Sheet folding apparatus, image forming apparatus, and image forming system

Abstract

The present application relates to a sheet folding device capable of coping with a plurality of folding types with a simple configuration, an image forming apparatus, and an image forming system. The sheet folding device includes a first folding roller, a second folding roller, and a third folding roller, a guide member capable of rotating to a first posture that prevents a sheet from entering a return transport path and a second posture that allows the sheet to be transported from one of a main transport path and the return transport path to the other, a motor that rotates the second folding roller in one of a forward rotation that rotates the second folding roller in a manner to transport a sheet on the return transport path from a merging position to a branching position while transporting a sheet on the main transport path in a transport direction and a reverse rotation that is in a direction opposite to the forward rotation, and a drive force transmission mechanism that rotates the guide member from the second posture to the first posture in conjunction with the forward rotation of the second folding roller and rotates the guide member from the first posture to the second posture in conjunction with the reverse rotation of the second folding roller.

Description

Technical Field

[0001] This invention relates to a sheet folding apparatus, an image forming apparatus, and an image forming system. Background Technology

[0002] Previously, sheet folding devices were known to fold sheets into a prescribed shape (e.g., Z-shaped fold, outward tri-fold, or bi-fold) after an image has been formed by an image forming apparatus. However, when connecting a sheet folding device to an existing image forming apparatus to construct an image forming system, the overall system size becomes larger.

[0003] To address this issue, Patent Document 1 discloses a sheet folding device that can be installed within the body of an image forming apparatus. Patent Document 1 further states that "this sheet folding device is adapted to alternately perform inward and outward folding, a so-called Z-shaped folding, along the sheet transport direction."

[0004] However, due to the limited space within the image forming apparatus, it is difficult to install large and complex sheet folding devices. Therefore, as with the sheet folding device described in Patent Document 1, there is a limitation on the types of folding methods.

[0005] The purpose of this invention is to provide a sheet folding device that can handle various types of folding with a simple structure.

[0006] [Patent Document 1] Japanese Patent Application Publication No. 2020-189717 Summary of the Invention

[0007] To address the aforementioned technical problems, one aspect of the present invention is characterized by comprising: a conveying unit that conveys a sheet along a main conveying path in a conveying direction; a first folding roller and a second folding roller, which are arranged facing each other and sandwiching the main conveying path; a third folding roller, which is arranged facing each other and sandwiching a return conveying path, the return conveying path branching from the main conveying path at a branching position upstream of the first folding roller in the conveying direction, and merging with the main conveying path at a merging position upstream of the branching position in the conveying direction; and a guiding member capable of switching between a first posture and a second posture, the first posture preventing the sheet conveyed along the main conveying path in the conveying direction from entering the return conveying path through the branching position. The path, the second posture allowing the sheet to be conveyed from one of the main conveying path and the return conveying path to the other via the branch position; a motor that causes the second folding roller to rotate in one of a forward rotation or a reverse rotation opposite to the forward rotation, the forward rotation being a rotation that conveys the sheet on the main conveying path along the conveying direction while simultaneously conveying the sheet on the return conveying path from the confluence position to the branch position; and a drive force transmission mechanism that, in conjunction with the forward rotation of the second folding roller, causes the guide member to rotate from the second posture to the first posture, and in conjunction with the reverse rotation of the second folding roller, causes the guide member to rotate from the first posture to the second posture.

[0008] According to the present invention, a sheet folding device with a simple structure that can handle a variety of folding types can be obtained. Attached Figure Description

[0009] Figure 1 The image forming apparatus shown is an external view.

[0010] Figure 2 The diagram shows the internal structure of the sheet folding unit and the sheet packing unit.

[0011] Figure 3A The diagram shown is of the sheet folding unit as seen from a direction orthogonal to the sheet along the main conveying path. Figure 3B The diagram shows a sheet folding unit in the width direction of the sheet, viewed from a direction orthogonal to the sheet on the main conveying path.

[0012] Figure 4 The diagram shown is a hardware configuration diagram of the sheet folding unit.

[0013] Figure 5 Figures (A)-(C) illustrate variations in the folding method that can be achieved by the sheet folding unit.

[0014] Figure 6 The diagram shown is a flowchart of the three-fold process.

[0015] Figure 7 Figures (A) and (B) show the state of the sheet folding unit before folding the sheet at the first folding position.

[0016] Figure 8 Figures (A) and (B) show the state of the sheet folding unit when the sheet is folded at the first folding position.

[0017] Figure 9 Figures (A) and (B) show the state of the sheet folding unit before folding the sheet at the second folding position.

[0018] Figure 10 Figures (A) and (B) show the state of the sheet folding unit after the sheet is folded at the second folding position.

[0019] Figure 11 The diagram shows a flowchart of the folding process.

[0020] Figure 12 (A)-(F) show the state diagrams of the sheet folding unit during the folding process.

[0021] Figure 13 (A) and (B) show the state diagrams of the sheet arriving at the conveyor rollers before the sheet packing unit.

[0022] Figure 14 (A) and (B) show the state diagrams of the sheet packing unit when the sheet is discharged to the discharge tray without binding.

[0023] Figure 15 (A) and (B) show the state diagrams of sheet binding units undergoing binding processing.

[0024] Figure 16 The image shows the view from the thickness direction of the sheet. Figure 15 (B) The paper packaging unit of the order.

[0025] Figure 17 (A) and (B) show the state diagrams of the sheet packing unit when the sheet that has undergone binding is discharged into the discharge tray.

[0026] Figure 18 Figures (A) and (B) show the internal structure of the punching and perforation unit.

[0027] Figure 19 The image shown is an external view of the image forming system. Detailed Implementation

[0028] Hereinafter, the image forming apparatus 110 according to the present invention will be described with reference to the accompanying drawings. Figure 1 This is an external view of the image forming apparatus 10. The image forming apparatus 10 is a device for forming images on a sheet S (typically paper). Figure 1 As shown, the image forming apparatus 10 includes a frame 11 and an image forming unit 12.

[0029] The frame 11 is a box-shaped structure that forms an internal space for housing the constituent parts of the image forming apparatus 10. Additionally, an internal space 13, operable from outside the image forming apparatus 10, is formed within the frame 11. The internal space 13 is located, for example, slightly above the center of the frame 11 in the vertical direction. Furthermore, the outer wall of the frame 11 is cut away, thus exposing the internal space 13 to the outside. Further, the sheet folding unit 20 (sheet folding device), the sheet assembly unit 30 (post-processing unit), and the punching and perforating unit 50 (described later) are also included. Figure 18 It can be installed in the internal space 13 of the machine body.

[0030] The image forming unit 12 forms an image on the sheet S contained in the tray, and discharges the sheet S with the formed image to the sheet folding unit 20, the sheet packing unit 30, or the punching and perforating unit 50. The image forming unit 12 can be an inkjet type that uses ink to form the image, or an electrophotographic type that uses toner to form the image. The configuration of the image forming unit 12 is known, so detailed description is omitted.

[0031] The sheet folding unit 20 is located on the conveying path of the sheet S from the image forming unit 12 to the sheet assembly unit 30. Figure 1 In the path indicated by the dashed arrow, the sheet S is installed in the internal space 13 of the image forming apparatus 10, downstream of the image forming unit 12 and upstream of the sheet assembly unit 30. That is, the sheet S for which the image has been formed by the image forming unit 12 is first transferred to the sheet folding unit 20 for the folding process described later, and then transferred to the sheet assembly unit 30 for the binding process described later.

[0032] Furthermore, the sheet folding unit 20 is configured to be detachable from the image forming apparatus 10. When the sheet folding unit 20 is removed, the sheet S for which the image has been formed by the image forming unit 12 is directly transferred to the sheet assembly unit 30 and subjected to binding processing. Further, in the position where the sheet folding unit 20 is removed in the machine body space 13, the punching and perforating unit 50 is configured to be detachable. When the punching and perforating unit 50 is installed, the sheet S for which the image has been formed by the image forming unit 12 is first transferred to the punching and perforating unit 50 for perforation processing (described later), and then transferred to the sheet assembly unit 30 for binding processing. Additionally, in the position where the sheet folding unit 20 is removed in the machine body space 13, the punching and perforating unit is not limited to; any unit that performs arbitrary processing on the sheet S can also be installed.

[0033] Figure 2 The diagram shows the internal structure of the sheet folding unit 20 and the sheet assembly unit 30. The sheet folding unit 20 and the sheet assembly unit 30 are modularized and can be connected to the input / output interfaces of the sheet S. Specifically, the input interface IN of the sheet folding unit 20 is configured to connect to the output interface of the image forming unit 12. Furthermore, the input interface of the sheet assembly unit 30 is configured to connect to both the output interface of the image forming unit 12 and the output interface OUT of the sheet folding unit 20.

[0034] The sheet folding unit 20 performs a folding process to fold the sheet S, whose image has been formed by the image forming unit 12, into a predetermined shape (e.g., a Z-shaped fold, an outward triple fold, or a bi-fold). Figure 2 As shown, the sheet folding unit 20 includes a frame 21, a pair of conveying rollers 22 (conveying section), a first folding roller 23, a second folding roller 24, a third folding roller 25, a guide plate 26 (guide component), a first stop 27a, and a second stop 27b (see reference). Figure 3A and Figure 3B ), drive force transmission mechanism 28 (refer to) Figure 3A and Figure 3B ).

[0035] The frame 21 is a box-shaped structure that forms the internal space for housing the constituent parts of the sheet folding unit 20. Furthermore, a main transport path Ph1 and a return transport path Ph2, serving as the passageway for the sheet S, are formed within the internal space of the frame 21. The main transport path Ph1 is a transport path from the input interface IN connected to the image forming unit 12 to the output interface OUT connected to the sheet assembly unit 30. Hereinafter, the direction from the input interface IN to the output interface OUT on the main transport path Ph1 will be labeled as the "transport direction". The return transport path Ph2 is a loop-shaped transport path that branches off from the main transport path Ph1 at branch position A and merges with the main transport path Ph1 at merging position B. Furthermore, the merging position B is located upstream of the main transport path than the branch position A.

[0036] The conveyor roller pair 22 conveys the sheet S along the main conveyor path Ph1 in the conveying direction. The conveyor roller pair 22, located upstream of the branch position A and downstream of the confluence position B in the conveying direction (i.e., between branch position A and confluence position B), consists of a drive roller 22a and a driven roller 22b arranged facing each other, sandwiching the main conveyor path Ph1. The drive roller 22a and driven roller 22b are supported by a frame 21 and are rotatable. The conveyor motor 22c (see reference...) Figure 4 The driving force is transmitted to the drive roller 22a, which moves in the direction of conveying the sheet S in the conveying direction. Figure 2 The driven roller 22b, which clamps the main conveying path Ph1, is configured to face the drive roller 22a and is driven by the rotation of the drive roller 22a. Then, with the sheet S clamped between the drive roller 22a and the driven roller 22b, the sheet S is conveyed along the main conveying path Ph1 in the conveying direction by driving the conveying motor 22c.

[0037] The first folding roller 23 is rotatably supported on the frame 21 in a position facing the main conveying path Ph1. The second folding roller 24 is rotatably supported on the frame 21 in a position facing both the main conveying path Ph1 and the return conveying path Ph2. The third folding roller 25 is rotatably supported on the frame 21 in a position facing the return conveying path Ph2. Furthermore, the first folding roller 23 and the second folding roller 24 are configured to face each other, sandwiching the main conveying path Ph1, downstream of the branch position A in the conveying direction. Further, the second folding roller 24 and the third folding roller 25 are configured to face each other, sandwiching the return conveying path Ph2, between the branch position A and the confluence position B.

[0038] The first folding roller 23 is driven by the first folding motor 23a (see reference). Figure 4The first folding roller 23 rotates in both forward and reverse directions due to the driving force transmitted from it. The forward rotation of the first folding roller 23 is a rotation that moves the sheet S on the main conveying path Ph1 in the conveying direction. The reverse rotation of the first folding roller 23 is a rotation opposite to the forward rotation. The first folding motor 23a is configured to enable forward rotation of the first folding roller 23 and reverse rotation of the first folding roller 23.

[0039] The second folding roller 24 is controlled by the second folding motor 24a (see reference). Figure 4 The second folding roller 24 rotates in both forward and reverse directions due to the driving force transmitted from it. The forward rotation of the second folding roller 24 is a rotation that simultaneously transports the sheet S on the main conveying path Ph1 in the conveying direction and the sheet S on the return conveying path Ph2 from the confluence position B to the branch position A. The reverse rotation of the second folding roller 24 is the opposite of the forward rotation. The second folding motor 24a (motor) is configured to enable forward rotation of the second folding roller 24 and reverse rotation of the second folding roller 24.

[0040] The third folding roller 25 is driven by the third folding motor 25a (see reference). Figure 4 The driving force transmitted from the third folding roller 25 causes it to rotate in both the forward and reverse directions. The forward rotation of the second folding roller 25 is the rotation in the direction that transports the sheet S on the return conveying path Ph2 from the confluence position B to the branch position A. The reverse rotation of the third folding roller 25 is the rotation opposite to the forward rotation. The third folding motor 25a is configured to enable the third folding roller 25 to rotate in the forward direction and to rotate in the reverse direction.

[0041] Guide plate 26 is rotatably supported on frame 21 near branch position A. Guide plate 26 is configured to be able to Figure 7 (B) and Figure 10 The first posture shown in (B) and Figure 8 (B) and Figure 9 The sheet S rotates between the second postures shown in (B). The first posture allows the sheet S to be conveyed along the conveying direction on the main conveying path Ph1 while preventing the sheet S conveyed along the conveying direction on the main conveying path Ph1 from entering the guide plate 26 of the return conveying path Ph2 through the branch position A. On the other hand, the guide plate 26 in the first posture allows the sheet S on the return conveying path Ph2 to enter the main conveying path Ph1 through the branch position A. The second posture is the guide plate 26 that allows the sheet S to be conveyed from one of the main conveying path Ph1 and the return conveying path Ph2 to the other through the branch position A.

[0042] like Figure 7 (B) and Figure 10As shown in (B), the first stop 27a abuts against the guide plate 26 of the first posture to prevent the guide plate 26 from moving away from the second posture. Figure 7 (B) and Figure 10 (B) rotates clockwise. For example... Figure 8 (B) and Figure 9 As shown in (B), the second stop 27b abuts against the guide plate 26 of the first posture to prevent the guide plate 26 from moving away from the first posture. Figure 8 (B) and Figure 9 The guide plate 26 rotates counterclockwise (B). Thus, the guide plate 26 rotates only between the first and second positions (in other words, between the first stop 27a and the second stop 27b). In other words, the first stop 27a and the second stop 27b limit the range of rotation of the guide plate 26.

[0043] Figure 3A The diagram shown is of the sheet folding unit 20 as seen from a direction orthogonal to the sheet S on the main conveying path Ph1. Figure 3B The diagram shows the sheet folding unit 20 in the width direction of the sheet, as seen from a direction orthogonal to the sheet S on the main conveying path Ph1. Figure 3A and Figure 3B As shown, the rotation axes 23x, 24x, 25x, and 26x of the first folding roller 23, the second folding roller 24, the third folding roller 25, and the guide plate 26 extend along the width direction of the sheet S. The rotation axes 23x, 24x, 25x, and 26x are then disposed through a partition wall 21a inside the frame 21. A drive force transmission mechanism 28, clamping the partition wall 21a, is positioned on the opposite side from the first folding roller 23, the second folding roller 24, the third folding roller 25, and the guide plate 26.

[0044] The drive force transmission mechanism 28 drives the second folding roller 24 and guide plate 26 in a coordinated manner by distributing the driving force of the second folding motor 24a to the second folding roller 24 and guide plate 26. More specifically, the drive force transmission mechanism 28 is linked to the forward rotation of the second folding roller 24, causing the guide plate 26 to rotate from a second posture to a first posture. Conversely, the drive force transmission mechanism 28 is linked to the reverse rotation of the second folding roller 24, causing the guide plate 26 to rotate from the first posture to the second posture. Figure 3A and Figure 3B As shown, the driving force transmission mechanism 28 is composed of, for example, a torque limiter 28a and a driven gear 28b.

[0045] The output shaft of the second folding motor 24a is connected to the rotation shaft 24x of the second folding roller 24. A torque limiter 28a is mounted on the rotation shaft 24x of the second folding roller 24 and rotates integrally with the second folding roller 24. A driven gear 28b is mounted on the rotation shaft 26x of the guide plate 26 and rotates integrally with the guide plate 26. Then, the torque limiter 28a and the driven gear 28b mesh with each other.

[0046] Thus, the driving force of the second folding motor 24a is transmitted to the second folding roller 24, and simultaneously to the guide plate 26 via the torque limiter 28a and the driven gear 28b. More specifically, by rotating the second folding motor 24a forward, the guide plate 26 rotates from the second posture to the first posture while the second folding roller 24 rotates forward. On the other hand, by rotating the second folding motor 24a in reverse, the guide plate 26 rotates from the first posture to the second posture while the second folding roller 24 rotates in the opposite direction.

[0047] Furthermore, when the rotational torque is less than a threshold (i.e., the guide plate 26 moves away from the first stop 27a and the second stop 27b), the torque limiter 28a transmits the driving force of the second folding motor 24a to the driven gear 28b (in other words, the guide plate 26). On the other hand, when the rotational torque is above the threshold (i.e., the guide plate 26 abuts against the first stop 27a and the second stop 27b), the torque limiter 28a releases the transmission of the driving force from the second folding motor 24a to the driven gear 28b (in other words, the guide plate 26) (i.e., idles). Since the configuration of the torque limiter 28a, which switches between transmitting and releasing the driving force, is already known, a detailed description is omitted.

[0048] Furthermore, the number of teeth Z1 of the torque limiter 28a is greater than the number of teeth Z2 of the driven gear 28b (Z1>Z2). As a result, the drive force transmission mechanism 28 transmits the rotational speed increase of the second folding motor 24a to the guide plate 26. More specifically, when the second folding motor 24a rotates one revolution, the guide plate 26 rotates only a first number of revolutions (e.g., one revolution) relative to the second folding roller 24, and only a second number of revolutions (e.g., Z1 / Z2) more than the first number of revolutions. Thus, the guide plate 26 can be rapidly changed in posture.

[0049] The sheet folding unit 20 has a sheet sensor 29 (see reference) for detecting whether the sheet S has reached a specified position on the main conveying path Ph1 or the return conveying path Ph2. Figure 4 ) and rotary encoders 22z, 23z, 24z, 25z that detect the rotational speeds of each roller 22a, 23, 24, 25 (see reference) Figure 4Based on the detection results of sheet sensor 29 and rotary encoders 22z, 23z, 24z and 25z, the controller 100 described later is able to determine the position of sheet S in the main conveying path Ph1 and the return conveying path Ph2.

[0050] More specifically, after the controller 100 detects the sheet S via the sheet sensor 29, it determines the position of the sheet S based on the number of pulse signals output from the rotary encoders 22z, 23z, 24z, and 25z. This determines the timing of the subsequent steps S602, S604, S606, S1102, S1104, and S1106. Furthermore, the sheet sensor 29 can be located at multiple locations, not just one.

[0051] The sheet packaging unit 30 performs a binding process (post-processing) on ​​multiple sheets S (hereinafter referred to as "paper bundle Sb") on which images have been formed by the image forming unit 12, which are then bundled and bound together. In this embodiment, the sheet packaging unit 30 is described as an example of a post-processing unit, but specific examples of post-processing units (post-processing) are not limited to this. Figure 2 As shown, sheet packaging unit 30 includes a frame 31, a discharge tray 32, multiple conveyor roller pairs 33, 34, 35, 36, an inner tray 37, a tapping roller 38, a return roller 39, bottom baffles 40L and 40R, and side baffles 41L and 41R (see reference). Figure 16 ), Binding and Processing Department 42.

[0052] The frame 31 is a box-shaped structure that forms an internal space for housing the constituent parts of the sheet assembly unit 30. Furthermore, a transport path Ph3 is formed within the internal space of the frame 31, serving as a passageway for the sheet S. The discharge tray 32 is supported by the outer surface of the frame 31. The discharge tray 32 supports the sheet S or sheet bundle Sb conveyed by the transport rollers 33-36.

[0053] The conveyor roller pairs 33 to 36 are arranged at predetermined intervals along the conveyor path Ph3. The conveyor roller pairs 33 to 36 convey the sheet S along the conveyor path Ph3. The basic configuration of the conveyor roller pairs 33 to 36 is the same as that of the conveyor roller pair 22 in the sheet folding unit 20. However, the conveyor roller pair 36 consists of a drive roller 36a and a driven roller 36b that can contact and separate from the drive roller 36a. Furthermore, in order to achieve the sorting process of discharging the sheet S staggered in the width direction to the discharge tray 32, the conveyor roller pair 35 can also be configured to slide in the width direction.

[0054] The inner pallet 37 temporarily supports (stacks) multiple sheets S sequentially conveyed along the conveyor path Ph3. A striking roller 38 is supported above the inner pallet 37 at the front end of a rotating arm. The striking roller 38, through the rotation of the rotating arm, feeds the sheets S held by the conveyor roller pair 36 to the inner pallet 37. The return roller 39 guides the sheets S toward the bottom baffles 40L and 40R by abutting against and rotating against the upper surface of the sheets S supported by the inner pallet 37.

[0055] The bottom baffles 40L and 40R abut against the downstream ends of the sheet S supported by the inner tray 37 in the conveying direction, aligning the sheet S in the conveying direction. The side baffles 41L and 41R abut against the two ends of the sheet S supported by the inner tray 37 in the width direction, aligning the sheet S in the width direction. The binding processing unit 42 performs binding processing on the sheet bundle Sb supported by the inner tray 37. The binding processing performed by the binding processing unit 42 can be either needle binding processing, in which a binding needle passes through the sheet bundle Sb for binding, or crimp binding processing, in which the sheet bundle Sb is compressed and deformed for binding. In addition, the sheet binding unit 30 may also be provided with a needle binding processing unit that performs needle binding processing and a crimp binding processing unit that performs crimping processing, which are separated in the width direction and can operate independently of each other.

[0056] Alternatively, a manual binding slit can be provided on the frame 31 at a position facing the binding processing unit 42. Then, the user can insert the sheet bundle into the binding processing unit 42 through the manual binding slit, and the binding processing unit 42 can perform the binding process by pressing the manual binding button on the operation panel 110 (described later).

[0057] Figure 4 The diagram shown is a hardware configuration diagram of the sheet folding unit 20. (As shown...) Figure 4 As shown, the sheet folding unit 20 is configured to have a CPU (Central Processing Unit) 101, RAM (Random Access Memory) 102, ROM (Read Only Memory) 103, HDD (Hard Disk Drive) 104 and I / F 105 connected via a common bus 109.

[0058] CPU 101 is a computing unit that controls the overall operation of the sheet folding unit 20. RAM 102 is a volatile storage medium capable of high-speed reading and writing of information, and serves as the working area for CPU 101 when processing information. ROM 103 is a dedicated non-volatile storage medium for reading, storing programs such as firmware. HDD 104 is a non-volatile storage medium with a large capacity capable of reading and writing information, and stores the OS (operating system), various control programs, application programs, etc.

[0059] The sheet folding unit 20 uses the computing capabilities of the CPU 101 to process control programs stored in the ROM 103 and information processing programs (application programs) loaded from storage media such as the HDD 104 into the RAM 102. This processing constitutes a software control unit that includes various functional modules of the sheet folding unit 20. The combination of this software control unit and the hardware resources mounted on the sheet folding unit 20 forms functional modules that implement the functions of the sheet folding unit 20. That is, the CPU 101, RAM 102, ROM 103, and HDD 104 constitute a controller 100 that controls the operation of the sheet folding unit 20.

[0060] I / F105 is an interface for connecting motor 22c, first folding motor 23a, second folding motor 24a, third folding motor 25a, sheet sensor 29, rotary encoders 22z, 23z, 24z, and 25z, and operation panel 110 to the common bus 109. Controller 100 obtains information from sheet sensor 29, rotary encoders 22z, 23z, 24z, and operation panel 110 via I / F105 and activates conveyor motor 22c, first folding motor 23a, second folding motor 24a, and third folding motor 25a.

[0061] In addition, Figure 4 Only the components of the sheet folding unit 20 are shown in the illustration, but the controller 100 can also control the operation of the image forming unit 12 and the sheet packaging unit 30. In addition, the controller 100 can also operate the sheet folding unit 20 in conjunction with the image forming unit 12 and the sheet packaging unit 30 through mutual communication with the controller that controls the operation of the image forming unit 12 and the controller that controls the operation of the sheet packaging unit 30.

[0062] The operation panel 110 includes an operation unit that receives operations from the user and a display (notification unit) that notifies the user of information. The operation unit may include, for example, hard keys or a touch panel superimposed on the display. The operation panel 110 then obtains information from the operator through the operation unit and provides the information to the operator through the display. Furthermore, the specific example of the notification unit is not limited to a display; it may also be an LED light or a speaker.

[0063] Figure 5 The diagram shows the variations in the folding method that can be achieved by the sheet folding unit 20. Figure 5 Figure (A) shows a so-called "Z-shaped fold" in which a sheet S of full length L in the conveying direction is folded in opposite directions at a first folding position C1 at a distance of L / 4 from the front end and a second folding position C2 at a distance of L / 2 from the front end (i.e., on the upstream side of the conveying direction, which is closer to the first folding position than the first folding position). Figure 5Figure (B) shows a sheet S with a total length L in the conveying direction being folded in opposite directions at a first folding position C1 at a distance of L / 3 from the front end and a second folding position C2 at a distance of 2L / 3 from the front end (i.e., further upstream in the conveying direction than the first folding position), thus performing a so-called "outer triple fold". Figure 5 Figure (C) shows a so-called "fold" in which a sheet S of full length L in the conveying direction is folded at a fold position L / 2 from the front end.

[0064] Next, refer to Figures 6-10 This indicates that the sheet material S is folded into three sections. Figure 6 The diagram shown is a flowchart of the three-fold process. Figure 7 The diagram shows the state of the sheet folding unit 20 before folding the sheet at the first folding position C1. Figure 8 The diagram shows the state of the sheet folding unit 20 when the sheet is folded at the first folding position C1. Figure 9 The diagram shows the state of the sheet folding unit 20 before folding the sheet at the second folding position C2. Figure 10 The diagram shows the state of the sheet folding unit 20 after the sheet is folded at the second folding position C2.

[0065] The controller 100 starts based on the supply of sheet S from the image forming unit 12 via the input interface IN. Figure 6 The three-fold processing is shown. Furthermore, the folding method of the sheet S (in other words, the positions of the folding positions C1 and C2 in the conveying direction) can be indicated by the user via the operation panel 110, or by an external device via a communication network. That is, if the folding positions C1 and C2 are staggered in the conveying direction, it is possible to achieve… Figure 5 The Z-shaped fold shown in (A) and Figure 5 The two are shown in (B) as three folds.

[0066] First, the controller 100 causes the conveyor roller pair 22, the first folding roller 23, and the second folding roller 24 to rotate in the forward direction (S601). Thus, as... Figure 7 As shown, the orientation of the guide plate 26 changes to the first orientation. Additionally, the sheet S supplied via the input interface IN is conveyed along the main conveying path Ph1 in the conveying direction. Then, the controller 100 continues the processing of step S601 until the first folding position C1 reaches the branch position A (S602: No).

[0067] Next, when the controller 100 reaches the branch position A at the first folding position C1 (S602: Yes), it causes the conveyor roller pair 22 to rotate forward and the first folding roller 23, the second folding roller 24, and the third folding roller 25 to rotate in the opposite direction (S603). Thus, as... Figure 8As shown, the guide plate 26 changes its posture to the second posture. Furthermore, the sheet S enters the return conveyor path Ph2 with the first folding position C1 as its leading edge, and is held by the second folding roller 24 and the third folding roller 25. As a result, the sheet S is folded at the first folding position C1. Then, as... Figure 9 As shown, the controller 100 continues the processing of step S603 until the distance D1 from the clamping position of the first folding roller 23 and the second folding roller 24 to the front end of the sheet S is equal to the distance D2 to the second folding position C2 (S604: No).

[0068] Next, when the distances D1 and D2 become equal (S605: Yes), the controller 100 causes the conveyor roller pair 22, the first folding roller 23, and the second folding roller 24 to rotate in the forward direction (S605). Thus, as... Figure 10 As shown, the guide plate 26 changes to a first posture. Furthermore, the sheet S enters the clamping position of the first folding roller 23 and the second folding roller 24 with its front end and second folding position C2 as leading edges. As a result, the sheet S is folded at the second folding position C2, thus completing a Z-shaped fold.

[0069] Then, the controller 100 continues the processing of step S605 until the rear end of the sheet S passes the clamping position of the first folding roller 23 and the second folding roller 24 in the conveying direction (S606: No), that is, until the discharge of the triple-folded sheet S is completed. Further, when the rear end of the sheet S passes the clamping position of the first folding roller 23 and the second folding roller 24 in the conveying direction (S606: Yes), the controller 100 stops the conveying roller pair 22, the first folding roller 23 and the second folding roller 24, and ends the triple-folding process.

[0070] Next, refer to Figure 11 and Figure 12 This describes the folding process of folding sheet S in half. Figure 11 The diagram shows a flowchart of the folding process. Figure 12 The diagram shows the state of the sheet folding unit 20 during the bi-folding process. Furthermore, detailed explanations of the similarities to the tri-folding process are omitted, and the explanation focuses on the differences.

[0071] First, the controller 100 causes the conveyor roller pair 22, the first folding roller 23, and the second folding roller 24 to rotate in the forward direction (S1101). Thus, as... Figure 12 As shown in (A), the orientation of the guide plate 26 changes to the first orientation, and the sheet S is conveyed along the main conveying path Ph1 in the conveying direction. Then, the controller 100 continues the processing of step S1101 until the folding position C reaches the branch position A (S1102: No).

[0072] Next, when the folding position C reaches the branch position A (S1102: Yes), the controller 100 causes the conveyor roller pair 22 to rotate forward, and causes the first folding roller 23, the second folding roller 24, and the third folding roller 25 to rotate in the opposite direction (S1103). Thus, as... Figure 12 (B) Figure 12 As shown in (D), the guide plate 26 changes its posture to the second posture, and the sheet S enters the return conveyor path Ph2 with the folded position C as the leading edge. Then, the sheet S is clamped by the second folding roller 24 and the third folding roller 25 and folded in half at the folding position C. The controller 100 continues the processing of step S1103 until the rear end of the sheet S passes the clamping position of the second folding roller 24 and the third folding roller 25 (S1104: No).

[0073] Next, at the moment when the rear end of the sheet S is clamped by the second folding roller 24 and the third folding roller 25 (S1104: Yes), the controller 100 causes the first folding roller 23 and the second folding roller 24 to rotate forward (S1105). Furthermore, the controller 100 continues the forward rotation of the conveyor roller pair 22. Thus, as... Figure 12 (E) and Figure 12 As shown in (F), the posture of the guide plate 26 changes to the first posture, and the sheet S passes through the clamping position of the first folding roller 23 and the second folding roller 24 with the folded position C as the leading edge.

[0074] Then, the controller 100 continues the processing of step S1105 until the rear end of the sheet S passes the clamping position of the first folding roller 23 and the second folding roller 24 in the conveying direction (S1106: No), that is, until the discharge of the folded sheet S is completed. Further, when the rear end of the sheet S passes the clamping position of the first folding roller 23 and the second folding roller 24 in the conveying direction (S1106: Yes), the controller 100 stops the conveying roller pair 22, the first folding roller 23 and the second folding roller 24, and ends the folding process.

[0075] Furthermore, the controller 100 does not need to perform tri-folding or bi-folding processing on all sheets S on which images have been formed by the image forming unit 12. When discharging the sheet S without folding, the controller 100 only needs to rotate the transport roller pair 22, the first folding roller 23, and the second folding roller 24 forward according to the sheet S supplied from the image forming unit 12 through the input interface IN until the rear end of the sheet S passes the clamping position of the first folding roller 23 and the second folding roller 24 in the transport direction.

[0076] The control by which the controller 100, which folds the sheet S on which the image is formed by the image forming unit 12, in the sheet folding unit 20 and then transfers it to the sheet mounting unit 30, is an example of "first control". On the other hand, the control by which the controller 100, which transfers the sheet S on which the image is formed by the image forming unit 12, in the sheet folding unit 20 without folding it, to the sheet mounting unit 30, is an example of "second control". Then, the controller 100 may also be configured to switch between first control and second control based on instructions from the user via the operation panel 110 or instructions from an external device via a communication network.

[0077] Next, we will refer to Figures 13-17 To illustrate the action of ordering sheet material for 30 yuan. Figure 13 The diagram shown is a state diagram of sheet assembly unit 30 before sheet S reaches conveyor roller pair 36. Figure 14 The diagram shows the state of sheet packing unit 30 when sheet S is discharged into discharge tray 32 without binding. Figure 15 The image shown is a state diagram of sheet material assembly unit 30 undergoing binding processing. Figure 16 The image shows the view from the thickness direction of sheet S. Figure 15 (B) The paper packaging order is 30 yuan. Figure 17 The diagram shows the state of sheet assembly unit 30 when the sheet S, which has undergone binding processing, is discharged onto the discharge tray 32.

[0078] First, such as Figure 13 As shown, the sheet assembly unit 30 conveys the sheet S supplied from the sheet folding unit 20 along the conveying path Ph3 in the conveying direction via the forward rotating conveyor roller pair 33-35. At this time, the conveyor roller pair 36 is in a state where the driving roller 36a and the driven roller 36b are separated.

[0079] Next, without binding the sheet S, such as Figure 14 As shown in (A), sheet assembly unit 30 clamps sheet S with drive roller 36a and driven roller 36b. Then, as... Figure 14 As shown in (B), the sheet packing unit 30 discharges the sheet S to the discharge tray 32 by means of forward rotating conveyor rollers 36.

[0080] On the other hand, when binding sheet S is performed, such as Figure 15 As shown, the sheet packaging unit 30 receives the sheet S into the inner tray 37 by bringing the striking roller 38 and the return roller 39 into contact with and rotating the sheet S after it has passed through the conveyor roller pair 35. Additionally, as... Figure 16As shown, the sheet packaging unit 30 aligns the sheet S housed in the inner tray 37 in the width direction by moving the side baffles 41L and 41R in the width direction. Then, the sheet packaging unit 30 repeats this process... Figure 13 , Figure 15 and Figure 16 The process shown forms a sheet bundle Sb on the inner tray 37.

[0081] Next, the sheet binding unit 30 binds the sheet bundle Sb supported by the internal tray 37 via the drive binding processing unit 42. Then, as... Figure 17 As shown in (A), the sheet assembly unit 30 uses drive roller 36a and driven roller 36b to clamp the sheet bundle Sb. Then, as... Figure 14 As shown in (B), the sheet packing unit 30 discharges the sheet bundle Sb to the discharge tray 32 via the forward rotating conveyor roller pair 36 and the return roller 39.

[0082] According to the above-described implementation method, the following effects can be achieved, for example.

[0083] According to the above embodiments, various folding methods can be achieved by combining the forward and reverse rotations of the three folding rollers 23, 24, and 25. Furthermore, by switching the posture of the guide plate 26, the sheet S can be appropriately conveyed in the desired direction. Further, by using the drive force transmission mechanism 28 to rotate the second folding roller 24 and the guide plate 26 in tandem, the drive source for rotating the guide plate 26 can be omitted. As a result, a sheet folding unit 20 capable of handling various folding types can be realized with a simple configuration.

[0084] Furthermore, according to the above embodiment, by making the second rotational speed of the guide plate 26 greater than the first rotational speed of the second folding roller 24, the guide plate 26 can rapidly change its posture. This prevents unexpected actions such as bending of the sheet S, and improves the stability and accuracy of the folding process.

[0085] Furthermore, according to the above embodiment, while limiting the movable range of the guide plate 26 with the stop members 27a and 27b, by including a torque limiter 28a in the drive force transmission mechanism 28, the second folding roller 24 and the guide plate 26 can be rotated in conjunction with each other with a simple configuration. As a result, the sheet folding unit 20 can be further miniaturized.

[0086] Furthermore, according to the above embodiment, by arranging the folding rollers 23-25, the guide plate 26, and the drive force transmission mechanism 28 on opposite sides, sandwiching the isolation wall 21a, it is possible to prevent dust exiting the drive force transmission mechanism 28 from contaminating the sheet S. Additionally, it is possible to prevent dust exiting the sheet S from clogging the drive force transmission mechanism 28 and hindering the smooth transmission of drive force.

[0087] Furthermore, the sheet folding unit 20 described in the above embodiment can achieve particularly advantageous effects by being installed in the internal space 13 of the image forming apparatus 10, which has limited space. However, the sheet folding unit 20 is not the only type of unit that can be installed in the internal space 13. Moreover, the installation location of the sheet folding unit 20 is not limited to the internal space 13.

[0088] [Variation Example 1]

[0089] Figure 18 The diagram shows the internal structure of the punching and perforation unit 50 (punching and perforation section). Figure 18 The punching and perforating unit 50 shown is configured to be detachable from the position where the sheet folding unit 20 is removed from the internal space 13. That is, the image forming apparatus 10 is configured to allow for the replacement of the sheet folding unit 20 and the punching and perforating unit 50 depending on the application. Furthermore, since the configuration of the punching and perforating unit 50 is known, detailed description is omitted, but for example, the following configuration is also possible.

[0090] like Figure 18 As shown, the punching and perforating setting unit 50 includes a frame 51, a sheet sensor 52, perforating pins 53a and 53b, and a punching shavings hopper 54. The frame 51 has an internal space for housing the components of the punching and perforating setting unit 50. Furthermore, a transport path is formed within the internal space of the frame 51 for the sheet through which an image formed by the image forming unit 12 passes. The sheet sensor 52 detects whether the sheet S supplied from the image forming unit 12 has reached a predetermined position. The perforating pins 53a and 53b perforate the sheet S detected by the sheet sensor 52. Punching shavings falling from the sheet S fall into the punching shavings hopper 54. This achieves the perforation setting process of punching and perforating the sheet S.

[0091] [Variation Example 2]

[0092] Figure 19 The image shown is an external view of image forming system 1. Figure 19 As shown, the image forming system 1 comprises an image forming apparatus 10, a sheet folding device 20', and a sheet binding device 30'. The image forming apparatus 10, the sheet folding device 20', and the sheet binding device 30' are each capable of independent operation, but are also configured to be interconnected. Furthermore, the sheet folding device 20' shares the same configuration as the aforementioned sheet folding unit 20, and the sheet binding device 30' shares the same configuration as the aforementioned sheet binding unit 30.

[0093] Furthermore, this invention is not limited to the embodiments described above. Various modifications can be made without departing from its technical essence, and all technical matters encompassed in the technical concept described in the claims are subject to this invention. Although the above embodiments show preferred examples, those skilled in the art can implement various modifications based on the disclosed content. These modifications are also included within the technical scope described in the claims.

[0094] The contents of this invention are described below, for example.

[0095] <1>

[0096] A sheet folding device, characterized by comprising: a conveying section that conveys a sheet along a main conveying path in a conveying direction; a first folding roller and a second folding roller, which are arranged facing each other and grounded between the main conveying path; a third folding roller, which is arranged facing each other and grounded between the second folding roller and a return conveying path, the return conveying path branching from the main conveying path at a branch position upstream of the first folding roller in the conveying direction, and merging with the main conveying path at a merging position upstream of the branch position in the conveying direction; and a guiding member capable of switching between a first posture and a second posture, the first posture preventing the sheet conveyed along the main conveying path in the conveying direction from entering the return conveying path through the branch position. The second posture allows the sheet to be conveyed from one of the main conveying path and the return conveying path to the other through the branch position; a motor that causes the second folding roller to rotate in one of a forward rotation or a reverse rotation opposite to the forward rotation, the forward rotation being a rotation that conveys the sheet on the main conveying path along the conveying direction while simultaneously conveying the sheet on the return conveying path from the confluence position to the branch position; and a drive force transmission mechanism that, in conjunction with the forward rotation of the second folding roller, causes the guide member to rotate from the second posture to the first posture, and in conjunction with the reverse rotation of the second folding roller, causes the guide member to rotate from the first posture to the second posture.

[0097] <2>

[0098] According to the above <1> The sheet folding device is characterized in that: the driving force transmission mechanism transmits the driving force of the motor to the guiding component, so that the guiding component rotates at a second speed that is greater than the first speed of the second folding roller.

[0099] <3>

[0100] According to the above <2> The sheet folding device is characterized by comprising: a first stop member abutting against the guide member in the first posture to prevent the guide member from rotating in a direction away from the second posture; and a second stop member abutting against the guide member in the second posture to prevent the guide member from rotating in a direction away from the first posture; the driving force transmission mechanism has a torque limiter, which releases the transmission of driving force from the motor to the guide member when the guide member abuts against the first stop member or the second stop member and the rotational torque becomes above a threshold value.

[0101] <4>

[0102] According to the above <3> The sheet folding device is characterized in that it has an isolation wall through which the rotation axis of the second folding roller and the guide member passes, and the torque limiter is disposed on the opposite side of the second folding roller and the guide member through the isolation wall.

[0103] <5>

[0104] According to the above <1> Up to the above <4> The sheet folding apparatus according to any one of the claims, characterized in that: it has a controller for controlling the rotation of the first folding roller, the second folding roller, and the third folding roller; the first folding roller is capable of forward rotation to convey the sheet on the main conveying path in the conveying direction and reverse rotation in the opposite direction to the forward rotation; the third folding roller is capable of forward rotation to convey the sheet on the return conveying path from the confluence position to the branch position and reverse rotation in the opposite direction to the forward rotation; the control performed by the controller includes causing the first folding roller and the second folding roller to perform the forward rotation until the first folding position of the sheet reaches the branch position. At the moment when the first folding position reaches the branching position, the first folding roller, the second folding roller, and the third folding roller are rotated in the reverse direction until the distance from the clamping position of the first folding roller and the second folding roller to the front end of the sheet on the return conveying path and the distance to the second folding position, which is further upstream in the conveying direction than the first folding position, are equal. At the moment when the distance from the clamping position to the front end of the sheet and the distance to the second folding position are equal, the first folding roller, the second folding roller, and the third folding roller are rotated in the forward direction until the rear end of the sheet passes the clamping position in the conveying direction.

[0105] <6>

[0106] According to the above <1> Up to the above <5> The sheet folding apparatus according to any one of the claims is characterized in that: it has a controller for controlling the rotation of the first folding roller, the second folding roller and the third folding roller, the first folding roller being capable of forward rotation to convey the sheet on the main conveying path in the conveying direction and reverse rotation in the opposite direction to the forward rotation, the third folding roller being capable of forward rotation to convey the sheet on the return conveying path from the confluence position to the branch position and reverse rotation in the opposite direction to the forward rotation, the control performed by the controller including causing the first folding roller and the second folding roller to perform the forward rotation until the folding position of the sheet reaches the branch position, and when the folding position of the sheet reaches the branch position, causing the first folding roller, the second folding roller and the third folding roller to perform the reverse rotation until the rear end of the sheet passes the clamping position of the second folding roller and the third folding roller.

[0107] <7>

[0108] An image forming apparatus, characterized by comprising: a frame; an image forming unit housed within the frame for forming an image on a sheet, and the aforementioned... <1> Up to the above <6> The sheet folding device described in any one of the following is detachably supported on the frame and folds the sheet on which an image has been formed by the image forming section.

[0109] <8>

[0110] According to the above <7> The image forming apparatus is characterized by comprising: a post-processing unit supported by the frame, which performs post-processing on the sheet on which an image has been formed by the image forming unit, wherein the sheet folding device is configured to be detachable from the frame at a position on the conveying path of the sheet from the image forming unit to the post-processing unit that is downstream of the image forming unit and upstream of the post-processing unit.

[0111] <9>

[0112] According to the above <8> The image forming apparatus is characterized in that the post-processing is a binding process in which multiple sheets having images formed by the image forming unit are bundled and bound together.

[0113] <10>

[0114] According to the above <8> or the above <9> The image forming apparatus is characterized in that it has a controller capable of switching between a first control and a second control, wherein the first control is a control that transfers the sheet on which the image has been formed by the image forming unit to the post-processing unit after it has been folded by the sheet folding device, and the second control is a control that transfers the sheet to the post-processing unit without folding it by the sheet folding device.

[0115] <11>

[0116] According to the above <7> Up to the above <10> The image forming apparatus according to any one of the following is characterized in that: in the position where the sheet folding device is removed from the frame, a punching and perforating part is detachably configured to punch through a hole in the sheet on which an image is formed by the image forming part.

[0117] <12>

[0118] An image forming system, characterized by comprising: an image forming apparatus for forming an image on a sheet, and the above-mentioned [device / system] connected to the image forming apparatus. <1> Up to the above <8> The sheet folding device described in any one of the following.

Claims

1. A sheet folding device, characterized in that... include: The conveying section conveys the sheet material along the main conveying path in the conveying direction; The first folding roller and the second folding roller, which sandwich the main conveying path, are arranged facing each other and to the ground; The third folding roller, which sandwiches the return conveying path, is arranged opposite to the second folding roller. The return conveying path branches off from the main conveying path at a branch position upstream of the first folding roller in the conveying direction, and merges with the main conveying path at a merging position upstream of the conveying direction, which is also upstream of the branch position. A guiding component capable of switching between a first posture and a second posture, wherein the first posture prevents the sheet being conveyed along the conveying direction on the main conveying path from entering the return conveying path through the branch position, and the second posture allows the sheet to be conveyed from one of the main conveying path and the return conveying path to the other through the branch position; A motor that causes the second folding roller to rotate in one of two directions: forward rotation or a reverse rotation opposite to the forward rotation. The forward rotation is a rotation that simultaneously conveys the sheet on the main conveying path along the conveying direction and the sheet on the return conveying path from the confluence position to the branch position. A driving force transmission mechanism, which, in conjunction with the forward rotation of the second folding roller, causes the guide member to rotate from the second posture to the first posture, and, in conjunction with the reverse rotation of the second folding roller, causes the guide member to rotate from the first posture to the second posture. The drive force transmission mechanism transmits the driving force of the motor to the guide member, causing the guide member to rotate at a second speed that is greater than the first speed of the second folding roller. The sheet folding device further includes: A first stop abuts against the guide member in the first posture to prevent the guide member from rotating in a direction away from the second posture. A second stop abuts against the guide member in the second posture to prevent the guide member from rotating in a direction away from the first posture. The driving force transmission mechanism has a torque limiter. When the guide member abuts against the first stop or the second stop and the rotational torque becomes above a threshold, the torque limiter releases the transmission of driving force from the motor to the guide member.

2. The sheet folding device according to claim 1, characterized in that: It has an isolation wall through which the rotation axis of the second folding roller and the guide member pass. The torque limiter is disposed on the opposite side of the second folding roller and the guide member, separated by the isolation wall.

3. The sheet folding device according to claim 1, characterized in that: It has a controller for controlling the rotation of the first folding roller, the second folding roller, and the third folding roller. The first folding roller is capable of forward rotation to convey the sheet on the main conveying path in the conveying direction, and reverse rotation in the opposite direction to the forward rotation. The third folding roller is capable of forward rotation to convey the sheet on the return conveying path from the confluence position to the branch position, and reverse rotation in the opposite direction to the forward rotation. The control performed by the controller includes, The first folding roller and the second folding roller are rotated in the forward direction until the first folding position of the sheet reaches the branching position; At the moment when the first folding position reaches the branching position, the first folding roller, the second folding roller, and the third folding roller are rotated in the opposite direction until the distance from the clamping position of the first folding roller and the second folding roller to the front end of the sheet on the return conveying path and the distance to the second folding position, which is further upstream in the conveying direction than the first folding position, are equal. When the distance from the clamping position to the front end of the sheet and the distance to the second folding position are equal, the first folding roller, the second folding roller, and the third folding roller are rotated in the forward direction until the rear end of the sheet passes the clamping position in the conveying direction.

4. The sheet folding device according to claim 1, characterized in that: It has a controller for controlling the rotation of the first folding roller, the second folding roller, and the third folding roller. The first folding roller is capable of forward rotation to convey the sheet on the main conveying path in the conveying direction, and reverse rotation in the opposite direction to the forward rotation. The third folding roller is capable of forward rotation to convey the sheet on the return conveying path from the confluence position to the branch position, and reverse rotation in the opposite direction to the forward rotation. The control performed by the controller includes, The first folding roller and the second folding roller are rotated in the forward direction until the folded position of the sheet reaches the branch position, and When the sheet reaches the branch position at the folding position, the first folding roller, the second folding roller, and the third folding roller are rotated in the opposite direction until the rear end of the sheet passes the clamping position of the second folding roller and the third folding roller.

5. An image forming apparatus, characterized in that... include: Frame; An image forming unit, housed within the frame, forms an image on the sheet, and The sheet folding device according to claim 1 is detachably supported on the frame and folds the sheet on which an image has been formed by the image forming part.

6. The image forming apparatus according to claim 5, characterized in that... include: The post-processing unit, supported by the frame, performs post-processing on the sheet on which the image has been formed by the image forming unit. The sheet folding device is configured such that it can be loaded and unloaded relative to the frame at a position on the sheet transport path from the image forming unit to the post-processing unit, which is further downstream than the image forming unit and further upstream than the post-processing unit.

7. The image forming apparatus according to claim 6, characterized in that: The post-processing is a binding process that involves bundling and binding together multiple sheets of material on which images have been formed by the image forming unit.

8. The image forming apparatus according to claim 6, characterized in that: The device has a controller capable of switching between a first control and a second control. The first control is the control of transferring the sheet on which an image has been formed by the image forming unit to the post-processing unit after it has been folded by the sheet folding device. The second control is the control of transferring the sheet to the post-processing unit without folding it by the sheet folding device.

9. The image forming apparatus according to claim 5, characterized in that: In the position where the sheet folding device is removed from the frame, a punching and perforating setting part is detachably configured to punch holes in the sheet on which the image is formed by the image forming part.

10. An image forming system, characterized in that... include: An image forming apparatus for forming an image on a sheet, and The sheet folding device of claim 1, which is connected to the image forming apparatus.

Images