Sheet processing apparatus and image forming system

Abstract

To provide a technique of accurately aligning a sheet bundle according to a sheet processing device that bundles and binds a plurality of sheets on which images are formed.SOLUTION: A sheet processing device comprises a conveying part for conveying sheets in a conveyance direction; a tray for stacking a plurality of the sheets as sheet bundles conveyed by the conveying part; a sheet regulation member for regulating a position in a conveyance direction of the sheet bundles stacked on the tray by coming into contact with an end potion of the sheet bundles on a downstream side in the conveyance direction; a pressing member for pressing the sheet bundles stacked on the tray via movement in a width direction of the sheet bundles; and a binding part for binding the sheet bundles stacked on the tray. The pressing member is provided so as to surround the binding part, as viewed from the width direction.SELECTED DRAWING: Figure 7

Description

[Technical field]

[0001] The present invention relates to a sheet processing apparatus and an image forming system. [Background technology]

[0002] Conventionally, there has been known an image forming system including an image forming apparatus that forms an image on a sheet, and a sheet processing apparatus that processes the sheet on which the image has been formed by the image forming apparatus. A typical example of processing by the sheet processing apparatus is a binding process in which a plurality of sheets on which images have been formed are bound together.

[0003] A sheet processing device that performs binding processing includes, for example, a tray for loading a stack of sheets, a binding section for binding the stack of sheets loaded on the tray, a sheet regulating member for regulating the position of the stack of sheets loaded on the tray, and a pressing member for pressing the stack of sheets in the thickness direction upstream of the binding section in the sheet transport direction (see, for example, Patent Documents 1 and 2). Summary of the Invention [Problem to be solved by the invention]

[0004] However, especially in the case of sheets on which an image is formed by an inkjet method, the edges in the width direction may warp (curl) as the ink dries. Therefore, there is a problem that the sheet stack cannot be aligned with high precision if the sheet stack is pressed only on the upstream side in the transport direction from the binding part.

[0005] The present invention has been made to solve such problems, and aims to provide a technology for precisely aligning a sheet stack in a sheet processing device that binds multiple sheets on which images are formed into a stack. [Means for solving the problem]

[0006] In order to solve the above problem, one aspect of the present invention includes a conveying section that conveys a sheet in a conveying direction, a tray that stacks a plurality of sheets conveyed by the conveying section as a sheet bundle, a sheet regulating member that contacts an end of the sheet bundle on a downstream side in the conveying direction to regulate a position in the conveying direction of the sheet bundle stacked on the tray, a pressing member that moves in a thickness direction of the sheet bundle to press the sheet bundle stacked on the tray, and a binding section that binds the sheet bundle stacked on the tray, the pressing member being provided to surround the binding section when viewed in the thickness direction. The pressing member includes an I-shaped first pressing member that presses the sheet bundle on one side of the sheet bundle in the width direction from the binding portion, and an L-shaped second pressing member that presses the sheet bundle on the other side of the sheet bundle in the width direction from the binding portion and on the upstream side of the sheet bundle in the conveying direction from the binding portion. It is characterized by: Effect of the Invention

[0007] According to the present invention, in a sheet processing apparatus that bundles and binds a plurality of sheets on which images are formed, the sheet bundle can be aligned with high precision. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a schematic diagram of an image forming system. [Diagram 2] FIG. 2 is a hardware configuration diagram of the image forming system. [Diagram 3] FIG. 4 is a perspective view of a staple tray, a jogger fence, a trailing end fence, and a pressing member. [Figure 4] FIG. 4 is an enlarged perspective view of the rear end fence and the pressing member. [Diagram 5] 4 is a cross-sectional view of the rear end fence and the pressing member taken perpendicular to the width direction. FIG. [Figure 6] FIG. [Figure 7] FIG. 13 is a diagram showing the state in which two points at the downstream end of the stack of paper are stapled. [Figure 8] FIG. 13 is a diagram showing the state in which the left end of the paper stack is bound. [Figure 9] FIG. 13 is a diagram showing the state in which the right edge of the paper stack is bound at an angle. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. Fig. 1 is a schematic diagram of an image forming system 600 including a paper processing device 300 (sheet processing device) as an embodiment of a sheet processing device according to the present invention, and an image forming device 200 that supplies paper P (sheet), which is a sheet-like medium after image formation, to the paper processing device 300.

[0010] The present invention can be applied not only to the image forming system 600 consisting of the image forming device 200 and the paper processing device 300, but also to an image forming device equipped with an image forming means for forming an image on paper P and a folding processing means for performing a folding process on the paper P on which the image has been formed.

[0011] [Schematic configuration of image forming system 600] The image forming method of the image forming apparatus 200 constituting the image forming system 600 according to this embodiment is not limited. For example, the image forming apparatus 200 may be an inkjet type image forming unit that includes an image processing circuit, a liquid ejection head that ejects liquid, and a transport device that transports paper P to the liquid ejection head, and that forms an image by attaching the ejected liquid to the paper P. Alternatively, an electrophotographic type image forming unit that includes an image processing circuit, a photoconductor, an optical writing device, a developing device, a transfer device, and a fixing device may be used. Alternatively, a thermal transfer type image forming unit may be used.

[0012] The image processing circuit converts image data read by a scanner unit when the image forming apparatus 200 is a copier or image data input from an external information processing device such as a personal computer into image data suitable for image formation processing, and outputs the converted image data to the image forming unit.

[0013] When the image forming device 200 is equipped with an inkjet type image forming unit, the timing at which the liquid ejection head ejects ink droplets is controlled based on image data input from an image processing circuit, and the transport of the paper P to the position at which the ink droplets land is controlled, and the ink droplets are ejected at a predetermined timing and adhered to the paper P to form an image.

[0014] When the image forming apparatus 200 includes an electrophotographic image forming unit, an optical writing device optically writes on a photoconductor based on an image signal output from an image processing circuit to form an electrostatic latent image on the surface of the photoconductor. Then, a developing device develops the electrostatic latent image formed on the surface of the photoconductor by optical writing with toner, and a transfer device transfers the toner image on the surface of the photoconductor visualized by the developing device to a sheet of paper P. Then, a fixing device fixes the toner image transferred to the sheet of paper P to the sheet of paper P.

[0015] The paper P on which the toner image has been fixed by the image forming apparatus 200 is sent to the paper processing apparatus 300, where the desired post-processing is performed.

[0016] [Overall configuration of the paper-sheet processing device 300] Further, a paper processing device 300 serving as a sheet processing device is attached to the side of the image forming device 200 as shown in FIG.

[0017] The sheet-processing device 300 is configured to be able to perform predetermined post-processing by controlling the operation of various components in the sheet-processing device 300 using a control program executed by a control unit configured with hardware such as a CPU and a storage element. Note that the control unit including the sheet-processing device 300 is not shown in Fig. 1. The control unit may be provided in both the image forming device 200 and the sheet-processing device 300, or may be provided in either one of them and configured to control the entire image forming system 600.

[0018] The paper P carried into the paper processing device 300 from the image forming device 200 passes through the entrance transport path A and is transported inside. A punch unit 311 is disposed in the entrance transport path A as a post-processing unit that performs hole punching. If hole punching is not performed, the paper P is simply transported downstream through the entrance transport path A. If no other post-processing is performed, the first branch claw 312 is set in a state in which it guides the paper P to the upper transport path B as shown in FIG. 1. This causes the paper P to be discharged to the proof tray 313.

[0019] Furthermore, when performing "edge binding processing" in which the edges of the sheets P are aligned and bound, the first branching claw 312 is switched from the state shown in FIG. 1 to a state in which the sheets P are guided to the second branching claw 314. Then, the second branching claw 314 is set to a state in which the sheets P are guided from the intermediate conveying path C to the staple tray 323, as shown in FIG. 1. When multiple sheets P are carried in under this state, a predetermined number of sheets P can be guided to the staple tray 323 (tray) and the binding processing can be performed.

[0020] Then, the ends of a paper stack Pb (sheet stack) formed by stacking a predetermined number of sheets P on the staple tray 323 are aligned, and an end-stitching process is performed by an end-stitching staple unit 321 (stitching section), and the stapled paper stack Pb is discharged to a paper output tray 324.

[0021] When center folding or center stapling and center folding is performed, the first branching claw 312 is switched from the state shown in FIG. 1 and the second branching claw 314 is set to the state shown in FIG. 1 to guide the paper P to the intermediate transport path C. Then, when the trailing end of the paper P in the transport direction passes the second branching claw 314, the second branching claw 314 is switched and the intermediate transport roller 325 is rotated in the reverse direction. Then, the paper P is transported to the saddle stitching processing unit 400 via the lower transport path D.

[0022] The above configuration will be described in more detail below. The entrance transport path A is a transport path common to the upper transport path B, the middle transport path C, and the lower transport path D, located upstream of each of them. On the entrance transport path A, an entrance sensor 315 for detecting the paper P received from the image forming device 200, an entrance roller 316 downstream of the entrance sensor 315, a punch unit 311, and a first branch claw 312 and a second branch claw 314 downstream of the entrance sensor 315 are sequentially arranged.

[0023] The first branching claw 312 is biased in a certain direction by an elastic member such as a spring. When post-processing such as binding is not performed, the first branching claw 312 is held in a state in which it guides the paper P to the upper transport path B, as shown in Fig. 1. When the solenoid that drives the first branching claw 312 is turned on and a driving force is applied in a direction against the bias of the spring to rotate, the first branching claw 312 is in a state in which it guides the paper P toward the intermediate transport path C. Therefore, when the solenoid is off, the paper P is distributed to the upper transport path B, and when the solenoid is on, the paper P is distributed to the intermediate transport path C. The paper P distributed to the upper transport path B is discharged to the proof tray 313 by the proof intermediate roller 317 and the proof paper discharge roller 318.

[0024] Similarly to the first branch claw 312, the second branch claw 314 is also biased in a certain direction by an elastic member such as a spring, and is usually held in a state in which it guides the paper P from the intermediate conveyance path C to the staple tray 323, as shown in Fig. 1. When the paper P is to be discharged without being stapled, it is discharged to the paper output tray 324.

[0025] At this time, the paper P sent to the intermediate conveying path C is loaded onto the paper output tray 324 while being shifted a certain amount in the direction perpendicular to the conveying direction by shift discharge rollers 326 configured to move the paper P sent to the intermediate conveying path C by a certain amount in the direction perpendicular to the conveying direction of the paper P by a driving means. The shift amount of the shift discharge rollers 326 is determined based on the paper detection information detected by the entrance sensor 315, the size information of the paper P, etc.

[0026] When edge-stitching the paper stack Pb, the paper P transported to the intermediate transport roller 325 is brought into contact with the staple tray 323 by the pendulum motion of the tapping roller 327 that aligns the paper P, and is transported in the opposite direction to the sheet transport direction by the return roller, and its rear end is abutted against rear end fences 330a and 330b as sheet regulating members, so that its position in the transport direction is aligned. The entrance roller 316, the intermediate transport roller 325, the shift discharge roller 326, and the roller 327 are an example of a transport section.

[0027] In the following description, in the transport direction of the paper P transported by the rollers 327, the side where the paper P is supplied to the staple tray 323 is referred to as the "downstream side of the transport direction," and the side where the paper P is discharged from the staple tray 323 is referred to as the "upstream side of the transport direction." Additionally, the direction parallel to the surface of the paper stack Pb loaded on the staple tray 323 and perpendicular to the transport direction is referred to as the "width direction of the paper stack Pb (or staple tray 323)." Furthermore, the direction perpendicular to the transport direction and the width direction is referred to as the "thickness direction of the paper stack Pb."

[0028] Jogger fences 328a and 328b for aligning the width direction position of the paper P are disposed on the staple tray 323. A staple tray paper presence sensor 329 for detecting the presence or absence of the paper P on the staple tray 323 is disposed below the staple tray 323. An end-stitching staple unit 321 for performing a stapling process on the end of a paper stack Pb formed from a plurality of sheets of paper P is disposed at the downstream end (the end on the downstream side in the conveying direction of the paper P) which is the stapling position 322 of the paper P loaded on the staple tray 323.

[0029] Furthermore, the sheet stack Pb stacked on the staple tray 323 is pressed by pressure plates 331a and 331b (pressing members). The pressure plates 331a and 331b press the sheet stack Pb stacked on the staple tray 323 from the thickness direction of the sheet stack Pb.

[0030] The jogger fences 328a, 328b are disposed at both ends in the width direction of the staple tray 323, and slide toward and away from each other. The jogger fences 328a, 328b contact the sheet stack Pb stacked on the staple tray 323 from the width direction, thereby regulating the position of the sheet stack Pb in the width direction. The rear end fences 330a, 330b contact the downstream end in the transport direction, thereby regulating the position of the sheet stack Pb in the transport direction. The pressing plates 331a, 331b press the sheet stack Pb from the thickness direction. Details of the rear end fences 330a, 330b and the pressing plates 331a, 331b will be described later with reference to FIGS. 3 to 9.

[0031] The edge-stitching staple unit 321 staples the paper-sheet bundle Pb aligned by the jogger fences 328a, 328b, the rear end fences 330a, 330b, and the pressure plates 331a, 331b. The edge-stitching staple unit 321 may staple the paper-sheet bundle Pb using staples, or may staple the paper-sheet bundle Pb without using staples. As shown in Figs. 7 and 8, the edge-stitching staple unit 321 is configured to be movable in the width direction. As shown in Fig. 9, the edge-stitching staple unit 321 is configured to be rotatable around a rotation axis extending in the thickness direction. The specific configuration of the edge-stitching staple unit 321 is already known, so a detailed description will be omitted.

[0032] [Schematic configuration of saddle stitching processing unit 400] When performing saddle stitching and center folding, the paper P guided to the lower conveying path D by the intermediate conveying roller 325 and the second branch claw 314 is conveyed by the switchback conveying roller 341 and the movable roller 342 to the saddle stitching processing unit 400 located below.

[0033] The saddle stitching unit 400 is provided with a rear end fence 410 that is movable in the conveying direction of the paper P. The paper P is conveyed until its leading edge abuts against the rear end fence 410. At that time, the rear end fence 410 is moved in accordance with paper size information (size information in the conveying direction of the paper P) from the image forming device 200 so that the saddle stitching process and center folding process are performed at a target position, the abutment position of the leading edge of the paper P is changed, and the paper P is made to wait at a predetermined position.

[0034] By repeating the above-mentioned conveying operation for multiple sheets of paper P, the positions of the ends of the sheets P that contact the rear end fence 410 are aligned, and the ends of the paper stack Pb are aligned. This completes the alignment operation in the conveying direction of the paper stack Pb, with the center-folding position (folding position) for the paper stack Pb also being in a predetermined position that is specified in advance.

[0035] Next, the saddle stitching jogger fence 420 aligns the sheet bundle Pb in the width direction, completing the alignment operation of the sheet bundle in the width direction.

[0036] Thereafter, the binding position (which also corresponds to the later folding position) corresponding to the center of the paper stack Pb in this waiting position is moved to the position of the saddle stitch stapler 430, the stitcher is driven, and the binding process is performed between the stitcher and the clincher, thereby performing the saddle stitch process on the paper stack Pb.

[0037] As rear end fence 410 moves downward, saddle-stitched paper stack Pb is transferred to a position where the saddle stitching position faces folding blade 440. Folding blade 440 moves toward the nip of folding roller pair 450, contacts paper stack Pb near the stapled portion of paper stack Pb from a direction substantially perpendicular to the paper stack, and pushes it toward the nip.

[0038] The sheet stack Pb is pushed by the folding blade 440 as a pushing member and guided to the nip of the folding roller pair 450, and is pushed into the nip of the folding roller pair 450, which has been rotated in advance. The folding roller pair 450 pressurizes the sheet stack Pb pushed into the nip and transports it in the discharge direction. This pressurized transport operation folds the sheet stack Pb in the center, and a simply bound sheet stack Pb is formed.

[0039] Thereafter, the simply bound paper stack Pb is discharged onto the saddle stitch tray 344 by the saddle stitch paper discharge rollers 460.

[0040] When only center folding is to be performed on the paper stack Pb, the above-described saddle stitching process is not performed, and the rear end fence 410 is made to wait in advance at a predetermined position so that a predetermined position of the paper stack Pb becomes the binding position by the saddle stitching stapler 430. Then, an alignment operation is performed in the conveying direction of the ends of the multiple paper sheets P conveyed via the lower conveying path D, and the paper sheets are aligned in the width direction by the saddle stitching jogger fence 420, and then folding process is performed by the folding blade 440.

[0041] Fig. 2 is a hardware configuration diagram of an image forming system 600. As shown in Fig. 2, the image forming system 600 includes a central processing unit (CPU) 101, a random access memory (RAM) 102, a read only memory (ROM) 103, a hard disk drive (HDD) 104, and an interface (I / F) 105, which are connected via a common bus 109. The CPU 101, the RAM 102, the ROM 103, and the HDD 104 constitute a controller 100 that controls the operation of the image forming system 600.

[0042] The CPU 101 is a computing means and controls the operation of the entire image forming system 600. The RAM 102 is a volatile storage medium capable of reading and writing information at high speed, and is used as a working area when the CPU 101 processes information. The ROM 103 is a read-only non-volatile storage medium in which programs such as firmware are stored. The HDD 104 is a non-volatile storage medium capable of reading and writing information and has a large storage capacity, and stores an OS (Operating System), various control programs, application programs, etc.

[0043] The image forming system 600 processes a control program stored in the ROM 103, an information processing program (application program) loaded from a storage medium such as the HDD 104 to the RAM 102, and the like, by the arithmetic function of the CPU 101. This processing constitutes a software control unit including various functional modules of the image forming system 600. The combination of the software control unit thus constituted and the hardware resources mounted on the image forming system 600 constitutes a functional block that realizes the functions of the image forming system 600.

[0044] The I / F 105 is an interface that connects the image forming apparatus 200 and the paper processing apparatus 300 to a common bus 109. That is, the controller 100 controls the image forming apparatus 200 and the paper processing apparatus 300 through the I / F 105. More specifically, the controller 100 controls the image forming apparatus 200 to form an image on a sheet and supplies the sheet on which the image has been formed to the paper processing apparatus 300. The controller 100 also controls the paper processing apparatus 300 to bind the sheets on which the image has been formed by the image forming apparatus 200.

[0045] 2 shows an example in which the image forming apparatus 200 and the paper-sheet processing apparatus 300 are controlled by a common controller 100, but a controller for controlling the image forming apparatus 200 and a controller for controlling the paper-sheet processing apparatus 300 may be provided independently. The image forming apparatus 200 and the paper-sheet processing apparatus 300 may operate in conjunction with each other by the two controllers transmitting and receiving information.

[0046] FIG. 3 is a perspective view of the staple tray 323, the jogger fences 328a, 328b, the rear end fences 330a, 330b, and the pressing plates 331a, 331b. FIG. 4 is an enlarged perspective view of the rear end fence 330a and the pressing plate 331a. FIG. 5 is a cross-sectional view of the rear end fence 330a and the pressing plate 331a perpendicular to the width direction. FIG. 6 is a plan view of the rear end fence 330a and the pressing plate 331a. FIG. 7 is a diagram showing a state in which two points at the downstream end of the paper stack Pb are stapled. FIG. 8 is a diagram showing a state in which the left end of the paper stack Pb is stapled. FIG. 9 is a diagram showing a state in which the right end of the paper stack Pb is stapled obliquely.

[0047] 3, the rear end fences 330a, 330b and the pressing plates 331a, 331b are disposed downstream in the transport direction from the staple tray 323. The rear end fence 330a and the pressing plate 331a, and the rear end fence 330b and the pressing plate 331b are each integrally configured. Furthermore, the rear end fence 330a and the pressing plate 331a, and the rear end fence 330b and the pressing plate 331b are disposed on one side and the other side of the width direction of the paper stack Pb with respect to the center of the width direction of the paper stack Pb.

[0048] The rear end fence 330a and the pressing plate 331a, and the rear end fence 330b and the pressing plate 331b are configured to be able to move independently in the width direction. Note that the rear end fence 330a and the pressing plate 331a and the rear end fence 330b and the pressing plate 331b have the same basic structure except that their positions in the width direction are reversed, so the rear end fence 330a and the pressing plate 331a will be described in detail below.

[0049] As shown in FIGS. 4 and 5, the rear end fence 330a includes a first fence 21 (first regulating member) and a second fence 22 (second regulating member). The pressing plate 331a includes a first pressing plate 23 (first pressing member) and a second pressing plate 24 (second pressing member). The first pressing plate 23 is supported by the first fence 21 via a support shaft 25. The second pressing plate 24 is supported by the second fence 22 via support shafts 26 and 27. The first pressing plate 23 and the second pressing plate 24 are urged toward the paper stack Pb stacked on the staple tray 323 by coil springs 28 (urging members) fitted around the support shafts 25 to 27, respectively.

[0050] The first fence 21 has an I-shaped outer shape when viewed in the thickness direction. The first fence 21 is composed of a bottom wall 21a, a top wall 21b, and a rear wall 21c. The bottom wall 21a and the top wall 21b are disposed opposite each other at a predetermined interval in the thickness direction. The rear wall 21c connects the downstream ends of the bottom wall 21a and the top wall 21b to each other. The rear wall 21c is formed with a guide groove 21d extending in the thickness direction. Furthermore, the support shaft 25 is supported by the bottom wall 21a and the top wall 21b and extends in the thickness direction.

[0051] The second fence 22 has an L-shaped outer shape when viewed in the thickness direction. The second fence 22 is composed of a bottom wall 22a, a top wall 22b, and a rear wall 22c. The bottom wall 22a and the top wall 22b are disposed opposite each other at a predetermined interval in the thickness direction. The rear wall 22c connects the downstream ends of the bottom wall 22a and the top wall 22b to each other. The rear wall 22c is formed with a guide groove 22d extending in the thickness direction. The support shafts 26, 27 are supported by the bottom wall 22a and the top wall 22b at positions spaced apart in the width direction and extend in the thickness direction.

[0052] Further, a staple unit abutment portion 30 is provided on a frame formed integrally with the second fence 22. This staple unit abutment portion 30 is a portion that abuts against the main body frame of the edge-stitching staple unit 321 when the edge-stitching staple unit 321 moves as shown in Figures 7 to 9. Therefore, when the edge-stitching staple unit 321 moves toward the right in the width direction in Figure 4, the main body frame of the edge-stitching staple unit 321 abuts against the staple unit abutment portion 30, and thereafter, the edge-stitching staple unit 321 and the rear end fence 330a move together toward the right in the width direction in Figure 4.

[0053] Further, a torsion spring 31 is provided between the rear end fence 330a and the main body frame of the staple tray 323. This torsion spring 31 acts to bias the rear end fence 330a to the home position shown in Fig. 7. Therefore, when the edge-stitching staple unit 321 moves from the right to the left in the width direction in Fig. 4, the rear end fence 330a moves to the home position shown in Fig. 7 by the action of the torsion spring 31.

[0054] The first pressing plate 23 has an I-shaped outer shape when viewed in the thickness direction, similar to the first fence 21. The first pressing plate 23 is configured to be movable in the thickness direction along the support shaft 25 and the guide groove 21d. As shown in FIG. 5(A), when no sheets are loaded on the staple tray 323, the first pressing plate 23 abuts against the bottom wall 21a by the biasing force of the coil spring 28. On the other hand, as shown in FIG. 5(B), when a stack of paper sheets Pb is loaded on the staple tray 323, the first pressing plate 23 moves toward the top wall 21b against the biasing force of the coil spring 28 to press the stack of paper sheets Pb toward the bottom wall 21a.

[0055] The first pressing plate 23 is composed of a pressing portion 23a and a guide portion 23b. The pressing portion 23a is disposed downstream of the guide portion 23b in the transport direction and is parallel to the bottom wall 21a. The guide portion 23b is disposed upstream of the pressing portion 23a in the transport direction and is inclined toward the upstream side in the transport direction in a direction away from the paper stack Pb stacked on the staple tray 323.

[0056] The second pressing plate 24 has an L-shaped outer shape when viewed in the thickness direction, similar to the second fence 22. The second pressing plate 24 is configured to be movable in the thickness direction along the support shafts 26, 27 and the guide groove 22d. The second pressing plate 24 is also configured with a pressing portion 24a and a guide portion 24b. The configuration and function of the second pressing plate 24 are common to the first pressing plate 23, so a detailed description will be omitted.

[0057] Each of the multiple sheets guided to the staple tray 323 by the roller 327 is guided by the guide portions 23b, 23b and enters between the bottom walls 21a, 22a and the pressing portions 23a, 24a. The downstream end of the paper stack Pb abuts against the back walls 21c, 22c, and the position in the transport direction is regulated. Furthermore, the paper stack Pb loaded on the staple tray 323 is clamped between the bottom walls 21a, 22a and the pressing portions 23a, 24a, and thus the floating in the thickness direction is regulated.

[0058] As shown in Fig. 6, the second fence 22 is configured to be rotatable around a support shaft 29 (rotation axis) extending in the thickness direction. That is, the second fence 22 is configured to be rotatable between the abutting posture shown in Fig. 6(A) and the inclined posture shown in Fig. 6(B). The second pressing plate 24 rotates together with the second fence 22 between the abutting posture and the inclined posture.

[0059] The abutting posture is a posture in which the rear wall 22c is perpendicular to the transport direction. That is, the second fence 22 and the second pressing plate 24 are in the abutting posture when aligning the position of the paper stack Pb in the transport direction. The inclined posture is a posture rotated a predetermined angle (e.g., 45°) from the abutting posture. More specifically, the inclined posture is a posture in which the center side in the width direction is displaced downstream in the transport direction and the end side in the width direction is displaced upstream in the transport direction compared to the abutting posture. That is, the second fence 22 and the second pressing plate 24 change posture to the inclined posture in accordance with the binding position 322 of the paper stack Pb after aligning the position of the paper stack Pb in the transport direction.

[0060] FIG. 7 is a diagram for explaining a case where two-point stapling is performed on the downstream end of the paper stack Pb. As shown in FIG. 7, the edge-stitching staple unit 321 is configured to be movable in the width direction (from the position indicated by the solid line to the position indicated by the dotted line) at a position facing the downstream end of the paper stack Pb stacked on the staple tray 323. The edge-stitching staple unit 321 staples the paper stack Pb in an area surrounded by the rear end fence 330a and the pressing plate 331a, or in an area surrounded by the rear end fence 330b and the pressing plate 331b. In other words, the pressing plates 331a and 331b are provided so as to surround the edge-stitching staple unit 321. More specifically, the first pressing plate 23 presses the paper stack Pb stacked on the staple tray 323 against the bottom wall 21a on one side of the edge-stitching staple unit 321 in the width direction. Further, the second pressing plate 24 presses the sheet stack Pb stacked on the staple tray 323 against the bottom wall 22a on the other side of the edge-stitching staple unit 321 in the width direction and on the upstream side of the edge-stitching staple unit 321 in the transport direction.

[0061] 8 is a diagram for explaining a case where one-point stapling is performed on the left end of the downstream end of the paper stack Pb. As shown in Fig. 8, the rear end fence 330b, the pressure plate 331b, and the end-stapling staple unit 321 are moved in the width direction, so that the paper stack Pb can be stapled at any position on the left end in the width direction. The rear end fence 330a, the pressure plate 331a, and the end-stapling staple unit 321 can also perform the same operation.

[0062] 9 is a diagram for explaining a case where the end of the paper stack Pb is obliquely bound at a corner of the downstream end. As shown in FIG. 9, the rear end fence 330a, the pressure plate 331a, and the end-stitching staple unit 321 are moved to the right end in the width direction, and then the end-stitching staple unit 321 is rotated 45° counterclockwise. Since the staple unit abutment portion 30 provided on the main body frame of the rear end fence 330a abuts against the main body frame of the end-stitching staple unit 321, the rear end fence 330a and the pressure plate 331a also rotate counterclockwise around the support shaft 29. Then, after the end-stitching staple unit 321 has finished rotating, the binding portion of the end-stitching staple unit 321 is operated to perform the oblique binding process at the corner of the paper stack Pb. As described above, since the rear end fence 330a and the pressure plate 331a also rotate in accordance with the rotation of the edge-stitching staple unit 321, it is possible to maintain the alignment accuracy of the paper stack Pb before the rotation of the edge-stitching staple unit 321. Note that the rear end fence 330b, the pressure plate 331b, and the edge-stitching staple unit 321 can also perform the same operation.

[0063] According to the above embodiment, for example, the following advantageous effects are achieved.

[0064] According to the above embodiment, by pressing the paper stack Pb so as to surround the edge-stitching staple unit 321 with the pressing plates 331a and 331b, the binding position 322 by the edge-stitching staple unit 321 can be appropriately pressed. This allows the paper stack Pb that curls due to drying of ink, etc. to be aligned with high accuracy. As a result, the paper stack Pb with the downstream end aligned can be stapled by the edge-stitching staple unit 321. The pressing plates 331a and 331b do not need to surround the entire circumference of the edge-stitching staple unit 321, but by surrounding as wide an area as possible of the periphery of the edge-stitching staple unit 321, the above-mentioned action and effect become more pronounced.

[0065] Note that "surrounding the edge-stitching staple unit 321" is not limited to being continuously surrounding the edge-stitching staple unit 321, and as shown in Fig. 6, there may be a gap between the first pressing plate 23 and the second pressing plate 24. The gap between the first pressing plate 23 and the second pressing plate 24 is appropriately set within a range in which the binding position 322 of the paper stack Pb supported by the staple tray 323 does not curl or leave any undulations, for example.

[0066] Further, each of the pressing plates 331a, 331b is not limited to being composed of two parts, the first pressing plate 23 and the second pressing plate 24, and may be composed of one part or three or more parts. The same applies to the rear end fences 330a, 330b. For example, the paper-processing device 300 may omit the first pressing plate 23 and press at least two sides of the periphery of the rectangular edge-stitching staple unit 321 with the second pressing plate 24. However, it is preferable that the paper-processing device 300 presses three sides of the edge-stitching staple unit 321 with the first pressing plate 23 and the second pressing plate 24.

[0067] In addition, when pressing the range corresponding to the three sides of the end-stitching staple unit 321, it is desirable that the portions of the first pressing plate 23 and the second pressing plate 24 extending in the transport direction of the paper P (in other words, the portions corresponding to the left and right sides of the end-stitching staple unit 321) extend downstream in the transport direction of the paper P from the binding position 322 by the end-stitching staple unit 321, as shown in FIG. 7.

[0068] Furthermore, according to the above embodiment, by configuring the second pressing plate 24 to be rotatable around the support shaft 29, as shown in FIG. 9, even when the end-stitching staple unit 321 is rotated to staple the paper stack Pb, the paper stack Pb can be pressed so as to surround the end-stitching staple unit 321.

[0069] Furthermore, according to the above embodiment, the rear end fence 330a and the pressure plate 331a, and the rear end fence 330b and the pressure plate 331b are made movable independently in the width direction, so that the paper stack Pb can be pressed to surround the end-stitching staple unit 321 even when the binding position 322 of the end-stitching staple unit 321 is moved in the width direction.

[0070] Furthermore, according to the above embodiment, by providing guide portions 23b, 24b on the first pressing plate 23 and the second pressing plate 24, the sheet guided to the staple tray 323 by the roller 327 can be smoothly inserted between the bottom walls 21a, 22a and the pressing portions 23a, 24a.

[0071] Furthermore, the paper-sheet processing apparatus 300 according to the above embodiment provides particularly advantageous effects when processing sheets supplied from the inkjet image forming apparatus 200. However, the paper-sheet processing apparatus 300 is not limited to the inkjet image forming apparatus 200, and also provides advantageous effects when applied to an image forming system 600 that includes a device that applies liquid (e.g., pretreatment liquid) to a sheet or a device that applies heat to a sheet to dry it.

[0072] The present invention is not limited to the above-described embodiment, and various modifications are possible without departing from the technical gist of the present invention. The present invention covers all technical matters included in the technical ideas described in the claims. The above-described embodiment shows a preferred example, but a person skilled in the art can realize various modifications from the disclosed contents. Such modifications are also included in the technical scope described in the claims. [Explanation of symbols]

[0073] 21: First fence (first sheet restricting member) 21a, 22a: Bottom wall 21b,22b: Ceiling wall 21c,22c: Back wall 21d, 22d: Guide groove 22: Second fence (second sheet regulating member) 23: First pressing plate 23a, 24a: Pressing portion 23b, 24b: Guide section 24: Second pressure plate 25,26,27,29: Support shaft 28: Coil spring 100: Controller 101: CPU 102: RAM 103: ROM 104: HDD 105: Interface 109: Common bus 200: Image forming device 300: Paper processing device (sheet processing device) 311: Drilling unit 312: First branch claw 313: Proof tray 314: Second branch claw 315: Inlet sensor 316: Entrance roller 317: Proof intermediate roller 318: Proof ejection roller 321: Edge stitching staple unit 322 Binding position 323: Staple tray (tray) 324: Paper output tray 325: Intermediate conveyor roller 326: Shift discharge roller 327: Coro 328a, 328b: Jogger fence 329: Staple tray paper presence sensor 330a, 330b: Rear end fence (seat regulating member) 331a, 331b: Pressing plate (pressing member) 341: Switchback conveyor roller 342: Moving roller 344: Saddle stitch tray 400: Processing unit 410: Rear fence 420: Jogger Fence 430: Stapler 440: Folding blade 450: Pair of folding rollers 460: Paper ejection roller 600: Image forming system [Prior art documents] [Patent documents]

[0074] [Patent Document 1] JP 2013-86881 A [Patent Document 2] JP 2012-218900 A

Claims

1. A conveying unit that conveys the sheet in a conveying direction; a tray that stacks the plurality of sheets conveyed by the conveying unit as a sheet bundle; a sheet regulating member that abuts against an end of the sheet stack on a downstream side in the conveying direction to regulate a position of the sheet stack stacked on the tray in the conveying direction; a pressing member that presses the sheet stack stacked on the tray by moving in a thickness direction of the sheet stack; a binding unit that binds the sheet bundle loaded on the tray, The pressing member is provided so as to surround the binding portion when viewed in the thickness direction, The pressing member is a first pressing member having an I-shape that presses the sheet bundle on one side of the binding portion in a width direction of the sheet bundle; a second pressing member having an L-shape that presses the sheet stack on the other side of the stitching portion in the width direction and on the upstream side of the stitching portion in the conveying direction, the second pressing member having an L-shape that presses the sheet stack on the other side of the stitching portion in the width direction and on the upstream side of the stitching portion in the conveying direction.

2. The sheet processing apparatus according to claim 1 , wherein the second pressing member is configured to be rotatable about a rotation axis extending in the thickness direction.

3. The first pressing member is disposed at the center side in the width direction of the sheet, 3. The sheet processing apparatus according to claim 1, wherein the second pressing member is disposed on an outer side in a width direction of the sheet.

4. The sheet regulating member is configured to be movable in a width direction of the sheet stack, 4. The sheet processing apparatus according to claim 1, wherein the pressing member is supported by the sheet regulating member and moves in the width direction together with the sheet regulating member.

5. the sheet regulating member and the pressing member are disposed on one side and the other side, respectively, of a center in the width direction, 5. The sheet processing apparatus according to claim 4, wherein the sheet regulating members and the pressing members on one side and the other side in the width direction are configured to be independently movable in the width direction.

6. 6. The sheet processing apparatus according to claim 1, wherein an end portion of the pressing member on the upstream side in the transport direction is inclined in a direction away from the sheet stack toward the upstream side in the transport direction.

7. an image forming apparatus for forming an image on a sheet; 7. The sheet processing apparatus according to claim 1, further comprising: a sheet processing device for processing a plurality of sheets on which images are formed by the image forming apparatus; An image forming system comprising:

Images