Sheet processing device and image forming system

Abstract

To provide a configuration capable of obliquely binding a corner part of a sheet with a compact constitution.SOLUTION: When a stapling unit 400 performs the binding processing on the corner part on the R side in the widthwise direction of a sheet in a second posture for performing the oblique binding, first, the sheet is conveyed in the second conveying direction β2 by a raking paddle to perform the abutting operation of abutting the downstream end edge of the sheet in the second conveying direction β2 against a rear end regulating member 290 and the shift operation of moving the sheet to the F side in the widthwise direction by an alignment part 270A. Thereafter, a moving and rotating part rotates the staple unit from the first posture to the second posture, and the binding process is performed by the staple unit 400 in the second posture.SELECTED DRAWING: Figure 24

Description

[Technical field]

[0001] The present invention relates to a sheet processing apparatus that performs a binding process on sheets, and an image forming system that includes the sheet processing apparatus. [Background technology]

[0002] The sheet processing device has a binding section such as a staple unit that performs a stapling process on sheets, and performs the stapling process on a predetermined position of the sheets by moving the staple unit to the sheets placed on the placement section. Patent Document 1 discloses a configuration in which, when side stitching, in which the stapling process is performed in a direction along the width direction of the sheets, is performed by moving the sheets to a predetermined position, the sheets are moved in a direction opposite to the movement direction of the staple unit. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2006-248685 A Summary of the Invention [Problem to be solved by the invention]

[0004] The staple unit has a staple head (first part) from which staples can be protruded, and an anvil member (second part) that is disposed opposite the staple head and performs a stapling process on the sheets by clamping the sheets between the staple head and the anvil member. In such a staple unit, a rear side surface, such as a surface that constitutes the frame of the staple unit or a surface of a part of the cartridge that holds the staples, is located behind the position where the staple head and the anvil member perform the stapling process, and when the staple unit is viewed from the side, the staple head, the anvil member and the rear side surface form an approximately U-shape.

[0005] Here, there is a case where the staple unit is used to perform oblique binding, in which the corners of the sheets are bound in a direction oblique to the width direction of the sheets. In this case, the posture of the staple unit is a second posture that is oblique to the first posture in side binding. In recent years, there is a demand for compact devices. In particular, the installation space of a sheet processing device (so-called internal finisher) installed in the internal space of the image forming device is limited. For this reason, when performing oblique binding on sheets of maximum size using the staple unit, there is a risk that the sheet transported to the position where the binding process is performed will come into contact with a part of the rear side surface of the staple unit in the second posture, making it impossible to perform oblique binding on the corners of the sheets.

[0006] An object of the present invention is to provide a sheet processing apparatus and an image forming system that are capable of diagonally binding corners of sheets with a compact configuration. [Means for solving the problem]

[0007] The sheet processing apparatus of the present invention includes a first transport unit that transports a sheet in a first transport direction, a placement unit that places the sheet transported in the first transport direction by the first transport unit, a second transport unit that transports the sheet on the placement unit that has been transported in the first transport direction in a second transport direction opposite to the first transport direction, abutting unit against which a downstream edge in the second transport direction of the sheet transported in the second transport direction by the second transport unit is abutted, and abutting unit that moves in a width direction of the sheet that intersects with the first transport direction while abutting against an edge along the first transport direction of the sheet placed on the placement unit. a shift section that moves the sheet conveyed by the first conveying section in the width direction, a binding section that performs a binding process on the sheet whose downstream end edge in the second conveying direction is abutted against the abutment section and that is moved in the width direction by the shift section, and a moving and rotating section that moves the binding section in the width direction and further rotates the binding section between a first position and a second position inclined with respect to the first position, and the binding section includes a first portion, a second portion that is disposed opposite to the first portion and performs the binding process on the sheet by sandwiching the sheet between the first portion and the second portion, and the binding section is and a rear side surface that is arranged downstream in the second conveying direction of a position where the binding process is performed on the sheet between the first portion and the second portion when the binding portion is in one posture, the first posture is a posture in which the binding portion performs binding processing on a downstream end portion of the sheet in the second conveying direction in a direction along the width direction, and the second posture is a posture in which the binding portion performs binding processing on a corner portion on one end side of the downstream end portion of the sheet in the second conveying direction in a direction inclined with respect to the width direction, and when the binding portion performs binding processing on the corner portion on one end side of the sheet in the width direction in the second posture, The method includes abutting operation in which the second conveying unit conveys the sheet in the second conveying direction and abuts the downstream edge of the sheet in the second conveying direction against the abutment unit, and a shift operation in which the shift unit moves the sheet to the other end side in the width direction and to a position where the sheet will not contact the rear side when the binding unit is in the second position, relative to the position of the sheet conveyed to the storage unit by the first conveying unit, and then the moving and rotating unit rotates the binding unit from the first position to the second position, and the binding process is performed by the binding unit in the second position.

[0008] The sheet processing apparatus of the present invention includes a first transport unit that transports a sheet in a first transport direction, a placement unit that places the sheet transported in the first transport direction by the first transport unit, a second transport unit that transports the sheet on the placement unit that has been transported in the first transport direction by the first transport unit in a second transport direction opposite to the first transport direction, an abutment unit against which a downstream edge in the second transport direction of the sheet transported in the second transport direction by the second transport unit is abutted, and a width of the sheet that intersects with the first transport direction in a state where the sheet abuts against an edge along the first transport direction of the sheet placed on the placement unit. a shift section that moves in a width direction of the sheet conveyed by the first conveying section to move the sheet in the width direction, a binding section that performs a binding process on the sheet whose downstream end edge in the second conveying direction is abutted against the abutment section and that has been moved in the width direction by the shift section, and a moving and rotating section that moves the binding section in the width direction and further rotates the binding section between a first position and a second position inclined with respect to the first position, and the binding section includes a first portion and a second portion that is disposed opposite to the first portion and performs the binding process on the sheet by clamping the sheet between the first portion and the second portion. and a rear side surface that is arranged downstream in the second conveying direction of a position where the binding process is performed on the sheet by the first portion and the second portion when the binding unit is in a first position, the first position is a position where the binding unit performs the binding process on a downstream end portion of the sheet in the second conveying direction in a direction along the width direction, and the second position is a position where the binding unit performs the binding process on a corner portion on one end side of the downstream end portion of the sheet in the second conveying direction in a direction inclined with respect to the width direction, and the binding unit performs the binding process on a corner portion on one end side of the width direction of the sheet in the second position. When performing a binding process at a corner, the shift section performs a shift operation to move the sheet, which has been transported to the placement section by the first transport section, to a position on the other end side in the width direction and to a position where the sheet will not contact the rear side surface when the binding section is in the second position, and the moving and rotating section performs a rotation operation to rotate the binding section from the first position to the second position, and then the second transport section transports the sheet in the second transport direction and performs an abutment operation to abut the downstream end edge of the sheet in the second transport direction against the abutment section,The binding process is performed by the binding unit in the second position. Effect of the Invention

[0009] According to the present invention, it is possible to perform oblique binding on the corners of sheets with a compact configuration. [Brief description of the drawings]

[0010] [Figure 1] 1 is a cross-sectional view showing a schematic configuration of an image forming system according to an embodiment. [Diagram 2] FIG. 1 is a cross-sectional view showing a schematic configuration of a sheet processing apparatus according to an embodiment. [Diagram 3] FIG. 2 is a block diagram showing a main part of a control configuration of the sheet processing apparatus according to the embodiment. [Figure 4] FIG. 1 is a perspective view of a sheet processing apparatus according to an embodiment. [Diagram 5] FIG. 1 is a schematic perspective view of a sheet binding device according to an embodiment. [Figure 6] FIG. 2 is an exploded perspective view of a base portion of the sheet binding device according to the embodiment. [Figure 7] FIG. 2 is an exploded perspective view of a stapler moving unit of the sheet binding device according to the embodiment. [Figure 8] 13 is a perspective view showing a relationship between a cam groove and a stapler holding unit according to the embodiment. FIG. [Figure 9] FIG. 2A is a perspective view of a stapler holding unit according to the embodiment, and FIG. 2B is a cross-sectional view of a stapler moving unit according to the embodiment. [Figure 10] FIG. 2 is a perspective view of a stapler moving unit according to the embodiment. [Figure 11] FIG. 4 is a perspective view of a cam groove according to the embodiment. [Figure 12] FIG. 4 is a perspective view showing a relationship between a cam groove and a moving portion according to the embodiment. [Figure 13] FIG. 4 is a plan view of a cam groove according to the embodiment. [Figure 14] 1A is a plan view showing the relationship between the cam groove and the stapler moving unit in the home position, and FIG. 1B is a plan view showing the relationship between the cam groove and the moving portion. [Figure 15]13A is a plan view showing the relationship between the cam groove and the stapler moving unit at the oblique binding position on the front side, and FIG. 13B is a plan view showing the relationship between the cam groove and the moving portion. [Figure 16] 13A is a plan view showing the relationship between the cam groove and the stapler moving unit at the oblique binding position on the rear side, and FIG. 13B is a plan view showing the relationship between the cam groove and the moving portion. [Figure 17] 5A and 5B are plan views showing main components around a processing tray according to a comparative example, in which FIG. 5A shows a state in which a large-sized sheet is received, and FIG. 5B shows a state in which a small-sized sheet is received. [Figure 18] FIG. 2 is a plan view showing a main configuration around the processing tray according to the embodiment, in which the staple unit is in a home position. [Figure 19] FIG. 2 is a plan view showing a main configuration around the processing tray according to the embodiment, illustrating a state in which the first sheet is received. [Figure 20] FIG. 2 is a plan view showing a main configuration around the processing tray according to the embodiment, illustrating a state in which the first sheet is aligned. [Figure 21] FIG. 2 is a plan view showing a main configuration around the processing tray according to the embodiment, illustrating a state in which a second sheet is received. [Figure 22] FIG. 2 is a plan view showing a main configuration around the processing tray according to the embodiment, illustrating a state in which a second sheet is aligned. [Figure 23] FIG. 4 is a plan view showing a main configuration around the processing tray according to the embodiment, illustrating a state when a sheet stack is shifted. [Figure 24] FIG. 13 is a plan view showing a main configuration around the processing tray according to the embodiment, illustrating a state in which diagonal binding is being performed on a corner of a sheet stack. [Diagram 25] FIG. 2 is a plan view showing a main configuration around the processing tray according to the embodiment, illustrating a state in which a sheet stack is being discharged. [Figure 26] FIG. 11 is a plan view showing a main configuration around a processing tray according to another example of the embodiment, illustrating a state in which the first sheet is received. [Figure 27] FIG. 11 is a plan view showing a main configuration around a processing tray according to another example of the embodiment, illustrating a state when a first sheet is shifted. [Figure 28] 13 is a plan view showing a main configuration around a processing tray according to another example of the embodiment, illustrating a state in which a first sheet is abutted against a trailing end regulating member. FIG. [Figure 29] FIG. 11 is a plan view showing a main configuration around a processing tray according to another example of the embodiment, illustrating a state in which a first sheet is aligned. [Diagram 30] FIG. 11 is a plan view showing a main configuration around a processing tray according to another example of the embodiment, illustrating a state in which a second sheet is received. [Diagram 31] FIG. 11 is a plan view showing a main configuration around a processing tray according to another example of the embodiment, illustrating a state when a second sheet is shifted. [Diagram 32] FIG. 11 is a plan view showing a main configuration around a processing tray according to another example of the embodiment, illustrating a state in which a second sheet is abutted against a trailing end regulating member. [Diagram 33] FIG. 11 is a plan view showing a main configuration around a processing tray according to another example of the embodiment, illustrating a state in which a second sheet is aligned. [Diagram 34] FIG. 13 is a plan view showing a main configuration around a processing tray according to another example of the embodiment, illustrating a state in which a corner of a sheet stack is being obliquely bound. [Diagram 35] FIG. 13 is a plan view showing a main configuration around a processing tray according to another example of the embodiment, illustrating a state in which a sheet stack is discharged. [Diagram 36] FIG. 2 is a perspective view of a stapler unit according to the embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] The embodiment will be described with reference to Figs. 1 to 25 and 36. First, the schematic configuration of the image forming system of the embodiment will be described with reference to Fig. 1. In the following description, the front side (F side) is the side where the user operates the device, that is, the front side of the device, and is, for example, the side where an operation unit such as a button or an operation panel for operating the image forming system is located. Also, the rear side (R side) is the opposite side to the front side in the width direction of the sheet described later, that is, the back side of the device.

[0012] [Image formation system] 1 is a cross-sectional view showing a schematic configuration of an image forming system according to the present embodiment. The image forming system 1000A includes an image forming apparatus 100, a punch unit 150, and a sheet processing apparatus 200A. The image forming apparatus 100 is a copier, a printer, a facsimile, a multifunction machine having a plurality of these functions, or the like, and forms an image on a sheet such as paper or a plastic sheet. In this embodiment, the printer is an electrophotographic printer, and a sheet on which a toner image has been formed is discharged from a first discharge section 101 or a second discharge section 102. The image forming apparatus 100 may be an inkjet type image forming apparatus.

[0013] In the image forming apparatus of this embodiment, although detailed illustration is omitted, a toner image is formed on a sheet in an image forming unit 103. Simply put, the surface of a photosensitive drum is charged and exposed to light to form an electrostatic latent image on the photosensitive drum. This electrostatic latent image is then developed into a toner image by a developing device using a developer. The toner image formed on the photosensitive drum is transferred to a sheet, and is then fixed to the sheet by heating and pressing it in a fixing device. The sheet with the fixed toner image passes through a transport path 104 and is sent to a first discharge unit 101 or a second discharge unit 102.

[0014] The image forming apparatus 100 of the present embodiment includes an image forming apparatus main body 110 including an image forming section 103, a conveying path 104, a first discharge section 101, and a second discharge section 102, and an image reading section 120 disposed above the image forming apparatus main body 110. The image reading section 120 reads an image on a document and transmits the read image signal to the image forming apparatus main body 110. The image forming apparatus main body 110 includes a first housing section 111 in which the image forming section 103 is disposed, and a second housing section 112 in which a part of the conveying path 104, the first discharge section 101, and the second discharge section 102 are disposed, and the second housing section 112 is disposed above the first housing section 111. The image reading section 120 is disposed above the second housing section 112. The second housing is also provided with an operation panel (not shown) that allows a user to input instructions (printing conditions, mode settings, etc.) to the image forming apparatus 100, the punching unit 150, and the sheet processing apparatus 200A.

[0015] In this embodiment, with this configuration, there is an internal space 130 surrounded by the first housing section 111, the second housing section 112, and the image reading section 120. Then, a sheet is discharged from the first discharge section 101 or the second discharge section 102 into the internal space 130. Also, a punch unit 150, a sheet processing device 200A, and the like are detachably attached to this internal space 130. In this embodiment, the image forming system 1000A is configured by installing the punch unit 150 and the sheet processing device 200A, but either one of them, or another device performing sheet processing, may be installed.

[0016] The punch unit 150 is connected to the first discharge section 101, and can receive the sheet discharged from the first discharge section 101 and perform a punching process on the sheet. The sheet processing device 200A is connected to the sheet discharge section of the punch unit 150, and can receive the sheet discharged from the punch unit 150. Then, as will be described in detail later, it can perform a predetermined process such as stapling on the sheet. It is possible to deliver a sheet to the sheet processing device 200A without performing a punching process in the punch unit 150, and it is also possible to discharge the sheet in the sheet processing device 200A without performing a predetermined process. It is possible that the sheet discharged from the second discharge section 102 is discharged to a sheet placement surface 160 above the punch unit 150 and the sheet processing device 200A.

[0017] 1, rails 131 are arranged in the internal space 130, and the punch unit 150 and the sheet processing device 200A can be attached and detached in the directions of arrows α1 and α2 along the rails 131. It is also possible to omit the punch unit 150 and directly connect the sheet processing device 200A to the first discharge section 101. Also, by making the punch unit 150 and the sheet processing device 200A detachable in this manner, it is possible to handle jammed sheets.

[0018] For example, if a sheet jams in the first discharge section 101, the punch unit 150 and the sheet processing device 200A are pulled out in the direction of the arrow α1 to expose the first discharge section 101. If a sheet jams in the punch unit 150, only the sheet processing device 200A is pulled out in the direction of the arrow α1 to expose the punch unit 150. When mounting the punch unit 150 and the sheet processing device 200A in the image forming apparatus 100, they are pushed in in the direction of the arrow α2. As described above, in this embodiment, since the sheet processing device 200A is disposed in the internal space 130 of the image forming apparatus 100, it is required to reduce the size of the sheet processing device 200A.

[0019] [Sheet processing device] The configuration of the sheet processing apparatus 200A of this embodiment will be described with reference to Fig. 2. The sheet processing apparatus 200A includes a conveying path 210A, pre-processing rollers 211A and 212A as a first conveying section, a processing tray 220 as a placement section, an upper discharge roller (nip member) 230A and a lower discharge roller 230B as a pair of discharge rotors (discharge section), a pick-up paddle 240A as a second conveying section, a trailing end drop member 250A as a sheet drop section, an alignment section 270A as a shift section, a return member 280, a trailing end regulating member 290 as a butting section, a stacking tray 300 as a stacking section, a sheet pressing paddle 320A, and the like. A sheet received from the image forming apparatus 100 or the punch unit 150 is conveyed to the conveying path 210A.

[0020] The sheet conveyed from the conveying path 210A is either directly discharged to the stacking tray 300 or placed on the processing tray 220 depending on the mode of processing the sheet. Note that direct discharge to the stacking tray 300 means that the sheet is discharged to the stacking tray 300 without being conveyed backward to a position on the processing tray 220 where stapling can be performed. In other words, the sheet processing device 200A has a mode in which the sheet stapled by the staple unit 400 is discharged to the stacking tray 300, and a mode in which the sheet is discharged to the stacking tray 300 without stapling by the staple unit 400. In this embodiment, the sheet can be aligned by the alignment section 270A without being placed on the processing tray 220. Also, the sheet can be aligned on the processing tray 220, and the staple unit 400 can staple the sheet placed on the processing tray 220. Furthermore, the sheet or sheet stack placed on the processing tray 220 can be discharged onto the stacking tray 300 by a pair of discharge rotating bodies, such as an upper discharge roller 230A and a lower discharge roller 230B. The configuration of each section will be described in detail below.

[0021] [Transport path] The conveying path 210A is a path for conveying a sheet in a first conveying direction (a predetermined direction), and includes an upper guide 2101 for guiding the upper surface of the conveyed sheet, and a lower guide 2102 for guiding the lower surface of the sheet. In the conveying path 210A, pre-processing rollers 211A and 212A and upstream rollers (entrance rollers) 213a and 213b are arranged as a first conveying section (a pair of conveying rotating bodies). These are arranged in pairs so as to be spaced apart in the sheet width direction (arrow γ direction in FIG. 4) intersecting with the sheet conveying direction (first conveying direction, arrow β direction in FIG. 2 (left-right direction)).

[0022] The pre-processing rollers 211A and 212A are a first transport unit and a pair of transport rotating bodies that transport a sheet, and at least one of them rotates while sandwiching a sheet. The upstream rollers 213a and 213b are at least one of them rotates while sandwiching a sheet. The upstream rollers 213a and 213b are disposed at the entrance of the sheet processing apparatus 200A, and receive the sheet transported from the upstream side of the sheet processing apparatus 200A and transport it to the transport path 210A. Then, the sheet that has passed through the transport path 210A reaches the pre-processing rollers 211A and 212A.

[0023] The pre-processing rollers 211A and 212A form a pre-processing nip portion 211a capable of nipping and transporting a sheet. The pre-processing nip portion 211a nips the sheet and transports it in the first transport direction, and the sheet is discharged from the transport path 210A. The pre-processing rollers 211A and 212A can be brought into contact with or separated from each other, or the nip pressure can be changed.

[0024] [Processing tray] The processing tray 220 as a placement unit is disposed downstream in the sheet conveying direction (first conveying direction) of the conveying path 210A and vertically below the conveying path 210A. The processing tray 220 is inclined with respect to a horizontal plane so that the upstream side in the first conveying direction is lower than the downstream side. The processing tray 220 temporarily places a sheet conveyed to the downstream side in the first conveying direction by the pre-processing rollers 211A and 212A. The processing tray 220 can stack a plurality of sheets, and the aligning unit 270A aligns the sheets in the width direction and moves them in the width direction (shifts the sheets) on the processing tray 220. At the upstream end of the processing tray 220 in the first conveying direction, a rear end regulating member 290 is disposed as an abutting unit against which the upstream edge in the first conveying direction of the sheet placed on the processing tray 220 (the downstream edge in the second conveying direction opposite to the first conveying direction, the rear end of the sheet) is abutted. A part of the processing tray 220 (for example, the downstream end in the first transport direction) may protrude vertically upward beyond the transport path 210A.

[0025] Further, a staple unit 400 is disposed upstream of the processing tray 220 in the first transport direction as a binding section that performs a binding process on sheets. The staple unit 400 performs a stapling process (binding process) as a predetermined process on the sheet stack that has been aligned in the width direction and regulated at the rear end by the processing tray 220. The staple unit 400 constitutes a part of a sheet binding device 410 as described later, and is capable of changing a staple position with respect to the sheet stack, and moves according to the staple position. Note that the predetermined process may be other processes such as punching other than stapling. The sheet or sheet stack placed on the processing tray 220 is discharged to the stacking tray 300 by upper discharge rollers 230A and lower discharge rollers 230B as described later.

[0026] [Scraping paddle] The take-in paddle 240A as a second transport section transports the sheet on the processing tray 220 in a second transport direction opposite to the first transport direction. The take-in paddle 240A has a paddle section 2401 as a rotating member, a paddle arm 2402 as a support section that supports the paddle section 2401, and a swing fulcrum 2403 that swingably supports the paddle arm 2402. That is, the paddle arm 2402 can swing up and down around the swing fulcrum 2403, and the paddle section 2401 is rotatably provided at the tip of the paddle arm 2402.

[0027] The pick-up paddle 240A can swing around a swing fulcrum 2403 between a return position where the paddle portion 2401 contacts the upper surface of the sheet on the processing tray 220 to convey the sheet in the second conveying direction, and an upper retreat position where the paddle portion 2401 retreats above the return position. The swing fulcrum 2403 is disposed upstream in the first conveying direction from a pre-processing nip portion 211a, which is a nip position where the sheet is sandwiched between the pre-processing rollers 211A and 212A, and vertically above the pre-processing nip portion 211a. The paddle arm 2402 extends downstream in the first conveying direction from the swing fulcrum 2403, and the paddle portion 2401 is provided at its tip. A pair of pick-up paddles 240A are disposed on both sides in the width direction of an upper discharge roller 230A, which will be described later.

[0028] [Rear end drop part] A pair of trailing end drop members 250A serving as sheet drop sections are provided on both sides of the pair of take-in paddles 240A. That is, the pair of trailing end drop members 250A are disposed on both sides of the take-in paddle 240A in the width direction, and move vertically in conjunction with the take-in paddle 240A as described below, thereby coming into contact with the upper surface of the upstream side of the sheet in the first conveying direction, and dropping the upstream end (rear end) of the sheet toward the processing tray 220. Note that the trailing end drop members 250A may be driven separately from the take-in paddle 240A.

[0029] The trailing end dropping member 250A has a rotation shaft 2501 as a rotation center downstream in the first transport direction from the pre-processing rollers 211A, 212A as a pair of transport rollers. The trailing end dropping member 250A extends from the rotation shaft 2501 to the upstream side in the first transport direction and is rotatable about the rotation shaft 2501 from an upper position above the pre-processing rollers 211A, 212A to a lower position below the pre-processing rollers 211A, 212A. By rotating from the upper position to the lower position, the trailing end dropping member 250A abuts against the sheet transported by the pre-processing rollers 211A, 212A from above and drops the sheet onto the processing tray 220 below.

[0030] [Return part] The returning member 280 further transports the sheet transported by the take-in paddle 240A toward the trailing end regulating member 290 as described above, and brings the trailing end of the sheet into contact with the trailing end regulating member 290 to regulate the trailing end position of the sheet. Such a returning member 280 is formed of a knurled belt 281, and by rotating and driving the knurled belt 281, the returning member 280 further takes in the sheet transported upstream in the first transport direction by the take-in paddle 240A, and brings the trailing end into contact with the trailing end regulating member 290. The returning member 280 is movable between a contact position where it can contact the sheet and a retracted position retracted upward from the contact position, and moves to the contact position when the sheet is transported toward the trailing end regulating member 290, and moves to the retracted position when the sheet on the processing tray 220 is transported toward the stacking tray 300.

[0031] [Discharge roller] The upper discharge roller 230A and the lower discharge roller 230B constitute a pair of discharge rotors and a discharge section, and transport and discharge the sheet transported downstream in the first transport direction by the pre-processing rollers 211A and 212A downstream in the first transport direction from the processing tray 220. Specifically, the upper discharge roller 230A and the lower discharge roller 230B discharge the sheet stapled by the staple unit 400 to the stacking tray 300. The upper discharge roller 230A can move between a clamping position (contact position) where the sheet is clamped between the upper discharge roller 230A and the lower discharge roller 230B and a retracted position retracted upward from the clamping position, and clamps the sheet between the upper discharge roller 230A and the lower discharge roller 230B at the clamping position. That is, the upper discharge roller 230A functions as a nipping member that nips the sheet between the lower discharge roller 230B at the clamping position. The upper discharge rollers 230A and the lower discharge rollers 230B are arranged in pairs spaced apart from each other in the width direction of the sheet, and are arranged on the inner side in the width direction of the pair of pick-up paddles 240A in this embodiment.

[0032] The upper discharge roller 230A and the lower discharge roller 230B hold a sheet or a sheet bundle at the clamping position, and the lower discharge roller 230B rotates to convey the clamped sheet or sheet bundle. The upper discharge roller 230A is a driven roller that rotates following the rotation of the lower discharge roller 230B, but may be driven. That is, in this embodiment, the upper discharge roller 230A is a driven rotor, and the lower discharge roller 230B is a driving rotor. The upper discharge roller 230A functions as a nip member that can hold a sheet between the lower discharge roller 230B at the clamping position, but this nip member may be another rotor such as a belt instead of a roller, or may be an abutting member that abuts against the sheet without rotating like a lever member. The lower discharge roller 230B may be a rotor such as a belt other than a roller.

[0033] The upper discharge roller 230A can rotate around the rotation shaft 2301 between the clamping position and the retreat position. In other words, the upper discharge roller 230A can move up and down between the clamping position and the retreat position. The upper discharge roller 230A is provided at the tip of a discharge arm 2302 serving as a support. The rotation shaft 2301 is provided coaxially with the swing fulcrum 2403 described above, and is disposed upstream in the first conveying direction from the pre-processing nip portion 211a where the pre-processing rollers 211A and 212A clamp the sheet, and vertically above the pre-processing nip portion 211a. The discharge arm 2302 is extended from the rotation shaft 2301 to the downstream side in the first conveying direction, and the upper discharge roller 230A is provided at the tip of the discharge arm 2302. The rotation shaft 2301 does not have to be disposed coaxially with the swing fulcrum 2403, but in this embodiment, the rotation shafts of the upper discharge roller 230A and the pick-up paddle 240A are disposed coaxially.

[0034] The pivot shaft 2301 is disposed upstream in the first conveying direction of a discharge nip portion where the upper discharge roller 230A nips the sheet between the lower discharge roller 230B and the upper discharge roller 230A at the clamping position. In addition, the upper discharge roller 230A is located vertically above the pre-processing nip portion 211a where the pre-processing rollers 211A and 212A nips the sheet at the retracted position, and the pivot shaft 2301 is located vertically above the center of the upper discharge roller 230A at the retracted position.

[0035] Since the positional relationship between the rotation shaft 2301 and the pre-processing nip portion 211a is defined as described above, the upper discharge roller 230A allows the sheet that has passed through the pre-processing nip portion 211a to move toward the stacking tray 300 when in the retracted position. Meanwhile, the upper discharge roller 230A moves downward from the retracted position toward the clamping position by rotating counterclockwise in FIG. 2 about the rotation shaft 2301. Then, the upper discharge roller 230A moves to the clamping position, whereby the sheet can be clamped between the upper discharge roller 230A and the lower discharge roller 230B.

[0036] [Matching part] The alignment unit 270A as a shift unit moves in a shift direction (width direction) intersecting with the first transport direction while being in contact with an edge of the sheet transported downstream in the first transport direction by the pre-processing rollers 211A and 212A, thereby moving the sheet in the shift direction. The alignment unit 270A has a pair of alignment plates 271A arranged to face each other in the shift direction.

[0037] The pair of alignment plates 271A are disposed further downstream than the downstream end of the conveying path 210A in the first conveying direction, and align the sheet in the width direction by moving in the width direction and contacting the width direction edge of the sheet. In this embodiment, the alignment plates 271A are disposed on both sides of the sheet in the width direction placed on the processing tray 220, and are movable in the width direction. The pair of alignment plates 271A extend from the upstream side to the downstream side in the first conveying direction with respect to the upper discharge roller 230A and the lower discharge roller 230B. The pair of alignment plates 271A have the same configuration. The pair of alignment plates 271A move in the shift direction by the drive of the front side (F side) alignment plate moving motor MT16 and the rear side (R side) alignment plate moving motor MT17 (see FIG. 3) as the drive unit.

[0038] The alignment plate 271A is formed so that the width in the vertical direction is wider on the downstream side in the first transport direction. That is, the alignment plate 271A has a first plate portion 2701 on the downstream side in the first transport direction, and a second plate portion 2702 formed so as to be continuous with the first plate portion 2701 on the upstream side in the first transport direction. The first plate portion 2701 has a larger area in the vertical direction than the second plate portion 2702 so that the first plate portion 2701 can abut against the sheet even if the leading end side of the transported sheet is curled upward or downward. On the other hand, the second plate portion 2702 is formed so that the height in the vertical direction is lower than that of the first plate portion 2701 so that the second plate portion 2702 does not interfere with the trailing end dropping member 250A even if the trailing end dropping member 250A is located at a lower position. In addition, the upper edge of the second plate portion 2702 is inclined so as to become lower toward the upstream side in the first transport direction.

[0039] The first plate portion 2701 is formed so as to straddle the upper discharge rollers 230A and the lower discharge rollers 230B from the upstream side to the downstream side in the first transport direction. This allows at least the first plate portion 2701 to come into contact with the sheet even when the sheet is discharged by a first shift discharge process described later. The second plate portion 2702 is located on the processing tray 220 and is formed continuously with the first plate portion 2701 in the first transport direction. This allows at least the second plate portion 2702 to come into contact with the sheet placed on the processing tray 220 by a second shift discharge process described later.

[0040] [Loading tray] As described above, the stacking tray 300 as a stacking section stacks sheets discharged by the upper discharge roller 230A and the lower discharge roller 230B. The stacking tray 300 is provided on the downstream side of the processing tray 220 in the first transport direction and is movable vertically downward. The stacking tray 300 is inclined with respect to the horizontal plane so that the upstream side in the first transport direction is lower than the downstream side. The stacking tray 300 is supported so as to be movable in the vertical direction along rails arranged in the vertical direction, for example, and is raised and lowered by driving a stacking tray lifting motor MT20 (FIG. 3) as a lifting means.

[0041] At the upstream end of the stacking tray 300 in the first transport direction, there are provided an upright surface 310a as a stacking side regulating means for regulating the upstream end (rear end) in a predetermined direction of the sheet or sheet bundle stacked on the stacking tray 300, and a rear end presser 310b for pressing the rear end of the sheet abutting against the upright surface 310a. The rear end presser 310b is inclined toward the downstream side in the first transport direction as it goes upward, so that even if the rear end of the sheet is curled upward, it can be pressed by this rear end presser 310b. In addition, a sheet presser paddle 320A is provided coaxially with the rotation axis of the lower discharge roller 230B.

[0042] The stacking tray 300 can be raised and lowered by a stacking tray lifting motor MT20 between a first stacking position and a second stacking position that is lower than the first stacking position. The second stacking position is a position where the stacking tray 300, which has been lowered when discharging sheets onto the stacking tray 300, switches to an upward movement. When discharging sheets, the stacking tray 300 is raised and lowered, and the sheet pressing paddle 320A rotates, so that the sheet or sheet stack on the stacking tray 300 is pressed down by the sheet pressing paddle 320A.

[0043] [Control configuration of sheet processing device] The control configuration of the sheet processing apparatus 200A will be described with reference to Fig. 3. Fig. 3 is a block diagram showing the motors and sensors of the sheet processing apparatus 200A. Signals from these sensors are input to a control unit 203 as a control means, and the motors are controlled by the control unit 203. The control unit 203 is communicably connected to a control unit of the image forming apparatus 100, and controls the entire sheet processing apparatus 200A.

[0044] Such a control unit 203 has a CPU (Central Processing Unit), a ROM (Read Only Memory), and a RAM (Random Access Memory). The CPU controls each unit while reading a program corresponding to a control procedure stored in the ROM. Working data and input data are stored in the RAM, and the CPU performs control by referring to the data stored in the RAM based on the above-mentioned programs, etc.

[0045] The conveying motor MT11 drives either of the upstream rollers (entrance rollers) 213a and 213b, either of the pre-processing rollers 211A and 212A, the pick-up paddle 240A, and the return member 280. The upper processing motor MT12 raises and lowers the pick-up paddle 240A, the trailing end drop member 250A, and the upper discharge roller (nip member) 230A. In this embodiment, in addition to the above, there are provided a return lift motor MT13 for raising and lowering the returning member 280, a discharge roller motor MT14 for driving the upper discharge roller 230A, a sheet pressing motor MT15 for driving the sheet pressing (bundle pressing) paddle 320A, an F-side alignment plate moving motor MT16 for moving (laterally moving) the front alignment plate 271A in the width direction, an R-side alignment plate moving motor MT17 for moving (laterally moving) the rear alignment plate 271A in the width direction, an STP moving motor MT18 for moving the staple unit (STP) 400 to change the staple position, an STP motor MT19 for driving the staple unit 400 to staple the sheet bundle, and a loading tray lift motor MT20 for raising and lowering the loading tray 300.

[0046] Each sensor will be described with reference to FIG. 2. First, the entrance sensor SN11 is provided on the conveying path 210A and detects the leading edge of a sheet conveyed to the conveying path 210A. The processing upper HP sensor SN12 detects the home positions of the take-in paddle 240A, the trailing end drop member 250A, and the upper discharge roller (nip member) 230A. The return lift HP sensor SN13 detects the home position of the return member 280 (a position retracted from the processing tray 220). The processing tray sheet detection sensor SN14 detects the presence or absence of a sheet on the processing tray 220. The sheet pressing HP sensor SN15 detects the home position of the sheet pressing paddle 320A.

[0047] The F-side alignment plate HP sensor SN16 and the R-side alignment plate HP sensor SN17 respectively detect that the front alignment plate 271A and the rear alignment plate 271A are in positions (home positions) spaced apart in the width direction from the sheets placed on the processing tray 220. The stapler movement HP sensor SN18 detects that the staple unit 400 is in the home position. The sheet detection sensor SN19 detects the top sheet placed on the stacking tray 300. The stacking tray encoder sensor SN20 detects the position of the stacking tray 300 in the lifting / lowering direction. The stacking tray lower limit position detection sensor SN21 detects the lower limit position of the stacking tray 300. The control unit 203 performs various controls, as described below, based on the signals of these sensors.

[0048] [Control of each mode] Next, the control of each mode of this embodiment will be described. In this embodiment, there are a straight discharge mode in which a sheet sent to the sheet processing device 200A is discharged directly to the stacking tray 300 without undergoing a predetermined process, a shift mode in which a sheet sent to the sheet processing device 200A is shifted in the width direction (shifted) and discharged to the stacking tray 300, and a staple mode in which a sheet sent to the sheet processing device 200A is stapled as a predetermined process and discharged to the stacking tray 300. Each of these modes is selected by the user.

[0049] In the shift mode, there are a case where the shift operation is performed on a sheet (first sheet, small size sheet) having a first length in the sheet conveying direction (first conveying direction), and a case where the shift operation is performed on a sheet (second sheet, large size sheet) having a second length in the first conveying direction longer than the first length. The small size sheet is, for example, a sheet having a length in the first conveying direction that is equal to or shorter than a predetermined length, and the large size sheet is, for example, a sheet having a length in the first conveying direction that is longer than the predetermined length. The predetermined length is, for example, a so-called A4 vertical size in which an A4 size paper is sent in a vertical direction (the direction in which the long side is the conveying direction). In the shift mode, a productivity priority mode that prioritizes productivity and an alignment priority mode that prioritizes sheet alignment can be selected and executed.

[0050] The productivity priority mode as the first shift discharge process is a mode in which the sheet transported downstream in the first conveying direction by the pre-processing rollers 211A, 212A is not transported in the second conveying direction by the pick-up paddle 240A, but is shifted in the shift direction by the alignment section 270A by driving the F-side alignment plate moving motor MT16 and the R-side alignment plate moving motor MT17, and is discharged onto the stacking tray 300 by the upper discharge rollers 230A and the lower discharge rollers 230B.

[0051] The alignment priority mode as the second shift discharge process is a mode in which a sheet transported downstream in the first conveying direction by pre-processing rollers 211A, 212A is transported in the second conveying direction on processing tray 220 by pick-up paddle 240A, and after the downstream edge of the sheet in the second conveying direction is abutted (regulated) against trailing end regulating member 290, the sheet is shifted in the shift direction by alignment section 270A by driving F-side alignment plate moving motor MT16 and R-side alignment plate moving motor MT17 without performing a specified processing by staple unit 400, and is discharged onto stacking tray 300 by upper discharge rollers 230A and lower discharge rollers 230B.

[0052] [Manual Binding] The outline of the external configuration of the sheet processing apparatus 200A of the present embodiment configured as described above is as shown in FIG. 4. In the sheet processing apparatus 200A of the present embodiment, a manual insertion section 204 is provided on the front side in the width direction, into which a user can manually insert a sheet or a sheet bundle from outside. The manual insertion section 204 is a section into which a corner of a sheet bundle is inserted when a user performs manual binding by stapling the sheet bundle from outside the apparatus. When a user inserts a sheet bundle into the manual insertion section 204 and presses an operation button 205, the staple unit 400 moves to this position and performs stapling. Note that a detection section for detecting the insertion of a sheet bundle into the manual insertion section 204 may be provided, and when the detection section detects the sheet bundle, the staple unit 400 may be moved to perform stapling. In this case, the operation button 205 may be omitted.

[0053] [Sheet binding device] Next, the sheet binding device 410 of this embodiment will be described with reference to Fig. 5 to Fig. 16(b). First, the overall configuration of the sheet binding device 410 will be described with reference to Fig. 5 to Fig. 10. In Figs. 5 and 6, the right front side of the figure is the front side (F side) of the device, and the left rear side is the rear side (R side). In Fig. 8, the right front side of the figure is the rear side (R side) of the device, and the left rear side is the front side (F side).

[0054] As shown in Fig. 5, the sheet binding device 410 has a base portion 420 and a stapler movement unit 450. As shown in Fig. 6, the base portion 420 includes a base 411, a cam groove 430 as a guide portion, a drive unit 440, and the like. The cam groove 430 and the drive unit 440 are fixed onto the base 411. Also fixed onto the base 411 are an HP sensor 412 (the above-mentioned stapler movement HP sensor SN18) that detects the home position (HP) of the staple unit 400, and an abutment member 413.

[0055] As shown in FIG. 7, the stapler moving unit 450 includes a stapler unit 400, a stapler holding unit 460, and the like. The stapler unit 400 performs a stapling process on a sheet whose downstream edge in the second transport direction is abutted against the trailing end regulating member 290 and moved in the width direction by the alignment portion 270A. As shown in FIG. 9(b), FIG. 10, and FIG. 36, the stapler unit 400 includes a unit frame 402, a staple cartridge 403, a staple head 404, an anvil member 405, and the like. The unit frame 402 includes a pair of metal side plates 402a, a pair of resin frames 402b disposed between the pair of side plates 402a, and the like. The staple cartridge 403 is detachably provided on the unit frame 402 and holds staples. The staple cartridge 403 is mounted between the pair of resin frames 402b.

[0056] The staple head 404 as the first part is a part that supplies the staples held in the staple cartridge 403 to a position where the staple processing is performed, and in this embodiment, is disposed below the anvil member 405. The anvil member 405 as the second part is a part that is disposed opposite the staple head 404 and performs the staple processing on the sheets by clamping the sheets between the staple head 404 and the staple head 404. In this embodiment, the anvil member 405 is disposed above the staple head 404 and moves up and down by being driven by the staple driving mechanism 407. The anvil member 405 is formed with a bending groove 405a for bending the tip of the staple that is supplied from the staple head 404 and penetrates the sheet stack. The staple driving mechanism 407 is a mechanism that moves the anvil member 405 up and down by being driven by the STP motor MT19 (FIG. 3).

[0057] The staple unit 400 has an insertion section 401 for inserting a sheet stack between the staple head 404 and the anvil member 405. The insertion section 401 has a substantially U-shape when the staple unit 400 is viewed from either side in the width direction. That is, the staple unit 400 has a rear side surface 408 disposed downstream in the second conveying direction from a position where the staple head 404 and the anvil member 405 perform the stapling process on the sheets. The position where the stapling process is performed is a position where the staples protrude from the staple head 404 and a position where the bending grooves 405a of the anvil member 405 are formed.

[0058] In this embodiment, the back side surface 408 is composed of a first end surface 408a, a second end surface 408b, and a third end surface 408c. The first end surface 408a is a surface of a pair of metal side plates 402a constituting the unit frame 402, which is located on both sides of the insertion section 401 in the width direction and faces the upstream side in the second transport direction. The second end surface 408b is a surface of a pair of resin frames 402b constituting the unit frame 402, which is located on both sides of the insertion section 401 in the width direction and faces the upstream side in the second transport direction. The third end surface 408c is a surface of the staple cartridge 403 that is located between the pair of resin frames 402b and is exposed to the upstream side in the second transport direction. In this embodiment, the first, second, and third end surfaces 408a, 408b, and 408c are located on approximately a single plane, so they are collectively referred to as the back side surface 408.

[0059] The stapler holding unit 460 has a slide plate 461 as a moving portion, a rotating plate 462 as a rotating holding portion, and an engaging portion 465. The engaging portion 465 has a first roller 463 as a first protrusion, and a second roller 464 as a second protrusion.

[0060] [Base part] As described above, the base portion 420 has the cam groove 430 and the like fixed on the base 411. As shown in Fig. 8, the cam groove 430 guides the movement of the staple unit 400 in a first direction and a second direction opposite to the first direction. Note that Fig. 8 shows the relationship between the stapler holding unit 460 and the cam groove 430 of the stapler moving unit 450, omitting the staple unit 400.

[0061] The first and second directions, which are the moving directions of the staple unit 400, are the above-mentioned width direction (the direction of the arrow γ in Figs. 4, 5 and 8), and the staple unit 400 reciprocates between the F side and the R side in the width direction by being guided by the cam groove 430. The above-mentioned HP sensor 412 is disposed near the end of the cam groove 430 on the F side, and the abutting member 413 is disposed near the end of the cam groove 430 on the R side. The detailed configuration of the cam groove 430 will be described later.

[0062] As shown in Figs. 5 and 6, the drive unit 440 as a drive section reciprocates the staple unit 400 in the width direction along the cam groove, and has a motor 441 (the above-mentioned STP movement motor MT18) as a drive source and a belt 442. The belt 442 is stretched around a drive pulley (not shown) to which drive is transmitted from an output shaft of the motor 441, and a driven pulley 443. In this embodiment, the motor 441 and the drive pulley are disposed on the R side in the width direction, and the driven pulley is disposed on the F side, and the belt 442 is disposed across the width direction. As described later, a stapler moving unit 450 is fixed to the belt 442, and the stapler moving unit 450 reciprocates in the width direction along the cam groove 430 by the rotation of the belt 442.

[0063] The drive section for moving the staple unit 400 may be configured other than the above-mentioned belt. For example, a motor and a pinion gear to which the drive is transmitted from the output shaft of the motor are provided on the staple unit 400 side, and a rack gear is provided along the width direction on the base 411 side. Then, the pinion gear and the rack gear are engaged with each other. By driving the motor on the staple unit 400 side, the staple unit 400 moves along the rack gear due to the engagement between the pinion gear and the rack gear. In this way, the drive section may be configured to self-propel the staple unit 400.

[0064] [Stapler moving unit] As shown in Fig. 7, the stapler moving unit 450 has a stapler unit 400, a cable holder 451, a cover 452, a belt holder 453, an inclination regulating member 454, a contact portion 455, a stapler holding unit 460, and the like. The stapler unit 400 is capable of performing a stapling process on a sheet stack. The cable holder 451 is a holder that holds a cable that is connected to the device body of the sheet processing device 200A. The cover 452 covers a connection portion between the stapler unit 400 and a cable that is disposed via the cable holder 451. The stapler unit 400 is driven by power supplied from the device body via this cable.

[0065] The belt holder 453 is connected to the belt 442 of the drive unit 440. The inclination regulating member 454, as described later, regulates the inclination angle of the staple unit 400. The contact portion 455 is a member that comes into contact with an abutment member 413 provided on the base portion 420 and triggers inclination of the staple unit 400 when the staple unit 400 performs oblique binding on the R side, as described later.

[0066] As shown in Figures 7 and 9(a), the stapler holding unit 460 is an integral assembly of a slide plate 461, a rotating plate 462, a first roller 463, and a second roller 464, and moves along the cam groove 430 together with the staple unit 400.

[0067] The slide plate 461 moves along the cam groove 430 together with the staple unit 400. For this purpose, a belt holder 453 is fixed to the slide plate 461, and the slide plate 461 moves along the cam groove 430 by the rotation of the belt 442. The slide plate 461 also has a guide hole 461a as a through portion through which the first roller 463 and the second roller 464 pass and which allows the first roller 463 and the second roller 464 to move in accordance with the rotation of the staple unit 400.

[0068] The rotating plate 462 holds the staple unit 400 rotatably relative to the slide plate 461, and the staple unit 400 is fixed integrally to the upper surface of the rotating plate 462. The rotating plate 462 is disposed on the upper surface of the slide plate 461 so as to be rotatable relative to the slide plate 461. A contact portion 455 is fixed to the rotating plate 462, and when the stapler moving unit 450 moves to the R side and the contact portion 455 contacts the abutment member 413, the rotating plate 462 and the staple unit 400 rotate relative to the slide plate 461. A first roller 463 and a second roller 464 are fixed to the rotating plate 462 with an interval therebetween.

[0069] The first roller 463 and the second roller 464 are provided so as to be movable in the width direction together with the staple unit 400 and rotatable together with the staple unit 400, and engage with the cam groove 430. At least the outer circumferential surfaces of the first roller 463 and the second roller 464 that engage with the cam groove 430 are formed into a cylindrical shape. Such first roller 463 and second roller 464 are rotatably fixed to the surface of the rotating plate 462 opposite to the side to which the staple unit 400 is fixed, i.e., the lower surface. The first roller 463 and the second roller 464 do not have to rotate.

[0070] The first roller 463 and the second roller 464 are provided so as to protrude downward from the rotating plate 462, and the protruding amounts are different from each other. That is, the first roller 463 as a first protrusion protrudes more from the rotating plate 462 than the second roller 464 as a second protrusion. The first roller 463 and the second roller 464 are disposed at a predetermined interval from each other, and protrude downward from the slide plate 461 through a guide hole 461a formed in the slide plate 461 located below the rotating plate 462.

[0071] The guide hole 461a of the slide plate 461 is a curved opening so as to guide the first roller 463 and the second roller 464 in the rotation direction of the staple unit 400, and at least the inner peripheral edge of the guide hole 461a is formed in a substantially semicircular shape. In this embodiment, the inner peripheral edge of the guide hole 461a is a semicircle with a diameter that is slightly larger than the distance between the outer peripheral surface of the first roller 463 and the outer peripheral surface of the second roller 464. This allows the first roller 463 and the second roller 464 to move along the inner peripheral edge of the guide hole 461a. In addition, the width of the guide hole 461a is larger than the diameter of the first roller 463 and the second roller 464, and is formed so as to smoothly guide the first roller 463 and the second roller 464. Note that the outer peripheral edge of the guide hole 461a may be formed in a substantially semicircular shape so that the first roller 463 and the second roller 464 can move along the outer peripheral edge of the guide hole 461a.

[0072] Furthermore, a straight line connecting both ends of the semicircle of the guide hole 461a is approximately parallel to the width direction which is the moving direction of the staple unit 400. Therefore, when the staple unit 400 is not inclined with respect to the width direction, the first roller 463 and the second roller 464 are positioned so as to be aligned approximately parallel to the width direction and are positioned at both ends of the semicircle of the guide hole 461a. Then, the first roller 463 and the second roller 464 hold the arc-shaped plate portion 461b on the inside of the guide hole 461a at this position.

[0073] When the slide plate 461 is driven by the drive unit 440 to move in the width direction, the first roller 463 and the second roller 464 engage with the cam groove 430 and the slide plate 461 moves along the cam groove 430. At this time, the arc-shaped plate portion 461b of the slide plate 461 is sandwiched between the first roller 463 and the second roller 464, which allows the slide plate 461 and the rotation plate 462 to move stably together.

[0074] In the above example, the rotating plate 462 is disposed between the staple unit 400 and the slide plate 461, and the first roller 463 and the second roller 464 provided on the rotating plate 462 are disposed so as to penetrate the slide plate 461. However, if the staple unit 400 is rotatable with respect to the slide plate 461, the positions of the slide plate 461 and the rotating plate 462 may be interchanged. For example, the staple unit 400 and the rotating plate 462 may be disposed so as to sandwich the slide plate 461, and the staple unit 400 and the rotating plate 462 may be fixed via an arm or the like. In short, the stapler holding unit 460 may be configured so as to allow the staple unit 400 to move along the cam groove 430 and to rotate at a position where the staple unit 400 performs oblique stapling on the F side and the R side, which will be described later.

[0075] Moreover, the guide hole 461a is not limited to the configuration curved in a semicircular shape as described above. For example, it may be a circular hole with a diameter slightly larger than the distance between the most distant positions of the outer circumferential surfaces of the first roller 463 and the second roller 464 on a straight line connecting the center of the first roller 463 and the center of the second roller 464. In short, the guide hole 461a only needs to be formed so that the first roller 463 and the second roller 464 pass through it and guide the first roller 463 and the second roller 464 so as to rotate together with the staple unit 400.

[0076] As shown in Figs. 9(b) and 10, the stapler moving unit 450 is constructed by assembling the stapler unit 400 to the stapler holding unit 460. As shown in Fig. 9(b), the stapler unit 400 is disposed at an inclination in accordance with the inclination of the processing tray 220 described above, and the insertion section 401 into which the sheet stack to be stapled is inserted faces obliquely upward. In addition, the above-mentioned inclination regulating member 454 is disposed on the rear surface of the stapler unit 400 opposite to the insertion section 401, and the inclination of the stapler unit 400 is regulated by the inclination regulating member 454 abutting against the base 411. This makes it possible to prevent the stapler unit 400 from being inclined too much when the stapler unit 400 moves in the width direction. The vertical position of the inclination regulating member 454 is adjustable.

[0077] [Cam groove] Next, the cam groove 430 will be described with reference to FIGS. 11 to 13. Here, the first and second directions are directions along the width direction, and the first direction is indicated by an arrow γ1, and the second direction is indicated by an arrow γ2. In this embodiment, the first direction is a direction toward the F side along the width direction, and the second direction is a direction toward the R side along the width direction. The relationship between the first and second directions may be reversed depending on the configuration of the device. Also, the direction of the arrow β1 shown in FIGS. 11 to 13 is the first transport direction described above, and the direction of the arrow β2 is the second transport direction described above. The first transport direction β1 is a direction in which the sheet is transported toward the processing tray 220 by the above-mentioned pre-processing rollers 211A and 212A, and the second transport direction β2 is a direction in which the sheet on the processing tray 220 is transported toward the trailing end regulating member 290 by the above-mentioned pick-up paddle 240A.

[0078] The cam groove 430 has a first groove portion 431, a second groove portion 432, a third groove portion 433, a fourth groove portion 434, a fifth groove portion 435, a sixth groove portion 436, and a seventh groove portion 437. In this embodiment, the second groove portion 432, the third groove portion 433, the sixth groove portion 436, and the seventh groove portion 437 are disposed on the downstream side of the first groove portion 431 in the first direction γ1, that is, on the F side. On the other hand, the fourth groove portion 434 and the fifth groove portion 435 are disposed on the downstream side of the first groove portion 431 in the second direction γ2, that is, on the R side. Note that the width of each groove portion is slightly larger than the diameter of the first roller 463 and the second roller 464, and the first roller 463 and the second roller 464 can enter and are guided without rattling. In this embodiment, the outer diameters of the first rollers 463 and the second rollers 464 are the same, and the widths of the grooves are also the same. Each groove will be described in detail below.

[0079] The first groove portion 431 is formed along the first direction γ1. The second groove portion 432 is formed along a direction inclined with respect to the first direction γ1 from the downstream end of the first groove portion 431 in the first direction γ1. That is, the second groove portion 432 is inclined with respect to the width direction, and the inclination direction is a direction toward the downstream side of the first conveying direction β1 as it approaches the downstream side of the first direction γ1. The third groove portion 433 is formed along the first direction γ1 from the downstream end of the first groove portion 431 in the first direction γ1. That is, the third groove portion 433 is formed on the downstream side of the first groove portion 431 in the first direction γ1 as if the first groove portion 431 is directly extended downstream.

[0080] The fourth groove portion 434 is formed from the downstream end of the first groove portion 431 in the second direction γ2 along a direction inclined with respect to the second direction γ2. That is, the fourth groove portion 434 is inclined with respect to the width direction, and the inclination direction is a direction toward the downstream side of the first conveying direction β1 as it approaches the downstream side in the second direction γ2. The fifth groove portion 435 is formed from the downstream end of the first groove portion 431 in the second direction γ2 along the second direction γ2. That is, the fifth groove portion 435 is formed downstream of the first groove portion 431 in the second direction γ2 as if the first groove portion 431 were directly extended downstream.

[0081] The sixth groove portion 436 is formed downstream of the second groove portion 432 in the first direction γ1 along a direction inclined in the opposite direction to the second groove portion 432 with respect to the first direction γ1. That is, the sixth groove portion 436 is inclined with respect to the width direction, and the inclination direction is a direction toward the upstream side of the first conveying direction β1, i.e., the downstream side of the second conveying direction β2, as it approaches the downstream side in the first direction γ1. A switching groove portion 438 is provided between the second groove portion 432 and the sixth groove portion 436, which switches the rotation direction of the first roller 463 relative to the second roller 464, as described later.

[0082] The seventh groove 437 is formed along the first direction γ1 from the downstream end in the first direction γ1 of the sixth groove 436. The seventh groove 437 is located at the same position as the first groove 431 and the third groove 433 in the first conveying direction β1, and when the first roller 463 enters the seventh groove 437 as described below, the stapler moving unit 450 faces in the same direction as when the first roller 463 and the second roller 464 are located in the first groove 431.

[0083] [Relationship between each groove and the first and second rollers] Next, the relationship between the above-mentioned grooves and the first and second rollers 463 and 464 will be described with reference to Figs. 11 to 16(b). In this embodiment, among the above-mentioned grooves, the third groove 433 is formed to have a shallower groove depth than the other grooves. As described above, the first and second rollers 463 and 464 have different protruding amounts from the rotating plate 462. This causes the first and second rollers 463 and 464 to enter the grooves by different amounts. In addition, the second roller 464 is disposed upstream of the first roller 463 in the first direction γ1, i.e., on the R side.

[0084] Although the first roller 463 and the second roller 464 are different in length to make the amount of protrusion from the rotating plate 462 different, they may be the same length as long as the amount of penetration into the groove is different. For example, by changing the mounting position in the height direction (depth direction of the groove) relative to the rotating plate 462, it is possible to change the amount of penetration of the first roller 463 and the second roller 464 into the groove even if they are the same length.

[0085] Here, the stapler moving unit 450 moves in the first direction γ1 and the second direction γ2, and the first roller 463 and the second roller 464 are positioned in any of the grooves described above, so that the posture of the staple unit 400 can be changed. Specifically, the staple unit 400 can be changed between a first posture and a second posture inclined with respect to the first posture. In this embodiment, the drive unit 440 that moves the staple unit 400, the stapler holding unit 460 that holds the staple unit 400, and the cam groove 430 constitute a moving and rotating section 470 (FIG. 5) that moves the staple unit 400 in the width direction and further rotates the staple unit 400 between the first posture and the second posture inclined with respect to the first posture. Note that the moving and rotating section 470 may be configured to perform the moving operation and the rotating operation by separate motors.

[0086] The first posture is a posture in which the staple unit 400 performs a stapling process on the downstream end of the sheet in the second conveying direction β2 in a direction along the width direction, i.e., a flat stapling posture. The second posture is a posture in which the staple unit 400 performs a stapling process on a corner on one end side or the other end side (F side or R side in this embodiment) in the width direction of the downstream end of the sheet in the second conveying direction β2 in a direction inclined with respect to the width direction, i.e., a diagonal stapling posture. Note that the inclination direction with respect to the width direction is opposite between the second posture on the F side and the second posture on the R side.

[0087] The sheet binding device 410 of this embodiment is capable of performing a first binding process in which the staple unit 400 in a first position performs flat stapling on the downstream end (rear end) of the sheet in the second conveying direction β2, a second binding process in which the staple unit 400 in a second position performs diagonal stapling on one end side (F side) of the downstream end (rear end) of the sheet in the second conveying direction β2, and a third binding process in which the staple unit 400 in the second position performs diagonal stapling on the other end side (R side) of the downstream end (rear end) of the sheet in the second conveying direction β2.

[0088] 14(a) and (b) show the state where the stapler moving unit 450 is at the home position (HP). At the home position, the staple unit 400 is in the same position as the first position, but does not perform a stapling process on the sheets. Figs. 15(a) and (b) show the second position on the F side, and Figs. 16(a) and (b) show the second position on the R side.

[0089] [First groove and F side groove] First, the relationship between the first groove portion 431, and the second groove portion 432, the third groove portion 433, the sixth groove portion 436, and the seventh groove portion 437 on the downstream side of the first groove portion 431 in the first direction γ1, i.e., the F side, and the first roller 463 and the second roller 464 will be described. The first roller 463 can engage with the first groove portion 431 and the second groove portion 432 by entering the first groove portion 431 and the second groove portion 432 with a first entering amount. On the other hand, the second roller 464 can engage with the first groove portion 431 and the third groove portion 433 by entering the first groove portion 431 and the third groove portion 433 with a second entering amount smaller than the first entering amount.

[0090] The third groove portion 433 has a step surface 439 as a restricting portion that restricts the intrusion of the first roller 463 from the first groove portion 431 and allows the intrusion of the second roller 464 from the first groove portion 431. That is, the first groove portion 431 and the second groove portion 432 are formed so that the groove depth is deeper than the first intrusion amount. On the other hand, the third groove portion 433 is formed so that the groove depth is shallower than the first intrusion amount and deeper than the second intrusion amount. The step surface 439 between the third groove portion 433 and the first groove portion 431 restricts the intrusion of the first roller 463 from the first groove portion 431 and allows the intrusion of the second roller 464 from the first groove portion 431.

[0091] Therefore, when the stapler moving unit 450 moves downstream in the first direction γ1 along the first groove 431 toward the third groove 433, the first roller 463, which is downstream in the first direction γ1 from the second roller 464, abuts against the step surface 439. The step surface 439 is formed parallel to the inclination direction of the second groove 432, and is on the same plane as the inner wall surface 432a on the upstream side of the second groove 432 in the first conveying direction β1, i.e., the third groove 433 side. Therefore, when the stapler moving unit 450 tries to move further downstream in the first direction γ1 while abutting against the step surface 439, the first roller 463 is guided to the second groove 432 along the inclination of the step surface 439.

[0092] On the other hand, the second roller 464, which is located upstream of the first roller 463 in the first direction γ1, reaches the position of the step surface 439 after the first roller 463 is guided by the second groove portion 432 as the stapler moving unit 450 moves downstream in the first direction γ1. The amount of penetration of the second roller 464 into the groove portion is smaller than the amount of penetration of the first roller 463 into the groove portion, and the third groove portion 433 is formed deeper than the amount of penetration of the second roller 464 into the groove portion. Therefore, the second roller 464 enters the third groove portion 433 without abutting against the step surface 439 as the stapler moving unit 450 moves downstream in the first direction γ1.

[0093] By such an operation, the first roller 463 enters the second groove portion 432, and the second roller 464 enters the third groove portion 433, and the rotation plate 462 to which the first roller 463 and the second roller 464 are fixed rotates relative to the slide plate 461. At this time, the first roller 463 rotates about the second roller 464 along the guide hole 461a formed in the slide plate 461, thereby allowing the first roller 463 to enter the second groove portion 432 and the rotation plate 462 to rotate.

[0094] Then, when the stapler moving unit 450 moves further downstream in the first direction γ1, the first roller 463 reaches the switching groove 438 as shown in FIG. 15(b). The first roller 463 can enter the switching groove 438, and in this embodiment, the switching groove 438 has the same depth as the second groove 432. The switching groove 438 is formed approximately parallel to the first groove 431. Therefore, when the first roller 463 is positioned in the switching groove 438, the position of the first roller 463 relative to the second roller 464 in the first transport direction β1 is stabilized.

[0095] That is, when the first roller 463 is in the second groove 432, the positional relationship with the second roller 464 changes depending on the position of the first roller 463 on the second groove 432, and the angle of the staple unit 400 held by the rotating plate 462 also changes. In contrast, when the first roller 463 enters the switching groove 438, the angle of the staple unit 400 is stable regardless of the position of the first roller 463 on the switching groove 438. Then, in this position, the staple unit 400 is in the second posture as shown in FIG. 15(a) for performing oblique binding on the F side as described above. Thus, in this embodiment, the switching groove 438 functions as a positioning groove for the first roller 463 for putting the staple unit 400 in the second posture on the F side. Note that the staple unit 400 may be in the second posture with the first roller 463 positioned in the second groove 432.

[0096] The restricting portion that restricts the first roller 463 from entering through the first groove portion 431 and allows the second roller 464 to enter through the first groove portion 431 is not limited to the above-mentioned step surface 439. For example, the restricting portion may be something like a horizontal bar provided at the upstream end of the third groove portion 433 in the first direction γ1 at a position shallower than the first intrusion amount and deeper than the second intrusion amount. In this case, the third groove portion may be the same depth as the first groove portion.

[0097] Next, a description will be given of the relationship between the sixth groove portion 436 and the seventh groove portion 437 formed continuously with the switching groove portion 438 on the downstream side of the switching groove portion 438 in the first direction γ1, and the first rollers 463 and the second rollers 464. The sixth groove portion 436 and the seventh groove portion 437 have a depth that allows the first rollers 463 to enter, and in this embodiment, they are set to the same depth as the second groove portion 432.

[0098] As described above, the first roller 463 enters the second groove portion 432, and when the stapler moving unit 450 moves downstream in the first direction γ1, the first roller 463 enters the sixth groove portion 436 through the switching groove portion 438. At this time, the first roller 463 rotates around the second roller 464 along the guide hole 461a formed in the slide plate 461. The rotation direction at this time is opposite to the rotation direction when the first roller 463 enters the second groove portion 432 from the first groove portion 431. As a result, the rotation direction of the first roller 463 relative to the second roller 464 is switched by the switching groove portion 438, and the first roller 463 can enter the sixth groove portion 436 and the rotation plate 462 can rotate.

[0099] Next, when the stapler moving unit 450 moves further downstream in the first direction γ1, the first roller 463 enters the seventh groove 437 as shown in FIG. 14(b). As described above, the seventh groove 437 is formed along the first direction γ1, and is located at the same position as the first groove 431 and the third groove 433 with respect to the first conveying direction β1. Therefore, when the first roller 463 enters the seventh groove 437, the first roller 463 rotates around the second roller 464 along the guide hole 461a formed in the slide plate 461, and the rotating plate 462 and the staple unit 400 held thereby assume a position as shown in FIG. 14(a). This position is the same as the position when the first roller 463 and the second roller 464 are in the first groove 431. In this embodiment, the position of the first roller 463 in the seventh groove 437 is set as the home position (HP) of the stapler moving unit 450.

[0100] In this embodiment, the above-mentioned manual binding operation is possible at this home position, that is, at the position where the first roller 463 enters the seventh groove portion 437. That is, when the stapler moving unit 450 is located at the home position, the portion of the staple unit 400 that performs the binding process is located at the manual insertion portion 204 (FIG. 4). Therefore, when the user inserts a sheet stack into the manual insertion portion 204 in this state, the sheet stack enters the portion that performs the binding process, and the binding process becomes possible.

[0101] [R side groove] Next, the relationship between the fourth groove portion 434 and the fifth groove portion 435 on the downstream side of the first groove portion 431 in the second direction γ2, i.e., on the R side, and the first roller 463 and the second roller 464 will be described. The second roller 464 can enter the fourth groove portion 434, and the first roller 463 can enter the fifth groove portion 435. In this embodiment, the fourth groove portion 434 has the same depth as the third groove portion 433, and the fifth groove portion 435 has the same depth as the first groove portion 431. The fourth groove portion 434 may also have the same depth as the fifth groove portion 435.

[0102] As described above, the abutting member 413 is disposed near the end of the R side of the cam groove 430. The abutting member 413 as the abutted portion is disposed outside the first groove portion 431 to the seventh groove portion 437 as shown in Fig. 12 and Fig. 13. In this embodiment, the abutting member 413 is disposed at the downstream end of the first groove portion 431 in the second direction γ2 and on the downstream side of the fourth groove portion 434 in the first conveying direction β1. On the other hand, the rotating plate 462 is provided with an abutting portion 455.

[0103] When the stapler moving unit 450 moves downstream in the second direction γ2 along the first groove 431 and approaches the vicinity of the downstream end of the first groove 431 in the second direction γ2, the abutting portion 455 abuts against the abutting member 413. Then, when the stapler moving unit 450 further moves downstream in the second direction γ2, the abutting portion 455 abuts against the abutting member 413, causing the rotating plate 462 to rotate. At this time, the second roller 464 rotates about the first roller 463 along the guide hole 461a formed in the slide plate 461. As a result, the second roller 464 enters the fourth groove 434 formed in a direction inclined with respect to the second direction γ2 from the downstream end of the first groove 431 in the second direction γ2. As a result, the staple unit 400 held by the rotating plate 462 rotates in a direction opposite to the rotation direction when the first roller 463 described above enters the second groove 432.

[0104] That is, when the second roller 464 is in a position where it can enter the fourth groove portion 434 from the first groove portion 431, the abutment portion 455 provided on the rotating plate 462 comes into contact with the abutting member 413. Then, as the staple unit 400 moves in the second direction from this position, the staple unit 400 rotates, and the second roller 464 enters the fourth groove portion 434.

[0105] A positioning groove 434a is provided on the downstream side of the fourth groove 434 in the second direction γ2 so as to be continuous with the fourth groove 434. The positioning groove 434a has the same depth as the fourth groove 434 and is formed parallel to the first groove 431. In addition, a fifth groove 435 is formed on the downstream side of the first groove 431 in the second direction γ2 from the downstream end of the first groove 431 in the second direction γ2 along the second direction γ2.

[0106] As described above, when the second roller 464 enters the fourth groove portion 434 and the stapler moving unit 450 moves further downstream in the second direction γ2, the first roller 463, which is located upstream of the second roller 464 in the second direction γ2, moves directly through the first groove portion 431. Then, as shown in FIG. 16(b), the second roller 464 enters the positioning groove portion 434a and the first roller 463 enters the fifth groove portion 435. Then, at this position, the staple unit 400 assumes the second posture as shown in FIG. 16(a) for performing oblique stapling on the R side as described above.

[0107] The positioning groove 434a stabilizes the posture of the staple unit 400, similar to the above-mentioned switching groove 438. However, the staple unit 400 may be in the second posture with the second roller 464 positioned in the fourth groove 434, in which case the positioning groove 434a may be omitted. The fifth groove 435 is an extension of the first groove 431 in order to move the second roller 464 to the positioning groove 434a, and the fifth groove 435 may be omitted as long as the staple unit 400 can be in the second posture even if the first roller 463 has not moved to the fifth groove 435.

[0108] [Issues with diagonal binding] Next, problems that arise when performing oblique stapling on a corner of a sheet stack will be described with reference to Figures 17(a) and (b). First, the comparative example in Figures 17(a) and (b) shows a state in which oblique stapling is performed on the R-side corner of the downstream end (rear end) of the sheet in the second transport direction β2. The comparative example shows a case in which the staple unit 400 is moved in advance to a position (oblique stapling position) for performing oblique stapling on the R side before the sheet is transported to the processing tray 220 and transported in the second transport direction β2 toward the rear end regulating member 290.

[0109] In this embodiment and comparative example, the staple-less stapling unit 400A is disposed on the R side of the diagonal binding position. That is, in this embodiment and comparative example, in addition to the staple unit (first binding section) 400 that performs the stapling process on the sheets using staples, a staple-less stapling unit (second binding section) 400A that performs the stapling process on the sheets without using staples is provided. The staple-less stapling unit 400A is a device that binds the sheets without making holes in them by entangling the fibers of the sheets with pressure.

[0110] When performing the oblique binding as described above, the staple unit 400 takes a second posture that is inclined at the corner of the sheet with respect to the first posture when performing the flat stitching. At this time, if the staple unit 400 is set to the second posture before the sheet is abutted against the trailing end regulating member 290, there is a risk that a part of the trailing end of the sheet may contact the staple unit 400, as shown in Figs. 17(a) and 17(b). As described above, the staple unit 400 has a rear side surface 408 on the downstream side of the insertion section 401 in the second conveying direction β2. When the staple unit 400 is in the first posture, the rear side surface 408 is located downstream in the second conveying direction β2 from the sheet abutment surface (position of the broken line L) of the trailing end regulating member 290 against which the trailing end of the sheet abuts when performing the binding process. Therefore, when the staple unit 400 is in the first posture, even if the sheet is inserted into the insertion section 401 for the binding process, the trailing end of the sheet will not contact the rear side surface 408.

[0111] On the other hand, when the staple unit 400 is in the second position, as shown in FIGS. 17(a) and 17(b), a part of the rear side surface 408 is located upstream of the sheet abutment surface (position of the broken line L) of the rear end regulating member 290 in the second conveying direction β2. Here, when the size in the width direction of the sheet processing device 200A is reduced in order to reduce the size of the device, the amount by which the staple unit 400 can be moved in the width direction to set the staple unit 400 in the second position is limited. For this reason, for example, as shown in FIG. 17(a), when a large-sized sheet Sa is conveyed downstream in the second conveying direction β2, there is a risk that the rear end of the sheet Sa may come into contact with a corner 408d of the rear side surface 408. In addition, as shown in FIG. 17(b), when a sheet Sb smaller than the sheet Sa is conveyed downstream in the second conveying direction β2, there is a risk that the rear end of the sheet Sb may come into contact with a part of the surface of the rear side surface 408.

[0112] If a part of the sheet comes into contact with the staple unit 400 in this way, there is a risk that the corners of the sheets cannot be diagonally bound or the sheets may be bent. Therefore, in order to prevent interference between the staple unit 400 and the sheets when performing diagonal binding, it is required to move the staple unit 400 to a position where it does not interfere with the sheets. Taking this into consideration, it is difficult to reduce the size of the device.

[0113] In particular, if the staple-less staple unit 400A is disposed on the R side of the oblique binding position on the R side as described above, the range in which the staple unit 400 can move in the width direction is limited, and the above-mentioned problem is likely to occur. Even if such a staple-less staple unit 400A is not provided, the same problem may occur because the range of movement of the staple unit 400 in the width direction has become narrower due to recent demands for miniaturization of devices. In this embodiment, the following control is performed to solve such problems.

[0114] [Control of diagonal binding in the embodiment] 18 to 25, the control when performing diagonal stapling at a corner of a sheet in this embodiment will be described. In this embodiment, when the staple unit 400 performs stapling processing at a corner on one end side of the sheet in the width direction in the second posture, the sheet is shifted to the other end side in the width direction and then the staple unit 400 is set to the second posture at the one end side in the width direction as follows.

[0115] That is, after performing the abutting operation and the shifting operation on the sheet conveyed to the processing tray 220, the moving and rotating part 470 rotates the staple unit 400 from the first position to the second position, and the staple unit 400 in the second position performs the binding process, i.e., the diagonal binding. Here, the abutting operation is an operation in which the sheet on the processing tray 220 is conveyed in the second conveying direction β2 by the pick-up paddle 240A, and the downstream end edge (rear end edge) of the sheet in the second conveying direction β2 is abutted against the rear end regulating member 290. Also, the shifting operation is an operation in which the sheet is moved in the width direction by the alignment part 270A to the position where the sheet is conveyed to the processing tray 220 by the pre-processing rollers 211A and 212A. In this embodiment, the sheet is shifted in the width direction to the side opposite to the side where the sheet is to be diagonally bound. That is, when diagonal binding is performed on a corner on one end side of the sheet in the width direction, the sheet is moved to the other end side in the width direction.

[0116] The shift amount of the sheet at this time is an amount that satisfies the following condition. That is, the sheet is moved by the alignment section 270A to the other end side in the width direction with respect to the position of the sheet transported to the processing tray 220, and to a position where the sheet does not contact the rear side surface 408 when the staple unit 400 is in the second posture. Specifically, a portion of the rear side surface 408 of the staple unit 400 in the second posture that is located upstream in the second transport direction β2 from the abutment surface of the rear end regulating member 290 against the sheet (a portion above the position of the dashed line L in FIGS. 17(a) and 17(b)) is defined as a "portion X." In this case, in the shift operation, the sheet is shifted until a corner on one end side of the sheet in the width direction is located on the other end side of the portion X in the width direction.

[0117] The reason why the sheet can be shifted to such a position is because the sheet processing apparatus 200A of this embodiment is capable of executing a shift discharge process for shifting and discharging the sheet. In this embodiment, the sheet is aligned based on a center reference that matches the center position of the sheet in the width direction with the center position of the processing tray 220 in the width direction. In this embodiment, the sheet can be shifted a predetermined amount (for example, 15 mm) from the center reference position to one end side and the other end side in the width direction and discharged. Therefore, by performing the shift operation within this predetermined range, it is possible to shift the sheet to perform diagonal binding as described above without increasing the size of the apparatus.

[0118] In addition, the timing of performing the abutting operation and the shifting operation may be either one first, but in this embodiment, the abutting operation is performed first. That is, when the staple unit 400 performs the stapling process on the corners in the width direction of the sheets in the second posture, the shifting operation is performed after the abutting operation.

[0119] In addition, when side stitching is performed, such a shift operation is not performed. That is, when the staple unit 400 performs the binding process on the downstream end of the sheet in the second conveying direction β2 in the first posture, the above-mentioned shift operation is not performed, and the staple unit 400 in the first posture performs the binding process on the sheet in a state where the downstream end edge in the second conveying direction β2 is abutted against the trailing end regulating member 290 by the abutting operation. However, even when side stitching is performed, the sheet aligning operation by the aligning section 270A is performed.

[0120] The control contents of this embodiment will be specifically described below using as an example a case where diagonal binding is performed on the corner on the R side of a sheet bundle formed by binding two sheets. Note that the following describes a case where diagonal binding is performed on the corner on the R side as the corner on one end side of the rear end of the sheet in the width direction, but when diagonal binding is performed on the corner on the F side, the operation is the same as when diagonal binding is performed on the corner on the R side, except that the direction in which the sheets are moved by the shift operation is reversed.

[0121] FIG. 18 shows a state where the staple unit 400 is in the home position. Next, as shown in FIG. 19, the first sheet S1 is received in the processing tray 220, and is transported in the second transport direction β2 by the pick-up paddle 240A to abut the sheet S1 against the rear end regulating member 290. In this embodiment, at this time, the staple unit 400 is moved from the home position to immediately before the position where the R-side corner is obliquely bound. Specifically, the stapler moving unit 450 is moved until the second roller 464 of the stapler moving unit 450 is positioned at the entrance of the fourth groove portion 434 of the cam groove 430, in other words, until the abutting portion 455 abuts against the abutting member 413. At this point, the staple unit 400 remains in the first posture.

[0122] Next, as shown in Fig. 20, a pair of alignment plates 271A of alignment portion 270A are brought into contact with both widthwise edges of sheet S to align the first sheet S1. Then, as shown in Fig. 21, the pair of alignment plates 271A are moved away from the sheet, and the second sheet S2 is received in the processing tray 220. Then, the second sheet S2 is transported in the second transport direction β2 by the pick-up paddle 240A to abut sheet S2 against the trailing end regulating member 290, and the second sheet S2 is aligned by the pair of alignment plates 271A as shown in Fig. 22.

[0123] When the alignment of the final sheet of the sheet bundle ST to be formed, that is, the second sheet S2 in this embodiment, is completed, the sheet bundle ST is clamped by a pair of alignment plates 271A and moved in the width direction to the F side, as shown in Fig. 23. That is, a shift operation is performed by the pair of alignment plates 271A to move the sheet bundle ST to the F side opposite to the R side where the diagonal binding is performed.

[0124] After the sheet bundle ST is moved to the F side in the width direction, as shown in FIG. 24, the staple unit 400 is rotated from the first posture to the second posture at a position where the sheet bundle ST is diagonally bound at the corner on the R side of the rear end portion of the sheet bundle ST. In this embodiment, the position at which the sheet bundle ST is shifted to the F side as described above is the position at which the sheet bundle ST is diagonally bound at the corner on the R side. Therefore, after the shifting operation, the staple unit 400 is set to the second posture while keeping the position of the sheet bundle ST in the width direction as it is. Then, the binding process is performed at this position. That is, the sheet bundle ST is diagonally bound at the corner on the R side of the rear end portion of the sheet bundle ST. Thereafter, as shown in FIG. 25, the sheet bundle ST that has been diagonally bound is discharged to the stacking tray 300 by the upper discharge roller 230A and the lower discharge roller 230B.

[0125] In the above description, the staple unit 400 is set to the second posture at the position where the sheet stack ST is shifted and then the staple unit 400 is set to the second posture to perform the diagonal binding. However, depending on the position of the sheet stack after the shift operation and the position where the staple unit 400 performs the diagonal binding, the sheet stack may be further moved in the width direction after the staple unit 400 is set to the second posture. For example, after the shift operation is performed on the sheet stack ST, the staple unit 400 is rotated from the first posture to the second posture. Then, the sheet stack is moved in the direction opposite to the direction in which the shift operation was performed, and the staple unit 400 performs the binding process. In any case, the shift operation may be performed on the sheets before the staple unit 400 is rotated from the first posture to the second posture.

[0126] In this manner, in this embodiment, when performing diagonal binding on the corners of the sheets, the sheets are shifted in the direction opposite to the position where the diagonal binding is performed, and then the staple unit 400 is rotated from the first position to the second position. Therefore, even if the movement amount of the staple unit 400 to the diagonal binding position is not large, interference between the staple unit 400 and the sheets when performing the diagonal binding can be prevented. As a result, the device can be made more compact.

[0127] [Another embodiment] Next, another example of this embodiment will be described with reference to Figures 26 to 35. In the above example, a case where the shift operation is performed on the sheet before the staple unit 400 is rotated to the second position has been described. However, as described below, the shift operation may be performed on the sheet after the staple unit 400 is rotated to the second position.

[0128] That is, after the moving and rotating part 470 rotates the staple unit 400 from the first position to the second position, the sheet conveyed downstream in the first conveying direction β1 by the pre-processing rollers 211A, 212A is shifted without being conveyed in the second conveying direction β2 by the pick-up paddle 240A. Thereafter, the sheet is conveyed in the second conveying direction β2 by the pick-up paddle 240A, and abutting operation is performed to abut the rear end of the sheet against the rear end regulating member 290, and then the staple unit 400 in the second position performs the binding process.

[0129] The control contents according to another example of the present embodiment will be specifically described below, taking as an example a case where diagonal binding is performed on a corner on the R side of a sheet bundle formed by binding two sheets. Note that the following describes a case where diagonal binding is performed on a corner on the R side as a corner on one end side of the rear end of the sheets in the width direction, but when diagonal binding is performed on a corner on the F side, the operation is the same as when diagonal binding is performed on a corner on the R side, except that the direction in which the sheets are moved by the shift operation is reversed.

[0130] 26, when the first sheet S1 is received in the processing tray 220, the staple unit 400 is rotated from the first position to the second position on the R side in the width direction. The timing for rotating the staple unit 400 may be before the sheet S1 is transported to the processing tray 220, or during the transport. In addition, the state shown in FIG. 26 is, for example, a state in which the sheet has been dropped into the processing tray 220 by the trailing end dropping member 250A, and the sheet is not transported in the second transport direction β2 by the pick-up paddle 240A.

[0131] Next, as shown in FIG. 27, the pair of alignment plates 271A moves the first sheet S1 toward the F side in the width direction. In this state, the trailing end of the sheet S1 does not abut against the trailing end regulating member 290. In this embodiment, as described above, the alignment plate 271A has a first plate portion 2701 on the downstream side in the first transport direction, and a second plate portion 2702 formed so as to be continuous with the first plate portion 2701 on the upstream side in the first transport direction (see FIG. 2). Therefore, in relation to the first transport direction β1, the alignment plate 271A abuts against the sheet on the processing tray 220 over a wide range, so that a stable shift operation is possible even if the trailing end of the sheet does not abut against the trailing end regulating member 290.

[0132] After shifting the sheet S1 to the F side, as shown in Fig. 28, the sheet S1 is conveyed in the second conveying direction β2 by the pick-up paddle 240A, and abuts against the trailing end regulating member 290. At this time, the R-side alignment plate 271A is separated from the sheet S1. Next, as shown in Fig. 29, the R-side alignment plate 271A is brought into contact with the sheet S1, and the sheet S1 is sandwiched between the pair of alignment plates 271A. This performs alignment for the first sheet S1.

[0133] Next, with the R-side alignment plate 271A separated from the sheet S1, the second sheet S2 is transported to the processing tray 220 as shown in Fig. 30. The state in Fig. 30 is also a state in which the sheet has been dropped onto the processing tray 220 by the trailing end dropping member 250A, and the sheet is not transported in the second transport direction β2 by the pick-up paddle 240A.

[0134] Next, as shown in FIG. 31, the R-side alignment plate 271A is brought into contact with the end of the sheet S2, and the second sheet S2 is moved to the F side in the width direction. At this time, the F-side alignment plate 271A does not move because the first sheet S1 is there. After the sheet S2 is shifted to the F side, as shown in FIG. 32, the sheet S2 is conveyed in the second conveying direction β2 by the pick-up paddle 240A, and the sheet S2 is abutted against the trailing end regulating member 290. At this time, the R-side alignment plate 271A is separated from the sheet S1. Next, as shown in FIG. 33, the R-side alignment plate 271A is brought into contact with the sheet S2, and the sheet S2 is sandwiched between the pair of alignment plates 271A. In this way, the second sheet S2 is aligned.

[0135] When the alignment of the final sheet of the sheet bundle ST to be formed, the second sheet S2 in this embodiment, is completed, the staple unit 400 in the second position performs diagonal stapling on the R-side corner of the sheet bundle ST as shown in Fig. 34. Thereafter, as shown in Fig. 35, the sheet bundle ST after the diagonal stapling is discharged onto the stacking tray 300 by the upper discharge rollers 230A and the lower discharge rollers 230B.

[0136] In this manner, in the present embodiment, when performing the diagonal binding on the corner of the sheet, the staple unit 400 is in the second posture, and before the sheet on the processing tray 220 is abutted against the trailing end regulating member 290, the sheet is shifted in the opposite direction to the position where the diagonal binding is performed. Then, the sheet is abutted against the trailing end regulating member 290 after the shift operation is completed. Therefore, even if the staple unit 400 is in the second posture, it is possible to prevent the sheet from interfering with the staple unit 400. Therefore, in the present embodiment, it is possible to prevent the staple unit 400 from interfering with the sheet when performing the diagonal binding without increasing the movement amount of the staple unit 400 to the diagonal binding position. As a result, it is possible to make the device compact. In the present embodiment, the shift operation and the abutment operation are performed after the rotation operation of rotating the staple unit 400 by the moving rotation part 470 is performed. However, the order of the rotation operation and the shift operation may be reversed, or they may be performed simultaneously. In any case, it is sufficient that the rotation operation and the shift operation are completed before the abutment operation is completed.

[0137] In the above embodiment, the sheet processing device 200A is arranged in the internal space 130 of the image forming apparatus 100, but the sheet processing device of the present invention may be, for example, attached to the side of the image forming apparatus. The sheet processing device may be controlled by a control unit included in the image forming apparatus. The present invention is also applicable to a configuration without the staple-less staple unit 400A.

[0138] The disclosure of this embodiment also includes the following configuration.

[0139] (Configuration 1) a first conveying unit that conveys the sheet in a first conveying direction; a placement section for placing the sheet conveyed in the first conveying direction by the first conveying section; a second conveying section that conveys the sheet on the stacking section conveyed by the first conveying section in a second conveying direction opposite to the first conveying direction; an abutting portion against which a downstream edge of the sheet in the second transport direction, the sheet being transported in the second transport direction by the second transport portion, is abutted; a shift unit that moves in a width direction of the sheet that intersects with the first transport direction while being in contact with an edge along the first transport direction of the sheet placed on the placement unit, thereby moving the sheet transported by the first transport unit in the width direction; a binding unit that performs a binding process on the sheet whose downstream end edge in the second conveying direction is abutted against the abutting unit and which is moved in the width direction by the shift unit; a moving and rotating unit that moves the binding unit in the width direction and further rotates the binding unit to a first position and a second position inclined with respect to the first position, the binding section has a first portion, a second portion disposed opposite the first portion and configured to sandwich the sheet between the first portion and the second portion to perform the binding process on the sheet, and a rear surface disposed downstream in the second conveying direction of a position where the binding process is performed on the sheet between the first portion and the second portion when the binding section is in a first posture; the first posture is a posture in which the binding unit performs a binding process on a downstream end of the sheet in the second conveying direction in a direction along the width direction, the second posture is a posture in which the binding portion performs a binding process on a corner portion on one end side of the width direction of the downstream end portion of the sheet in the second conveying direction in a direction inclined with respect to the width direction, When the binding unit performs a binding process on a corner on one end side of the width direction of the sheet in the second posture, abutting operation is performed in which the second conveying unit conveys the sheet in the second conveying direction and a downstream end edge of the sheet in the second conveying direction is abutted against the abutting unit, and a shift operation is performed in which the shift unit moves the sheet to the other end side in the width direction and to a position where the sheet does not contact the rear side surface when the binding unit is in the second posture, relative to the position of the sheet conveyed to the placement unit by the first conveying unit, and then the moving and rotating unit rotates the binding unit from the first posture to the second posture, and the binding process is performed by the binding unit in the second posture. A sheet processing apparatus comprising: (Configuration 2) When the binding unit performs the binding process on the corner portion of the sheets in the second posture, the shift operation is performed after the abutting operation is performed. 2. The sheet processing apparatus according to claim 1, (Configuration 3) When the binding unit performs a binding process on the downstream end portion of the sheet in the second conveying direction in the first posture, the binding unit in the first posture performs a binding process on the sheet in a state in which the downstream end edge in the second conveying direction is abutted against the abutment portion by the abutment operation without performing the shift operation. 3. The sheet processing apparatus according to configuration 1 or 2. (Configuration 4) a first conveying unit that conveys the sheet in a first conveying direction; a placement section for placing the sheet conveyed in the first conveying direction by the first conveying section; a second conveying section that conveys the sheet on the placement section conveyed by the first conveying section in a second conveying direction opposite to the first conveying direction; an abutting portion against which a downstream edge of the sheet in the second transport direction, the sheet being transported in the second transport direction by the second transport portion, is abutted; a shift unit that moves in a width direction of the sheet that intersects with the first transport direction while being in contact with an edge along the first transport direction of the sheet placed on the placement unit, thereby moving the sheet transported by the first transport unit in the width direction; a binding unit that performs a binding process on the sheet whose downstream end edge in the second conveying direction is abutted against the abutting unit and which is moved in the width direction by the shift unit; a moving and rotating unit that moves the binding unit in the width direction and further rotates the binding unit to a first position and a second position inclined with respect to the first position, the binding section has a first portion, a second portion disposed opposite the first portion and configured to sandwich the sheet between the first portion and the second portion to perform the binding process on the sheet, and a rear surface disposed downstream in the second conveying direction of a position where the binding process is performed on the sheet between the first portion and the second portion when the binding section is in a first posture; the first posture is a posture in which the binding unit performs a binding process on a downstream end of the sheet in the second conveying direction in a direction along the width direction, the second posture is a posture in which the binding portion performs a binding process on a corner portion on one end side of the width direction of the downstream end portion of the sheet in the second conveying direction in a direction inclined with respect to the width direction, When the binding unit performs a binding process on a corner on one end side of the width direction of the sheet in the second posture, the shift unit performs a shift operation to move the sheet, which has been transported to the placement unit by the first transport unit, to the other end side in the width direction and to a position where the sheet will not contact the rear side surface when the binding unit is in the second posture, and the moving and rotating unit performs a rotation operation to rotate the binding unit from the first posture to the second posture, and then the second transport unit transports the sheet in the second transport direction and performs an abutment operation to abut the downstream end edge of the sheet in the second transport direction against the abutment unit, and then the binding unit in the second posture performs the binding process. A sheet processing apparatus comprising: (Configuration 5) When the binding unit performs a binding process on the downstream end of the sheet in the second transport direction in the first posture, the binding unit performs the abutting operation without performing the shifting operation on the sheet transported downstream in the first transport direction by the first transport unit, and performs the binding process on the sheet in a state in which the downstream end edge in the second transport direction is abutted against the abutting unit by the binding unit in the first posture. 5. The sheet processing apparatus according to configuration 4. (Configuration 6) an image forming apparatus having an image forming unit that forms an image on a sheet; 6. An image forming system comprising: the sheet processing apparatus according to any one of configurations 1 to 5, which performs binding processing on sheets on which images have been formed by the image forming unit. [Explanation of symbols]

[0140] 200A···Sheet processing device 211A, 212A: Pre-treatment roller 220 Processing tray 240A···Sweeping paddle 270A...Matching section 290 .... Rear end regulating member 400··· Staple unit (binding section) 404 Staple head (first part) 405 Anvil member (second part) 408...Rear side 410 Sheet binding device 470....Moving and rotating part

Images