless operation. In addition, there is a problem that the paper fibers may be torn, making it impossible to perform the stapling process properly.

[0059] In contrast, in this embodiment, the pressure force and pressure application time are determined (or may be referred to as adjusted) based on the drive current value when the first set of paper stacks is bound and the number of sheets of paper to be pressure bound. By taking into consideration the drive current value when the first set of paper stacks is bound, it is possible to determine, for example, whether the fiber direction of the paper to be pressure bound is a direction that is easy to bind. This allows pressure binding to be performed with an appropriate pressure force, and the bound paper stack has an appropriate binding force, resulting in a high-quality paper stack.

[0060] The pressure force and pressure application time when performing pressure binding are determined (adjusted) by, for example, a control unit. The control unit is illustrated in FIG. 14 described later. In this embodiment, it is not necessary to determine the fiber direction of the paper to be pressure bound. By using the drive current value when binding the first bundle of papers, it is possible to determine whether the fiber direction of the paper to be pressure bound is a direction that is easy to bind, and the result of such determination is used to adjust the pressure conditions (pressure force, pressure application time, etc.).

[0061] 7 is a schematic side view for explaining an example of the stapler 2 in this embodiment. Like the stapler 2a, the stapler 2 has upper crimping teeth 40, lower crimping teeth 41, an arm 42, a first spring support portion 43, a spring 44, a second spring support portion 45, and a rotor 48. The stapler 2 in this example has a gear 46 and a motor 47.

[0062] The motor 47 is provided, for example, on a side surface, and the gear 46 is provided, for example, inside the stapler 2. The gear 46 is linked to the motor 47 and the second spring support portion 45. The motor 47 is controlled, for example, by a control portion, and how the motor 47 is controlled can be set, for example, by the operation portion 102.

[0063] 1A shows a state in which the motor 47 is stationary. 1B shows a state in which the motor 47 rotates in the direction of the arrow in the figure, causing the gear 46 to rotate in the direction of the arrow in the figure. When the gear 46 rotates as shown in the figure, the second spring support portion 45 moves in the direction of the arrow. This causes the spring 44 to expand, making it possible to increase the pressing force.

[0064] (c) shows a state in which the motor 47 rotates in the direction of the arrow in the figure, causing the gear 46 to rotate in the direction of the arrow in the figure. The motor 47 in (c) rotates in the opposite direction to the direction of rotation in (b). When the gear 46 rotates as shown in the figure, the second spring support portion 45 moves in the direction of the arrow. This causes the spring 44 to contract, making it possible to weaken the pressing force. In this way, the stapler 2 of this example has a pressing force adjustment mechanism.

[0065] Fig. 8 is a schematic side view for explaining an example of the stapleless stapling operation of the stapler 2 in this embodiment. Fig. 8 shows that the stapler 2 in Fig. 7 operates in the order of (a), (b), (c), (d), and (e) in chronological order. The illustrated example is an example of adjustment of the pressing pressure time of the stapler 2.

[0066] 8(a)-(c) show the same operation as in Fig. 6(a)-(c). When the paper sheets P are transported to the binding unit and a specified number of sheets are bundled, the arm 42 rotates, the upper crimping teeth 40 move in a direction to abut against the bundle of paper sheets P, and the upper crimping teeth 40 and the lower crimping teeth 41 operate in a direction to mesh with each other. As described above, in (c), the arm 42 rotates further, and the first spring support portion 43 moves forward so as to pull the spring 44. As a result, the upper and lower crimping teeth mesh with each other, and the fibers of the bundle of paper sheets P are entangled, thereby performing stapleless stapling processing.

[0067] In this example, as shown in (d), when the upper and lower crimping teeth are crimping the stack of paper P, the machine stops for T seconds. This increases the time for the fibers of the paper P to be entangled at maximum crimping, and increases the binding force. Therefore, even if there are a large number of sheets of paper P, the staple-free binding process can be performed with sufficient binding force, and the staple-free binding process can be performed appropriately.

[0068] In addition, by changing the stop time depending on the number of sheets of paper P, a satisfactory binding force can be obtained whether the bundle of sheets P contains a small number of sheets or a large number of sheets. In other words, the bound bundle of sheets has an appropriate binding force. The stop time in (d) is also called the pressing time.

[0069] FIG. 8(e) shows the same operation as FIG. 6(d), in which the arm 42 rotates further and the first spring support portion 43 rotates to a position returning to the original state of FIG. 6(a).

[0070] The pressure binding means in this embodiment can adjust the pressure force, for example, as shown in Fig. 7, and can adjust the pressure application time, for example, as shown in Fig. 8. The word "adjust" may also be referred to as "set," "determine," "change," etc.

[0071] The ease of stapleless binding (pressure binding) varies depending on the fiber direction of the paper (also called grain direction), even for the same stack of paper. Therefore, even if the number of sheets is the same, pressure binding may or may not be performed properly depending on the fiber direction of the paper. For this reason, when changing the pressure force of pressure binding depending on the number of sheets of paper, it is not sufficient to simply weaken the pressure force when there are a small number of sheets and strengthen the pressure force when there are a large number of sheets. For this reason, with conventional technology, excessive pressure is applied when there are a small number of sheets, causing problems such as tearing of the paper fibers, as well as insufficient pressure when there are a large number of sheets.

[0072] As described above, in this embodiment, the pressure-bonding force and pressure-bonding time are adjusted based on the drive current value when the first set of paper bundles is bound and the number of sheets of paper to be pressure-bound. By considering the drive current value when the first set of paper bundles is bound, it is possible to determine whether the fiber direction of the sheets to be pressure-bound is a direction that is easy to bind. By considering the drive current value and the number of sheets of paper, pressure-bonding can be performed appropriately, and for example, it is possible to prevent the fiber of the paper from being torn when there are only a few sheets, and to prevent the bundle of sheets from coming apart when there are many sheets. As a result, a bundle of sheets of paper with good quality can be formed.

[0073] The drive current value when the first bundle of papers is bound may also be referred to as the drive current value for the first bundle. How the drive current value for the first bundle is used to adjust the pressure bonding conditions (pressure bonding force, pressure bonding time, etc.) can be appropriately selected, and several examples are described below. For example, the drive current value for the first bundle may be compared with a comparative drive current value, and it is possible to determine whether the fiber direction of the paper is a direction that is easy to press-bind, based on the magnitude relationship. In addition, the drive current value for the first bundle may be compared with the drive current value for the second bundle, and it is possible to determine whether the fiber direction of the paper is a direction that is easy to press-bind, based on the magnitude relationship. The drive current value when the second bundle of papers is bound may also be referred to as the drive current value for the second bundle.

[0074] In this embodiment, how the pressure force and pressure application time are changed can be appropriately selected according to the drive current value and the number of sheets of paper. An example is shown below. For example, when the paper has a fiber direction that makes it easy to bind with pressure and there are only a few sheets, the pressure is weakened, or the pressure application time is shortened, or the pressure is weakened and the pressure application time is shortened.For example, when the paper has a fiber direction that makes it difficult to bind with pressure and there are many sheets, the pressure is strengthened, or the pressure application time is lengthened, or the pressure is strengthened and the pressure application time is lengthened.

[0075] In this embodiment, a method for determining (judging) whether the fiber direction of the paper is a direction that is easy to press-bind can be appropriately selected. An example of such a method will be described with reference to Figs. 9A, 9B, and 10.

[0076] 9A is a schematic perspective view showing an example of pressure binding a first stack of sheets P. The illustrated example is an example in which the corners of the sheets P are bound parallel to the main scanning direction. 9B is a schematic perspective view showing an example of pressure binding the second bundle of sheets P. The illustrated example is an example in which the corners of the sheets P are bound parallel to the sub-scanning direction. The stacks of paper are counted in units. The white arrow in the figure shows the direction in which the stack of paper P is discharged (discharged).

[0077] The staple-less stapler 2 (pressure binding means) in this embodiment is capable of performing binding processing by changing the angle of the binding portion, and binds the first bundle of sheets and the second bundle of sheets at different angles.

[0078] As shown in the figure, the bound portion in this example has a linear shape when viewed in a plane. The bound portion may be parallel to the main scanning direction as shown in Fig. 9A, or parallel to the sub-scanning direction as shown in Fig. 9B. Alternatively, the bound portion may be oblique to the main scanning direction and the sub-scanning direction as shown in Fig. 4.

[0079] In this way, by binding the first and second bundles of paper at different angles, it is possible to determine whether the paper fiber direction is suitable for pressure binding from the difference in the drive current value at this time. For example, and not by way of limitation, if the drive current value for the second bundle is smaller than the drive current value for the first bundle, it can be determined that the paper fiber direction of the second bundle is suitable for pressure binding, and that the paper fiber direction of the first bundle is difficult for pressure binding.

[0080] Such a determination is made by, for example, a control unit. The control unit may be provided in the post-processing device 1, or may be provided in a device separate from the post-processing device 1. The drive current value when the stack of sheets is stapled is obtained by measuring the current value flowing through the motor 49 that operates the rotating body 48 of the post-processing device 1. More specifically, this is as follows.

[0081] The pressure binding means has a pressure member (e.g., a rotating body 48, an upper pressure tooth 40) that binds a stack of paper sheets, and the pressure member is operated by a motor 49. The drive current value when the stack of paper sheets is bound is obtained by measuring the maximum value of the current flowing through the motor 49 from when the motor 49 starts to rotate for pressure binding to when it stops rotating. Such a maximum current value may be called the instantaneous value of the current flowing through the motor 49 when the stack of paper sheets is bound. The motor 49 that operates the pressure member may be called a pressure member drive means, a pressure member drive motor, etc. In addition, the pressure member operated by the motor 49 includes at least the rotating body 48 and may include the upper pressure tooth 40, and may further include the lower pressure tooth 41, the first spring support portion 43, the spring 44, and the second spring support portion 45.

[0082] The maximum value of the current flowing through the motor 49 from when the motor 49 starts to rotate for crimping to when it stops rotating can be measured by reading the current value flowing through the circuit in the motor. For example, the control unit drives the motor 49 by passing a predetermined current through the motor 49, and the device performs a binding operation at a constant current value, and the binding load when binding a stack of paper becomes higher than the constant current value for a moment. For this reason, the current value flowing through the motor 49 when binding a stack of paper that is difficult to bind is different from the current value flowing through the motor 49 when binding a stack of paper that is easy to bind. Therefore, by measuring the current value flowing through the motor 49 when binding a stack of paper, that is, the drive current value when binding a stack of paper, it is possible to determine whether the stack of paper is easy to bind or difficult to bind.

[0083] The drive current value will be explained in a schematic manner with reference to Fig. 15, but the drive current value in the present invention is not limited to the example shown in the figure. In the schematic diagram shown in Fig. 15, the vertical axis represents the current value flowing through the motor 49, and the horizontal axis represents time. As shown in Fig. 15(a), in the binding operation, the binding operation is performed at a constant current value, and the binding load when the stack of paper sheets is bound momentarily becomes higher than the constant current value.

[0084] Also, as shown in FIG. 15(b), the current value when stapling a difficult stack of papers is different from the current value when stapling a stack of easy papers. When performing a binding operation at a constant speed (current), for example, if the stack of papers is thin, the binding operation can be performed without much load on the motor (the binding force is low), so the current value is low. On the other hand, for example, if the stack of papers is thick, force is required to bind the papers during the binding operation, so the motor load is high and the current value is high accordingly. For these reasons, a difference in the current value occurs. For this reason, it is possible to determine whether the stack of papers is easy to bind or difficult to bind based on the drive current value.

[0085] For convenience of explanation, the drive current value is explained in this example in which the drive current value of the first part and the drive current value of the second part are compared, but such a concept of the drive current value can be applied to other examples as well. For example, such a concept of the drive current value can be applied to an example in which the crimping conditions are adjusted by considering the drive current value of the first part without considering the drive current value of the second part.

[0086] This example will be described again. The control unit obtains the difference between the drive current value when the first bundle of sheets is bound and the drive current value when the second bundle of sheets is bound, and determines the pressure-bonding force and pressure-bonding time of the pressure-bonding binding means based on the difference in drive current value and the number of sheets to be pressure-bonded. In this case, the pressure-bonding force and pressure-bonding time of the pressure-bonding binding means can be determined with high accuracy.

[0087] In addition to the above, a method of determining whether the fiber direction of the paper is suitable for pressure binding may be a method of comparing with a comparative drive current value stored in the device in advance. In other words, the drive current value when binding the first bundle of paper may be compared with a comparative drive current value stored in the device in advance to determine whether the fiber direction of the paper is suitable for pressure binding.

[0088] This example will be described again. The control unit obtains the difference between the drive current value when the first set of paper stacks is bound and a comparative drive current value stored in advance in the device, and determines the pressure-binding force and pressure-binding time of the pressure-binding means based on the difference in drive current values ​​and the number of sheets to be pressure-bound. In this case, the pressure-binding conditions can be determined when the first set of paper stacks is bound.

[0089] In this way, when comparing with the comparative drive current value, the first stack of sheets may be pressure-stitched as shown in Fig. 9A or pressure-stitched as shown in Fig. 9B. For example, it is possible to determine whether the fiber direction of the sheets is suitable for pressure-stitching from the drive current value when pressure-stitching is performed as shown in Fig. 9A or 9B.

[0090] For example, but not limited to, if the drive current value when binding the first set of paper sheets is smaller than the drive current value for comparison, it can be determined that the paper fiber direction is a direction that makes it easy to perform pressure binding. On the other hand, for example, if the drive current value when binding the first set of paper sheets is larger than the drive current value for comparison, it can be determined that the paper fiber direction is a direction that makes it difficult to perform pressure binding.

[0091] In the example shown in Figures 9A and 9B, the short side direction of the paper P is the discharge direction (white arrow), and this is also referred to as horizontal setting. This embodiment is not limited to this, and the paper P may be vertically set, with the long side direction being the discharge direction (white arrow). Even in the case of vertical setting, by changing the movement distance of the stapleless stapler 2, it is possible to perform pressure binding so that the direction of the bound portion is along the main scanning direction, or pressure binding so that the direction of the bound portion is along the sub-scanning direction. Also, even in the case of vertical setting, it is possible to determine the fiber direction of the paper P by changing the drive current value.

[0092] The driving current value for comparison stored in advance in the device can be appropriately selected, and for example, the value at the time of the previous binding process may be set. Alternatively, the user or operator may set the driving current value.

[0093] The obtained drive current value may be stored for each sheet of paper. When performing the binding operation from the next time onwards, the stored drive current value is read and the binding process can be performed based on the type and orientation of the paper, without performing the binding operation to determine the fiber direction of the paper.

[0094] When acquiring the drive current value of the first copy, the bundle of papers on which the image is actually formed may be crimped to acquire the drive current value, or the bundle of papers for acquiring the drive current value may be crimped. In the former case, there is an advantage that the bundle of papers for acquiring the drive current value is not wasted, but there is a possibility that an appropriate binding force cannot be obtained for the bundle of papers of the first copy. On the other hand, in the latter case, an appropriate binding force can be obtained for the bundle of papers of the first copy, but the bundle of papers for acquiring the drive current value is separately consumed. The former and the latter can be selected as appropriate, and may be selectable by the user, for example. From the viewpoint of improving quality, it is preferable to perform the latter, that is, crimping the bundle of papers for acquiring the drive current value, determining the grain direction of the paper, and then crimping the bundle of papers on which the image is actually formed.

[0095] Similarly, in the example of comparing the drive current value of the first copy with the drive current value of the second copy, the drive current value may be obtained by crimping and binding a stack of papers on which an image is actually formed, or the stack of papers used to obtain the drive current value may be crimped and bound.

[0096] FIG. 10 is a flowchart illustrating an example of the processing of this embodiment. The post-processing device 1 receives the paper P (S1). The stapler 2 moves to a stapling position (S2). The stapling position is, for example, the position shown in FIG. 9A. The stapler 2 performs a stapling operation (S3). In this case, the direction of the stapled portion is aligned with the main scanning direction, as shown in FIG. 9A.

[0097] The drive current value when the stapler 2 performs the staple operation is read (S4). In this example, the read drive current value is stored in an arbitrary storage unit. The stapler 2 moves to the HP (home position) position (S5). The HP position is, for example, the position shown by reference symbol 2' in FIG. 9A.

[0098] The stack of papers is discharged (S6). After the stack of papers is discharged, it is determined whether the second copy has been stapled (S7). If the second copy has not been stapled (NO), the stapler 2 is rotated 90 degrees (S8). Next, the process of S2 is performed again. In this case, since the stapler 2 has been rotated 90 degrees, the direction of the stapled portion is aligned with the sub-scanning direction, as shown in FIG. 9B, for example. The drive current value at this time is read and stored in the memory unit.

[0099] Next, the processes of S4 to S6 are carried out. If the determination in S7 is YES, that is, if the second copy has been bound, the drive current value when the second copy was bound is compared with the drive current value when the first copy was bound (S9). This makes it possible to determine whether the direction of the fibers of the paper P is suitable for pressure binding. Based on the result of this determination, the pressure force and pressure application time are adjusted to bind the designated number of copies (S10).

[0100] The staple-less stapler 2 (compression binding means) in this embodiment is capable of changing the number of stitches per stack of paper, and changes the number of stitches based on the drive current value when the first stack of paper is stapled. By changing the number of stitches taking into account the drive current value of the first stack of paper, compression binding can be performed without being affected by the fiber direction of the paper, and a stack of paper can be formed with the desired binding force. The change in the number of stitches is controlled by, for example, the control unit.

[0101] An example of this case will be described with reference to Figures 11 and 12. Figure 11 shows an example of the case where binding processing is performed without considering the drive current value and the fiber direction of the paper, and Figure 12 shows an example of the case where binding processing is performed with consideration given to the drive current value and the fiber direction of the paper.

[0102] 11 is a schematic plan view of the main part showing the position of the binding portion 38 when two binding points are performed. As shown in the figure, a total of six binding strokes are performed along the sides of the paper P. The word "two places" means that there are two groups of adjacent binding points 38, and is a name given for convenience.

[0103] In the example shown in FIG. 11, satisfactory binding can be performed when the grain direction (fiber direction) is favorable for binding force, but satisfactory binding cannot be performed when the grain direction weakens the binding force.

[0104] Fig. 12 is a schematic plan view of the main part showing the position of the binding portion 38 when stapling in two places is performed, and is an example of the case of the grain direction in which the binding force is weaker. As shown in the figure, in this example, the number of binding strokes per stack of paper is increased compared to Fig. 11, from a total of 6 strokes to a total of 8 strokes. This is expected to improve the binding force. In other words, in the case of the grain direction in which the binding force is weaker, by increasing the number of binding strokes, it is possible to form a stack of paper with sufficient binding force.

[0105] As described above, in this embodiment, at least one of the clamping force and the clamping pressure time is adjusted depending on the drive current value and the number of sheets of paper of the first copy. In addition, by changing the number of stitches, the quality of the stack of paper can be further improved.

[0106] The number of staple strokes per bundle of paper is also simply referred to as the number of staple strokes. The number of staple strokes per bundle of paper can also be said to be the number of stapled portions 38 per copy. Also, in FIG. 12, two staples are used.

[0107] FIG. 13 is a flowchart for explaining an example of a case where the number of stitches is changed. A print command is received and it is determined whether or not to perform the staple-free binding mode (S21). Whether or not to perform the staple-free binding mode can be selected, for example, from the operation unit 102. If the staple-free binding mode is to be performed, the drive current value is read (S22). Note that the read drive current value is used to determine whether or not the direction of the fibers of the paper P is suitable for pressure binding, as described in the above example.

[0108] Next, it is determined whether the binding is a rear diagonal binding (S23). The rear diagonal binding is, for example, a binding process such as the example shown in Fig. 4. If the binding is not a rear diagonal binding (NO in S23), for example, two-point binding is set as the binding process method (S24).

[0109] After the process of S24 is performed, or if the answer is YES in S23, the pressing force is adjusted in consideration of the binding processing method (S25). For example, the pressing force is adjusted differently for the processing method using rear diagonal binding and the processing method using two-point binding. However, this embodiment is not limited to a configuration that performs such processing. The adjustment of the pressing force may be performed by a control unit of the post-processing device 1, or may be performed by a control unit of any device in the image forming system. Furthermore, the post-processing device 1 may or may not have a control unit.

[0110] After adjusting the pressure, the paper is received and pressure binding is performed. In the pressure binding process in this example, first, using the read drive current value, it is determined whether the grain direction is favorable for binding force (S26). If the grain direction is not favorable for binding force (NO in S26), the number of stitches is increased (S28). The number of stitches is increased, for example, as described in FIG. 11 and FIG. 12. The case where the grain direction is not favorable for binding force can be rephrased as the case where the grain direction is weaker for binding force.

[0111] Next, the pressure application time is adjusted (S27). In this example, the pressure application time is adjusted taking into consideration the items adjusted in the previous process. This can be changed as appropriate, but for example, the pressure application time is adjusted taking into consideration the adjusted pressure force conditions as well as the adjusted number of stitches conditions. Here, the pressure application time is also adjusted taking into consideration the number of sheets in the paper stack.

[0112] The stapler 2 performs the stapling operation based on the adjusted pressure and pressure application time (S29). In this example, for example, rear diagonal stapling or two-point stapling is selected. When the stapling operation is complete, the stack of sheets is transported and discharged (S30, S31). Next, it is determined whether the specified number of sheets has been passed (S32). If not, sheets are accepted again and the process from the adjustment of the pressure (S25) onwards is repeated.

[0113] 14 is an example of a control block diagram of this embodiment. The image forming system 100 of this embodiment includes an image forming apparatus 101 and a post-processing apparatus 1, and may include other devices as necessary. The image forming apparatus 101 or the image forming system 100 may include an operation unit 102.

[0114] The post-processing device 1 has, for example, a control unit 103, an alignment means 104, a pressure binding means (staple-less stapler 2), a second loading means (paper output tray 17), and in addition, a first loading means (staple tray 20), a stapler with staples 3, etc.

[0115] The alignment means 104 aligns the stack of sheets stacked on the first stacking means. The alignment means 104 may be called an alignment member, and includes, for example, a tapping roller, a return roller 21, a reference fence 22, a jogger fence 23, and the like.

[0116] The control unit 103 controls, for example, the alignment unit 104, the stapleless stapler 2, the stapler with staple 3, the paper discharge tray 17, etc. The second stacking unit is a stacking unit on which the bundle of discharged paper sheets is stacked after pressure binding, and the height of the stacking surface is variable. The control unit 103 can control the height of the stacking surface of the second stacking unit.

[0117] The control unit 103 controls the pressure binding means and the like, and when controlling the pressure binding means, for example, controls to change the angle of the binding part, control to change the number of binding strokes, etc. The control unit 103 controls the pressure binding means and the like based on the drive current value of the first set and the number of sheets.

[0118] For example, aspects of the present invention are as follows. <1> a first stacking means for temporarily stacking the transported paper; a pressure binding means for performing pressure binding on the stack of paper sheets loaded on the first loading means; A control unit, The pressure binding means binds a stack of sheets together without using staples, The control unit determines the pressing force and pressing time of the pressing and binding means based on a drive current value measured by the following measurement method when the first bundle of sheets is bound and the number of sheets to be pressed and bound. A post-processing device comprising: [Measurement method] The pressure-bonding binding means has a pressure-bonding member that binds the stack of papers, and the pressure-bonding member is operated by a motor, and the drive current value when the stack of papers is bound is determined by measuring the maximum value of the current flowing through the motor from the time the motor starts to rotate for pressure bonding to the time it stops rotating. <2> The pressure-bonding binding means is capable of performing a binding process by changing an angle of the binding portion, The control unit controls to change the angle of the binding unit between the first bundle of paper sheets and the second bundle of paper sheets. Characterized by <1> The post-processing device according to claim 1 . <3> The control unit obtains a difference between a drive current value when a first bundle of sheets is bound and a drive current value when a second bundle of sheets is bound, and determines a pressure force and a pressure application time of the pressure binding means based on the difference in drive current value and the number of sheets to be pressure bound. Characterized by <2> The post-processing device according to claim 1 . <4> The control unit obtains a difference between a drive current value when the first bundle of sheets is bound and a comparative drive current value stored in advance in the device, and determines a pressure force and a pressure application time of the pressure binding means based on the difference in drive current values ​​and the number of sheets to be pressure bound. Characterized by <1> The post-processing device according to claim 1 . <5> The pressure binding means is capable of changing the number of stitches per bundle of paper sheets, The control unit performs control to change the number of stitches based on a drive current value when a first bundle of sheets is stapled. Characterized by <1> from <3> 2. The post-processing device according to claim 1 , <6> Alignment means for aligning the stack of paper sheets loaded on the first loading means; and a second stacking means for stacking the bundle of sheets that has been subjected to the compression binding and discharged, The pressure binding means performs pressure binding on the stack of sheets aligned by the alignment means, the second loading means has a loading surface with a variable height; The control unit controls the height of the loading surface of the second loading means. Characterized by <1> from <5> 2. The post-processing device according to claim 1 , <7> an image forming apparatus for forming an image on a sheet; a post-processing device that receives a sheet on which an image is formed by the image forming device, The post-treatment device includes: <1> from <6> The post-processing device according to any one of the preceding claims. 1. An image forming system comprising: [Explanation of symbols]

[0119] 1 Aftertreatment device 2 Stapleless Stapler 18 Driven roller 20 Staple Tray 23 Jogger Fence 24 Release claw 38 Binding 40 Upper crimping teeth 41 Lower crimping teeth 42 Arm 43 First spring support 44 Spring 45 Second spring support 46 Gear 47 Motor 48 Rotating Body 49 Motor 100 Image forming system 101 Image forming device 102 Operation section [Prior art documents] [Patent documents]

[0120] [Patent Document 1] JP 2015-199235 A

Claims

1. a first stacking means for temporarily stacking the transported paper; a pressure binding means for performing pressure binding on the stack of sheets of paper loaded on the first loading means; A control unit, The pressure binding means binds a stack of sheets together without using staples, The control unit determines the pressing force and pressing time of the pressing and binding means based on a drive current value measured by the following measurement method when the first bundle of sheets is bound and the number of sheets to be pressed and bound. A post-processing device comprising: [Measurement method] The pressure-bonding binding means has a pressure-bonding member that binds the stack of papers, and the pressure-bonding member is operated by a motor, and the drive current value when the stack of papers is bound is determined by measuring the maximum value of the current flowing through the motor from the time the motor starts to rotate for pressure bonding to the time it stops rotating.

2. The pressure-bonding binding means is capable of performing a binding process by changing an angle of the binding portion, The control unit controls to change the angle of the binding unit between the first set of paper sheets and the second set of paper sheets. The post-processing device according to claim 1 .

3. The control unit obtains a difference between a drive current value when a first bundle of sheets is bound and a drive current value when a second bundle of sheets is bound, and determines a pressure force and a pressure application time of the pressure binding means based on the difference in drive current value and the number of sheets to be pressure bound. The post-processing device according to claim 2 .

4. The control unit obtains a difference between a drive current value when the first bundle of sheets is bound and a comparative drive current value stored in advance in the device, and determines a pressure force and a pressure application time of the pressure binding means based on the difference in drive current value and the number of sheets to be pressure bound. The post-processing device according to claim 1 .

5. The pressure binding means is capable of changing the number of stitches per bundle of paper sheets, The control unit performs control to change the number of stitches based on a drive current value when the first bundle of sheets is stapled. The post-processing device according to claim 1 .

6. an alignment means for aligning a stack of sheets of paper stacked on the first stacking means; and a second stacking means for stacking the bundle of sheets that has been subjected to the compression binding and discharged, The pressure binding means performs pressure binding on the stack of sheets aligned by the alignment means, the second loading means has a loading surface with a variable height; The control unit controls the height of the loading surface of the second loading means. The post-processing device according to claim 1 .

7. an image forming apparatus for forming an image on a sheet; a post-processing device that receives a sheet on which an image has been formed by the image forming device, The post-processing device is a post-processing device according to any one of claims 1 to 6.

1. An image forming system comprising:

Images