Sheet processing apparatus, sheet processing method, and image forming system

Abstract

A sheet processing apparatus includes a center folder and a back pressure binder. The center folder performs center folding on a sheet bundle including a plurality of sheets. A back crimp binder includes a back former and a crimp binder. A back former forms a back on the sheet bundle subjected to the central fold. A crimp binding device performs crimp binding on the sheet bundle subjected to the central fold.

Description

Technical Field

[0001] This disclosure relates to sheet processing apparatus, sheet processing method, and image forming system. Background Technology

[0002] A sheet processing apparatus is known to perform a "binding process" that binds sheet-like recording media into bundles. Various binding processes are known as performed in the sheet processing apparatus. For example, "end stitching" (or "end binding") and "saddle stitching" (or "central binding") are known. "End stitching" (or "end binding") is used to bind the ends of the sheet bundle. "Saddle stitching" (or "central binding") is used to fold the sheet bundle in half and bind the sheet bundle at a portion near the folded position. Central binding is primarily used in the production of books such as pamphlets.

[0003] In order to provide a centrally bound booklet that can align the cuts even without cutting, a central binding device is disclosed which forms a square ridge fold on the booklet after pressing and binding at the binding positions on both sides away from the central fold position (for example, see Patent Document 1).

[0004] In addition, in order to provide a crimping central binding device, a central binding device that performs crimping binding at a position away from the folded position has been disclosed (for example, see Patent Document 2).

[0005] In addition, a saddle-shaped binding device is disclosed, which is a saddle-shaped binding device with a square spine fold on the back of the booklet. The purpose is to provide a booklet with improved aesthetics by making it difficult for the staples to shift from the center of the back. The stop plate is provided with a groove for inserting the staples (for example, see Patent Document 3).

[0006] In addition, in order to provide a booklet that does not require staples, a crimping central binding device is disclosed that performs crimping binding in the center of the booklet and then performs a central folding process (for example, see Patent Document 4).

[0007] Additionally, a binding device is disclosed that forms a toner layer for bonding at the end of, for example, a sheet, and heats and pressurizes the toner layer in an electrophotographic imaging apparatus to bond the sheets together (see, for example, Patent Document 5).

[0008] List of cited references Patent documents [Patent Document 1] Japanese Unexamined Patent Application Publication No. 2014-031268 [Patent Document 2] Japanese Patent No. 6089675 [Patent Document 3] Japanese Unexamined Patent Application Publication No. 2004-168012 [Patent Document 4] Japanese Patent No. 5361858 [Patent Document 5] Japanese Unexamined Patent Application Publication No. 2004-209858 Summary of the Invention

[0009] Technical issues The aforementioned patent documents disclose prior art methods for centrally binding and folding the spine of a booklet. However, when using these prior art methods to produce centrally bound booklets, the following problems exist: when turning pages, an uncoordinated feeling occurs when the pages are unfolded, or the crimped portion may peel off due to the load applied to it by the page-turning action. In other words, in the conventional art, when using crimp binding for saddle-shaped binding (central binding), there are problems with the quality and binding strength of the finished product.

[0010] The purpose of this invention is to provide a sheet processing apparatus that can form a crimped saddle-shaped bound booklet that will not peel off due to page turning and can be easily opened.

[0011] Solution to the problem According to one embodiment of the present invention, a sheet processing apparatus includes a central folder and a back crimping stapler. The central folder performs a central fold on a bundle of sheets comprising multiple sheets. The back crimping stapler includes a back forming device and a crimping stapler. The back forming device forms a back on the sheet bundle to which the central fold has been applied. The crimping stapler performs crimping stapler on the sheet bundle to which the central fold has been applied.

[0012] Effects of the present invention According to this disclosure, a crimped saddle-shaped bound booklet can be formed that will not peel off due to page turning and can be easily opened. Attached Figure Description

[0013] A more complete understanding of the embodiments of this disclosure and its many accompanying advantages and features can be readily obtained and understood from the following detailed description with reference to the accompanying drawings.

[0014] [ Figure 1 ] Figure 1 This is a diagram showing the overall structure of the image forming system according to the first embodiment.

[0015] [ Figure 2 ] Figure 2This is a diagram showing the internal structure of the post-processing apparatus according to the first embodiment.

[0016] [ Figure 3 ] Figure 3 This is a schematic diagram showing the end binding device viewed from the outlet side.

[0017] [ Figure 4A and Figure 4B ] Figure 4A and Figure 4B This is a schematic diagram showing the structure of the crimping teeth of the crimping end binding processing unit.

[0018] [ Figure 5A , Figure 5B , Figure 5C , Figure 5D and Figure 5E ] Figure 5A , Figure 5B , Figure 5C , Figure 5D and Figure 5E This is a diagram showing the movement position of the end-binding device.

[0019] [ Figure 6A , Figure 6B , Figure 6C , Figure 6D and Figure 6E ] Figure 6A , Figure 6B , Figure 6C , Figure 6D and Figure 6E This is a schematic diagram illustrating the action of the central binding device.

[0020] [ Figure 7A , Figure 7B and Figure 7C ] Figure 7A , Figure 7B and Figure 7C This is a cross-sectional view of the central binding press, which shows the operation of the central binding press.

[0021] [ Figure 8 ] Figure 8 This is a schematic diagram illustrating the pressing state performed by the crimping central binding device.

[0022] [ Figure 9 ] Figure 9 This is a schematic diagram showing the crimped central binding booklet in the first embodiment.

[0023] [ Figure 10 ] Figure 10 This is a hardware structure diagram of the control device for the post-processing unit.

[0024] [ Figure 11 ] Figure 11 This is a schematic diagram illustrating a first variation of the crimping central binding device.

[0025] [ Figure 12A and Figure 12B ] Figure 12A and Figure 12B It is a cross-sectional view along line BB showing the operation of the crimping central binder according to the first variation.

[0026] [ Figure 13A and Figure 13B ] Figure 13A and Figure 13B This is a cross-sectional view of the crimping central binder according to the second variation, which shows the operation of the crimping central binder.

[0027] [ Figure 14A and Figure 14B ] Figure 14A and Figure 14B This is a cross-sectional view of the crimping central binder according to the third variation, which shows the operation of the crimping central binder.

[0028] [ Figure 15A , Figure 15B and Figure 15C ] Figure 15A , Figure 15B and Figure 15C This is a cross-sectional view of the crimping central binder according to the fourth variation, which shows the operation of the crimping central binder.

[0029] [ Figure 16A , Figure 16B and Figure 16C ] Figure 16A , Figure 16B and Figure 16C This is a cross-sectional view of the crimping central binder according to the fifth variation, which shows the operation of the crimping central binder.

[0030] [ Figure 17 ] Figure 17 This is a schematic diagram showing the crimped central binding booklet in the fifth variation.

[0031] [ Figure 18 ] Figure 18This is a schematic diagram illustrating the sixth variation of the crimping central binding device.

[0032] [ Figure 19 ] Figure 19 This is a schematic diagram showing the crimped central binding booklet in the sixth variation.

[0033] [ Figure 20A , Figure 20B , Figure 20C and Figure 20D ] Figure 20A , Figure 20B , Figure 20C and Figure 20D This is a cross-sectional view of the crimping central binder according to the seventh variation, which shows the operation of the crimping central binder.

[0034] [ Figure 21 ] Figure 21 This is a schematic diagram showing the eighth variation of the crimping central binding device.

[0035] [ Figure 22A , Figure 22B and Figure 22C ] Figure 22A , Figure 22B and Figure 22C This is a cross-sectional view of the crimping central binder according to the eighth variation, which shows the operation of the crimping central binder.

[0036] [ Figure 23A and Figure 23B ] Figure 23 A and Figure 23B This is a schematic diagram of the crimped central binding booklet in the eighth variation.

[0037] [ Figure 24A and Figure 24B ] Figure 24A and Figure 24B This is a cross-sectional view of the crimping central binder according to the ninth variation, which shows the operation of the crimping central binder.

[0038] [ Figure 25 ] Figure 25 This is a diagram illustrating the overall structure of the image forming system according to the second embodiment.

[0039] [ Figure 26 ] Figure 26 This is a diagram showing the internal structure of the post-processing apparatus according to the second embodiment.

[0040] The accompanying drawings are intended to illustrate embodiments of this disclosure and should not be construed as limiting its scope. Unless explicitly stated otherwise, the drawings should not be considered to be drawn to scale. Furthermore, throughout several views, the same or similar reference numerals denote the same or similar parts. Detailed Implementation

[0041] In describing the embodiments shown in the accompanying drawings, specific terminology has been used for clarity. However, the disclosure of this specification is not intended to be limited to the specific terminology chosen, and it should be understood that each particular component includes all technical equivalents that have similar functionality, operate in a similar manner, and achieve similar results.

[0042] Hereinafter, embodiments of the invention will be described with reference to the accompanying drawings. As used herein, the singular forms "a," "an," and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise.

[0043] First Embodiment Hereinafter, a first embodiment of the sheet processing apparatus, sheet processing method, and image forming system according to the present invention will be described with reference to the accompanying drawings. Figure 1 This is a diagram showing the overall structure of an image forming system 100, such as an MFP (Multifunction Printer). For example... Figure 1 As shown, the image forming system 100 includes an image forming apparatus 101 and a post-processing apparatus 110. The image forming apparatus 101 forms an image on a sheet P (an example of a sheet) which is a sheet-like medium. The post-processing apparatus 110 performs prescribed post-processing on the sheet P on which the image is formed. The image forming system 100 corresponds to an embodiment of an image forming system having an in-body discharge space, wherein the post-processing apparatus 110 is disposed in the in-body discharge space (in-body discharge unit) of the image forming apparatus 101.

[0044] Image forming apparatus 101 forms an image on sheet P and discharges the image-formed sheet P to post-processing apparatus 110. Image forming apparatus 101 includes a tray, a conveyor, and an image forming device. The sheet P is held in the tray. The conveyor transports the sheet P held in the tray. The image forming device forms an image on the sheet P transported by the conveyor. The image forming device can perform known image forming methods. For example, the image forming device can use an inkjet method to form an image by spraying liquid ink onto the sheet P and allowing it to adhere to the sheet P, or it can use an electrophotographic method to form an image using toners.

[0045] The image forming apparatus 101 includes an operation panel 102 and a controller 103 for controlling the operation of the image forming apparatus 101. The configuration and operation of the image forming apparatus 101 correspond to configurations and operations known in the art, and therefore their detailed description will be omitted.

[0046] Next, the post-processing apparatus 110, which is an embodiment of the sheet processing apparatus according to the present disclosure, will be described in detail.

[0047] Figure 2 This is a diagram showing the internal structure of the post-processing apparatus 110 according to the first embodiment.

[0048] The post-processing apparatus 110 has the function of post-processing the sheet P on which the image has been formed by the image forming apparatus 101. The post-processing apparatus 110 performs a binding process, that is, it receives the sheet P on which the image has been formed from the image forming apparatus 101 through the receiving inlet 1100 of the sheet P, and binds a bundle Pb of multiple overlapping sheets.

[0049] Crimping is a binding process that involves pressing and deforming a bundle of multiple overlapping sheets P at the binding position. The binding process involves using staples to secure the bundle of sheets Pb at the binding position. Crimping includes end binding and center binding. End binding involves binding the ends of the bundle of sheets Pb. Center binding involves binding the central portion of the bundle of sheets Pb.

[0050] The post-processing apparatus 110 includes a first pair of conveying rollers 111 and a second pair of conveying rollers 112 that convey a sheet P brought in from the inlet 1100 along a conveying path. The first pair of conveying rollers 111 and the second pair of conveying rollers 112 convey the sheet P supplied from the image forming apparatus 101 along a first conveying path Ph1 within the post-processing apparatus 110.

[0051] The first transport path Ph1 is the path from the loading inlet 1100 of the sheet P of the image forming apparatus 101 to the inner tray 114.

[0052] End binding The post-processing unit 110 includes a return conveyor roller 113, an inner tray 114, an end baffle 115, a side baffle 116, a needle end binding processing unit 117, a crimping end binding processing unit 118, an exit roller pair 119, and an exit tray 120. The needle end binding processing unit 117 and the crimping end binding processing unit 118 serve as end binding units.

[0053] The return conveyor roller 113 is a conveyor roller that places the sheet P, which has passed through the second conveyor roller pair 112, onto the inner tray 114 and conveys the sheet P on the inner tray 114 toward the end baffle 115. The conveying direction of the return conveyor roller 113 is different from the conveying direction of the first conveyor roller pair 111 and the second conveyor roller pair 112, and corresponds to the direction (opposite direction) of the conveying direction of the first conveyor roller pair 111 and the second conveyor roller pair 112. Therefore, the conveying performed by the return conveyor roller 113 is called reversible conveying.

[0054] Sheet P, as sheet material, is conveyed to inner tray 114 by first conveyor roller pair 111, second conveyor roller pair 112, and return conveyor roller 113, and undergoes binding processing. First conveyor roller pair 111, second conveyor roller pair 112, return conveyor roller 113, and first conveyor path Ph1 form a conveyor that conveys sheet P to inner tray 114, which serves as a carrier.

[0055] The inner tray 114 serves as a temporary holder for multiple sheets P that are conveyed sequentially. The sheets P placed on the inner tray 114 are folded back and conveyed by the return conveyor roller 113 to a position where they collide with the end baffle 115. The end baffle 115 serves as an alignment member for aligning the ends of the sheets P in the changing conveying direction. The ends of the multiple sheets P placed on the inner tray 114 are aligned by the end baffle 115 to form a sheet bundle Pb.

[0056] A pair of side baffles 116 are provided along the width direction of the inner tray 114 (the width direction of the sheet P). In other words, a pair of side baffles 116 are provided at two sides of the inner tray 114 in a direction orthogonal to the direction in which the sheet P is turned and conveyed (i.e., the direction in which the sheet P is conveyed to the end baffle 115).

[0057] The side baffle 116 performs a "slow push," repeatedly contacting and separating from the width-direction edges of multiple sheets P placed on the inner tray 114. Through this "slow push," the width-direction edges of the multiple sheets P are also aligned. That is, the side baffle 116 functions as an alignment member for aligning the two ends (the two ends in the direction orthogonal to the conveying direction) of the sheets P placed on the inner tray 114 in the width direction.

[0058] The pin end binding processing unit 117 and the crimping end binding processing unit 118, as end binding units, perform binding processing on the ends of the sheet bundle Pb aligned by the end baffle 115 and the side baffle 116.

[0059] After the binding process is performed, the return conveyor roller 113 contacts and rotates the sheet bundle Pb placed on the inner tray 114. The direction of rotation at this time is opposite to the direction of rotation during the return conveyor. Therefore, the sheet bundle Pb with end stitching (end binding) is discharged from the first discharge outlet 1101 to the discharge tray 120 by the return conveyor roller 113.

[0060] The "end stitching" (or "end binding") performed on the sheet bundle Pb by the needle end binding processing unit 117 and the crimping end binding processing unit 118 includes various processes. For example, the "binding process" includes "parallel binding process", "oblique binding process", and "two-point binding process". In the "parallel binding process", along the sheet bundle Pb (refer to...) Figure 3In the "Tilt Binding Process," binding is performed on the side parallel to the main scanning direction. In the "Tilt Binding Process," binding is performed at the corners of the sheet bundle Pb. In the "Two-Point Binding Process," binding is performed at multiple points away in the width direction along the side parallel to the conveying direction of the sheet bundle Pb.

[0061] Figure 3 This is a schematic diagram of the end assembly unit 1110, which includes the needle end binding processing unit 117 and the crimping end binding processing unit 118, viewed from the direction of the first row outlet 1101 toward the end baffle 115.

[0062] like Figure 3 As shown, with the needle tip binding processing unit 117 and the crimping end binding processing unit 118 separated in the main scanning direction, the end binding unit 1110 is mounted on the end binding unit base member 151. The end binding unit 1110 is supported by a guide shaft 152 extending along the main scanning direction via the end binding unit base member 151. Therefore, both the needle tip binding processing unit 117 and the crimping end binding processing unit 118 are supported in a manner that allows them to move along the guide shaft 152.

[0063] The needle tip binding processing unit 117 includes a needle tip binding main scanning motor 161, a drive force transmission mechanism 162, and a needle tip binding processing unit base component 163. The needle tip binding processing unit 117 can move along the guide shaft 152 in the main scanning direction by the drive force of the needle tip binding main scanning motor 161.

[0064] The needle tip binding main scanning motor 161 generates a driving force for moving the needle tip binding processing unit 117. The driving force transmission mechanism 162 transmits the driving force of the needle tip binding main scanning motor 161 to the needle tip binding processing unit base component 163 via pulleys and a timing belt. As a result, the needle tip binding processing unit 117 can move along the guide shaft 152 in the main scanning direction.

[0065] The needle tip binding processing unit 117 includes a needle tip binding posture rotation motor 164, which rotates relative to the needle tip binding processing unit base component 163 with the needle binding rotation axis 165 as the center of rotation.

[0066] Additionally, the needle tip binding processing unit 117 includes a needle tip binding clamping motor 166, which causes the needle clamp 167 to perform an open-close operation. As a result, the needle passes through the sheet bundle Pb and is clamped, thus performing binding.

[0067] The crimping end binding processing unit 118 includes a crimping end binding main scanning motor 171, a drive force transmission mechanism 172, and a crimping end binding processing unit base component 173. The crimping end binding processing unit 118 can move along the guide shaft 152 in the main scanning direction by the drive force of the crimping end binding main scanning motor 171.

[0068] The crimping end-binding main scanning motor 171 generates a driving force to move the crimping end-binding processing unit 118. The driving force transmission mechanism 172 transmits the driving force of the crimping end-binding main scanning motor 171 to the crimping end-binding processing unit base component 173 via pulleys and a timing belt. As a result, the crimping end-binding processing unit 118 can move along the guide shaft 152 in the main scanning direction.

[0069] In addition, the crimping end binding processing unit 118 includes a crimping end binding posture rotation motor 174, which rotates relative to the crimping end binding processing unit base component 173 with the crimping binding rotation axis 175 as the rotation center.

[0070] Furthermore, the crimping end binding processing unit 118 includes a crimping end binding clamping motor 176. Driven by the crimping end binding clamping motor 176, the upper crimping teeth 177 move closer to or further away from the lower crimping teeth 178, performing an "opening and closing action." This opening and closing action allows the end of the sheet bundle Pb to be clamped between the concave and convex upper crimping teeth 177 and lower crimping teeth 178, pressing and deforming the sheet bundle Pb. Through this pressure deformation, the fibers of the sheets P contained in the sheet bundle Pb intertwine, forming a sheet bundle Pb composed of multiple sheets P. As described above, the binding based on pressure deformation is referred to as "crimping binding."

[0071] Figure 4A , Figure 4B This is a schematic diagram showing the structure of the upper crimping tooth 177 and the lower crimping tooth 178, which are crimping parts, of the crimping end binding processing unit 118.

[0072] like Figure 4A and Figure 4BAs shown, the crimping portion has a pair of upper crimping teeth 177 and lower crimping teeth 178. The upper crimping teeth 177 and lower crimping teeth 178 are arranged facing each other in the thickness direction of the sheet bundle Pb, such that the sheet bundle Pb placed on the inner tray 114 can be clamped between the upper crimping teeth 177 and lower crimping teeth 178. The upper crimping teeth 177 and lower crimping teeth 178 are formed in a concave-convex shape, wherein concave portions and convex portions are alternately formed. In addition, the upper crimping teeth 177 and lower crimping teeth 178 are formed such that the concave portions and convex portions are displaced, so that the upper crimping teeth 177 and lower crimping teeth 178 can engage with each other. The crimping portion is configured such that the upper crimping teeth 177 open and close (contact, separate) relative to the lower crimping teeth 178 by the driving force of the crimping end clamping motor 176.

[0073] During the process of conveying the multiple sheets P constituting the sheet bundle Pb to the inner tray 114, such as Figure 4A As shown, the upper crimping tooth 177 separates from the lower crimping tooth 178. Then, when all the sheets P contained in the sheet bundle Pb are placed on the inner tray 114, and the prescribed integration action (end integration action) is completed, the crimping end binding processing unit 118 moves to the binding position, as shown. Figure 4B As shown, the upper crimping tooth 177 and the lower crimping tooth 178 approach and engage. That is, the upper crimping tooth 177 and the lower crimping tooth 178 clamp the sheet bundle Pb at a predetermined binding position on the sheet bundle Pb, pressing the sheet bundle Pb from the thickness direction to deform it. Thus, the sheet bundle Pb placed on the inner tray 114 is crimped and bound. Then, the crimped and bound sheet bundle Pb is discharged from the first discharge outlet 1101 toward the discharge tray 120 by the discharge roller pair 119.

[0074] The crimping end binding processing unit 118 only needs to perform the function of crimping a specific portion of the sheet bundle Pb by applying pressure. Therefore, the upper crimping teeth 177 and lower crimping teeth 178 only need to be configured such that when the sheet bundle Pb is clamped by the upper crimping teeth 177 and lower crimping teeth 178 for binding, the upper crimping teeth 177 and lower crimping teeth 178 can mesh with each other to apply pressure to the sheet bundle Pb. Therefore, the structure capable of performing the action of closing the upper crimping teeth 177 and lower crimping teeth 178 is not limited to the structural example disclosed in this embodiment. For example, a linkage mechanism type crimping mechanism (for example, disclosed in Japanese Patent No. 6057167) can also be used, which uses a drive source that only rotates forward or backward and a linkage mechanism to perform the action of bringing the upper crimping teeth 177 and lower crimping teeth 178 closer (crimping) and separating. Alternatively, a direct-acting crimping mechanism can be used, which converts the rotational motion of the drive source into linear motion, so that the upper crimping teeth 177 and the lower crimping teeth 178 can perform crimping and separating actions linearly.

[0075] In addition, such as Figure 3As shown, the crimping section includes a binding tooth sliding mechanism that moves the upper crimping tooth 177 and the lower crimping tooth 178 relative to the frame of the crimping end binding processing unit 118. The binding tooth sliding mechanism includes a binding tooth sliding motor 179 and a drive transmission mechanism. The drive transmission mechanism is a linear motion conversion mechanism such as a gear and rack mechanism or a crankshaft mechanism that transmits the driving force of the binding tooth sliding motor 179. When the driving force from the binding tooth sliding motor 179 is transmitted to the upper crimping tooth 177 and the lower crimping tooth 178 through the drive transmission mechanism, the upper crimping tooth 177 and the lower crimping tooth 178 slide along their respective length directions (the length direction of the end mounting unit base member 151).

[0076] Here, the sliding movement of the upper crimping tooth 177 and the lower crimping tooth 178 is, for example, equivalent to the crimping mark length. Furthermore, the upper crimping tooth 177 and the lower crimping tooth 178 perform multiple crimping binding actions before and after the sliding movement. That is, when the crimping mark length of the upper crimping tooth 177 and the lower crimping tooth 178 is 10 mm, the sliding movement is also 10 mm. Therefore, through crimping before the sliding movement (first stroke) and crimping after the sliding movement (second stroke), a total crimping mark length of 20 mm can be obtained. As a result, the binding force is increased by approximately two times.

[0077] Summary of Binding Process Figure 5 is a diagram showing the positions of the needle end binding processing unit 117 and the crimping end binding processing unit 118 in each step of the binding process.

[0078] Figure 5A This indicates the standby state of the binding process.

[0079] like Figure 5A As shown, in standby mode, the needle tip binding processing unit 117 is located in the binding standby position HP1. The crimping end binding processing unit 118 is located in the crimping binding standby position HP2.

[0080] Figure 5B , Figure 5C This indicates the state in which the crimping end binding processing unit 118 performs tilt binding processing.

[0081] like Figure 5B As shown, before the first sheet P1 contained in the sheet bundle Pb is supplied to the inner tray 114, the crimping end binding processing unit 118 is moved and tilted and rotated in the main scanning direction so that the crimping end binding processing unit 118 is opposite to the first binding position B1. The movement and rotation of the crimping end binding processing unit 118 are controlled by... Figure 10 The controller 19 of the control device shown below controls the device.

[0082] Next, as Figure 5CAs shown, with the crimping end binding processing unit 118 positioned opposite the first binding position B1, the controller 19 performs a "slow push" whenever the sheet P is fed to the inner tray 114. The slow push is performed by controlling the side baffle 116 to slide in the width direction by the controller 19.

[0083] Next, in Figure 5C In the state shown, the controller 19 repeatedly performs the loading and alignment of sheet P until the number of sheets P contained in the sheet bundle Pb reaches the specified number N.

[0084] Next, when the controller 19 detects that the number of sheets P placed on the inner tray 114 has reached the specified number N, it activates the crimping end binding processing unit 118 to perform crimping binding at the first binding position B1 of the sheet bundle Pb placed on the inner tray 114.

[0085] Next, controller 19 discharges the sheet bundle Pb, which has been crimped at the first binding position B1, into the discharge tray 120. Additionally, controller 19 moves the crimped end binding processing unit 118 to... Figure 5A The crimping and binding standby position shown is HP2.

[0086] Figure 5D and Figure 5E This indicates that the needle tip binding processing unit 117 performs two binding processes.

[0087] The second binding position B2 and the third binding position B3 are separated from each other in the main scanning direction. Before the first sheet P1 contained in the sheet bundle Pb is supplied to the inner tray 114, the controller 19 moves the needle tip binding processing unit 117 in the main scanning direction so that the needle tip binding processing unit 117 can be aligned with the second binding position B2. Next, as Figure 5D As shown, the controller 19 causes the side baffle 116 to perform a slow push when the needle tip binding processing unit 117 has moved to the position where the needle tip binding processing unit 117 faces the second binding position B2.

[0088] Next, in Figure 5D In the state shown, the controller 19 repeatedly performs the loading and alignment of sheet P until the number of sheets P contained in the sheet bundle Pb reaches the specified number N.

[0089] Next, when the controller 19 detects that the number of sheets P placed on the inner tray 114 has reached the specified number N, it activates the needle tip binding processing unit 117 to perform binding processing at the first binding position B1 of the sheet bundle Pb placed on the inner tray 114.

[0090] Next, as Figure 5EAs shown, the controller 19 positions the needle tip binding processing unit 117 opposite to the third binding position B3, and performs binding processing on the sheet bundle Pb placed on the inner tray 114 at the third binding position B3.

[0091] exist Figures 5A-5E In the example, in the two-position binding, binding is performed at the second binding position B2, and then at the third binding position B3. However, the execution order of the two bindings is not limited to this. That is, two-position binding can be performed, such that the second binding position B2 is bound after the third binding position B3. When the number of sheets in the bound bundle is consecutive, for example, for odd-numbered sheet bundles, binding is performed at the third binding position B3 after binding at the second binding position B2, and for even-numbered sheet bundles, binding is performed at the second binding position B2 after binding at the third binding position B3. By performing the binding process in a different order of binding positions according to the order of the number of bound copies in the whole, the efficiency of the binding process can be improved.

[0092] Next, controller 19 discharges the sheet bundle Pb, which has been bound at the second binding position B2 and the third binding position B3, into the discharge tray 120. Additionally, as... Figure 5A As shown, the controller 19 moves the needle tip binding processing unit 117 to the binding standby position HP1.

[0093] In the above embodiments, examples of oblique binding at the corners of the sheet bundle Pb or binding at two locations of the sheet bundle Pb were described. However, the present invention can also be applied to binding three or more portions of the sheet bundle Pb separated in the main scanning direction.

[0094] Overview of the crimping central binding processing unit Here, return Figure 2 The section describing the crimping and central binding part of the post-processing device 110 will be explained in detail. For example... Figure 2 As shown, the post-processing device 110, in addition to the return conveyor roller 113, the internal tray 114 and the side baffle 116, also includes a movable end baffle 131, a folding plate 132, a pair of folding rollers 133, a folding plate engaging roller 134, a central folding book discharge roller pair 135 and a central folding book discharge tray 136.

[0095] The movable end baffle 131, the folding plate 132, and the folding roller pair 133 constitute a central folder. In addition, the folding plate 132, the folding roller pair 133, and the folding plate engaging roller 134 constitute a crimping central binding device.

[0096] The movable end baffle 131 is a mechanism that moves the end of the sheet P placed on the inner tray 114 along the conveying direction and aligns the central folding position set near the center of the conveying direction of the sheet P with the position of the folding plate 132.

[0097] After the sheet bundle Pb, comprising a predetermined number N sheets of sheet P, is loaded onto the inner tray 114 and aligned, the movable end baffle 131 moves to adjust the central fold position of the sheet bundle Pb to be opposite the folding plate 132. Alternatively, during the stage of loading the predetermined number N sheets of sheet P constituting the sheet bundle Pb, the movable end baffle can be moved to align the central fold position of the sheet bundle Pb with the folding plate 132, thus loading the sheet P onto the inner tray 114. In either case, the central fold position of the sheet bundle Pb is adjusted to a position where the folding plate 132 presses into the folding roller pair 133. Then, with these adjustments made, the central binding is performed by the action of the folding plate 132, the folding roller pair 133, and the folding plate engaging roller 134.

[0098] More specifically, the return conveyor roller 113, at a timing when the sheet P conveyed from the image forming apparatus 101 is placed on the inner tray 114 via the second conveyor roller pair 112, redirects the sheet P toward the movable end baffle 131. This series of redirecting conveyors constitutes a conveying process. At this time, the movable end baffle 131 can be moved to a position corresponding to the central folding position, or it can be in the same position as the end baffle 115.

[0099] Multiple sheets P, conveyed sequentially, are temporarily placed on the inner tray 114. A movable end baffle 131 is provided for the inner tray 114 such that the movable end baffle 131 can move towards the conveying direction side compared to the end baffle 115. The movable end baffle 131 is a component that can move along the inner tray 114 in the conveying direction of the sheet P. The movable end baffle 131 is a structural element that changes the position of the sheet P by moving according to the conveying direction length of the sheet P placed on the inner tray 114 (the same as the conveying direction length in the diverted conveying) under the control of the controller 19. The position of the movable end baffle 131 is set to be at the center position of the conveying direction length of the sheet P, opposite to the folding plate 132.

[0100] Side baffle 116 aligns the sheet P or sheet bundle Pb placed on the inner tray 114 in the main scanning direction (width direction). The crimping and central binding processing unit crimps and centrally binds the sheet bundle Pb aligned by the movable end baffle 131 and the side baffle 116. The crimped and centrally bound sheet bundle Pb is discharged from the central folding booklet discharge roller pair 135 and placed on the central folding booklet discharge tray 136 via the second discharge outlet 1102.

[0101] The action of crimping the central binding device Reference Figures 6A-6E The operation of the central binding device is explained.

[0102] Figures 6A-6E This is a schematic diagram mainly showing the folding plate 132, which is a folding plate component, the folding roller pair 133, which is a folding roller pair component, and the folding plate engaging roller 134, which is a folding plate engaging component, constituting the central binding device.

[0103] Figures 6A-6E This indicates a summary of the central folding binding performed through the actions of these components. Figure 6A This indicates that after the conveying and loading steps, the sheet bundle Pb is loaded onto the inner tray 114 and the ends of the sheets P are aligned, resulting in all sheets P being aligned. Figure 6A In the middle, the folding plate 132, the folding roller pair 133, and the folding plate locking roller 134 are in the initial position.

[0104] In the initial position, the folding plate 132 is approximately perpendicular to the sheet bundle Pb and moves away from the surface of the sheet bundle Pb. In the initial position, the folding plate 132 is opposite to the folding position where the sheet bundle Pb is folded. This is achieved by the folding plate movement motor 141, which constitutes the folding plate component movement mechanism. Figure 10 The sheet bundle Pb moves forward and backward in the thickness direction. In the central folding process, where the central portion of the conveying direction length is folded as part of the sheet bundle Pb, the folding plate 132 moves forward and backward relative to the sheet bundle Pb between a pressing position and a retracting position. A crease is formed at the pressing position. After the central portion of the sheet bundle Pb is folded, the folding plate 132 is removed from the sheet bundle Pb at the retracting position. The retracting position of the folding plate 132 corresponds to the initial position (HP position).

[0105] The folding roller pair 133 is symmetrically arranged with respect to the centerline of the folding plate 132. That is, the folding roller pair 133 is symmetrically arranged with respect to the centerline of the folding plate 132 moving along the direction of movement when folding the sheet P. The folding roller pair 133 is connected to the folding roller rotation motor 142 (see reference). Figure 10 The folding roller pair 133 rotates as described above. Additionally, the folding roller pair 133 is moved by a folding roller pair motor 143 (see reference 143) which constitutes the pressure mechanism. Figure 10 This structure allows the folding rollers 133 to approach and separate.

[0106] The distance between the pair of rollers included in the folding roller pair 133 is adjusted under the control of the controller 19. When the sheet bundle Pb is pressed by the folding plate 132 toward the clamping position of the folding roller pair 133, the roller pair of the folding roller pair 133 is set to the "receiving position" under the control of the controller 19. At the receiving position, the clamping position is separated according to a predetermined separation amount. In addition, the controller 19 can also set the position of the folding roller pair 133 to a position further away from the receiving position before the start of the central fold. The "receiving position" for receiving the sheet bundle Pb can also be described as the position of the folding roller pair 133 during the standby state of the central fold binding. Therefore, the receiving position also corresponds to the standby position.

[0107] The folding plate clamping roller 134 of the crimping binder is a cylindrical roller component. The rotation axis of the folding plate clamping roller 134 is configured to pass through both ends of the cylindrical outer periphery. The folding plate clamping roller 134 is supported by an axis so that it can rotate about the rotation axis. The folding plate clamping roller 134 has clamping teeth 134a on the outer periphery (outer circumferential surface) of its cylindrical portion. Multiple teeth are provided on the clamping teeth 134a. Furthermore, the folding plate clamping roller 134 has flanges 134b at both ends of the cylindrical portion. The outer diameter of each flange 134b is larger than the outer diameter of the clamping teeth 134a. The flanges 134b, as flanges, have the same diameter at both ends of the cylindrical portion.

[0108] The engaging and pressing teeth 134a of the folding plate engaging roller 134 are gear-shaped portions with gear-like protrusions and recesses repeatedly formed at predetermined intervals on the cylindrical outer peripheral surface of the folding plate engaging roller 134. These protrusions and recesses are formed parallel to the rotation axis of the folding plate engaging roller 134.

[0109] First, in the crimping central binding of this embodiment, a central folding process is performed. In the central folding process, the controller 19 first adjusts the position of the roller pair of the folding roller pair 133 via the folding roller pair movement motor 143, making the sheet bundle Pb receivable. The folding roller pair movement motor 143 adjusts the gap at the clamping position of the folding roller pair 133. This adjustment amount (separation amount) is used to create a gap such that the folding plate 132 presses the sheet bundle Pb near the center in the conveying direction (length direction) to the clamping position (gap) of the folding roller pair 133, allowing the folding plate 132 to advance while pressing the sheet bundle Pb. Therefore, for example, the adjustment amount of the gap at the receiving position of the folding roller pair 133 is changed based on the specified number N of sheets P included in the sheet bundle Pb, and dimensional information including the size and thickness of the sheets P.

[0110] That is, as a pre-stage of the central folding process, when the folding plate 132 guides the sheet bundle Pb between the rollers of the folding roller pair 133 (clamping position), the controller 19 separates the rollers so that the folding plate 132 and the sheet bundle Pb can pass between the rollers. For example, at this time, in the position between the rollers constituting the folding roller pair 133, i.e., the "receiving position", the outer peripheries of the rollers are somewhat separated from each other.

[0111] Next, as Figure 6B As shown, the folding plate 132 guides the sheet bundle Pb to the clamping position of the folding roller pair 133. At this time, the folding roller pair 133 is pressurized by the folding roller pair pressure member 144 (see reference). Figure 8 The elastic force of the folding roller is pressed against the sheet bundle Pb. In other words, the degree to which the sheet bundle Pb is pressed by the folding plate 132 is determined by the elastic force of the folding roller on the pressing member 144. Through the pressing of the sheet bundle Pb by the folding roller 133 and the forward movement of the folding plate 132, folds are formed on the sheet bundle Pb.

[0112] Information used to adjust the receiving position of the folding rollers 133 (the type and thickness of sheet P, and the number of sheets P contained in a sheet bundle Pb) is preset in the controller 19 via the operation panel 102. That is, when the central folding process begins, the controller 19 calculates an adjustment value based on the preset number of sheets P contained in the sheet bundle Pb, the type of sheet P (mainly the difference in thickness), etc., and adds the thickness of the folding plate 132 to the adjustment value. The controller 19 uses the value thus calculated as the gap adjustment amount.

[0113] like Figure 6B As shown, the folding plate 132, acting as a rack-and-pinion pressing plate, presses the sheet bundle Pb towards the folding roller pair 133, whose gap has been adjusted, and advances it. At this time, the folding roller pair 133, acting as a central folder, rotates according to the traveling speed of the folding plate 132, pressing the sheet bundle Pb in a direction orthogonal to the traveling direction of the folding plate 132 (sub-scanning direction). That is, the folding plate 132 and the advancing sheet bundle Pb guided by the folding plate 132 are pressed between the folding roller pair 133. When the sheet bundle Pb is pressed into the folding roller pair 133, the pressing position of the sheet bundle Pb bends. Thus, folding is performed. When the sheet bundle Pb is guided (pressed) between the folding roller pair 133 by the folding plate 132, the gap between the folding roller pair 133 expands to twice the thickness of the sheet bundle Pb.

[0114] Furthermore, such as Figure 6C As shown, the front end of the folding plate 132 continues to advance to a position significantly beyond the clamping position of the folding roller pair 133, performing a central fold of the sheet bundle Pb. In this central fold, a portion of the sheet bundle Pb (the approximately central portion in the conveying direction) becomes the crease Fp (see reference). Figure 9 ). In execution Figure 6B , Figure 6CThe process shown is the central folding process, such as... Figure 6C As shown, the folding plate clamping roller 134 is in a retracted position after the front end of the folding plate 132 has passed the clamping position.

[0115] Next, as Figure 6D As shown, the folding plate engaging roller 134 moves from the retracted position toward the folding plate 132. At this time, the folding plate engaging roller 134 moves to an engaging position, which is the position where the folding plate engaging roller 134 and the folding plate 132 abut against each other through the sheet bundle Pb. When the folding plate engaging roller 134 moves to the engaging position, it becomes a pressing state in which the sheet bundle Pb is clamped between the folding plate 132 and the folding plate engaging roller 134. In this pressing state, by pressing the sheet bundle Pb from both sides, the concave and convex folding crimping teeth 132a formed at the front end of the folding plate 132 engages with the concave and convex portion, i.e., the engaging crimping teeth 134a, formed on the outer peripheral surface of the cylindrical portion of the folding plate engaging roller 134, and crimping is performed.

[0116] Furthermore, while the crease Fp of the sheet bundle Pb is being pressed, the sheet bundle Pb bends in the opposite direction to the travel direction of the folding plate 132 by the action of the flange 134b of the folding plate engaging roller 134 and the folding plate 132. The bending position (folding position) is defined by the flange 134b of the folding plate engaging roller 134. Therefore, the back surface Cb of the sheet bundle Pb forms a width corresponding to the distance between the flanges 134b of the opposing folding plate engaging rollers 134, starting from the center of the length of the sheet bundle Pb in the sheet conveying direction. In addition, creases f (see reference) are formed at various positions of the flange 134b of the folding plate engaging roller 134. Figure 9 At this point, the crease f forms two points sandwiching the back Cb. That is, this process is equivalent to the back-side crimping process, in which two creases f are formed on one side, the back is formed on the other side, and crimping is performed on the back Cb simultaneously. The flange 134b of the folding plate engaging roller 134 and the folding plate 132 are equivalent to the back forming device. In addition, the folding plate 132 and the folding plate engaging roller 134 are equivalent to the crimping device. Furthermore, as Figure 9 As shown, multiple stripes (press marks) that are approximately orthogonal to the crease f are formed by the folding pressing teeth 132a of the folding plate 132 and the engaging pressing teeth 134a of the folding plate engaging roller 134, i.e. Figure 9 The crimp mark group Ct is shown.

[0117] That is, while the sheet bundle Pb is pressed and clamped by the folding plate 132 and the folding plate clamping roller 134, the controller 19 moves the folding plate clamping roller 134 in the width direction (main scanning direction) of the sheet bundle Pb. During this width-direction movement, the folding plate clamping roller 134 rotates while moving. In other words, while the sheet bundle Pb is pressed against the folding plate 132, the folding plate clamping roller 134 rotates while moving in the width direction of the sheet bundle Pb. At this time, the flange portion 134b of the folding plate clamping roller 134 clamps the sheet bundle Pb protruding in the thickness direction of the folding plate clamping roller 134, thus surrounding the sheet bundle Pb. As a result, a back surface Cb is formed on the sheet bundle Pb, and the back surface Cb formed on the sheet bundle Pb can be crimped and bound simultaneously with or after its formation. That is, refer to... Figure 6D The action described is to simultaneously perform the back forming process (back folding process) and the back crimping and binding process.

[0118] Finally, as Figure 6E As shown, controller 19 causes the folding plate engaging roller 134 to retract in the width direction of the sheet bundle Pb, and causes the folding plate 132 to retract to the retracted position. Then, controller 19 causes the folding roller pair 133 to rotate to convey the sheet bundle Pb, so that the sheet bundle Pb passes between the folding roller pair 133, and the central crimped booklet with the back Cb crimped and bound is discharged into the central folded booklet discharge tray 136 (see reference). Figure 2 ).

[0119] As described above, in this embodiment, the post-processing apparatus 110 performs a central folding process on the sheet bundle Pb during crimping and central binding. Then, it performs a back folding process on the centrally folded sheet bundle Pb to form the back side Cb. Next, crimping and binding is performed on the back side Cb simultaneously or after its formation, thereby completing the central binding. That is, in the crimping and central binding method, which is an embodiment of the sheet processing method of the present invention, a back forming process is performed after the central folding, and a crimping and binding process (back crimping and binding process) is performed on the back side Cb simultaneously or after its formation. As a result, unlike conventional methods, a crimped and centrally bound booklet can be formed that does not peel off due to folding or page-turning operations and can be easily opened.

[0120] When performing the back forming process and the crimping and binding process sequentially, for example, two rollers corresponding to the folding plate engaging roller 134 can be configured, with only the engaging and crimping teeth 134a provided on one folding plate engaging roller 134 and only the flange portion 134b provided on the other folding plate engaging roller 134. With such a structure, the back forming process and the crimping and binding process can be performed in any order.

[0121] Figures 7A-7CThis is a cross-sectional view of the crimping center binder, viewed from the sheet conveying direction side at the center position of the thickness of the folded plate 132, showing the operation of the crimping center binder.

[0122] The central position of the thickness of the folding plate 132 corresponds to the center line of the central fold. The folding plate 132 has a folding pressing tooth 132a on the sheet pressing surface opposite to the folding plate engaging roller 134 in the traveling direction. The folding pressing tooth 132a is formed in a concave-convex shape as a folding plate pressing tooth.

[0123] Figure 7A Corresponding to Figure 6C The state shown. As already explained, in Figure 6C In the state shown, the folding plate 132 presses the sheet bundle Pb to a position beyond the clamping position of the folding roller pair 133.

[0124] When the sheet bundle Pb is pushed into the clamping position of the folding roller pair 133 by the folding plate 132 and moves forward in parallel, the folding plate engaging roller 134 is positioned on the outer side of the width direction of the sheet bundle Pb, which has been centrally folded to form a booklet shape. This standby position corresponds to the initial position (HP position). In the initial position (HP position), the folding plate engaging roller 134 is located on the outer side of the main scanning direction relative to the sheet bundle Pb that is being pressed into the clamping position of the folding roller pair 133 and moving forward. Therefore, the initial position (HP position) is equivalent to the position where the folding plate engaging roller 134 is separated from the sheet bundle Pb. Figures 7A-7C The diagram only shows the engaging and pressing teeth 134a, one of the constituent elements of the folding plate engaging roller 134.

[0125] The folding plate clamping roller 134 (clamping and pressing teeth 134a) is scanned by the folding plate clamping roller scanning motor 145 (see reference). Figure 10 The sheet bundle Pb moves in the main scanning direction. In the crimping center binder, a crimping roller guide 146 is provided as a contact / separation mechanism for the folding plate crimping roller. The crimping teeth 134a of the folding plate crimping roller 134 move along the crimping roller guide 146 in the main scanning direction.

[0126] The engaging roller guide 146 is longer than the sheet bundle Pb in the main scanning direction. The portion of the engaging roller guide 146 located outside the main scanning direction at the end of the sheet bundle Pb separates from the crease portion of the sheet bundle Pb at the clamping position of the folding roller pair 133. In addition, the portion of the engaging roller guide 146 located inside the end of the sheet bundle Pb at the clamping position of the folding roller pair 133 in the main scanning direction is close to the crease portion of the sheet bundle Pb.

[0127] Therefore, the engaging and pressing teeth 134a of the folding plate engaging roller 134 do not contact the crease portion formed on the sheet bundle Pb at the end of the sheet bundle Pb and at a position further outward in the main scanning direction than the end. The engaging and pressing teeth 134a and the folding plate 132 move in a manner that clamps the crease portion further outward in the main scanning direction than the end. Furthermore, the engaging and pressing teeth 134a move along the engaging roller guide 146 in the main scanning direction. Thus, the portions of the sheet bundle Pb with creases clamped by the engaging and pressing teeth 134a and the folding plate 132 are sequentially crimped and bound.

[0128] Figure 7B Equivalent to Figure 6D The state is equivalent to the pressure state in which the sheet bundle Pb, held between the folding plate 132 and the folding plate engaging roller 134, is pressed down by the folding plate 132 against the engaging and pressing teeth 134a, thereby deforming it. When scanning is performed with the folding plate engaging roller 134 located at the crease of the sheet bundle Pb and forming the back Cb by the folding plate engaging roller 134, the folding roller pair 133 is in a pressure state in which the sheet bundle Pb is held by the folding roller pair 133 and does not move, and the sheet bundle Pb is not pushed back. The controller 19 controls the folding roller pair 133 to maintain the pressure state. That is, when the sheet bundle Pb is crimped and centrally bound, the folding roller pair 133 is controlled to maintain the pressure state so that the folding plate 132 is not pressed back by the folding plate engaging roller 134.

[0129] Furthermore, when the folding plate 132 is pressed by the folding plate engaging roller 134, the teeth of the engaging pressing teeth 134a engage with the folding pressing teeth 132a, clamping the sheet bundle Pb. The engaging pressing teeth 134a are the engaging pressing teeth of the folding plate engaging roller 134. The folding pressing teeth 132a are provided on the pressing surface of the folding plate 132 and function as folding plate pressing teeth. As a result, the back side Cb of the sheet bundle Pb is pressed and deformed in the main scanning direction, thereby performing back pressing binding processing.

[0130] In the folding and pressing toothed portion 132a, similar to the rack teeth of a rack and pinion mechanism, protrusions and recesses are arranged at predetermined intervals in the main scanning direction (see reference). Figure 7A , Figure 7B and Figure 7C If the scanning motor 145 is scanned via the folding clamping roller (refer to...) Figure 10When the folding engagement roller 134 scans in the main scanning direction, the engagement position of the engagement pressing teeth 134a of the folding engagement roller 134 and the folding pressing teeth 132a of the folding plate 132 moves in the main scanning direction. This movement of the engagement position crimps and binds the back side Cb of the sheet bundle Pb. During the crimping and binding process, by pressing the folding roller pair 133 towards the clamping position, the folding plate engagement roller 134 can reciprocate in the main scanning direction while maintaining the engagement position. This prevents the sheet bundle Pb and the folding plate 132 from falling off due to the pressure of the folding plate engagement roller 134.

[0131] As described above, when the engaging crimping teeth 134a of the folding plate engaging roller 134 approaches the back side Cb of the sheet bundle Pb, the engaging crimping teeth 134a moves in an inclined direction from the outer side of the sheet bundle Pb in the width direction toward the back side Cb. Therefore, the engaging crimping teeth 134a of the folding plate engaging roller 134 approaches from a direction that does not collide with the width direction end of the back side Cb of the sheet bundle Pb, and the engaging position with the folding crimping teeth 132a of the folding plate 132 begins from the inner side of the width direction end of the sheet bundle Pb. This prevents the end of the sheet bundle Pb from curling up when the folding plate engaging roller 134 passes through it.

[0132] like Figure 7C As shown, after the back Cb of the sheet bundle Pb is crimped and bound, the crimping teeth 134a of the folding plate crimping roller 134 passes along the main scanning direction to a position outside the other end (the end opposite to the standby position) of the sheet bundle Pb in the width direction, and moves in the central folding discharge direction to a position away from the folding crimping teeth 132a of the folding plate 132.

[0133] When the next sheet bundle Pb is continuously crimped and centrally bound, the engaging crimping teeth 134a move in the opposite direction in the main scanning direction. In other words, for Figure 7B The odd-numbered sheet bundle Pb moves from left to right in the engaging crimping teeth 134a. Figure 7B The even-numbered sheet bundle Pb moves from right to left with the engaging crimping teeth 134a.

[0134] This embodiment illustrates a folding plate engaging roller contact / separation mechanism with a structure including an engaging roller guide 146 and a folding plate engaging roller scanning motor 145 (see reference). Figure 10 However, it is not limited to this. It may also include a moving motor that moves the folding plate clamping roller 134 so that the folding plate clamping roller 134 can move forward and backward along the central folding discharge direction.

[0135] Figure 8 This is a schematic diagram showing the state of the sheet bundle Pb being pressed by the central binding press.

[0136] like Figure 8 As shown, the folding plate 132 is a folding plate component that guides the sheet bundle Pb, which is placed and stacked on the inner tray 114, toward the clamping position of the folding roller pair 133 in a predetermined direction near the center of the conveying direction.

[0137] Additionally, the folding roller pair 133 is equivalent to a folding roller pair component that clamps the sheet bundle Pb guided by the folding plate 132 toward the clamping position and further advances the sheet bundle Pb in the direction of travel.

[0138] That is, the folding roller pair 133 is forced toward the folding plate 132 by the folding roller pressure member 144, and the folding roller pair 133 clamps the folding plate 132 and the sheet bundle Pb in the clamping position. This force is applied so that the folding roller pair 133 presses against the folding plate 132 as it passes through the clamping position. The folding roller pair pressure member 144 is an elastic member such as a spring. Therefore, while the folding roller pair 133 is pressing against the folding plate 132, the folding plate 132 and the sheet bundle Pb are in a state that can be pushed back by the elastic force as they travel between the folding roller pair 133 (in the clamping position).

[0139] exist Figure 6B and Figure 6C In this state, the folding roller pair 133 presses and conveys the sheet bundle Pb towards the folding plate 132. Therefore, during the passage of the sheet bundle Pb through the folding roller pair 133, the crease portion is pressed by the traveling end of the folding plate 132. This folding process is thus performed on the sheet bundle Pb. Furthermore, in Figure 6D In the state of pressing and binding, when the folding rollers 133 are pressing the sheet bundle Pb, the sheet bundle Pb is held by the folding plate clamping rollers 134.

[0140] With the sheet bundle Pb sandwiched between the folding plate engaging roller 134 and the folding plate 132, the folding plate engaging roller 134 is pressed towards the folding plate 132 by the folding plate engaging roller pressing member 147. The folding plate engaging roller 134 is a roller-shaped member supported by its shaft. The rotation axis of the folding plate engaging roller 134 is an axis extending along the direction in which the folding roller 133 is subjected to force by the folding plate 132.

[0141] The folding plate engaging roller 134 has engaging and pressing teeth 134a and flanges 134b. The engaging and pressing teeth 134a is a cylindrical portion having a predetermined width in the direction of rotation axis. The flanges 134b are flanges provided at both ends of the cylindrical portion in the direction of rotation axis.

[0142] The snap-fitting teeth 134a are pressured by the folding plate snap-fitting roller pressure member 147, pressing the sheet bundle Pb sandwiched between the snap-fitting teeth 134a and the folding plate 132, thereby performing a snap-fitting binding process. When the snap-fitting teeth 134a presses against the folding plate 132, the portion of the sheet bundle Pb held by the end of the folding plate 132 in the thickness direction and the flange portion 134b oriented in the direction along the folding plate 132. As a result, the portion of the sheet bundle Pb held by the flange portion 134b and the folding plate 132 folds. This folding direction is opposite to the traveling direction of the folding plate 132. At this time, folded portions are formed at two points spaced apart in the thickness direction of the folding plate 132. As a result, two folded edges are formed on the sheet bundle Pb by the central snap-fitting. As a result, a square ridge-shaped back is formed on the folded portion of the sheet bundle Pb, and a back Cb, which is a generally flat portion, is formed between the folded edges. That is, the square spine is folded by back-press binding.

[0143] Booklet Bk Figure 9 This is a perspective view of booklet Bk, which represents an example of a booklet formed by the aforementioned central binding and crimping.

[0144] like Figure 9 As shown, during the central folding of the sheet bundle Pb, the sheet bundle Pb is folded at the crease Fp. This forms the booklet Bk, with a square spine on the back surface Cb. On the back surface Cb, crimping marks Ct are formed at predetermined intervals along its length. The crimping marks Ct are formed by the pressure deformation of the engaging crimping teeth 134a and the folding plate 132. The crimping marks Ct can be formed at positions overlapping with the folded position (crease Fp) of the sheet bundle Pb during the central folding process. In the booklet Bk, the portion that moves due to the page-turning action corresponds to the two creases f forming the back surface Cb. The two creases f are formed near both sides of the crimping marks Ct.

[0145] Therefore, the booklet Bk formed by the central binding and crimping binding processes in this embodiment has a structure that does not apply load to the crimping portion when turning pages at the crease f, and a structure that prevents the binding portion from peeling off due to the page turning process. Furthermore, since the crease f is formed at two locations sandwiching the back Cb, either of the creases f formed at the two locations can move during the page turning process. The crease f is located at a position that does not overlap with the crease portion Fp that is pressed into the clamping position of the folding roller pair 133 by the folding plate 132. The crease portion Fp is the binding position of the crimping binding process.

[0146] Therefore, when turning the page, the page is turned at the crease f, and the crease Fp corresponding to the center of the opened booklet Bk is bound. This structure prevents pages from being turned across the binding. In other words, because the central fold line (crease f) is symmetrically arranged on both sides of the binding position, opening to the left and right is also equal. This also helps maintain the quality of the booklet Bk.

[0147] Control Configuration Figure 10 This is a hardware configuration diagram of the controller 19 that controls the operation of the post-processing device 110 according to the first embodiment.

[0148] like Figure 10 As shown, the controller 19 is configured such that a central processing unit (CPU) 11, random access memory (RAM) 12, read-only memory (ROM) 13, hard disk drive (HDD) 14 and interface (I / F) 15 are connected via a common bus 16.

[0149] CPU 11 is the arithmetic unit, controlling the overall operation of post-processing device 110. RAM 12 is a volatile storage medium capable of high-speed reading and writing of information, used as the working area for CPU 11 to process information. ROM 13 is a dedicated non-volatile storage medium for reading, storing firmware and other programs. HDD 14 is a non-volatile storage medium with a large storage capacity, allowing information to be read and written. HDD 14 stores the operating system (OS), various control programs, application programs, etc.

[0150] The post-processing unit 110 processes, for example, a control program stored in ROM 13 and an information processing program (application program) loaded from a storage medium such as HDD 14 into RAM 12 using the computing functions of the CPU 11. This processing enables a software control unit that includes various functional modules of the post-processing unit 110. The combination of the software control unit configured in this way and the hardware resources installed on the post-processing unit 110 forms a functional block that implements the functions of the post-processing unit 110. Specifically, the CPU 11, RAM 12, ROM 13, and HDD 14 form a controller 19 (control unit) that controls the operation of the post-processing unit 110.

[0151] I / F 15 is an interface that connects the first conveyor roller pair 111, the second conveyor roller pair 112, the return conveyor roller 113, the side baffle 116, the discharge roller pair 119, the movable end baffle 131, the folding plate moving motor 141, the folding roller pair rotating motor 142, the folding roller pair moving motor 143, the folding plate clamping roller scanning motor 145, the needle end binding main scanning motor 161, the needle end binding posture rotating motor 164, the needle end binding clamping motor 166, the crimping end binding main scanning motor 171, the crimping end binding posture rotating motor 174, the crimping end binding clamping motor 176, the binding tooth sliding motor 179, the crimping roller moving motor 188, and the operation panel 102 to the common bus 16.

[0152] The controller 19 activates the first conveyor roller pair 111, the second conveyor roller pair 112, the return conveyor roller 113, the side baffle 116, the discharge roller pair 119, the movable end baffle 131, the folding plate moving motor 141, the folding roller pair rotating motor 142, the folding roller pair moving motor 143, the folding plate clamping roller scanning motor 145, the needle end binding main scanning motor 161, the needle end binding posture rotating motor 164, the needle end binding clamping motor 166, the crimping end binding main scanning motor 171, the crimping end binding posture rotating motor 174, the crimping end binding clamping motor 176, the binding tooth sliding motor 179, and the crimping roller moving motor 188 via the I / F 15.

[0153] If you have already referred Figure 1 As described, the image forming apparatus 101 includes an operation panel 102. The operation panel 102 includes an operation device and a display (notification unit). The operation device receives input from a user. The display notifies the user of information. The operation device may include, for example, physical input buttons and a touchscreen overlaid on the display. The operation panel 102 then obtains information from the user via the operation device and provides the information to the user via the display. Specific examples of the notification unit are not limited to a display; they may be a light-emitting diode (LED) lamp or a speaker. The post-processing apparatus 110 may include the same operation panel 102 as described above.

[0154] First variation Next, refer to Figure 11 The first variation of the crimping central binding device will be described.

[0155] The difference between the crimping center binder of the first modification and the crimping center binder of the first embodiment is that, instead of the folding plate engaging roller 134, which is a roller member that rotates and moves in the main scanning direction, the folding plate engaging member has a folding plate engaging mold 181, which is a plate member extending in the main scanning direction (the length direction of the back Cb). Furthermore, for structural elements common to both the crimping center binder of this modification and the first embodiment, the same reference numerals are used, and detailed descriptions are omitted.

[0156] Figure 11 This is a schematic diagram illustrating a first variation of the crimping central binding device.

[0157] The folding roller pair 133 is pressed against each other by the folding roller pair pressure member 144 while holding the folding plate 132 and the sheet bundle Pb.

[0158] Additionally, the folding plate engaging mold 181 has a die-pressing portion 181a on the surface opposite to the folding plate 132. This die-pressing portion 181a has a plurality of teeth in the length direction that serve as an engaging and pressing tooth assembly. The folding plate 132 has a folding and pressing tooth portion 132a on the surface opposite to the folding plate engaging mold 181, which serves as a folding plate pressing tooth assembly. The folding and pressing tooth portion 132a engages with the die-pressing portion 181a as an engaging and pressing tooth assembly. When the folding plate 132 presses the sheet bundle Pb toward the folding roller pair 133, and the crease of the sheet bundle Pb reaches the position where the folding plate 132 and the folding plate engaging mold 181 can engage, the folding plate engaging mold 181 moves toward the folding plate 132 side, pressing the sheet bundle Pb to perform crimping and binding. At this time, because the folding roller pair 133 is pressed towards the folding plate 132 by the folding roller pair pressing member 183, the folding plate 132 is prevented from being pushed back by the pressing force of the folding roller pair pressing member 144 on the folding plate clamping mold 181. Through the pressing force of the folding plate clamping mold 181, the pressing and fastening of the die-pressing portion 181a based on the folding plate clamping mold 181 is performed. As a result, a crimping mark group Ct consisting of multiple crimping marks is formed in the longitudinal direction of the back surface Cb. The orientation of the crimping marks included in the crimping mark group Ct indicates a direction approximately perpendicular to the folding mark f. Furthermore, by utilizing the pressing force of the folding plate clamping mold 181, the flange portion 181b of the folding plate clamping mold 181 can perform a square ridge folding of the sheet bundle Pb.

[0159] Figure 12A and Figure 12B This is a cross-sectional view showing the operation of the crimping central binding device in the first modified example.

[0160] Figure 12A , Figure 12B This is a cross-sectional view of the crimping central binder along the BB line, viewed from the side of the sheet conveying direction, at the center line of the central fold, i.e., at the center of the thickness of the folded plate 132. Figure 12A Corresponding toFigure 6C The folding plate 132 presses the sheet bundle Pb to a position beyond the clamping position of the folding roller pair 133. The folding plate clamping mold 181 is in the standby position (HP position), separating from the sheet bundle Pb in the central folding discharge direction.

[0161] Folding plate mold closing 181 moves the folding plate mold closing movement motor 182 (see reference) Figure 10 Move towards the folding plate side.

[0162] Figure 12B Corresponding to Figure 6D The sheet bundle Pb is pressed against the folding plate 132 by the folding plate clamping mold 181. Thus, the teeth of the mold pressing portion 181a of the folding plate clamping mold 181 engage with the folding pressing teeth 132a provided on the pressing surface of the folding plate 132, clamping the sheet bundle Pb. By applying pressure to the folding plate clamping mold 181 using the folding plate clamping mold pressing member 183, the back of the sheet bundle Pb is crimped and bound.

[0163] Second variation Next, refer to Figure 13A and Figure 13B A second variation of the crimping central binding device will be described.

[0164] The difference between the crimping central binding device of the second modification and the crimping central binding device of the first modification is that, on the folding plate 184, the concave and convex crimping teeth are not uniformly arranged in the width direction, but are arranged locally (discontinuously) in multiple locations as folding plate crimping tooth assemblies. Furthermore, in the folding plate locking mold 185, crimping tooth assemblies are arranged at positions opposite to the folding plate crimping tooth assemblies as locking crimping tooth assemblies. Locking crimping tooth assemblies are not arranged in generally flat areas. Additionally, the same reference numerals are used to denote common components of this modification's crimping central binding device as those of the first embodiment, and detailed descriptions are omitted.

[0165] Figure 13A and Figure 13B It is a cross-sectional view of the crimping central binder according to the second variation, which shows the operation of the crimping central binder.

[0166] Figure 13A , Figure 13B This is a cross-sectional view of the second modified example of the crimping central binder, viewed from the sheet conveying direction side, at the center line of the central fold, i.e., the center position of the thickness of the folded plate 132.

[0167] Figure 13A Corresponding to Figure 6CThe folding plate 184 presses the sheet bundle Pb to a position beyond the clamping position of the folding roller pair 133. The folding plate clamping mold 185 is in the standby position (HP position) and leaves the sheet bundle Pb in the central folding discharge direction.

[0168] Folding plate mold closing 185 moves via folding plate mold closing motor 182 (see reference) Figure 10 Move towards the folding plate side.

[0169] Figure 13B Corresponding to Figure 6D The sheet bundle Pb is pressed against the folding plate 184 by the folding plate clamping mold 185. Thus, the teeth of the crimping portion 185a of the folding plate clamping mold 185 and the teeth of the crimping teeth 184a provided on the pressing surface of the folding plate 184 clamp the sheet bundle Pb. By applying pressure to the folding plate clamping mold 185 using the folding plate clamping mold pressing member 183, the back of the sheet bundle Pb is crimped and bound.

[0170] Third variation Next, refer to Figure 14A and Figure 14B The third variation of the crimping central binding device will be described.

[0171] The difference between the crimping central binder of the third modification and the crimping central binder of the first modification is that the folding plate engaging member is configured such that the folding plate engaging member (folding plate engaging mold 186) does not move linearly to engage with the folding plate 132 while facing it, but moves along a rotational trajectory by sequentially engaging the concave and convex crimping teeth. Furthermore, the same reference numerals are used to denote the common components of the crimping central binder of this modification and the first embodiment, and detailed descriptions are omitted.

[0172] Figure 14A and Figure 14B This is a cross-sectional view showing the operation of the crimping central binding device in the third variation.

[0173] Figure 14A and Figure 14B This is a cross-sectional view of the third modified example of the crimping central binder, viewed from the sheet conveying direction side, at the center line of the central fold, i.e., the center position of the thickness of the folded plate 132.

[0174] Figure 14A Corresponding to Figure 6C The folding plate 132 presses the sheet bundle Pb to a position beyond the clamping position of the folding roller pair 133. The folding plate clamping mold 186 is in the standby position (HP position) and leaves the sheet bundle Pb in the central folding discharge direction.

[0175] Folding plate mold closing 186 moves via folding plate mold closing motor 182 (see reference) Figure 10 It moves toward the folding plate 132 side, and moves along the rotation trajectory in such a way that the teeth of the pressing part 186a of the folding plate engaging with the teeth of the folding pressing tooth part 132a of the folding plate 132 in sequence.

[0176] Figure 14B Corresponding to Figure 6D The sheet bundle Pb is pressed against the folding plate 132 by the folding plate clamping mold 186. Thus, the teeth of the crimping portion 186a of the folding plate clamping mold engage with the teeth of the folding crimping teeth 132a provided on the pressing surface of the folding plate 132, clamping the sheet bundle Pb. By applying pressure to the folding plate clamping mold 186 using the folding plate clamping mold pressing member 183, the back of the sheet bundle Pb is crimped and bound.

[0177] The pressing portion 186a of the folding plate clamping mold 186 is not a plane, but a curved surface. Therefore, the teeth of the pressing portion 186a can also be set on the curved surface, so that the pressing portion 186a of the folding plate clamping mold 186 moves on the rotation trajectory, and the teeth of the pressing portion 186a of the folding plate clamping mold 186 engage sequentially with the teeth of the folding pressing tooth portion 132a of the folding plate 132.

[0178] As described above, the teeth of the pressing portion 186a of the folding plate clamping mold 186 engage sequentially with the teeth of the folding pressing tooth portion 132a of the folding plate 132. As a result, the pressure applied during crimping and binding can be reduced, enabling the equipment to be miniaturized.

[0179] Fourth variation Next, refer to Figure 15A-15C The fourth variation of the crimping central binding device will be described.

[0180] The difference between the crimping central binding device of the fourth modification and the crimping central binding device of the first embodiment is that the folding plate 132 is provided with a crimping roller 187, which has teeth on its outer periphery and is movable at its front end in the main scanning direction. Furthermore, the same reference numerals are used to denote common components of the crimping central binding device of this modification and those of the first embodiment, and detailed descriptions are omitted.

[0181] Figure 15A-15C This is a cross-sectional view showing the operation of the crimping central binding device in the fourth variation.

[0182] Figure 15A-15C This is a cross-sectional view of the fourth modified example of the crimping central binder, taken from the sheet conveying direction side, at the center line of the central fold, i.e., the center position of the thickness of the folded plate 132. Figure 15A Corresponding to Figure 6CThe folding plate 132 presses the sheet bundle Pb to a position beyond the clamping position of the folding roller pair 133. The folding plate clamping roller 134 and the pressing roller 187 are in the standby position (HP position), separated from the sheet bundle Pb in the central folding discharge direction.

[0183] The pressing roller 187, serving as the first roller component, is supported by a pressing roller guide rail 132b. The pressing roller guide rail 132b is arranged along the length direction (main scanning direction) of the folding plate 132. A pressing roller movement motor 188 (see reference...) Figure 10 The pressing roller 187 moves in the main scanning direction of the sheet bundle Pb.

[0184] Figure 15B Corresponding to Figure 6D The folding plate engaging roller 134, as the second roller component, is guided by the engaging roller guide 146 to approach the pressing roller 187, and is pressed onto the pressing roller 187 via the sheet bundle Pb. The teeth of the engaging pressing teeth 134a of the folding plate engaging roller engage with the teeth 187a provided on the pressing surface of the pressing roller 187, clamping the sheet bundle Pb. At this time, the folding plate engaging roller 134 is pressurized by the folding plate engaging roller pressing component 147. As a result, the sheet bundle Pb is deformed by the teeth of the engaging pressing teeth 134a of the folding plate engaging roller 134 and the teeth of the pressing teeth 187a provided on the pressing surface of the pressing roller 187. As a result, the back side Cb of the sheet bundle Pb is pressed and secured.

[0185] Fifth variation Next, refer to Figures 16A-16C The fifth variation of the crimping central binding device will be explained.

[0186] The difference between the crimping central binding device of the fifth modification and the crimping central binding device of the first embodiment is that the crimping teeth of the folding plate with concave and convex shapes are not uniformly arranged in the main scanning direction, but are arranged locally (discontinuously). In addition, the same reference numerals are used to mark the common components of the crimping central binding device of this modification and the first embodiment, and detailed descriptions are omitted.

[0187] Figures 16A-16C This is a cross-sectional view showing the operation of the crimping central binding device in the fifth variation.

[0188] Figures 16A-16C This is a cross-sectional view of the fifth modified example of the crimping central binder, taken from the sheet conveying direction side, at the center line of the central fold, i.e., the center position of the thickness of the folded plate 184.

[0189] Figure 16A Corresponding to Figure 6CThe folding plate 184 presses the sheet bundle Pb to a position beyond the clamping position of the folding roller pair 133. The folding plate engaging roller 134 is in the standby position (HP position) and is separated from the sheet bundle Pb in the central folding discharge direction.

[0190] Thus, the engaging crimping teeth 134a of the folding plate engaging roller 134 and the folding crimping teeth 184a provided on the pressing surface of the folding plate 184 clamp the sheet bundle Pb and engage. By applying pressure to the folding plate engaging roller 134 by the folding plate engaging roller pressing member 147, the back of the sheet bundle Pb is crimped and bound.

[0191] Figure 16B Corresponding to Figure 6D The sheet bundle Pb is pressed against the folding plate 184 by the folding plate engaging roller 134. Thus, the teeth of the engaging pressing teeth 134a of the folding plate engaging roller 134 engage with the teeth of the pressing teeth 184a provided on the pressing surface of the folding plate 184, clamping the sheet bundle Pb. When the teeth of the engaging pressing teeth 134a of the folding plate engaging roller 134 engage with the teeth of the pressing teeth 184a of the folding plate 184, the folding plate engaging roller 134 is pressed by the folding plate engaging roller pressing member 147. Thus, through the teeth of the engaging pressing teeth 134a of the folding plate engaging roller 134 and the teeth of the pressing part 187a of the pressing roller 187, the sheet bundle Pb is pressed and deformed. Thus, the back side Cb of the sheet bundle Pb is crimped and secured.

[0192] Figure 17 This is a schematic diagram representing the booklet Bk formed in the fifth variation.

[0193] like Figure 17 As shown, the back Cb of booklet Bk is formed as a square ridge. Furthermore, the back Cb is crimped at specified intervals, and crimp marks Ct are formed at specified intervals along the length direction of the back Cb (the width direction of the sheet bundle Pb).

[0194] Sixth variation Next, refer to Figure 18 and Figure 19 The sixth variation of the crimping central binding device will be described.

[0195] The difference between the sixth variation of the crimping central binder and the first embodiment lies in that the teeth of the engaging crimping teeth 134a of the folding plate engaging roller 134 are not arranged parallel to the main scanning direction, but are formed as "helical teeth" that are, for example, inclined relative to the main scanning direction. Here, the teeth of the engaging crimping teeth 134a are inclined at an angle of, for example, 15 degrees. Furthermore, for structural elements common to both the sixth variation and the first embodiment, the same reference numerals are used, and detailed descriptions are omitted.

[0196] Figure 19 This is a schematic diagram representing the centrally bound booklet in the sixth variation.

[0197] like Figure 19 As shown, the back Cb of booklet Bk is formed as a square ridge. Furthermore, the back Cb is crimped and bound, and the crimp marks included in the crimp mark group Ct are arranged in a manner that is inclined relative to the length direction of the back Cb (the width direction of the sheet bundle Pb).

[0198] Seventh variation Next, refer to Figures 20A-20D The seventh variation of the crimping central binding device will be described.

[0199] The difference between the crimping central binding device of the seventh modification and the crimping central binding device of the first embodiment is that the folding plate clamping roller 134 scans in a figure-eight pattern. Furthermore, the same reference numerals are used to label the common components of the crimping central binding device of this modification and the first embodiment, and detailed descriptions are omitted.

[0200] Figures 20A-20D This is a cross-sectional view showing the operation of the crimping central binding device in the seventh variation.

[0201] Figures 20A-20D This is a cross-sectional view of the seventh modified example of the crimping central binder, taken from the sheet conveying direction side, at the center line of the central fold, i.e., the center position of the thickness of the folded plate 132.

[0202] Figure 20A Corresponding to Figure 6C The folding plate 132 presses the sheet bundle Pb to a position beyond the clamping position of the folding roller pair 133. The folding plate engaging roller 134 is in the standby position (HP position) and is separated from the sheet bundle Pb in the central folding discharge direction.

[0203] The folding plate clamping roller 134 is supported by the clamping roller guide rail 146a. The folding plate clamping roller 134 is guided by the folding plate clamping roller scanning motor 145 (see reference). Figure 10 The folding engaging roller 134 moves along the engaging roller guide 146a. The movement of the folding engaging roller 134 is controlled by the controller 19. Figure 10 )control.

[0204] The engagement roller guide 146a is configured to connect the engagement and pressing teeth 134a of the folding plate engagement roller 134 with the folding pressing teeth 132a of the folding plate 132, and the engagement and pressing teeth 134a disengaging from the folding plate 132. Through the engagement roller guide 146a, within a predetermined range along the length of the folding plate 132, the folding plate engagement roller 134 approaches the folding plate 132; in other ranges, the folding plate engagement roller 134 disengages from the folding plate 132.

[0205] Figure 20B Corresponding to Figure 6D The folding plate engaging roller 134 is guided by the engaging roller guide 146a. With the sheet bundle Pb sandwiched between it and the folding plate 132, it is pressed from a first predetermined position in the width direction of the sheet bundle Pb toward the folding plate 132, thereby engaging the folding plate engaging roller 134 with the folding plate 110. At this time, the engaging pressing teeth 134a of the folding plate engaging roller engage with the folding pressing teeth 132a provided on the pressing surface of the folding plate 132, sandwiching the sheet bundle Pb. By applying pressure to the folding plate engaging roller 134 by the folding plate engaging roller pressing member 147, the back side Cb of the sheet bundle Pb is crimped and bound.

[0206] like Figure 20B As shown, the folding plate clamping roller 134 is guided by the clamping roller guide 146a and moves to a retracted position in the main scanning direction. In this retracted position, the folding plate clamping roller 134 performs binding by pressing approximately half of the width direction of the sheet bundle Pb through the end of the sheet bundle.

[0207] Next, as Figure 20C As shown, the folding plate clamping roller 134 is guided by the clamping roller guide rail 146a, and leaves the sheet bundle Pb again in the retraction position, moving in the opposite direction of the main scanning direction.

[0208] Next, as Figure 20D As shown, the folding plate clamping roller 134 is guided by the clamping roller guide 146a, presses the sheet bundle Pb again from the second predetermined position, and moves in the main scanning direction until the folding plate clamping roller 134 passes the other end of the sheet bundle Pb.

[0209] The folding plate clamping roller 134 is guided by the clamping roller guide rail 146a and moves along an 8-shaped trajectory. This presses together the entire length region of the back Cb for binding.

[0210] The sheet bundle Pb is deformed by pressing the back Cb of the folding plate clamping roller 134, thereby performing crimping and square ridge folding. Since the folding plate clamping roller 134 performs crimping and square ridge folding sequentially while moving in the main scanning direction, the pressing force can be concentrated at the processing point. As a result, the pressing force can be reduced, and the equipment can be miniaturized. On the other hand, if the sheet bundle Pb undergoes unintended deformation (e.g., sheet wrinkling), the sheet wrinkles may accumulate and expand as it moves along the main scanning direction.

[0211] The folding plate clamping roller 134 moves along a figure-eight track. This allows for processing of the first half of the sheet width from the center towards one end, followed by processing of the second half from the center towards the other end. Consequently, even in the event of unintended deformation of the sheet bundle Pb (e.g., sheet wrinkling), the accumulation of sheet wrinkles can be halved.

[0212] Eighth variation Next, refer to Figure 21 The eighth variation of the crimping central binding device will be described.

[0213] The difference between the crimping center binder of the eighth modification and the crimping center binder of the first embodiment is that the pressing surface of the folding plate 132 does not have concave-convex crimping teeth, and the cylindrical outer periphery of the folding plate engaging roller does not have folding crimping teeth 132a, which are concave-convex folding crimping teeth. Instead, a heating unit is provided on the cylindrical outer periphery of the folding plate engaging roller 191. Furthermore, the same reference numerals are used to denote common components of this modification and the first embodiment, and detailed descriptions are omitted.

[0214] Figure 21 This is a schematic diagram showing the eighth variation of the crimping central binding device.

[0215] The folding roller pair 133 is pressed against each other by the folding roller pair pressure member 144 while holding the folding plate 132 and the sheet bundle Pb.

[0216] Furthermore, in this modified example, the folding plate engaging roller 191, as a folding plate engaging heating component, is pressed towards the folding plate 132 by the folding plate engaging roller pressing component 147 while the sheet bundle Pb is sandwiched between it and the folding plate 132. Using this pressing force and heat, the sheet bundle Pb is bonded together with a colorant using the heated pressing portion 191a of the folding plate engaging roller 191 and the folding plate 132. Moreover, by using the flange portions 191b formed at both ends of the cylindrical portion of the folding plate engaging roller 191, a square ridge folding back forming treatment can be applied to the sheet bundle Pb.

[0217] The folding plate clamping roller 191 constituting the toner crimping binder is a cylindrical roller component. The rotation axis of the folding plate clamping roller 191 is configured to pass through both ends of the cylindrical outer periphery that clamps the folding plate clamping roller 191. The folding plate clamping roller 191 is supported by an axis so that it can rotate about the rotation axis as the center of rotation. The folding plate clamping roller 191 has a heated pressing portion 191a on its cylindrical outer periphery (cylindrical outer peripheral surface). The folding plate clamping roller 191 has flange portions 191b at both ends of its cylindrical outer peripheral surface, and these flange portions 191b have an outer diameter larger than that of the heated pressing portion 191a. The flange portions 191b have the same diameter at both ends of the cylindrical outer peripheral surface.

[0218] The heated pressing part 191a of the folding plate clamping roller 191 is heated by a heater provided inside the folding plate clamping roller 191.

[0219] Figures 22A-22C This is a cross-sectional view showing the operation of the crimping central binding device in the eighth variation.

[0220] Figures 22A-22C Viewed from the sheet conveying direction side Figure 21 A cross-sectional view of the BB line section of the crimping central binder, the center line of the central fold, i.e., the central position of the thickness of the fold plate 132.

[0221] Figure 22A Corresponding to Figure 6C The folding plate 132 presses the sheet bundle Pb to a position beyond the clamping position of the folding roller pair 133. The folding plate engaging roller 191 is in the standby position (HP position) and is separated from the sheet bundle Pb in the central folding discharge direction.

[0222] The folding plate clamping roller 191 (heated pressing part 191a) is scanned by the folding plate clamping roller scanning motor 145 (see reference). Figure 10 The folding plate clamping roller 191 moves along the main scanning direction (the width direction of the sheet bundle Pb). In the crimping center binder, a clamping roller guide 146 is provided as a contact / separation mechanism for the folding plate clamping roller. The folding plate clamping roller 191 moves along the clamping roller guide 146 in the main scanning direction.

[0223] Figure 22B Corresponding to Figure 6D The sheet bundle Pb is pressed against the folding plate 132 by the folding plate clamping roller 191, and the heated pressing part 191a of the folding plate clamping roller 191 is pressed against the pressing surface of the folding plate 132, thereby being heated and pressurized. As a result, the back Cb of the sheet bundle Pb is crimped and bound.

[0224] Figure 22CThis indicates that after the sheet bundle Pb is crimped and bound along the entire length of the back side Cb by the folding plate clamping roller 191, the folding plate clamping roller 191 moves away from the sheet bundle Pb in the central folding discharge direction.

[0225] Figure 23A This is a schematic diagram of the sheet bundle Pb before the central crimping (including central folding and crimping) in the eighth variation.

[0226] Figure 23A Corresponding to Figure 6A The state. For example... Figure 23A As shown, at the crease of booklet Bk, an adhesive toner image tn is formed using an image forming apparatus 101 and then bonded. The adhesive toner image corresponds to the adhesive medium formed at the bonding portion of the sheet bundle Pb. Furthermore, a detailed method for the image forming apparatus 101 to form the adhesive toner image tn is, for example, a known technique disclosed in Japanese Patent Application Publication No. 2004-209858.

[0227] Figure 23B This is a schematic diagram of the booklet Bk formed by central folding and crimping in the eighth variation.

[0228] like Figure 23B As shown, a square ridge is formed on the back Cb of booklet Bk. Furthermore, a toner image "tn" for bonding is heated again on the back Cb. Thus, the toner image "tn" on the overlapping portions of multiple sheets P forming the square ridge (back Cb) exerts adhesive force, allowing for toner-pressed binding.

[0229] Ninth variation Next, refer to Figure 24A and Figure 24B The ninth variation of the crimping central binding device will be described.

[0230] The difference between the crimping central binder of the ninth modification and the crimping central binder of the eighth modification is that, instead of the folding plate engaging roller 134, which is a roller member that rotates and moves in the main scanning direction, the folding plate engaging member has a folding plate engaging mold 192, which is a plate member that extends in the width direction. Furthermore, the same reference numerals are used to denote the common constituent elements of this modification and the first embodiment, and detailed descriptions are omitted.

[0231] Figure 24A and Figure 24B This is a cross-sectional view showing the operation of the crimping central binding device in the ninth variation.

[0232] Figure 24A and Figure 24BThis is a cross-sectional view of the crimping central binder, taken from the side of the sheet conveying direction, at the center line of the central fold, i.e., the center position of the thickness of the folded plate 132.

[0233] Figure 24A Corresponding to Figure 6C The folding plate 132 presses the sheet bundle Pb to a position beyond the clamping position of the folding roller pair 133. The folding plate clamping mold 192 is in the standby position (HP position), separating from the sheet bundle Pb in the central folding discharge direction.

[0234] Folding plate mold closing 192 moves the folding plate mold closing motor 182 (see reference) Figure 10 Move towards the folding plate side.

[0235] Figure 24B Corresponding to Figure 6D The sheet bundle Pb is pressed against the folding plate 132 by the folding plate clamping mold 192. The heated pressing part 192a of the folding plate clamping roller is pressed against the pressing surface of the folding plate 132, thereby heating and pressurizing the clamped sheet bundle Pb. As a result, the back of the sheet bundle Pb is crimped and secured.

[0236] Second Embodiment Next, a second embodiment of the image forming system of the present invention will be described.

[0237] Figure 25 This is a diagram illustrating the overall structure of an image forming system 200, such as an MFP (Multifunction Printer), as a second embodiment of an image forming system.

[0238] The image forming system 200 has the function of forming an image on a sheet P (medium) and performing post-processing on the sheet P with the image formed. For example... Figure 25 As shown, the image forming system 200 includes an image forming apparatus 201 and a post-processing apparatus 210. The post-processing apparatus 210 is a console-type device arranged adjacent to the image forming apparatus.

[0239] Image forming apparatus 201 forms an image on sheet P and discharges the image-formed sheet P to post-processing apparatus 210. Image forming apparatus 201 includes a tray, a conveyor, and an image forming device. Sheet P is stored in the tray. The conveyor transports the sheet P stored in the tray. The image forming device forms an image on the sheet P transported by the conveyor. The image forming device can be an inkjet image forming apparatus that uses ink to form an image, or an electrophotographic image forming apparatus that uses toners to form an image. Image forming apparatus 201 includes an operation panel 202 and a controller 203 that controls the operation of image forming apparatus 201. The operation panel 202 has the same configuration as operation panel 102; therefore, a detailed description of operation panel 202 is omitted. Similarly, the controller 203 has the same configuration as controller 103; therefore, a detailed description of controller 203 is omitted. Any configuration of image forming apparatus 201 other than the above-described configuration is known; therefore, a detailed description of image forming apparatus 201 is omitted.

[0240] Figure 26 This is a diagram showing the internal structure of the post-processing device 210 in the second embodiment.

[0241] The post-processing apparatus 210 performs post-processing on the sheet P on which the image has been formed by the image forming apparatus 201. In this embodiment, the post-processing is a binding process where the sheet P with the formed image is bound as a bundle of sheets P. More specifically, the binding process in this embodiment includes so-called "crimping binding" and "stitching binding." Crimping binding is a process of applying pressure to the sheet bundle Pb at the crimping binding position to deform it, while stitching binding is a process of binding the sheet bundle Pb with staples. Crimping binding includes end binding and center binding. End binding is a process of binding the ends of the sheet bundle Pb, and center binding is a process of binding the central portion of the sheet bundle Pb.

[0242] The same reference numerals are used to mark the common components of the crimping central binding device in this embodiment and the first embodiment, and detailed descriptions are omitted.

[0243] Crimping Central Binding like Figure 26 As shown, the post-processing device 210 includes a folding plate 232, a pair of folding rollers 233, a folding plate engaging roller 234, a central folding booklet discharge roller pair 235, and a central folding booklet discharge tray 236.

[0244] The conveyor rollers place the sheet P on the central binding inner tray 237 and turn the sheet P on the central binding inner tray 237 toward the movable end baffle 238 for conveying.

[0245] Multiple sheets P, fed sequentially, are temporarily placed on the central binding inner tray 237. A movable end baffle 238 can move along the central binding inner tray 237 in the conveying direction of the sheets P. The movable end baffle 238 aligns the sheets P according to their dimensions, such that the folding plate 232 is aligned with the center position of the sheet's conveying length. Side baffles align the sheets P or sheet bundles Pb placed on the central binding inner tray 237 in the main scanning direction (width direction). The crimping central binder performs central binding on the sheet bundles Pb aligned by the movable end baffle 238 and the side baffles. The centrally bound sheet bundles Pb are discharged from the central folding booklet discharge roller pair 235 and placed on the central folding booklet discharge tray 236.

[0246] The embodiments disclosed herein are not limited to the above-described embodiments and variations. Based on the teachings, many additional modifications and variations are possible. The technical content contained in the technical concept recited in the claims is included within the technical scope of the claims. The above-described embodiments and variations are examples, and those skilled in the art can make various modifications and alterations based on these examples. Such modifications and alterations are included within the technical scope of the claims.

[0247] The aspects of this disclosure are as follows: First aspect In a first aspect, a sheet processing apparatus includes a central folder and a back-crimping stapler, the back-crimping stapler including a back-forming processing unit and a crimping and binding processing unit. The central folder performs a central fold on a bundle of sheets comprising multiple sheets. The back-crimping stapler forms a back on the centrally folded bundle of sheets and performs crimping and binding on the centrally folded bundle of sheets. The back-forming processing unit forms a back on the centrally folded bundle of sheets. The crimping and binding processing unit performs crimping and binding processing on the centrally folded bundle of sheets.

[0248] Second aspect In a second aspect, according to the sheet processing apparatus of the first aspect, the central folder includes: a folding plate for guiding a portion of the sheet bundle in a predetermined direction; and a pair of folding rollers for clamping the sheet bundle guided by the folding plate, causing the sheet bundle to advance in the predetermined direction.

[0249] Third aspect In a third aspect, according to the sheet processing apparatus of the first aspect, the back-pressing stapler includes: the folding plate; and a folding plate engaging member that engages with the folding plate via the sheet bundle.

[0250] Fourth aspect In the fourth aspect, according to the sheet processing apparatus of the third aspect, the folding plate engaging member is biased toward the folding plate, the folding plate engaging member clamps the back of the sheet bundle between itself and the folding plate and presses the back of the sheet bundle.

[0251] Fifth aspect In the fifth aspect, according to the sheet processing apparatus of the fourth aspect, the folding plate engaging member includes a roller rotatable about an axis, causing the folding plate engaging member to reciprocate in the longitudinal direction of the back side, performing the back side forming process of the sheet bundle forming the back side and the crimping and binding process.

[0252] Sixth aspect In the sixth aspect, according to the sheet processing apparatus of any one of the third to fifth aspects, the folding plate has concave and convex folding plate pressing teeth on the surface facing the folding plate engaging member, and the folding plate engaging member has concave and convex engaging pressing teeth that engage with the folding plate pressing teeth.

[0253] Seventh aspect In the seventh aspect, according to the sheet processing apparatus of any one of the third to sixth aspects, the folding plate engaging member moves in the longitudinal direction of the back side of the sheet bundle while performing the back forming process of forming the back side of the sheet bundle and the crimping assembly.

[0254] Eighth aspect In the eighth aspect, according to the sheet processing apparatus of the sixth or seventh aspect, the folding plate has a set of concave and convex folding plate pressing teeth on the surface opposite to the folding plate engaging member. The folding plate engaging member has a set of engaging pressing teeth, which discontinuously has a plurality of discontinuous protrusions and concave portions for engaging with the at least one set of folding plate pressing teeth. The folding plate moves toward the folding plate engaging member to perform the pressing and fastening.

[0255] Ninth aspect In the ninth aspect, according to the sheet processing apparatus of the third aspect, the folding plate engaging member includes a flat plate facing the folding plate, the flat plate moving toward the folding plate to perform the crimping.

[0256] Tenth aspect In the tenth aspect, according to the sheet processing apparatus of any one of the first to ninth aspects, the back-pressing stapler includes: a first roller having teeth; and a second roller engaging with the first roller via the sheet bundle.

[0257] Eleventh aspect In the eleventh aspect, according to the sheet processing apparatus of the sixth aspect, the folding plate engaging component includes: a cylindrical portion having engaging pressing teeth; and flange portions disposed at both ends of the cylindrical portion, each having a diameter larger than the diameter of the cylindrical portion.

[0258] Twelfth aspect In the twelfth aspect, according to the sheet processing apparatus of the eleventh aspect, the flange portions engage with each other across the opposing surfaces of the folding plate engaging members.

[0259] Thirteenth aspect In the thirteenth aspect, according to the sheet processing apparatus of any one of the first to twelfth aspects, the back-pressing stapler is configured to form two parallel creases along the length of the back side of the sheet bundle.

[0260] Fourteenth aspect In the fourteenth aspect, according to the sheet processing apparatus of the thirteenth aspect, the back side of the sheet bundle forms a generally flat portion between two mutually parallel creases.

[0261] Fifteenth aspect In the fifteenth aspect, according to the sheet processing apparatus of the sixth aspect, the engaging crimping teeth have a plurality of continuous protrusions and recesses repeatedly formed in the longitudinal direction relative to the back of the sheet bundle.

[0262] Sixteenth aspect In the sixteenth aspect, according to the sheet processing apparatus of the sixth aspect, the engaging crimping teeth have a plurality of continuous protrusions and recesses that are inclined in the longitudinal direction relative to the back of the sheet bundle and are repeatedly formed.

[0263] Seventeenth aspect In the seventeenth aspect, according to the sheet processing apparatus of the sixth aspect, the folding plate has folding pressing teeth on a portion of the surface facing the folding plate engaging member, the folding pressing teeth having a plurality of protrusions and recesses at multiple locations, and the folding plate has flat portions on other portions of the surface facing the folding plate engaging member that are different from the aforementioned portion.

[0264] Eighteenth aspect In the eighteenth aspect, an image forming system includes: an image forming apparatus for forming an image on a sheet; and a sheet processing apparatus according to any one of the first to seventeenth aspects, disposed within the body space of the image forming apparatus.

[0265] Nineteenth aspect In the nineteenth aspect, an image forming system includes: an image forming apparatus for forming an image on a sheet; and a sheet processing apparatus according to any one of the first to seventeenth aspects for performing a predetermined processing on the sheet on which the image formed by the image forming apparatus has formed.

[0266] Twentieth aspect In a twentieth aspect, a sheet processing method is a sheet processing method performed in a sheet processing apparatus, the sheet processing apparatus comprising: a central folder that performs a central fold on a sheet bundle containing multiple sheets; and a back crimping device that forms a back on the centrally folded sheet bundle and performs crimping on the centrally folded sheet bundle. The sheet processing method forms a back on the centrally folded sheet bundle by a back forming processing unit and performs crimping on the centrally folded sheet bundle.

[0267] Twenty-first aspect In the twenty-first aspect, according to the sheet processing apparatus of the second aspect, the back-pressing stapler further includes a folding plate engaging heater, the folding plate engaging heater comprising a heater for heating the sheet bundle and pressing the sheet bundle against the folding plate. The folding plate engaging heater heats the adhesive medium in the adhesive portion of the sheet bundle.

[0268] Twenty-second aspect In the twenty-second aspect, according to the sheet processing apparatus of the twenty-first aspect, the adhesive medium includes a toner image as a visible image.

[0269] Twenty-third aspect In the twenty-third aspect, according to the sheet processing apparatus of the twenty-first aspect, the folding plate engaging heater includes a roller rotatable about an axis, the folding plate engaging heater reciprocating in the longitudinal direction of the back of the sheet bundle, performing a back forming process in which the back of the sheet bundle is formed and the crimping device.

[0270] Twenty-fourth aspect In the twenty-fourth aspect, according to the sheet processing apparatus of the twenty-first aspect, the folding plate engaging heater includes a flat plate facing the folding plate, the flat plate moving toward the folding plate to perform the crimping.

[0271] Twenty-fifth aspect In the twenty-fifth aspect, an image forming system includes: an image forming apparatus for forming an image on a sheet; and a sheet processing apparatus according to any one of the twenty-first to twenty-fourth aspects for performing a predetermined processing on the sheet on which the image is formed by the image forming apparatus.

[0272] The above embodiments are illustrative and do not limit the invention. Therefore, many additional modifications and variations are possible based on the above teachings. For example, within the scope of the invention, elements and / or features of different illustrative embodiments can be combined with and / or substituted for each other.

[0273] This invention can be implemented in any convenient form, such as using dedicated hardware or a combination of dedicated hardware and software. This disclosure can be implemented as computer software applied by one or more networked processing devices. The processing facility can be any suitably programmed device, such as a general-purpose computer, a personal digital assistant, a mobile phone (e.g., a WAP or 3G compatible phone), etc. Because this disclosure can be applied as software, each aspect of this disclosure includes computer software executable on a programmable device. The computer software can be provided to a programmable device using any conventional carrier medium (carrier method). The carrier medium is capable of handling transient carrier methods, such as electrical, optical, microwave, acoustic, or radio frequency signals carrying computer code. An example of such a transient method is TCP / IP signals carrying computer code over an IP network (e.g., the Internet). The carrier medium can also include storage media for storing processor-readable code, such as floppy disks, hard disks, CD-ROMs, magnetic tape devices, or solid-state storage devices.

[0274] The functionality of embodiments of this disclosure can be implemented using circuitry or processing circuitry, including general-purpose processors, special-purpose processors, integrated circuits, application-specific integrated circuits (ASICs), digital signal processors (DSPs), field-programmable gate arrays (FPGAs), conventional circuitry, and / or combinations thereof configured or programmed to perform the disclosed functions. Processors are processing circuitry or circuits that include transistors and other circuitry. In this disclosure, circuitry, units, or devices are hardware that performs or is programmed to perform the functions. The hardware can be any hardware known in this disclosure or otherwise, programmed or configured to perform the functions. When the hardware can be considered a circuit-type processor, the circuitry, device, or unit is a combination of hardware and software, with the software used to configure the hardware and / or processor.

[0275] This patent application is based on and claims priority to Japanese Patent Application No. 2023-117060 filed with the Japan Patent Office on July 18, 2023, and Japanese Patent Application No. 2024-062264 filed with the Japan Patent Office on April 8, 2024, the entire disclosure of which is incorporated herein by reference.

[0276] List of reference numerals 19: Controller 100: Image Forming System 101: Image forming apparatus 102: Control Panel 110: Post-processing device 117: Needle tip binding processing unit 118: Crimping End Mounting Processing Unit 119: Discharge roller pair 120: Discharge tray 131: Movable end baffle 132: Folding board 132a: Folded crimping teeth 132b: Crimping roller guide rail 133: Folding roller pair 134: Folding plate clamping roller 134a: Engaging crimping teeth 134b: Flange portion 135: Central folding booklet discharge roller pair 136: Central folding booklet output tray 141: Folding plate moving motor 142: Folding roller to rotating motor 143: Folding roller to moving motor 144: Folding rollers pressurizing components 145: Folding plate card closing roller scanning motor 146: Clamping roller guide rail 147: Folding plate clamping roller pressure component 177: Upper pressure teeth 178: Downward-pressing contact teeth 181: Folding board mold assembly 181a: Molded joint 181b: Flange portion 182: Folding plate mold closing moving motor 183: Folding plate clamping and pressing component 184: Folding plate 184a: Teeth 185: Folding plate mold assembly 185a: Crimping part 186: Folding plate mold assembly 186a: Crimping part 187: Crimping Roller 187a: Teeth 188: Pressing roller moving motor 191: Folding plate clamping roller 191a: Heated pressing part 191b: Flange portion 192: Folding board mold assembly 192a: Heated pressing part

Claims

1. A sheet processing apparatus, comprising: A central folder that performs central folding on a bundle of sheets comprising multiple sheets; and Back-pressure binding device, The back-pressure binding device includes: A back forming device that forms a back on the sheet bundle to which the central fold is applied; and A crimping device performs crimping on the bundle of sheets that has been subjected to the central fold.

2. The sheet processing apparatus according to claim 1, in, The central folding mechanism includes: A folding plate guides a portion of the sheet bundle in a predetermined direction; and Folding roller pair, The folding roller pair is used for: Clamping the bundle of sheets guided by the folding plate; and The sheet bundle is advanced in the specified direction.

3. The sheet processing apparatus according to claim 2, in, The back-pressure binding device includes: The folded plate; and The folding plate engaging component engages with the folding plate via the sheet bundle.

4. The sheet processing apparatus according to claim 3, in, The folding plate engaging component is biased toward the folding plate, and The folding plate engaging component clamps the back of the sheet bundle between itself and the folding plate and presses the back of the sheet bundle.

5. The sheet processing apparatus according to claim 4, further comprising a controller configured to control the central folder and the back-pressing stapler. in, The folding plate engaging component includes a roller rotatable about an axis, and The controller is further configured to cause the folding plate to engage the components: Reciprocating along the length direction of the back; and Perform the back-side forming process and the crimping and binding process on the sheet bundle to form the back side.

6. The sheet processing apparatus according to any one of claims 3 to 5, in, The folding plate has a first tooth on the surface facing the folding plate engaging component. The first tooth has multiple protrusions and recesses. The folding plate engaging component has a second tooth that engages with the first tooth, and the second tooth has multiple protrusions and recesses.

7. The sheet processing apparatus according to any one of claims 3 to 6, in, The folding plate engaging component moves along the length of the back of the sheet bundle while performing a back forming process and a crimping assembly on the sheet bundle to form the back.

8. The sheet processing apparatus according to claim 6 or 7, in, The folding plate has at least one first set of teeth on the surface opposite to the folding plate engaging component. The first set of teeth has multiple protrusions and recesses. The folding plate engaging component has at least one second set of teeth, the second set of teeth having discontinuously distributed protrusions and recesses to engage with the at least one folding plate pressing tooth set, and The folding plate moves toward the folding plate engaging component to perform the crimping and fastening.

9. The sheet processing apparatus according to claim 3, in, The folding plate engaging component includes a flat plate facing the folding plate, and The flat plate moves toward the folding plate to perform the crimping and binding.

10. The sheet processing apparatus according to any one of claims 1 to 9, in, The back-pressure binding device includes: The first roller with teeth; and The second roller engages with the first roller via the sheet bundle.

11. The sheet processing apparatus according to claim 6, in, The folding plate engaging component includes: The cylindrical portion has the second tooth; and Flange portions are disposed at both ends of the cylindrical portion, and each has a diameter larger than the diameter of the cylindrical portion.

12. The sheet processing apparatus according to claim 11, in, The flange portion abuts against the sheet bundle held between the folding plate and the folding plate engaging member from opposite sides of the cylindrical portion.

13. The sheet processing apparatus according to any one of claims 1 to 12, in, The back-pressing stapler is configured to form two parallel creases along the length of the back of the sheet bundle.

14. The sheet processing apparatus according to claim 13, in, The back of the sheet bundle forms a generally flat portion between the two parallel creases.

15. The sheet processing apparatus according to claim 6, in, The engaging crimping teeth have a plurality of continuous protrusions and recesses that are repeatedly formed in the longitudinal direction relative to the back of the sheet bundle.

16. The sheet processing apparatus according to claim 6, in, The engaging crimping teeth have a plurality of continuous protrusions and recesses that are inclined in the longitudinal direction relative to the back of the sheet bundle and are repeatedly formed.

17. The sheet processing apparatus according to claim 6, in, The folding plate has folding pressing teeth on a first portion of the surface facing the folding plate engaging component. The folding pressing teeth have multiple protrusions and recesses at multiple locations. The folding plate has a flat portion on the surface facing the engaging member, in a second portion that is different from the first portion.

18. An image forming system, comprising: Image forming apparatus for forming an image on a sheet; and The sheet processing apparatus according to any one of claims 1 to 17 is disposed in the discharge space within the image forming apparatus.

19. An image forming system, comprising: Image forming apparatus for forming an image on a sheet; and The sheet processing apparatus according to any one of claims 1 to 17 performs a prescribed process on a sheet on which an image has been formed by the image forming apparatus.

20. A sheet processing method, comprising: Perform a central fold on a bundle of sheets containing multiple sheets; A back is formed on the sheet bundle subjected to the central fold; and The bundle of sheets subjected to the central fold is crimped.

21. The sheet processing apparatus according to claim 2, in, The back-press binding device further includes a folding plate engagement heater, the folding plate engagement heater comprising a heater for heating the sheet bundle and pressing the sheet bundle against the folding plate, and The folding plate engages with the heater to heat the adhesive medium in the bonding portion of the sheet bundle.

22. The sheet processing apparatus according to claim 21, in, The adhesive medium includes a toner image as a visible image.

23. The sheet processing apparatus according to claim 21, in, The folding plate engaging heater includes a roller rotatable about an axis, and The folding plate engaging heater reciprocates along the length of the back of the sheet bundle, performing a back forming process and a crimping assembly on the sheet bundle to form the back.

24. The sheet processing apparatus according to claim 21, in, The folding plate engaging heater includes a flat plate facing the folding plate, and The flat plate moves toward the folding plate to perform the crimping and binding.

25. An image forming system, comprising: Image forming apparatus for forming an image on a sheet; and The sheet processing apparatus according to any one of claims 21 to 24 performs a prescribed process on a sheet on which an image has been formed by the image forming apparatus.

Images