Post-processing device and image formation system

Abstract

To stabilize a position of a fold line of a recording medium bundle compared to a structure in which the fold line of the recording medium bundle is formed in a state that the recording medium bundle is supported by a support part.SOLUTION: A post-processing device includes: a loading part in which a recording medium bundle to be subjected to folding is loaded; a pressing part which moves in a thickness direction of the recording medium bundle, contacts a surface, and presses the recording medium bundle to form a folded part in the recording medium bundle; a rotation part which sandwiches the folded part formed by the pressing part and rotates to form a fold line in the recording medium bundle; and a support part which supports one end of the recording medium bundle, may open or close in the thickness direction of the recording medium bundle, and is turned in a closed state to support the recording medium bundle in a holding manner when the fold line is formed in the recording medium bundle by the pressing part and the rotation part.SELECTED DRAWING: Figure 8

Description

[Technical field]

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

[0002] With the aim of strengthening the folding of the recording material while avoiding the occurrence of wrinkles, prior art documents disclose an invention relating to an image forming apparatus that includes a holding section that holds the recording material, an extrusion member that makes linear contact with the recording material held in the holding section and pushes out the contacted portion, and at least a pair of extrusion members are arranged on opposite sides of the recording material, each of the pair rotates to pinch and pull in the portion of the recording material extruded by the extrusion member between the pair, and the force clamping the portion increases as it is pulled in. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2017-57038 Summary of the Invention [Problem to be solved by the invention]

[0004] When forming creases in a stack of recording media using a pressing unit and a rotating unit, the stack of recording media is not stable from the time the stack is pressed by the pressing unit to the time it is clamped in the rotating unit, resulting in variation in the position of the crease.

[0005] The present invention has an object to stabilize the position of the fold in the stack of recording media, as compared with a configuration in which the fold in the stack of recording media is formed in a state in which the stack of recording media is supported by a support portion. [Means for solving the problem]

[0006] The invention described in claim 1 is a post-processing device that includes a loading section for loading a stack of recording media to be folded, a pressing section that moves in the thickness direction of the stack of recording media to contact the surface and press the stack of recording media to form a folded portion in the stack of recording media, a rotating section that forms a crease in the stack of recording media by clamping and rotating the folded portion formed by the pressing section, and a support section that supports one end of the stack of recording media, is openable and closable in the thickness direction of the stack of recording media, and supports the stack of recording media by closing when a crease is formed in the stack of recording media by the pressing section and the rotating section. The invention described in claim 2 is the post-processing device described in claim 1, characterized in that the support section applies a predetermined pressure to the stack of recording media when in a closed state. The invention described in claim 3 is the post-processing device described in claim 2, characterized in that the pressure is a pressure at which the stack of recording media is slidably held. The invention described in claim 4 is the post-processing device described in claim 1, further comprising a binding mechanism for performing a binding process on the stack of recording media, wherein the support section is in a closed state when performing the binding process on the stack of recording media, and after the binding process is performed by the binding mechanism, the support section is maintained in the closed state, and a crease is formed in the stack of recording media by the pressing section and the rotating section. The invention described in claim 5 is the post-processing device described in claim 4, characterized in that the pressure applied by the support portion to the stack of recording media in the closed state when forming a fold is the same as the pressure applied by the support portion to the stack of recording media in the closed state when performing the binding process. The invention described in claim 6 is the post-processing device described in claim 4, characterized in that the pressure applied by the support portion to the stack of recording media in the closed state when forming a fold is weaker than the pressure applied by the support portion to the stack of recording media in the closed state when performing the binding process. The invention described in claim 7 is an image forming system comprising an image forming device that forms an image on a recording medium, and a post-processing device described in any of claims 1 to 6 that performs post-processing on the recording medium on which an image has been formed by the image forming device. Effect of the Invention

[0007] According to the invention of claim 1, the position of the fold in the stack of recording media can be stabilized, compared to a configuration in which the stack of recording media is fold-formed while the stack of recording media is supported by a support portion. According to the invention of claim 2, the stack of recording media can be pressed with the same degree of pressure regardless of the type or number of recording media that constitute the stack of recording media. According to the invention of claim 3, the folding process can be performed with the fold position stabilized without interfering with the movement of the stack of recording media during the folding process. According to the invention of claim 4, the position of the fold in the stack of recording media after the binding process can be stabilized compared to a configuration in which the stack of recording media is supported by a support portion and a fold is formed in the stack of recording media. According to the invention of claim 5, it is possible to easily control the post-processing device, compared to a case where the pressure applied to the stack of recording media is set for each processing operation. According to the invention of claim 6, the pressure applied to the recording medium stack can be set at a pressure appropriate for each processing operation, compared to a case where the pressure is set uniformly for each processing operation. According to the invention of claim 7, the position of the fold in the stack of recording media can be stabilized, compared to a configuration in which the stack of recording media is fold-formed while the stack of recording media is supported by a support portion. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a diagram illustrating an example of the overall configuration of an image forming system. [Diagram 2] FIG. 2 illustrates an example of a finisher unit. [Diagram 3] FIG. 2 is a diagram illustrating an example of the configuration of a control unit. [Figure 4] 4A and 4B are diagrams showing examples of end guides, in which FIG. 4A shows a movable end guide in one position, FIG. 4B shows the end guide in another position, and FIG. 4C shows the end guide in a closed state by an opening / closing mechanism. [Diagram 5] 5A and 5B are diagrams showing the folding knife and the folding roll as viewed from above, in which FIG. 5A shows a state in which the folding knife is retracted, and FIG. 5B shows a state in which the folding knife has advanced toward the folding roll. [Figure 6] 6A and 6B are diagrams illustrating the folding operation in this embodiment, in which FIG. 6A shows the state at the start of folding, FIG. 6B shows the state where the folding knife has advanced and contacted the stack of paper, FIG. 6C shows the state where the folding knife has advanced further and the stack of paper has contacted the folding roll, and FIG. 6D shows the state where the folding knife has advanced further and the folding roll has clamped the stack of paper to form a crease in the stack of paper. [Figure 7] 7A and 7B are diagrams illustrating the folding process performed when the end guide is in an open state, in which FIG. 7A shows the state before the folding knife presses against the stack of sheets, and FIG. 7B shows the state when the folding knife is pressing against the stack of sheets. [Figure 8] 8A and 8B are diagrams illustrating the folding process performed when the end guide is in a closed state, in which FIG. 8A shows the state before the folding knife presses against the stack of sheets, and FIG. 8B shows the state when the folding knife is pressing against the stack of sheets. [Figure 9] 1A to 1C are diagrams illustrating an outline of the operation of saddle stitching processing in the present embodiment. [Figure 10] FIG. 13 is a diagram showing an example of an intermediate position setting table. [Figure 11] 1A to 1C are diagrams illustrating an outline of the operation of a folding knife in a folding process according to the present embodiment. [Figure 12] 4A to 4C are diagrams illustrating an outline of the operation of the folding rolls in the folding process of the present embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] <Overall configuration of image forming system> Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings. FIG. 1 is a diagram showing an example of the overall configuration of an image forming system 1. As shown in FIG. 1 shows the image forming system 1 as viewed from the front side. The image forming system 1 shown in the figure includes an image forming device 2 that forms an image on paper P, which is an example of a recording medium, and a post-processing device 3 that processes the paper P on which the image has been formed by the image forming device 2. The method of forming an image in the image forming device 2 is not particularly limited, and the image forming device 2 forms an image on the paper P using, for example, an electrophotographic method or an inkjet method.

[0010] <Configuration of post-processing device> The post-processing device 3 is provided with a transport unit 4, an interleaf supply unit 5, a folding unit 6, and a finisher unit 7. The transport unit 4 transports the paper P output from the image forming device 2 downstream. The interleaf supply unit 5 supplies interleaf paper such as thick paper or window-opening paper to the paper P transported by the transport unit 4. The post-processing device 3 is also provided with a control unit 100 that controls each part of the post-processing device 3.

[0011] The folding unit 6 performs folding processes such as inner triple fold (C fold) and outer triple fold (Z fold) on the paper P transported from the transport unit 4. The finisher unit 7 is provided downstream of the folding unit 6, and performs binding processes such as stapling the paper stack and folding processes such as forming creases.

[0012] <Finisher unit configuration> FIG. 2 is a diagram showing an example of the finisher unit 7. As shown in FIG. Fig. 2 shows the finisher unit 7 as viewed from the front side of the image forming system 1. As shown in Fig. 2, the finisher unit 7 is provided with a punching unit 71, an edge-stitching stapler unit 72, and a saddle-stitching unit 73. The punching unit 71 performs a hole-punching process on the paper P. The edge-stitching stapler unit 72 performs a process of stapling the edges of the paper stack. The saddle-stitching unit 73 performs a binding process and a folding process on, for example, the center part of the paper stack to create a booklet.

[0013] The finisher unit 7 is provided with a first tray 74, a second tray 75, and a third tray 76. The first tray 74 holds sheets P that are not processed by the finisher unit 7 or sheets P that have only been punched. The second tray 75 holds end-stitched stacks of sheets. The third tray 76 holds booklets that have been bound and folded.

[0014] Furthermore, the finisher unit 7 is provided with a first transport path R1, a second transport path R2, and a third transport path R3. The first transport path R1 is a path for transporting paper P that is not to be processed by the finisher unit 7 or paper P that is to be only punched, and is connected to a first tray 74. The second transport path R2 is a path for transporting a stack of paper to be edge-stitched, and is connected to a second tray 75. The third transport path R3 is a path for transporting the stack of paper to the saddle stitching unit 73, and is connected to a third tray 76. The booklet produced by the saddle stitching unit 73 is transported to the third tray 76.

[0015] <Control Unit Configuration> FIG. 3 is a diagram showing an example of the configuration of the control unit 100. As shown in FIG. The control unit 100 has an arithmetic processing unit 110 that executes digital arithmetic processing according to a program, a secondary storage unit 120 that records information such as the program, and a communication unit 130 that transmits and receives information to and from an external device. The secondary storage unit 120 is realized by an existing information storage device such as an HDD (Hard Disk Drive), a semiconductor memory, or a magnetic tape.

[0016] The arithmetic processing unit 110 is provided with a CPU 111 as an example of a processor. The arithmetic processing unit 110 is also provided with a RAM 112 used as a working memory for the CPU 111, and a ROM 113 in which programs executed by the CPU 111 are stored. The arithmetic processing unit 110 is also provided with a non-volatile memory 114 that is rewritable and can retain data even when the power supply is interrupted. The non-volatile memory 114 is, for example, a static random access memory (SRAM) backed up by a battery, a flash memory, or the like.

[0017] In this embodiment, each process is executed by the CPU 111 reading a program stored in the secondary storage unit 120 or the ROM 113. The arithmetic processing unit 110, the secondary storage unit 120, and the communication unit 130 are connected via a bus or a signal line.

[0018] The program executed by CPU 111 may be provided to control unit 100 in a state where it is stored in a computer-readable recording medium such as a magnetic recording medium (magnetic tape, magnetic disk, etc.), an optical recording medium (optical disk, etc.), a magneto-optical recording medium, a semiconductor memory, etc. Also, the program executed by CPU 111 may be provided to control unit 100 using a communication means such as the Internet.

[0019] In this specification, the term "processor" refers to a processor in a broad sense, and includes general-purpose processors (e.g., CPU: Central Processing Unit, etc.) and dedicated processors (e.g., GPU: Graphics Processing Unit, ASIC: Application Specific Integrated Circuit, FPGA: Field Programmable Gate Array, programmable logic device, etc.). Furthermore, the operation of a processor may not only be performed by a single processor, but may also be performed by multiple processors located at physically separate locations working together. Furthermore, the order of each operation of a processor is not limited to the order described in this embodiment, and may be changed.

[0020] <Configuration of saddle stitching unit> Next, the saddle stitching unit 73 will be described with reference to Fig. 2. In this embodiment, the saddle stitching unit 73 is provided with a compile tray 731, a guide 732, a feed roll 733, an end guide 734, a paper alignment member 735, a stapler 736, a folding knife 737, and a folding roll 738, as shown in Fig. 2. The operation of each part of the saddle stitching unit 73 is controlled by the control unit 100. For example, the opening and closing mechanism of the end guide 734 (described in detail later), and the operations of the folding knife 737 and the folding roll 738 are controlled by the control unit 100.

[0021] The compile tray 731 holds the paper sheets P that are sequentially transported from the image forming device 2. This generates a paper stack of one or more sheets P. The number of sheets P in the paper stack is specified by the settings of the print process to be executed. In this specification, the term "paper stack" also includes a stack consisting of one sheet P. The compile tray 731 is an example of a stacking section that holds the paper stack to be folded.

[0022] The compile tray 731 has a plate-shaped paper stacking section 743 that is sized to accommodate the paper sheets P. An opening (not shown) is provided in the paper stacking section 743. The opening is, for example, a long hole having a length corresponding to the width of the paper sheets P and a width corresponding to the thickness of the folding knife 737 and several stacked sheets P, and is configured to allow the folding knife 737 and a stack of several stacked sheets P to pass through.

[0023] The guide 732 is disposed at a position facing the compile tray 731, and guides the paper P sent out from the feed roll 733. The guide 732 is disposed along the compile tray 731 with a gap between the guide 732 and the compile tray 731.

[0024] The feed roll 733 feeds the paper P conveyed from the image forming apparatus 2 toward the compile tray 731. When a print process is performed on a plurality of sheets of paper P, the feed roll 733 feeds the paper P a number of times corresponding to the number of sheets to be printed.

[0025] FIG. 4 is a diagram showing an example of the end guide 734. FIG. 4(A) is a diagram showing a state in which the movable end guide 734 is in one position, FIG. 4(B) is a diagram showing a state in which the end guide 734 is in another position, and FIG. 4(C) is a diagram showing a state in which the end guide 734 is closed by the opening / closing mechanism 740. The end guide 734 (see FIG. 2) is an example of a support part that supports a paper stack. As shown in FIG. 4(A), the end guide 734 has an abutment part 739 against which the lower end, which is one end of the paper stack, abuts. The paper P sent out by the feed roll 733 moves downward along the compile tray 731. Then, the lower end, which is one end of the paper stack, is supported by the abutment part 739.

[0026] Also, as shown in FIG. 4B, the end guide 734 moves in the vertical direction. This allows the position of the paper stack to be moved depending on the process to be performed on the paper stack. Specifically, the paper stack can be placed in different positions when binding and folding are performed. As an example, when the stapler 736 is located below the opening of the compile tray 731 as shown in FIG. 2, the end guide 734 first positions the center portion of the paper stack so that it corresponds to the stapler 736. Then, the paper stack is bound. Next, the end guide 734 moves upward and positions the center portion of the bound paper stack so that it corresponds to the opening of the compile tray 731. Then, the paper stack is folded.

[0027] The end guide 734 also includes an opening / closing mechanism 740 that can open and close in the thickness direction of the paper stack and can pinch and hold the paper stack by applying pressure. More specifically, as shown in FIG. 4A, when the end guide 734 is opened by the opening / closing mechanism 740 (hereinafter referred to as the "open state"), the paper stack is simply placed on the end guide 734 and is not pinched and held. On the other hand, as shown in FIG. 4C, when the end guide 734 is closed by the opening / closing mechanism 740 (hereinafter referred to as the "closed state"), the end guide 734 holds the paper stack by applying a predetermined pressure to the paper stack. Note that the predetermined pressure may be a pressure that allows the paper stack pinched by the end guide 734 to slide in the folding process by the folding knife 737 and the folding roll 738, which will be described later. Here, being slidable means that the paper stack can be moved by sliding it. In this embodiment, the end guide 734 is in a closed state and holds the paper stack when the folding knife 737 and the folding roll 738 form creases in the paper stack.

[0028] The paper-sheet alignment member 735 is a tamper that aligns the paper-sheet stack by pressing (tamping) the paper-sheet stack stacked on the compile tray 731. The paper-sheet alignment member 735 may also have a configuration in which it presses the paper-sheet stack from above to align the paper-sheet stack in the vertical direction together with an abutting portion 739 of the end guide 734. The paper-sheet alignment member 735 may perform an operation of aligning the paper sheets P every time the paper sheets P are transported onto the compile tray 731, or may align the paper sheets after the number of sheets P determined by the settings of the print process are stacked on the compile tray 731.

[0029] The stapler 736 performs a binding process on the stack of sheets loaded on the compile tray 731. The stapler 736 is an example of a binding mechanism. In this embodiment, the binding process is described assuming that a stack of sheets is bound using staples, but the binding process may be performed using a mechanism that does not use staples and that binds sheets of paper by pressing them together, for example.

[0030] The folding knife 737 is an example of a pressing unit that presses the paper stack. As shown in FIG. 2, the folding knife 737 is disposed at a position facing the compile tray 731. In this embodiment, the folding knife 737 is configured with a base 737A (see FIG. 5) having a length corresponding to the opening of the compile tray 731 and a plurality of protruding parts 737C (see FIG. 5) protruding from the base 737A toward the compile tray 731, and the protruding part 737C has a tip part 737E. The folding knife 737 is configured to be able to advance toward and retreat from the compile tray 731 to the width of the paper P. When the folding knife 737 is in the retracted position, it is disposed at a position that does not touch the paper stack loaded on the compile tray 731. When the folding knife 737 advances toward the compile tray 731, it passes through the opening of the compile tray 731 and reaches the folding roll 738 provided on the back side of the compile tray 731. Therefore, when the folding knife 737 advances toward the compile tray 731 with a stack of paper sheets stacked on the compile tray 731, it comes into contact with the surface of the stack of paper sheets and presses the stack of paper sheets toward the opening of the compile tray 731. As a result, the stack of paper sheets is bent at the position pressed by the folding knife 737 to form a bent portion 791 (see FIG. 6 ). In this embodiment, the operation of the folding knife 737 is controlled by the control unit 100.

[0031] The folding roll 738 is an example of a rotating part that forms a crease in the paper stack. As shown in FIG. 2, the folding roll 738 is disposed on the opposite side of the folding knife 737 across the compile tray 731. In this embodiment, the folding roll 738 is configured by a pair of rolls that are disposed vertically, and the pair of rolls includes a first folding roll 738A located on the upper side and a second folding roll 738B located on the lower side. The folding roll 738 pinches and rotates the paper on which the folding knife 737 has formed a folding portion 791 and which has been pushed out from the opening of the compile tray 731, thereby forming a crease in the paper stack. Furthermore, the folding roll 738 rotates while pressing the paper stack with the first folding roll 738A and the second folding roll 738B, and transports the paper stack. In this embodiment, the operation of the folding roll 738 is controlled by the control unit 100. In this embodiment, a transport roll 741 that transports the paper stack to the third tray is provided downstream of the folding roll 738 in the transport direction.

[0032] <Positional relationship between folding knife and folding roll> Figures 5(A) and (B) are views of the folding knife 737 and the folding roll 738 as viewed from above. Figure 5(A) shows a state in which the folding knife 737 has been retracted, and Figure 5(B) shows a state in which the folding knife 737 has advanced toward the folding roll 738. Figures 5(A) and (B) show the folding roll 738 as viewed from above, and therefore only the first folding roll 738A is shown, with the second folding roll 738B being omitted.

[0033] As shown in FIG. 5(A), each of the first folding roll 738A and the second folding roll 738B (not shown in FIG. 5) constituting the folding roll 738 is provided with a cylindrical rotating shaft 738N and a cylindrical elastic body 738C attached to the outer circumferential surface of the rotating shaft 738N. The elastic body 738C is made of, for example, rubber or soft resin. A plurality of elastic bodies 738C are provided, and are arranged in the axial direction of the rotating shaft 738N. A gap 738E is provided between the adjacent elastic bodies 738C. In this embodiment, the first folding roll 738A and the second folding roll 738B are in contact with each other at a contact portion 738G (see FIG. 5(A)).

[0034] Folding knife 737 (see FIG. 5(A)) is provided with base 737A extending along the axial direction of folding roll 738, and protruding portion 737C protruding from base 737A toward folding roll 738. A plurality of protruding portions 737C are provided at intervals along the longitudinal direction of folding knife 737 so as not to overlap each other. Note that folding knife 737 shown in FIG. 5 is just one example, and the number of protruding portions 737C and the positions of protruding portions 737C are not limited to this.

[0035] As shown in Fig. 5(B) , when the folding knife 737 moves toward the folding roll 738, the protruding portion 737C of the folding knife 737 enters the gap 738E of the elastic body 738C of the folding roll 738. Then, the tip 737E of the protruding portion 737C passes between the rotation shaft 738N of the first folding roll 738A (see Fig. 5(B)) and the rotation shaft 738N of the second folding roll 738B (not shown in Fig. 5(B)). Then, when the folding knife 737 advances further, the tip 737E of the protruding portion 737C moves to a position beyond the contact portion 738G between the first folding roll 738A and the second folding roll 738B.

[0036] <Folding operation> Figure 6 is a diagram illustrating the folding operation in this embodiment: Figure 6(A) shows the state at the start of folding, Figure 6(B) shows the state where the folding knife 737 has advanced and contacted the stack of sheets, Figure 6(C) shows the state where the folding knife 737 has advanced further and the stack of sheets has contacted the folding roll 738, and Figure 6(D) shows the state where the folding knife 737 has advanced further and the folding roll 738 has pinched the stack of sheets to form a fold in the stack of sheets.

[0037] In the folding process, the operations of the folding knife 737 and the folding roll 738 are controlled independently. Specifically, first, only the folding knife 737 operates to press the paper stack, and then the folding roll 738 operates together with the folding knife 737 to form a crease in the paper stack. Referring to FIG. 6, as shown in FIG. 6(A), at the start of the folding process, the folding knife 737 is positioned in a stopped state at the initial position in the saddle stitching unit 73. When the folding process starts, first, the folding knife 737 moves toward the paper stack. At this point, the folding roll 738 is stopped.

[0038] Next, as shown in Fig. 6(B), the folding knife 737 contacts and presses the paper stack, forming a folded portion 791 in the paper stack. At this point, the folding roll 738 is still stopped. Then, as the folding knife 737 advances further, the folding roll 738 comes into contact with a surface 792 of the paper stack opposite to the surface with which the folding knife 737 is in contact, as shown in Fig. 6(C).

[0039] After this, the folding knife 737 advances further, and the folding roll 738 starts to rotate. As the folding knife 737 advances, as shown in FIG. 6D, the tip 737E of the folding knife 737 moves beyond the contact point 738G between the first folding roll 738A and the second folding roll 738B while pressing the paper stack. The paper stack is then folded by the pressure of the folding knife 737 and by the pinching from the surface 792 side by the rotating folding roll 738. After advancing to a position described later, the folding knife 737 retreats and returns to the initial position. Meanwhile, the folding roll 738 rotates further to transport the folded paper stack downstream while pressing it.

[0040] <End guide operation> It has already been mentioned that the end guide 734 is provided with the opening / closing mechanism 740. Here, the saddle stitching process for the stack of sheets loaded on the compile tray 731 will be described, and the opening / closing operation of the end guide 734 in this saddle stitching process will be described. In the saddle stitching process, the stack of sheets is first bound using the stapler 736, and then folded. Note that the operation of each part of the saddle stitching unit 73 in the saddle stitching process is realized by the CPU 111 reading a program stored in the secondary storage unit 120 or ROM 113 into the RAM 112 and executing it.

[0041] FIG. 9 is a diagram for explaining an outline of the operation of the saddle stitching process in this embodiment. First, as an operation before the start of saddle stitching, the paper P sent out from the feed roll 733 is stacked on the compile tray 731 (S101). Next, the paper alignment member 735 presses the paper stack on the compile tray 731 to align the paper (S102).

[0042] When the saddle stitching process by the saddle stitching unit 73 starts, first, the opening / closing mechanism 740 closes the end guide 734 (S103). Next, the end guide 734 moves so that the binding position of the paper stack coincides with the stapling position of the stapler 736 (S104). The binding position of the paper stack is, for example, the center of the paper P. After the end guide 734 moves, the stapler 736 performs the binding process on the paper stack (S105). At this time, since the end guide 734 is in the closed state in S103, the paper stack is held down by the end guide 734 with a certain amount of pressure. This prevents the paper stack from being disturbed by the stapler 736 coming into contact with the paper stack during the binding process.

[0043] After the binding process is performed, the end guide 734 moves so that the position where the fold of the paper stack is formed (hereinafter referred to as the "folding position") faces the tip 737E of the folding knife 737 (S106). The folding position of the paper stack is, for example, the center part of the paper P, which is the same as the binding position. After the end guide 734 moves, the folding knife 737 and the folding roll 738 perform the folding process on the paper stack (S107). In the folding process, the folding knife 737 folds the paper stack while pressing the folding position of the paper stack, and advances from the opening of the compile tray 731 to the folding roll 738. Then, the folding roll 738 sandwiches the folded paper stack and further folds it while transporting it downstream. At this time, the end guide 734 is maintained in a closed state. In the closed state, the end guide 734 holds the paper stack with a pressure that causes the paper stack to slide due to the force generated when the folding knife 737 presses and folds the paper stack while passing through the opening. Therefore, when the folding knife 737 presses and folds the paper stack in the folding process, the paper stack is prevented from floating and becoming disarrayed.

[0044] When the folding process is completed and the paper stack is transported by the folding roll 738, the opening / closing mechanism 740 opens the end guide 734 (S108). In the above operation example, the binding process is performed in S104 and S105, and then the folding process is performed in S106 and S107. However, if only the folding process is performed without the binding process, S104 and S105 are omitted. In this case as well, the end guide 734 is closed in S103, and the folding process is performed in S106 and S107 while maintaining this closed state, and after the folding process is completed, the end guide 734 is opened in S108.

[0045] In the above operation example, the binding process and the folding process were performed after the end guide 734 was closed. Here, the pressure with which the end guide 734 presses the paper stack is set to a level at which the paper stack slides, but since the paper stack is not slid during the binding process, it may be pressed with a stronger pressure. That is, the paper stack may be pressed with the same pressure throughout the binding process and the folding process, or the paper stack may be pressed with a strength that does not move the paper stack during the binding process, and with a weaker strength during the folding process that causes the paper stack to slide.

[0046] As described above, in this embodiment, the end guide 734 is maintained in a closed state until the folding process is completed in the saddle stitching process. This point will be further described with reference to the drawings. FIG. 7 is a diagram for explaining the folding process performed when the end guide 734 is in an open state. FIG. 7(A) is a diagram showing a state before the folding knife 737 presses the paper stack, and FIG. 7(B) is a diagram showing a state in which the folding knife 737 is pressing the paper stack. FIG. 8 is a diagram for explaining the folding process performed when the end guide 734 is in a closed state. FIG. 8(A) is a diagram showing a state before the folding knife 737 presses the paper stack, and FIG. 8(B) is a diagram showing a state in which the folding knife 737 is pressing the paper stack.

[0047] As shown in FIGS. 7A and 7B, when folding is performed with the end guide 734 in the open state, the folding knife 737 presses the paper stack, causing the folded paper stack to bend and float above the compile tray 731. For this reason, the paper P of the paper stack may be displaced by the pressure of the folding knife 737 or the pinching force of the folding roll 738, and the fold position of the paper stack is not stable. On the other hand, as shown in FIGS. 8A and 8B, when folding is performed with the end guide 734 in the closed state, even if the folding knife 737 presses the paper stack, the end guide 734 holds down the paper stack, so the paper stack does not float above the compile tray 731. For this reason, even if the pressure of the folding knife 737 or the pinching force of the folding roll 738 acts on the paper stack, the paper P of the paper stack does not displace and the fold position of the paper stack is stable.

[0048] Next, a detailed overview of the operation of the folding process will be described. As described with reference to FIG. 6, in the folding process, the operations of the folding knife 737 and the folding roll 738 are controlled independently. Therefore, the operation of the folding knife 737 and the operation of the folding roll 738 in the folding process will be described separately. The operation of the folding knife 737 is performed in two stages: a first stage in which only the folding knife 737 operates, and a second stage in which the folding knife 737 operates together with the folding roll 738. The operation of the folding roll 738 is performed together with the operation of the folding knife 737 in the second stage.

[0049] In the first operation of the folding knife 737, the folding knife 737 moves to a position (hereinafter referred to as the "middle position") that is determined based on the amount of movement from the initial position. The middle position is, for example, a position where the surface 792 of the paper stack that is pressed and folded by the folding knife 737 comes into contact with the folding roll 738. The folding roll 738 starts to operate after the surface 792 of the paper stack comes into contact with the folding roll 738, thereby preventing the paper sheets P on the side of the surface 792 of the paper stack from being wound into the folding roll 738 earlier than the other paper sheets P.

[0050] Here, the position of the folding knife 737 where the paper stack comes into contact with the folding roll 738 differs depending on the conditions of the number of sheets of paper P to be folded and the basis weight. For example, if the type of paper P is different, the thickness will change even for a paper stack of the same number of sheets of paper P. Also, even for the same type of paper P, the thickness of the paper stack will change depending on the number of sheets loaded. Therefore, the amount of movement that identifies the intermediate position is adjusted based on the conditions of the number of sheets of paper P to be folded and the basis weight.

[0051] As an example, in this embodiment, an intermediate position setting table is prepared in advance in which the number of loaded sheets of paper P and the basis weight correspond to intermediate positions in the movement of the folding knife 737, and is stored in the secondary storage unit 120 (see FIG. 3) or the like. Then, when performing folding processing, the control unit 100 (see FIG. 3) refers to the intermediate position setting table, identifies the corresponding intermediate position according to the number of sheets of paper P in the paper stack to be processed and the basis weight, and calculates the movement amount of the folding knife 737.

[0052] 10 is a diagram showing an example of the intermediate position setting table. In the example shown in FIG. 10, the intermediate positions are set as follows: (a) a position where the tip 737E of the folding knife 737 is 1.5 mm before the contact portion 738G of the folding roll 738; and (b) a position where the tip 737E of the folding knife 737 is 3 mm before the contact portion 738G of the folding roll 738. Then, a correspondence relationship between the combination of the paper sheet P and the basis weight and the set intermediate position is determined, such as (a) being the reference position when the basis weight of the paper sheet P is 90 gsm or less and the number of stacked sheets is 5 or less, and (b) being the reference position when the basis weight of the paper sheet P is 91 gsm or more and the number of stacked sheets is 6 or more. In the first stage of the folding process, the control unit 100 controls the operation of the folding knife 737 by setting the movement amount of the folding knife 737 from the initial position to the intermediate position specified by the intermediate position setting table. The combinations of the number of sheets to be loaded and the basis weights shown in the intermediate position setting table of FIG. 10 and the setting values ​​of the intermediate positions shown in (a) and (b) are merely examples and are not limited to the values ​​shown.

[0053] <Overview of folding process> FIG. 11 is a diagram for explaining an outline of the operation of the folder knife 737 in the folding process of this embodiment. When folding processing is performed in this embodiment, first, the control unit 100 obtains information on the basis weight and number of sheets of paper P (S201). The basis weight information is obtained, for example, from the information on the print settings in the image forming device 2. Specifically, the basis weight of the paper P is specified based on the information on the type of paper P specified in the print settings. The information on the number of sheets may be extracted, for example, from the information on the print settings in the image forming device 2, or may be configured to be measured by providing a counter in the device itself.

[0054] Next, the control unit 100 uses the acquired information on basis weight and number of sheets to refer to the intermediate position setting table and acquires the movement amount of the folding knife 737 based on the information on the intermediate position (S202). Next, the control unit 100 starts the operation of the folding knife 737 (S203). Then, the control unit 100 moves the folding knife 737 based on the acquired movement amount, and then stops the operation of the folding knife 737 (YES in S204, S205). This is the first stage of operation.

[0055] Thereafter, the control unit 100 transitions to a second stage of operation and restarts the operation of the stopped folding knife 737 (S206). In the second stage of operation, the control unit 100 moves the folding knife 737 to a position where the tip 737E of the folding knife 737 passes over the contact portion 738G between the first folding roll 738A and the second folding roll 738B (S207). Thereafter, the control unit 100 moves the folding knife 737 to the initial position and stops the operation of the folding knife 737 (S208, S209).

[0056] FIG. 12 is a diagram for explaining an outline of the operation of the folding roll 738 in the folding process of this embodiment. The folding roll 738 is stopped until the first stage of the operation of the folding knife 737 is completed (S301). Then, after the folding knife 737 moves to an intermediate position and stops, the control unit 100 starts the operation of the folding roll 738 together with the start of the second stage of the operation of the folding knife 737 (S302). Note that the second stage of the operation of the folding knife 737 (FIG. 11, S206) and the operation of the folding roll 738 (S302) start simultaneously.

[0057] The folding rolls 738 pinch and rotate the folding portion 791 of the paper stack to form a crease in the paper stack and transport the paper stack downstream (S303). Then, after the paper stack passes the folding rolls 738, the control unit 100 stops the operation of the folding rolls 738 (YES in S304, S305).

[0058] The folding process is realized by the operation of the folding knife 737 described above with reference to FIG. 11 and the operation of the folding roll 738 described above with reference to FIG. 12, and a booklet is produced by a series of these operations.

[0059] Although the embodiment of the present invention has been described above, the technical scope of the present invention is not limited to the above embodiment. For example, in this embodiment, information on the number of stacked sheets of paper P and the basis weight is used to calculate the movement amount of the folding knife 737, but this is not limiting. For example, in addition to information on the number of stacked sheets of paper P and the basis weight, the hardness of the paper P and the surface condition of the paper P may be used. The condition for determining the movement amount of the folding knife 737 may be any condition that affects the formation of creases in the paper.

[0060] In addition, in the present embodiment, the folding knife 737 is stopped once after moving to a predetermined position and then resumes operation together with the folding roll 738, but when the operation of the folding knife 737 is resumed, the operation of the folding knife 737 may be started slightly earlier than the operation of the folding roll 738. This makes it possible to prevent the sheet P on the surface 792 side of the paper stack from being pinched by the folding roll 738 before the other sheets P.

[0061] On the other hand, a configuration may be adopted in which the operation of the folding knife 737 is not stopped when the folding knife 737 has moved to a predetermined position. In such a case, the control unit 100 controls the folding roll 738 to start operating at the same time as the folding knife 737 has moved to the predetermined position, thereby making it possible to realize this configuration.

[0062] Furthermore, when forming creases in the paper stack, the pressing speed at which the folding knife 737 presses the paper stack may be set faster than the rotation speed at which the folding roll 738 rotates while pinching the folded portion 791 of the paper stack. This makes it possible to prevent the paper P on the surface 792 side of the paper stack from being pinched by the folding roll 738 before other paper sheets P. Various other modifications and alternative configurations that do not depart from the scope of the technical concept of the present invention are included in the present invention.

[0063] <Additional Notes> (((1))) A post-processing device comprising: a loading section for loading a stack of recording media to be folded; a pressing section that moves in the thickness direction of the stack of recording media to contact its surface and press it to form a folded portion in the stack of recording media; a rotating section that forms a crease in the stack of recording media by clamping and rotating the folded portion formed by the pressing section; and a support section that supports one end of the stack of recording media, is openable and closable in the thickness direction of the stack of recording media, and supports the stack of recording media by closing when a crease is formed in the stack of recording media by the pressing section and the rotating section. (((2))) The post-processing device described in (((1))) is characterized in that the support section applies a predetermined pressure to the stack of recording media when in a closed state. (((3))) The post-processing device described in (((2))) is characterized in that the pressure is a pressure at which the stack of recording media is slidably held. (((4))) The post-processing device described in any one of (((1))) to (((3))) is further provided with a binding mechanism for performing a binding process on the stack of recording media, the support unit being in a closed state when performing the binding process on the stack of recording media, and after the binding process has been performed by the binding mechanism, the support unit is maintained in a closed state, and a crease is formed in the stack of recording media by the pressing unit and the rotating unit. (((5))) A post-processing device as described in any one of (((1))) to (((4))), characterized in that the pressure that the support section applies to the stack of recording media in the closed state when forming a fold is the same as the pressure that the support section applies to the stack of recording media in the closed state when performing a binding process. (((6))) A post-processing device as described in any one of ((1)) to (((4))), characterized in that the pressure applied by the support portion to the stack of recording media in the closed state when forming a fold is weaker than the pressure applied by the support portion to the stack of recording media in the closed state when performing a binding process. (((7))) An image forming system comprising: an image forming apparatus which forms an image on a recording medium; and a post-processing apparatus described in any one of ((1))) to (((6))) which performs post-processing on the recording medium on which an image has been formed by the image forming apparatus.

[0064] According to the invention (((1))), the position of the fold in the stack of recording media can be stabilized compared to a configuration in which the stack of recording media is supported by a support section and a fold is formed in the stack of recording media. According to the invention of (((2))), the stack of recording media can be pressed with the same degree of pressure regardless of the type or number of recording media constituting the stack. According to the invention (((3))), the folding process can be performed with the fold position stabilized without interfering with the movement of the recording medium stack during the folding process. According to the invention (((4))), the position of the fold in the stack of recording media after the binding process can be stabilized compared to a configuration in which the stack of recording media is supported by a support portion and a fold is formed in the stack of recording media. According to the invention of (((5))), the post-processing device can be controlled more easily than when the pressure applied to the stack of recording media is set for each processing operation. According to the invention (((6))), processing operations can be performed with pressure appropriate to each processing operation, compared to when the pressure applied to the recording medium stack is set uniformly for each processing operation. According to the invention (((7))), the position of the fold in the stack of recording media can be stabilized compared to a configuration in which the stack of recording media is supported by a support section and a fold is formed in the stack of recording media. [Explanation of symbols]

[0065] 1...image forming system, 2...image forming apparatus, 3...post-processing apparatus, 4...transport unit, 5...interleaf supply unit, 6...folding unit, 7...finisher unit, 71...punching unit, 72...edge-stitching stapler unit, 73...saddle-stitching unit, 100...control unit, 731...compile tray, 732...guiding guide, 733...feed roll, 734...end guide, 735...paper alignment member, 736...stapler, 737...folding knife, 738...folding roll, 739...butting unit, 740...opening / closing mechanism, 741...transport roll

Claims

1. a stacking section for stacking a stack of recording media to be folded; a pressing section that moves in a thickness direction of the recording medium bundle to contact a surface of the recording medium bundle and presses the recording medium bundle to form a folded portion; a rotating unit that forms a fold in the stack of recording media by pinching and rotating the folding portion formed by the pressing unit; a support section that supports one end of the recording medium stack, is openable and closable in a thickness direction of the recording medium stack, and is in a closed state when the pressing section and the rotating section form a fold in the recording medium stack, thereby supporting and holding the recording medium stack; A post-processing device comprising:

2. The post-processing device according to claim 1 , wherein the support section applies a predetermined pressure to the stack of recording media when the support section is in the closed state.

3. 3. The post-processing device according to claim 2, wherein the pressure is a pressure at which the stack of recording media is slidably held.

4. The recording medium bundle further includes a binding mechanism for performing a binding process on the recording medium bundle. The post-processing device according to claim 1, characterized in that the support section is in a closed state when performing a binding process on the stack of recording media, and after the binding process is performed by the binding mechanism, the support section is maintained in a closed state, and a crease is formed in the stack of recording media by the pressing section and the rotating section.

5. 5. The post-processing device according to claim 4, wherein the pressure applied by the support portion to the stack of recording media in the closed state when forming the fold is the same as the pressure applied by the support portion to the stack of recording media in the closed state when performing the binding process.

6. 5. The post-processing device according to claim 4, wherein the pressure applied by the support portion to the stack of recording media in the closed state when forming a fold is weaker than the pressure applied by the support portion to the stack of recording media in the closed state when performing a binding process.

7. an image forming apparatus for forming an image on a recording medium; a post-processing device according to claim 1 , which performs post-processing on a recording medium on which an image has been formed by the image forming device; An image forming system comprising:

Images