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

Abstract

To provide a sheet processing device capable of forming a crimped bound booklet that is easy to spread without causing peeling off of crimping binding by turning folded pages.SOLUTION: A sheet processing device includes: folding means that performs folding processing on a sheet bundle formed of a plurality of sheet materials; and back part crimping binding means that forms a back part in the sheet bundle that has been subjected to the folding processing and performs crimping binding processing on the back part. The back part crimping binding means includes: a back part formation part that forms the back part in the sheet bundle that has been subjected to folding processing; and a crimping binding part that performs crimping binding on the sheet bundle that has been subjected to folding processing.SELECTED DRAWING: Figure 6

Description

[Technical Field]

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

[0002] Sheet processing devices are known that can perform a "binding process" to bind a sheet bundle formed by bundling sheet-like recording media. There are several types of binding processes that can be performed by sheet processing devices. For example, an "end binding process" that binds the ends of the sheet bundle, and a "saddle stitching process" that folds the sheet bundle in half and stitches the sheets near the fold position, etc., are known. Saddle stitching is a binding method that is primarily used when creating books such as booklets.

[0003] In order to provide a saddle-stitched booklet with aligned edges without edge trimming, a saddle-stitching binding device has been disclosed that crimps and binds both sides away from the center fold position, and then performs a square spine fold to form a square spine in the booklet (see, for example, Patent Document 1).

[0004] Furthermore, for the purpose of providing a pressure saddle stitching device, a saddle stitching bookbinding device that pressure binds at a position away from the folding position has been disclosed (see, for example, Patent Document 2).

[0005] Also disclosed is a staple saddle stitching device that folds the spine of a booklet into a square spine, and that has a groove in the stopper plate for the staple to engage with, in order to prevent the staple from shifting from the center of the spine and provide a booklet that looks good (see, for example, Patent Document 3).

[0006] Furthermore, a pressure saddle stitch bookbinding device has been disclosed that performs a center folding process after pressure binding the center of a booklet, with the aim of providing a staple-free bound booklet (see, for example, Patent Document 4).

[0007] In addition, a bookbinding device has been disclosed that uses an electrophotographic image forming device to form an adhesive toner layer on the edges of sheets, and then heats and pressurizes this toner layer to bond the sheets together (see, for example, Patent Document 5). Summary of the Invention [Problem to be solved by the invention]

[0008] Patent Documents 1 to 5 disclose conventional techniques for pressure-bonding saddle stitching and folding the spine of a booklet. However, when these conventional techniques are used to form a saddle-stitched booklet, there are issues such as the feeling of discomfort in the spread when turning the pages, or the pressure-bonded portion being subjected to stress when turning the pages, causing the pressure-bonded portion to peel off. In other words, the conventional techniques have issues with the quality and binding strength of the finished product when pressure-bonding is used for saddle stitching.

[0009] An object of the present invention is to provide a sheet processing apparatus capable of forming a press-stitched saddle-stitched booklet that can be easily opened without the press-stitched binding coming off when the pages are turned over. [Means for solving the problem]

[0010] In order to solve the above problem, one aspect of the present invention is a method for manufacturing a sheet-like article, comprising: medium and a pressure binding means for performing pressure binding on the sheet bundle that has been subjected to the center folding. A sheet processing apparatus , the above Center-folding method The sheet bundle a folding plate member that guides the sheet bundle in a predetermined direction, and a pair of folding rollers that convey the sheet bundle guided by the folding plate member in the predetermined direction while sandwiching the sheet bundle, and The method is characterized in that the pressure binding process is performed. [Effects of the Invention]

[0011] According to the present invention, a press-stitched saddle-stitched booklet can be formed that is easy to open and that does not come apart when pages are turned over. [Brief explanation of the drawings]

[0012] [Figure 1] 1 is a diagram showing the overall configuration of an image forming system according to a first embodiment. [Figure 2] FIG. 2 is a diagram showing the internal structure of the post-processing device according to the first embodiment. [Figure 3] FIG. 4 is a schematic diagram of the edge binding processing section as seen from the discharge port side. [Figure 4] 5A and 5B are schematic diagrams illustrating the configuration of crimping teeth of the crimp-end binding processing section. [Figure 5] FIG. 4 is a diagram showing movement positions of an edge binding processing unit. [Figure 6] 5A and 5B are schematic diagrams illustrating the operation of the pressure-bonding saddle stitching processing section. [Figure 7] 10A and 10B are cross-sectional views showing the operation of the pressure saddle stitching processing section. [Figure 8] FIG. 10 is a schematic diagram showing the pressing state of the pressure binding saddle stitching processing section. [Figure 9] 1 is a schematic diagram of a pressure-bonded saddle-stitched booklet bound in the first embodiment. [Figure 10] FIG. 2 is a hardware configuration diagram of a control unit of the post-processing device. [Figure 11] FIG. 10 is a schematic diagram showing a first modified example of the pressure-bonding saddle stitching processing section. [Figure 12] BB cross-sectional view showing the operation of the first modified example of the pressure-bonding saddle stitching processing section. FIG. [Figure 13] 10A and 10B are cross-sectional views showing the operation of the pressure-bonding saddle stitching processing unit according to the second modification; [Figure 14] 10A and 10B are cross-sectional views showing the operation of the pressure-bonding saddle stitching processing unit according to the third modified example. [Figure 15] 10A and 10B are cross-sectional views showing the operation of the fourth modified example of the pressure-bonding saddle stitching processing section. [Figure 16] 13A and 13B are cross-sectional views showing the operation of the crimping saddle stitching processing unit according to the fifth modified example. [Figure 17] Schematic diagram of a laminated saddle-stitched booklet bound using variant example 5. [Figure 18] FIG. 13 is a schematic diagram showing a sixth modified example of the pressure-bonding saddle stitching processing section. [Figure 19] Schematic diagram of a laminated saddle-stitched booklet bound using variant example 6. [Figure 20] 13A and 13B are cross-sectional views showing the operation of the seventh modified example of the pressure-bonding saddle stitching processing section. [Figure 21] FIG. 13 is a schematic diagram showing a modified example 8 of the pressure-bonding saddle stitching processing section. [Figure 22] 13A and 13B are cross-sectional views showing the operation of the pressure-bonding saddle stitching processing unit according to Modification 8. [Figure 23] Schematic diagram of a laminated saddle-stitched booklet bound using variant example 8. [Figure 24] 13A and 13B are cross-sectional views showing the operation of a ninth modified example of the pressure-bonding saddle stitching processing section. [Figure 25] FIG. 10 is a diagram showing the overall configuration of an image forming system according to a second embodiment. [Figure 26] FIG. 10 is a diagram showing the internal structure of a post-processing device according to a second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0013] [First embodiment] A first embodiment of a sheet processing apparatus, a sheet processing method, and an image forming system according to the present invention will be described below with reference to the drawings. FIG. 1 is a diagram showing the overall configuration of an image forming system 100 as an embodiment of the image forming system. As shown in FIG. 1, the image forming system 100 includes an image forming apparatus 101 that forms an image on paper P, which corresponds to an example of a sheet material as a sheet-like medium, and a post-processing apparatus 110 that performs predetermined post-processing on the paper P on which the image has been formed. The image forming system 100 corresponds to an embodiment of an internal paper discharge type image forming system in which the post-processing apparatus 110 is arranged in an internal paper discharge space (internal paper discharge section) of the image forming apparatus 101.

[0014] The image forming apparatus 101 forms an image on a sheet P and discharges the sheet P with the image formed thereon to a post-processing device 110. The image forming apparatus 101 includes a tray for storing the sheet P, a transport unit for transporting the sheet P stored in the tray, and an image forming unit for forming an image on the sheet P transported by the transport unit. The image forming unit is capable of performing a known image forming method. For example, it may be an inkjet method in which liquid ink is ejected and adhered to the sheet P to form an image, or an electrophotographic method in which an image is formed using toner. 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 those known in the art, and therefore detailed description thereof will be omitted.

[0015] Next, a post-processing device 110 as an embodiment of a sheet processing device according to the present invention will be described in detail. Fig. 2 is a diagram showing the internal structure of the post-processing device 110 according to the first embodiment. The post-processing device 110 has a function of performing post-processing on sheets P on which images have been formed by the image forming device 101, and receives sheets P on which images have been formed from an inlet 1100 that receives sheets P from the image forming device 101, and performs binding processing to bind a sheet bundle Pb formed by bundling multiple sheets together.

[0016] More specifically, the binding process according to this embodiment includes "pressure binding," which binds a paper stack Pb formed by stacking multiple sheets of paper P by applying pressure to the binding position to deform the sheets, and "staple binding," which binds the paper stack Pb using staples at the binding position. Furthermore, pressure binding includes an end binding process that binds the ends of the paper stack Pb, and a saddle binding process that binds the center of the paper stack Pb.

[0017] The post-processing device 110 includes a first conveying roller pair 111 and a second conveying roller pair 112 for conveying the paper P carried in through the carry-in entrance 1100 along a conveying path. Inside the post-processing device 110, the first conveying roller pair 111 and the second conveying roller pair 112 convey the paper P supplied from the image forming device 101 along the first conveying path Ph1.

[0018] The first transport path Ph1 is a path extending from an entrance 1100 through which the paper P is transported from the image forming apparatus 101 to the internal tray 114.

[0019] [Edge Binding Processing] The post-processing device 110 includes a return conveying roller 113, an internal tray 114, an end fence 115, a side fence 116 (not shown), a staple end binding processing unit 117 and a crimp end binding processing unit 118 as end binding processing units, a pair of discharge rollers 119, and a discharge tray 120.

[0020] The return transport rollers 113 constitute transport rollers for transporting the paper P that has passed through the second transport roller pair 112 toward the end fence 115 while placing the paper P on the internal tray 114. The transport direction of the return transport rollers 113 is different from the transport direction of the first transport roller pair 111 and the second transport roller pair 112. In other words, the transport direction of the return transport rollers 113 is a direction that switches back from the transport direction of the first transport roller pair 111 and the second transport roller pair 112, and corresponds to the opposite direction to the direction of transport by the first transport roller pair 111 and the second transport roller pair 112. Therefore, transport by the return transport rollers 113 is referred to as switchback transport.

[0021] The first conveying roller pair 111, the second conveying roller pair 112, and the return conveying roller 113 convey the paper P as a sheet material to the internal tray 114 for binding processing. The first conveying roller pair 111, the second conveying roller pair 112, the return conveying roller 113, and the first conveying path Ph1 constitute a conveying means for conveying the paper P to the internal tray 114 as a stacking means.

[0022] The internal tray 114 corresponds to a stacking means for temporarily placing multiple sheets of paper P that are sequentially transported. The sheets of paper P placed on the internal tray 114 are switchback-transported by the return transport roller 113 to a position where they collide with the end fence 115. The end fence 115 constitutes an alignment member for aligning the ends of the sheets of paper P in the transport direction during switchback transport. The end fence 115 aligns the ends of the multiple sheets of paper P stacked on the internal tray 114, forming a paper stack Pb.

[0023] 2, a pair of side fences 116 are arranged in the width direction of the internal tray 114 (width direction of the paper P). In other words, in the direction perpendicular to the conveyance direction of the paper P by switchback conveyance, i.e., the conveyance direction when the paper P is conveyed to the end fence 115, a pair of side fences 116 are arranged on both side ends of the internal tray 114.

[0024] The side fences 116 perform a "jogging motion" in which they repeatedly come into contact with and separate from the widthwise edges of the multiple sheets of paper P loaded on the internal tray 114. This jogging motion also aligns the widthwise edges of the multiple sheets of paper P. In other words, the side fences 116 constitute alignment members for aligning both widthwise edges (both edges perpendicular to the conveying direction) of the sheets of paper P loaded on the internal tray 114.

[0025] The staple end binding processing unit 117 and the pressure end binding processing unit 118 as end binding processing units perform binding processing on the end of the sheet bundle Pb aligned by the end fence 115 and the side fence 116.

[0026] After the binding process is performed, the return conveyance rollers 113 come into contact with the sheet stack Pb placed on the internal tray 114 and rotate. The rotation direction at this time is opposite to the rotation direction when the switchback conveyance is performed. Therefore, the return conveyance rollers 113 discharge the sheet stack Pb that has been edge-stitched from the first discharge opening 1101 toward the discharge tray 120.

[0027] There are several types of "end binding processes" that the staple end binding processing unit 117 and the crimp end binding processing unit 118 perform on the paper stack Pb. For example, these include a "parallel binding process" that performs binding along one side of the paper stack Pb that is parallel to the main scanning direction (see FIG. 3), a "diagonal binding process" that performs binding at a corner of the paper stack Pb, and a "two-point binding process" that performs binding at multiple points spaced apart in the width direction along one side of the paper stack Pb that is parallel to the conveyance direction.

[0028] 3 is a schematic diagram of the edge binding processing unit 1110, including the staple-end binding processing unit 117 and the crimp-end binding processing unit 118, as seen from the first discharge opening 1101 in the direction of the end fence 115. As shown in FIG. 3, the edge binding processing unit 1110 is attached to an edge binding processing unit base member 151 with the staple-end binding processing unit 117 and the crimp-end binding processing unit 118 spaced apart from each other in the main scanning direction, and is supported by a guide shaft 152 extending in the main scanning direction via this edge binding processing unit base member 151. Therefore, both the staple-end binding processing unit 117 and the crimp-end binding processing unit 118 are supported so as to be movable along the guide shaft 152.

[0029] The staple end binding processing unit 117 includes a staple end binding main scanning movement motor 161, a drive force transmission mechanism 162, and a staple end binding processing unit base member 163, and is configured to be movable in the main scanning direction along the guide shaft 152 by the drive force of the staple end binding main scanning movement motor 161.

[0030] The staple-end binding main scanning movement motor 161 generates a driving force for moving the staple-end binding processing unit 117. The driving force transmission mechanism 162 transmits the driving force of the staple-end binding main scanning movement motor 161 to a staple-end binding processing unit base member 163 via a pulley and a timing belt. This makes it possible for the staple-end binding processing unit 117 to move in the main scanning direction along the guide shaft 152.

[0031] Furthermore, the staple-end binding processing unit 117 includes a staple-end binding posture rotation motor 164, and rotates relative to the staple-end binding processing unit base member 163 around a staple-end binding rotation shaft 165 as the center of rotation.

[0032] The staple-end binding processing unit 117 is also provided with a staple-end binding clinch motor 166, and performs the staple binding process by opening and closing a staple clincher 167 to pierce the paper stack Pb with a staple and then clinching the paper stack Pb.

[0033] The crimped end binding processing unit 118 includes a crimped end binding main scanning movement motor 171, a drive force transmission mechanism 172, and a crimped end binding processing unit base member 173, and is configured to be movable in the main scanning direction along the guide shaft 152 by the drive force of the crimped end binding main scanning movement motor 171.

[0034] The crimp-end binding main scanning movement motor 171 generates a driving force for moving the crimp-end binding processing unit 118. The driving force transmission mechanism 172 transmits the driving force of the crimp-end binding main scanning movement motor 171 to the crimp-end binding processing unit base member 173 via pulleys and a timing belt. This allows the crimp-end binding processing unit 118 to move in the main scanning direction along the guide shaft 152.

[0035] Furthermore, the crimp-end binding processing section 118 includes a crimp-end binding posture rotation motor 174, and rotates relative to the crimp-end binding processing section base member 173 around a crimp binding rotation shaft 175 as the center of rotation.

[0036] The crimp-end binding processing unit 118 also includes a crimp-end binding clinch motor 176, and the driving force of the crimp-end binding clinch motor 176 causes an "opening and closing operation" in which the upper crimping teeth 177 approach or move away from the lower crimping teeth 178. This opening and closing operation allows the end of the paper-sheet bundle Pb to be sandwiched between the uneven upper and lower crimping teeth 177 and 178, causing pressure deformation. This pressure deformation causes the fibers of the sheets P that make up the paper-sheet bundle Pb to become entangled, and a single paper-sheet bundle Pb made up of multiple sheets P is formed. This binding process using pressure deformation is referred to as "pressure binding."

[0037] FIG. 4 is a schematic diagram showing the configuration of upper and lower crimping teeth 177 and 178 as a crimping unit included in the crimp-end binding processing unit 118. As shown in FIG. 4, the crimping unit includes a pair of upper and lower crimping teeth 177 and 178. The upper and lower crimping teeth 177 and 178 are arranged to face each other in the thickness direction of the sheet stack Pb so as to be able to sandwich the sheet stack Pb placed on the internal tray 114. The upper and lower crimping teeth 177 and 178 are formed in an uneven shape with alternating concave and convex portions. Furthermore, the upper and lower crimping teeth 177 and 178 are formed with the concave and convex portions misaligned so as to mesh with each other. The crimping unit is configured so that the upper crimping teeth 177 open and close (contact and separation) with respect to the lower crimping teeth 178 by the driving force of a crimp-end binding clinch motor 176.

[0038] When the plurality of sheets P constituting the sheet bundle Pb are being supplied to the internal tray 114, the upper and lower pressure teeth 177 and 178 are spaced apart, as shown in FIG. 4A. Once all of the sheets P constituting the sheet bundle Pb have been placed on the internal tray 114 and a predetermined alignment operation (operation of aligning the edges) has been completed, the pressure-end binding processing unit 118 moves to the binding position, and the upper and lower pressure teeth 177 and 178 approach and mesh together, as shown in FIG. 4B. That is, the upper and lower pressure teeth 177 and 178 sandwich the predetermined binding position for the sheet bundle Pb, pressuring and deforming the sheet bundle Pb in the thickness direction. This causes the sheet bundle Pb placed on the internal tray 114 to be pressure-bound. The pressure-bound sheet bundle Pb is then discharged by the discharge roller pair 119 from the first discharge opening 1101 toward the discharge tray 120.

[0039] The crimp-end binding processing unit 118 only needs to perform the function of applying pressure to the sheet stack Pb and crimping a specific position, so it is sufficient if the upper and lower crimping teeth 177 and 178 can mesh and apply pressure when the sheet stack Pb is sandwiched between them and bound. Therefore, the configuration capable of closing the upper and lower crimping teeth 177 and 178 is not limited to the exemplary configuration disclosed in this embodiment. For example, a link mechanism-type crimping mechanism (such as that disclosed in Japanese Patent No. 6057167) that uses a drive source and a link mechanism that rotates forward or backward and performs the actions of moving the upper and lower crimping teeth 177 and 178 toward (crimping) and away from each other may be used. Alternatively, a linear-type crimping mechanism that linearly performs the actions of pressing and separating the upper and lower crimping teeth 177 and 178 from each other may be used.

[0040] 3, the crimping unit is provided with a binding tooth slide mechanism for moving the upper crimping teeth 177 and the lower crimping teeth 178 relative to the frame of the crimp-end binding processing unit 118. The binding tooth slide mechanism is composed of a binding tooth slide motor 179 and a drive transmission mechanism as a linear motion conversion mechanism such as a rack-and-pinion mechanism or a crankshaft mechanism that transmits the driving force of the binding tooth slide motor 179. When the driving force from the binding tooth slide motor 179 is transmitted to the upper crimping teeth 177 and the lower crimping teeth 178 by the drive transmission mechanism, the upper crimping teeth 177 and the lower crimping teeth 178 slide along their respective longitudinal directions (the longitudinal direction of the end-binding processing unit base member 151).

[0041] Here, the amount of slide movement of the upper crimping teeth 177 and the lower crimping teeth 178 is, for example, equal to the length of the crimp mark. The upper crimping teeth 177 and the lower crimping teeth 178 perform the crimp binding operation multiple times before and after the slide movement. In other words, when the length of the crimp mark by the upper crimping teeth 177 and the lower crimping teeth 178 is 10 mm, by also setting the amount of slide movement to 10 mm, the length of the crimp mark can be made 20 mm by combining the crimping operation before the slide movement (first hit) and the crimping operation after the slide movement (second hit), and the binding force is improved by approximately two times.

[0042] [Binding process overview] 5A and 5B are diagrams illustrating the positions of the staple-end binding processing unit 117 and the crimp-end binding processing unit 118 according to the process steps. FIG. 5A illustrates a standby state (standby state) for the binding process. As shown in FIG. 5A, in the standby state, the staple-end binding processing unit 117 is located at a staple-binding standby position HP1. The crimp-end binding processing unit 118 is located at a crimp-binding standby position HP2.

[0043] 5(b) and 5(c) illustrate an example of how the crimp-end binding processing unit 118 performs the diagonal binding process. As shown in Fig. 5(b), before the first sheet P1 of the sheet bundle Pb is supplied to the internal tray 114, the crimp-end binding processing unit 118 is moved in the main scanning direction and rotated diagonally so that the crimp-end binding processing unit 118 faces the first binding position B1. The movement and rotation of the crimp-end binding processing unit 118 are controlled by a controller 19 serving as a control means, which will be described later with reference to Fig. 10.

[0044] 5(c), the controller 19, with the crimp-end binding processing unit 118 positioned opposite the first binding position B1, executes a jogging operation each time a sheet P is transported to the internal tray 114. The jogging operation is executed by the controller 19 controlling the side fences 116 to slide in the width direction.

[0045] Next, in the state illustrated in FIG. 5(c), the controller 19 repeats the stacking and aligning operations of the sheets P until the number of sheets P for constituting the sheet bundle Pb reaches a predetermined number N.

[0046] Next, when the controller 19 detects that the number of sheets P placed on the internal tray 114 has reached a predetermined number N, it operates the crimp end binding processing unit 118 to perform a crimp binding operation on the first binding position B1 of the stack of sheets Pb placed on the internal tray 114.

[0047] Next, the controller 19 discharges the sheet bundle Pb that has been press-stitched at the first binding position B1 onto the discharge tray 120. Furthermore, the controller 19 moves the press-end binding processing unit 118 to the press-stitch standby position HP2 shown in FIG. 5(a).

[0048] 5(d) and 5(e) illustrate an example of how two-point binding is performed by the staple-end binding processing unit 117. The second binding position B2 and the third binding position B3 are spaced apart from each other in the main scanning direction. Before the first sheet P1 of the sheet bundle Pb is supplied to the internal tray 114, the controller 19 moves the staple-end binding processing unit 117 in the main scanning direction so that the staple-end binding processing unit 117 can face the second binding position B2. Next, as shown in FIG. 5(d), with the staple-end binding processing unit 117 moved to a position where it can face the second binding position B2, the controller 19 causes the side fence 116 to perform a jogging operation.

[0049] Next, in the state illustrated in FIG. 5(d), the controller 19 repeats the stacking and aligning operations of the sheets P until the number of sheets P for constituting the sheet bundle Pb reaches a predetermined number N.

[0050] Next, when the controller 19 detects that the number of sheets P placed on the internal tray 114 has reached a predetermined number N, it operates the staple end binding processing unit 117 to perform a staple binding operation on the first binding position B1 of the stack of sheets Pb placed on the internal tray 114.

[0051] Next, as shown in FIG. 5(e), the controller 19 causes the staple end binding processing unit 117 to face the third binding position B3, and performs a staple binding operation on the third binding position B3 of the paper stack Pb placed on the internal tray 114.

[0052] 5, in two-point binding, the binding process is performed at the second binding position B2 and then at the third binding position B3. However, the order in which two-point binding is performed is not limited to this. That is, two-point binding may be performed by binding at the third binding position B3 and then at the second binding position B2. In cases where the number of sets to be bound is consecutive, odd-numbered sets are bound at the second binding position B2 and then at the third binding position B3, and even-numbered sets are bound at the third binding position B3 and then at the second binding position B2. In this way, by performing the binding process by changing the order of the binding positions depending on the order of the total number of sets to be bound, the efficiency of the binding process can be improved.

[0053] Next, the controller 19 discharges the sheet bundle Pb stapled at the second binding position B2 and the third binding position B3 onto the discharge tray 120. Furthermore, as shown in FIG. 5(a), the controller 19 moves the staple-end binding processing unit 117 to the staple-stitch standby position HP1.

[0054] In the above embodiment, examples of diagonal binding or binding at two points at the corners of the paper stack Pb have been described, but the present invention is also applicable to cases where three or more points of the paper stack Pb spaced apart in the main scanning direction are bound.

[0055] [Outline of the pressure binding processing unit] 2, details of the part of the configuration of post-processing device 110 that performs the pressure saddle stitching process will be described. As shown in Fig. 2, post-processing device 110 includes return conveyance rollers 113, an internal tray 114, and a side fence 116 (not shown), as well as a movable end fence 131, a folding blade 132, a folding roller pair 133, a folding blade engagement roller 134, a center-folded booklet discharge roller pair 135, and a center-folded booklet discharge tray 136.

[0056] The movable end fence 131, the folding blade 132, and the pair of folding rollers 133 constitute a center folding means. The folding blade 132, the pair of folding rollers 133, and the folding blade engaging roller 134 constitute a pressure saddle stitching means.

[0057] The movable end fence 131 is a mechanism that moves the position of the end of the paper P placed on the internal tray 114 in the conveying direction, and aligns the center folding position, which is set near the center of the paper P in the conveying direction, with the position of the folding blade 132.

[0058] After the sheets P corresponding to the predetermined number N of sheets P constituting the sheet bundle Pb are stacked on the internal tray 114 and the alignment process is completed, the movable end fence 131 moves to adjust the center-fold position of the sheet bundle Pb to a position facing the folding blade 132. Alternatively, at the stage where the predetermined number N of sheets P constituting the sheet bundle Pb are being placed, the position of the movable fence may be moved so that the center-fold position of the sheet bundle Pb is a position facing the folding blade 132, and then the sheets P may be placed on the internal tray 114. In either case, the center-fold position of the sheet bundle Pb is adjusted to a position where it is pushed into the folding roller pair 133 by the folding blade 132. Then, with these adjustments made, the folding blade 132, the folding roller pair 133, and the folding blade engagement roller 134 operate to perform the pressure saddle stitching process.

[0059] More specifically, when the sheet P transported from the image forming apparatus 101 passes through the second transport roller pair 112 and is placed on the internal tray 114, the return transport roller 113 causes the sheet P to be switched back and transported toward the movable end fence 131. The series of steps leading up to this switchback transport corresponds to the transport step. At this time, the movable end fence 131 may have already moved to a position corresponding to the center-folding position, or may be in the same position as the end fence 115.

[0060] The internal tray 114 temporarily holds a plurality of sheets P that are conveyed sequentially. A movable end fence 131 that is movable toward the conveyance direction side of the end fence 115 is provided on the internal tray 114. This movable end fence 131 is a member that is movable in the conveyance direction of the sheets P along the internal tray 114. The movable end fence 131 is configured to move under the control of the controller 19 according to the conveyance direction length of the sheets P placed on the internal tray 114 (which is also synonymous with the conveyance direction length in switchback conveyance), thereby changing the position of the sheets P. The position of the movable end fence 131 is set so that the center position of the sheet P in the conveyance direction length is opposite the folding blade 132.

[0061] 2, the side fences 116 align the positions of the sheets P or the sheet stack Pb placed on the internal tray 114 in the main scanning direction (width direction). The pressure saddle stitching processing unit performs pressure saddle stitching on the sheet stack Pb aligned by the movable end fence 131 and the side fences 116. The sheet stack Pb that has been subjected to pressure saddle stitching is discharged by a pair of center-folded booklet discharge rollers 135 and loaded onto a center-folded booklet discharge tray 136 via a second discharge port 1102.

[0062] [Operation of pressure binding method] Next, the operation of the pressure saddle stitching means will be described with reference to FIG. 6 and other figures. FIG. 6 is a schematic diagram that mainly shows a folding blade 132 as a folding plate member constituting the pressure saddle stitching means, a folding roller pair 133 as a folding roller pair member, and a folding blade engagement roller 134 as a folding plate engagement member, and outlines the center-fold binding process performed by these operations. FIG. 6(a) illustrates a state in which, after the conveying process and the stacking process, a stack of sheets Pb is stacked on the internal tray 114, the edges of the sheets P are aligned, and the positions of all the sheets P are aligned. In FIG. 6(a), the folding blade 132, the folding roller pair 133, and the folding blade engagement roller 134 are located in their initial positions.

[0063] The initial position of the folding blade 132 is a position spaced from the surface of the sheet bundle Pb in a direction substantially perpendicular to the sheet bundle Pb. In the initial position, the folding blade 132 faces a folding position where the sheet bundle Pb is folded in the middle, and is configured to move back and forth in the thickness direction of the sheet bundle Pb by a folding blade movement motor 141 (FIG. 10) that constitutes a folding plate member movement mechanism. The folding blade 132 moves back and forth relative to the sheet bundle Pb between a push-in position for forming a fold in the middle folding process of folding the central portion of the sheet bundle Pb in the conveyance direction length as part of the sheet bundle Pb, and a retracted position where the folding blade 132 is removed from the sheet bundle Pb after folding the center of the sheet bundle Pb. The retracted position of the folding blade 132 corresponds to the initial position (HP position).

[0064] The pair of folding rollers 133 are arranged symmetrically with respect to the center line of the folding blade 132. That is, the pair of folding rollers 133 are arranged at symmetrical positions with respect to the center line along the movement direction when the folding blade 132 performs the center-folding operation on the sheet P. The pair of folding rollers 133 are configured to be rotated by a folding roller pair rotation motor 142 (see FIG. 10). The pair of folding rollers 133 are also configured to be able to move toward and away from each other by a folding roller pair contact / separation motor 143 (see FIG. 10) that constitutes a pressure mechanism.

[0065] The distance between the pair of rollers constituting the folding roller pair 133 is adjusted under the control of the controller 19. When the sheet stack Pb is pushed by the folding blade 132 toward the nip position of the folding roller pair 133, the pair of rollers of the folding roller pair 133 are set to an "acceptance position" under the control of the controller 19, where the nip position is spaced apart according to a predetermined separation amount. Note that the controller 19 may set the position of the folding roller pair 133 to a position further apart than the acceptance position before the start of the center-folding process. The "acceptance position" of the folding roller pair 133 when accepting the sheet stack Pb is also the standby position during the center-folding and binding process, and therefore also corresponds to the standby position.

[0066] The folding blade engagement roller 134, which constitutes the spine crimp binding means, is a cylindrical roller-shaped member with a rotation axis set in a direction penetrating both ends of the cylindrical portion, and is axially supported so as to be rotatable around this rotation axis. The folding blade engagement roller 134 has uneven engagement crimp teeth 134a on the outer periphery of the cylindrical portion (cylindrical outer circumferential surface). The folding blade engagement roller 134 also has flanges 134b on both ends of the cylindrical portion, the flanges 134b having a larger outer diameter than the engagement crimp teeth 134a. The flanges 134b have the same diameter on both ends of the cylindrical portion.

[0067] The engagement and crimping teeth 134a of the folding blade engagement roller 134 are gear-shaped portions in which irregularities are repeatedly formed at predetermined intervals on the cylindrical outer circumferential surface of the folding blade engagement roller 134. These irregularities are formed parallel to the rotation axis of the folding blade engagement roller 134.

[0068] The pressure-bonding saddle-stitching process according to this embodiment first executes a center-folding process. In the center-folding process, the controller 19 first adjusts the positions of the pair of rollers constituting the folding roller pair 133 using the folding roller pair contact / separation motor 143 to make the sheet stack Pb ready to be received. The folding roller pair contact / separation motor 143 adjusts the gap at the nip position of the folding roller pair 133. The adjustment amount (separation amount) at this time is set so that the folding blade 132 can push the vicinity of the center of the sheet stack Pb in the conveyance direction (length direction) into the nip position (gap) of the folding roller pair 133 and create a gap large enough to allow the folding blade 132 to advance through the nip position while pushing the sheet stack Pb. Therefore, the adjustment amount of the gap at the receiving position of the folding roller pair 133 is changed depending on the predetermined number N of sheets P constituting the sheet stack Pb and size information including the size and thickness of the sheets P.

[0069] That is, as a preliminary step to the center folding process, when the folding blade 132 guides the sheet bundle Pb to the nip position between the rollers of the folding roller pair 133, the controller 19 separates the rollers to allow the folding blade 132 and the sheet bundle Pb to pass between the rollers. At this time, at the "receiving position" which is the position of the rollers constituting the folding roller pair 133, for example, the outer peripheries of the rollers are slightly separated from each other.

[0070] Next, as shown in Figure 6(b), folding blade 132 guides sheet bundle Pb toward the nip position of folding roller pair 133. At this time, folding roller pair 133 is pressed toward sheet bundle Pb by the elastic force of folding roller pair pressure member 144 (see Figure 8). In other words, the degree to which sheet bundle Pb is pressed against folding blade 132 is determined by the elastic force of folding roller pair pressure member 144. At this time, the pressure of folding roller pair 133 against sheet bundle Pb and the advancement of folding blade 132 form a fold in sheet bundle Pb.

[0071] Information for adjusting the receiving position of the pair of folding rollers 133 (the type and thickness of the sheets P, and the number of sheets P constituting one unit of the sheet bundle Pb) is set in advance in the controller 19 via the operation panel 102. That is, when starting the center-folding process, the controller 19 calculates an adjustment value based on the number of sheets P constituting the sheet bundle Pb that have already been set, the type of sheets P (mainly differences in thickness), etc., and uses the value obtained by adding the thickness of the folding blade 132 to this as the gap adjustment amount.

[0072] As shown in FIG. 6B, the folding blade 132, which serves as a rack-type pressure blade, advances toward the folding roller pair 133, the gap of which has been adjusted, while pushing the sheet bundle Pb. At this time, the folding roller pair 133, which serves as a center folding means, rotates in accordance with the advancement speed of the folding blade 132 and presses the sheet bundle Pb in a direction perpendicular to the advancement direction of the folding blade 132 (the sub-scanning direction). That is, the folding blade 132 and the sheet bundle Pb guided by the advancement of the folding blade 132 are pushed between the folding roller pair 133. When the sheet bundle Pb is pushed into the folding roller pair 133, the pushed-in position of the sheet bundle Pb is bent, thereby performing center folding. When the folding blade 132 guides (pushes) the sheet bundle Pb between the folding roller pair 133, the gap between the folding roller pair 133 is widened by an amount equivalent to twice the thickness of the sheet bundle Pb.

[0073] 6(c), the tip of folding blade 132 continues to move to a position sufficiently beyond the nip position of folding roller pair 133, and the center-folding process for sheet stack Pb proceeds. During this center-folding process, a portion of sheet stack Pb (a portion approximately at the center in the conveying direction) becomes fold portion Fp (see FIG. 9). When the center-folding process shown in FIGS. 6(b) and 6(c) is being performed, folding blade engagement roller 134 is located in a retracted position spaced apart from the tip of folding blade 132 that has passed the nip position, as shown in FIG. 6(c).

[0074] 6(d), the folding blade engagement roller 134 moves from the retracted position toward the folding blade 132. The destination of this movement is an engagement position where the folding blade engagement roller 134 and the folding blade 132 come into contact with each other with the stack of sheets Pb interposed therebetween. When the folding blade engagement roller 134 moves to the engagement position, the folding blade 132 and the folding blade engagement roller 134 enter a pressing state in which they sandwich the stack of sheets Pb. In this pressing state, the stack of sheets Pb is pressed from both sides so that the folding pressure teeth 132a formed as a concave-convex shape at the tip of the folding blade 132 and the engaging pressure teeth 134a formed as a concave-convex shape on the cylindrical outer circumferential surface of the folding blade engagement roller 134 engage with each other, thereby performing pressure binding.

[0075] Furthermore, while pressure binding is being performed on the fold line portion Fp of the paper-sheet bundle Pb, the action of the flange portion 134b of the folding blade engagement roller 134 and the folding blade 132 causes the paper-sheet bundle Pb to be folded in the direction opposite to the moving direction of the folding blade 132. This folding position (folding position) is determined by the flange portion 134b of the folding blade engagement roller 134.

[0076] Therefore, the spine Cb (see FIG. 9) is formed in the paper stack Pb with a width corresponding to the distance between the flanges 134b of the folding blade engagement rollers 134 that face each other, starting from the center of the length in the conveying direction. Also, creases f (see FIG. 9) are formed as fold lines at the positions of the flanges 134b of the folding blade engagement rollers 134. The creases f formed at this time are formed in two places on either side of the spine Cb. In other words, this process corresponds to a spine pressure binding process in which the spine Cb is formed while forming two parallel creases f, and then pressure binding is performed on the spine Cb at the same time as or after the spine Cb is formed.

[0077] That is, the flange portion 134b of the folding blade engagement roller 134 and the folding blade 132 correspond to a spine forming portion. The folding blade 132 and the folding blade engagement roller 134 correspond to a pressure binding portion. The folding pressure teeth 132a of the folding blade 132 and the engagement pressure teeth 134a of the folding blade engagement roller 134 form a plurality of binding marks (pressure marks) that are approximately perpendicular to the fold f, namely, a pressure mark group Ct shown in FIG.

[0078] That is, the controller 19 causes the folding blade engaging roller 134 to scan in the width direction (main scanning direction) of the paper stack Pb while the folding blade 132 and the folding blade engaging roller 134 are pressing and clamping the paper stack Pb. When the folding blade engaging roller 134 moves in the width direction, the folding blade engaging roller 134 moves while rotating. That is, the folding blade engaging roller 134 moves while rotating along the width direction of the paper stack Pb while pressing the paper stack Pb against the folding blade 132.

[0079] At this time, the flange portion 134b of the folding blade engagement roller 134 envelops and pinches the sheet stack Pb protruding in the thickness direction of the folding blade engagement roller 134. This operation allows the spine Cb to be formed in the sheet stack Pb, and simultaneously or after the spine Cb is formed, the formed spine Cb can be pressure-stitched. In other words, the operation described in Fig. 6(d) corresponds to a spine pressure-stitching process in which the spine forming process (spine folding process) and the pressure-stitching process are performed simultaneously or sequentially.

[0080] 6(e), the controller 19 retracts the folding blade engagement roller 134 in the width direction of the sheet bundle Pb, and also retracts the folding blade 132 to the retracted position. Then, the controller 19 rotates the pair of folding rollers 133 to transport the sheet bundle Pb through the pair of folding rollers 133, and discharges the pressure-bonded saddle-stitched booklet with the spine Cb pressure-bonded to the center-folded booklet discharge tray 136 (see FIG. 2).

[0081] As described above, when performing a pressure saddle stitching process on a sheet bundle Pb, the post-processing device 110 according to this embodiment first performs a center folding process, and then performs a spine folding process to form a spine Cb of the center-folded sheet bundle Pb. Then, simultaneously with or after the spine Cb is formed, pressure binding is performed on the spine Cb, thereby completing the pressure saddle stitching process. That is, in the pressure saddle stitching process as an embodiment of the sheet processing method according to the present invention, a spine forming process is performed following the center folding process, and simultaneously with or after the spine Cb is formed, a pressure binding process (spine pressure binding process) is performed on the spine Cb. This, unlike conventional methods, makes it possible to form a pressure saddle stitched booklet that is easy to open and that does not come apart due to folding processes and page turning operations.

[0082] In addition, when the spine forming process and the pressure binding process are performed sequentially, for example, two rollers corresponding to the folding blade engaging roller 134 may be provided, one of the folding blade engaging rollers 134 having only the engaging pressure tooth portion 134a and the other folding blade engaging roller 134 having only the flange portion 134b. With such a configuration, the spine forming process and the pressure binding process can be performed in any order.

[0083] 7 is a cross-sectional view showing the operation of the pressure-bonding saddle stitching processing unit, as seen from the paper conveyance direction side at the center position of the thickness of the folding blade 132. The center position of the thickness of the folding blade 132 corresponds to the centerline of the center fold. The folding blade 132 has folding pressure teeth 132a as uneven folding plate pressure teeth on the sheet material pushing surface that faces the folding blade engagement roller 134 in the traveling direction.

[0084] Fig. 7(a) corresponds to the state illustrated in Fig. 6(c). As already explained, in the state illustrated in Fig. 6(c), the folding blade 132 pushes the sheet stack Pb to a position beyond the nip position of the pair of folding rollers 133.

[0085] When the folding blade 132 pushes the sheet bundle Pb into the nip position of the folding roller pair 133 and advances, the folding blade engagement roller 134 waits at a position outside the width direction of the sheet bundle Pb that has been folded into a booklet when the center-folding process has been performed on the sheet bundle Pb. This standby position corresponds to the initial position (HP position). The folding blade engagement roller 134 at this initial position (HP position) is on the outside in the main scanning direction of the sheet bundle Pb that has been pushed into the nip position of the folding roller pair 133 and advances, and corresponds to a position where it is separated from the sheet bundle Pb. Note that FIG. 7 shows only the engagement and crimping tooth portion 134a of the components of the folding blade engagement roller 134.

[0086] The folding blade engaging roller 134 (engagement pressure tooth portion 134a) is moved in the main scanning direction (width direction of the paper stack Pb) by a folding blade engaging roller scanning motor 145 (see FIG. 10). The pressure saddle stitching processing section is provided with an engagement roller guide rail 146 as a folding blade engaging roller contact / separation mechanism, and the engagement pressure tooth portion 134a of the folding blade engaging roller 134 is configured to move in the main scanning direction along the engagement roller guide rail 146.

[0087] The engaging roller guide rail 146 has a dimension longer than the dimension of the sheet stack Pb in the main scanning direction, and the portion outside the end of the sheet stack Pb in the main scanning direction is spaced apart from the fold of the sheet stack Pb that has passed the nip position of the folding roller pair 133. Also, the engaging roller guide rail 146 is configured to approach the fold of the sheet stack Pb that has passed the nip position of the folding roller pair 133 at the portion inside the end of the sheet stack Pb in the main scanning direction.

[0088] Therefore, the engagement pressure tooth portion 134a of the folding blade engagement roller 134 does not come into contact with the fold formed on the bundle of paper-sheets Pb on the outside including the end in the main scanning direction, but moves to pinch the fold on the inside of the end in the main scanning direction with the folding blade 132. Then, as the engagement pressure tooth portion 134a moves in the main scanning direction along the engagement roller guide rail 146, the positions where the fold of the bundle of paper-sheets Pb is pinched with the folding blade 132 are sequentially pressed and bound.

[0089] 7(b) corresponds to the state of FIG. 6(d), and corresponds to a pressurized state in which the engagement pressure tooth portion 134a of the folding blade engagement roller 134 is pressed against the folding blade 132, pressurizing and deforming the sheet stack Pb sandwiched between the folding blade 132. When the folding blade engagement roller 134 is located at the fold of the sheet stack Pb and the folding blade engagement roller 134 is scanning while forming the spine Cb, the folding roller pair 133 is in a pressurized state so as to sandwich and not move the sheet stack Pb so as not to push back the sheet stack Pb. The controller 19 controls the folding roller pair 133 to maintain the pressurized state. In other words, when the pressurized saddle stitching process is performed on the sheet stack Pb, the folding roller pair 133 is controlled to maintain the pressurized state so that the folding blade 132 does not retreat due to the pressure of the folding blade engagement roller 134.

[0090] Then, as a result of the folding blade engagement roller 134 pressing against the folding blade 132, the uneven teeth of the engagement crimping teeth portion 134a as the engagement crimping teeth provided on the folding blade engagement roller 134 and the uneven teeth of the folding crimping teeth portion 132a as the folding plate crimping teeth provided on the pushing surface of the folding blade 132 engage to sandwich the sheet bundle Pb. As a result, the spine Cb of the sheet bundle Pb is pressurized and deformed in the main scanning direction, and the spine crimp binding process is performed.

[0091] The folding pressure teeth 132a have recesses and protrusions arranged at predetermined intervals in the main scanning direction, like the rack teeth of a rack and pinion mechanism (see FIG. 7). When the folding blade engagement roller 134 is scanned in the main scanning direction by the folding blade engagement roller scanning motor 145 (see FIG. 10), the meshing position between the engagement pressure teeth 134a of the folding blade engagement roller 134 and the folding pressure teeth 132a of the folding blade moves in the main scanning direction. This movement of the meshing position (engagement position) performs pressure binding on the spine Cb of the sheet stack Pb. While pressure binding is being performed, the folding roller pair 133 is maintained in a pressed state toward the nip position so that the folding blade engagement roller 134 can move back and forth in the main scanning direction while maintaining the engagement position. This prevents the sheet stack Pb and the folding blade 132 from escaping due to the pressure of the folding blade engagement roller 134.

[0092] In this way, when the engagement and crimping teeth 134a of the folding blade engagement roller 134 approach the spine Cb formed on the stack of sheets Pb, they move obliquely from the outside in the width direction of the stack of sheets Pb toward the spine Cb. As a result, the engagement and crimping teeth 134a of the folding blade engagement roller 134 approach from a direction that will not collide with the widthwise end of the spine Cb of the stack of sheets Pb, and the position at which they engage with the folding and crimping teeth 132a of the folding blade 132 starts from the inside of the widthwise end of the stack of sheets Pb. This prevents the end from being turned up when the folding blade engagement roller 134 passes over the end of the stack of sheets Pb.

[0093] As shown in Figure 7(c), after performing pressure binding on the spine Cb of the paper stack Pb, the engaging pressure tooth portion 134a moves in the main scanning direction to a position outside the other end of the paper stack Pb in the width direction (the end opposite the waiting position), and then moves to a position where it is separated from the folding pressure tooth portion 132a in the center folding discharge direction.

[0094] When the next sheet bundle Pb is subsequently press-stitched, the main scanning direction is reversed, i.e., from left to right in FIG. 7(b) for odd-numbered copies and from right to left in FIG. 7(b) for even-numbered copies.

[0095] Although the folding blade engagement roller contact / separation mechanism according to this embodiment is configured using the engagement roller guide rail 146 and the folding blade engagement roller scanning motor 145 (see FIG. 10 ), the mechanism is not limited to this. A movement motor that moves the folding blade engagement roller 134 forward and backward in the center-folding discharge direction may also be provided.

[0096] 8 is a schematic diagram showing the state when the pressure saddle stitching unit presses the sheet stack Pb. As shown in Fig. 8, the folding blade 132 corresponds to a folding plate member that guides the vicinity of the center in the conveying direction of the sheet stack Pb placed and stacked on the internal tray 114 toward the nip position of the folding roller pair 133, which is a predetermined direction.

[0097] The pair of folding rollers 133 corresponds to a pair of folding rollers that sandwich the sheet bundle Pb guided by the folding blade 132 and advancing toward the nip position, and further advances the sheet bundle Pb in the advancing direction.

[0098] That is, the folding roller pair 133 is urged toward the folding blade 132 by the folding roller pair pressure member 144 so that the folding roller pair 133 sandwiches the paper stack Pb with the folding blade 132 at the nip position. This urging causes the folding roller pair 133 to press the folding blade 132 that passes through the nip position. Note that the folding roller pair pressure member 144 is an elastic member such as a spring, and therefore, while pressing the folding roller pair 133 toward the folding blade 132, it is in a state in which it can be pushed back by its elastic force when the folding blade 132 and the paper stack Pb proceed between the folding roller pair 133 (the nip position).

[0099] 6(b) and 6(c), the pair of folding rollers 133 conveys the sheet stack Pb while pressing it toward the folding blade 132, so that the sheet stack Pb is folded as it passes between the pair of folding rollers 133 by being pressed against the fold by the end of the folding blade 132 in the direction of travel. Also, in the state of FIG. 6(d), with the pair of folding rollers 133 pressing the sheet stack Pb, the folding blade engagement roller 134 holds the sheet stack Pb during pressure binding.

[0100] The folding blade engaging roller 134 is pressed against the folding blade 132 with the paper stack Pb sandwiched therebetween by a folding blade engaging roller pressure member 147. The folding blade engaging roller 134 is a roller-shaped member and is supported by a shaft. The rotation shaft of the folding blade engaging roller 134 is provided along the direction in which the folding roller pair 133 is biased against the folding blade 132.

[0101] The folding blade engagement roller 134 includes an engagement crimping tooth portion 134a as a cylindrical portion having a predetermined width in the rotation axis direction, and flange portions 134b as flange portions provided at both ends of the cylindrical portion in the rotation axis direction.

[0102] The engagement pressure tooth portion 134a presses the sheet stack Pb interposed between it and the folding blade 132 by the biasing force of the folding blade engagement roller pressure member 147, thereby performing pressure binding. Then, by being pressed toward the folding blade 132 by the engagement pressure tooth portion 134a, the portion of the sheet stack Pb sandwiched between the end of the folding blade 132 in the thickness direction and the flange portion 134b is oriented in the direction along the folding blade 132, and the portion of the sheet stack Pb sandwiched between the flange portion 134b and the folding blade 132 is folded. This folding direction is opposite the direction of entry of the folding blade 132. The folded portions are formed at two locations spaced a predetermined distance apart in the thickness direction of the folding blade 132, so that two fold lines are formed in the sheet stack Pb by the pressure binding operation. As a result, a square spine is formed in the folded portion of the sheet stack Pb, and a spine Cb, which is a substantially flat portion, is formed between the fold lines. That is, the spine is folded squarely by the spine crimp binding process.

[0103] [Booklet Bk] FIG. 9 is a perspective view illustrating a booklet Bk formed by the above-described crimping saddle stitching operation. As shown in FIG. 9, the booklet Bk is formed by folding the sheet bundle Pb at the crease Fp during the center-folding process, and a square spine is formed on the spine Cb. The spine Cb is then deformed by the engaging crimping teeth 134a and the folding blade 132, forming a group of crimping marks Ct at predetermined intervals along the length of the spine Cb. The group of crimping marks Ct can be formed at a position that overlaps the position (crease Fp) where the sheet bundle Pb is folded during the center-folding process. The two creases f that form the spine Cb are the movable portions of the booklet Bk when a page is turned. The two creases f are formed near both sides of the group of crimping marks Ct.

[0104] Therefore, the booklet Bk produced by the pressure saddle stitching process according to this embodiment is structured so that when a page is turned at the fold f, the load is not applied to the pressure bonded portion, and the structure does not induce peeling of the bound portion due to the page turning operation. Also, since the fold f is formed in two places on either side of the spine Cb, the fold f that moves during the page turning operation is in one of the two places. This fold f is in a position that does not overlap with the fold portion Fp that is pushed into the nip position of the folding roller pair 133 by the folding blade 132. The fold portion Fp then becomes the binding position for pressure binding.

[0105] Therefore, when a page is turned, the page is turned at the fold f, and the fold portion Fp, which corresponds to the center when the booklet Bk is opened, is bound, so the page is not turned across the binding position. In other words, because the center fold lines (fold f) are symmetrical on both sides of the binding position, the left and right pages can be opened evenly, and the quality of the booklet Bk is maintained.

[0106] [Control configuration] 10 is a hardware configuration diagram of a controller 19 that controls the operation of the post-processing device 110 according to the first embodiment. As shown in Fig. 10, the controller 19 includes a central processing unit (CPU) 11, a random access memory (RAM) 12, a read only memory (ROM) 13, a hard disk drive (HDD) 14, and an interface (I / F) 15, all of which are connected via a common bus 16.

[0107] The CPU 11 is a computing means and controls the overall operation of the post-processing device 110. The RAM 12 is a volatile storage medium capable of reading and writing information at high speed, and is used as a work area when the CPU 11 processes information. The ROM 13 is a read-only non-volatile storage medium in which programs such as firmware are stored. The HDD 14 is a non-volatile storage medium with a large storage capacity that is capable of reading and writing information, and in which an OS (Operating System), various control programs, application programs, etc. are stored.

[0108] The post-processing device 110 processes a control program stored in the ROM 13, an information processing program (application program) loaded into the RAM 12 from a storage medium such as the HDD 14, and the like using the arithmetic functions of the CPU 11. This processing constitutes a software control unit including various functional modules of the post-processing device 110. The software control unit thus constituted is combined with hardware resources installed in the post-processing device 110 to form functional blocks that realize the functions of the post-processing device 110. In other words, the CPU 11, RAM 12, ROM 13, and HDD 14 constitute a controller 19 (control unit) that controls the operation of the post-processing device 110.

[0109] The I / F 15 is an interface that connects the first conveying roller pair 111, the second conveying roller pair 112, the return conveying roller 113, the side fence 116, the discharge roller pair 119, the movable end fence 131, the folding blade moving motor 141, the folding roller pair rotation motor 142, the folding roller pair contact / separation motor 143, the folding blade engagement roller scanning motor 145, the staple end binding main scanning moving motor 161, the staple end binding posture rotation motor 164, the staple end binding clinch motor 166, the crimp end binding main scanning moving motor 171, the crimp end binding posture rotation motor 174, the crimp end binding clinch motor 176, the binding tooth slide motor 179, the crimping roller moving motor 188, and the operation panel 102 to the common bus 16.

[0110] The controller 19 operates, via the I / F 15, the first conveying roller pair 111, the second conveying roller pair 112, the return conveying roller 113, the side fence 116, the discharge roller pair 119, the movable end fence 131, the folding blade moving motor 141, the folding roller pair rotation motor 142, the folding roller pair contact / separation motor 143, the folding blade engagement roller scanning motor 145, the staple end binding main scanning moving motor 161, the staple end binding posture rotation motor 164, the staple end binding clinch motor 166, the crimp end binding main scanning moving motor 171, the crimp end binding posture rotation motor 174, the crimp end binding clinch motor 176, the binding tooth slide motor 179, and the crimp roller moving motor 188.

[0111] As already explained in FIG. 1, the image forming apparatus 101 includes an operation panel 102. The operation panel 102 includes an operation unit that accepts input operations from a user and a display (notification unit) that notifies the user of information. The operation unit includes, for example, hard keys, a touch panel superimposed on the display, etc. The operation panel 102 acquires information from the user through the operation unit and provides the information to the user through the display. Note that the notification unit is not limited to a display, and may be an LED lamp, a speaker, etc. Also, the post-processing device 110 may be provided with an operation panel 102 similar to the above.

[0112] [Variation 1] Next, a first modified example of the pressure-bonding saddle stitching processing unit will be described with reference to Fig. 11. The difference from the pressure-bonding saddle stitching processing unit according to the first embodiment is that the folding blade engaging member is not a roller member that moves while rotating in the main scanning direction, but is configured as a folding blade engaging die 181 as a blade member that extends in the main scanning direction (the longitudinal direction of the spine Cb). Note that components common to the pressure-bonding saddle stitching processing unit according to the first embodiment are given the same reference numerals, and detailed description thereof will be omitted.

[0113] 11 is a schematic diagram showing Modification 1 of the pressure saddle stitching processing section. The pair of folding rollers 133 sandwich the folding blade 132 and the sheet bundle Pb, and are pressed against each other by a folding roller pair pressure member 144.

[0114] Furthermore, the folding blade engagement die 181 is provided with a die crimping portion 181a including a plurality of concave and convex shapes serving as a group of engaging crimping teeth in the longitudinal direction on the surface facing the folding blade 132. The folding blade 132 is provided with folding crimping teeth 132a serving as a group of folding plate crimping teeth that engage with the die crimping portion 181a serving as the group of engaging crimping teeth on the surface facing the folding blade engagement die 181. The folding blade 132 pushes the sheet stack Pb into the pair of folding rollers 133, and when the fold of the sheet stack Pb reaches a position where the folding blade 132 and the folding blade engagement die 181 can engage with each other, the folding blade engagement die 181 moves toward the folding blade 132 and presses it, thereby performing crimp binding.

[0115] At this time, the folding roller pair 133 is pressed toward the folding blade 132 by the folding roller pair pressure member 144, so the folding blade 132 is prevented from being pushed back by the pressing force of the folding blade engagement die 181 generated by the folding blade engagement die pressure member 183. The pressing force of the folding blade engagement die 181 causes the die pressing portion 181a of the folding blade engagement die 181 to perform crimp binding. As a result, a crimping mark group Ct including multiple crimping marks is formed on the spine Cb along the longitudinal direction of the spine Cb. The direction of the crimping marks included in the crimping mark group Ct is approximately perpendicular to the fold f. In addition, the pressing force of the folding blade engagement die 181 causes the flange portion 181b of the folding blade engagement die 181 to perform a square spine fold on the paper-sheet bundle Pb.

[0116] Figure 12 is a cross-sectional view showing the operation of Variation 1 of the pressure-bonding saddle-stitch processing unit. It is a cross-sectional view taken along the BB line as seen from the paper conveyance direction side at the center line of the center fold, in other words, at the center position of the thickness of the folding blade 132. Figure 12(a) corresponds to the state of Figure 6(c). The folding blade 132 pushes the paper stack Pb to a position beyond the nip position of the folding roller pair 133, and the folding blade engagement die 181 is in the standby position (HP position) and is spaced apart from the paper stack Pb in the center-fold discharge direction.

[0117] The folding blade engaging die 181 is moved toward the folding blade by a folding blade engaging die moving motor 182 (see FIG. 10).

[0118] Figure 12(b) corresponds to the state of Figure 6(d). The folding blade engagement die 181 is pressed against the folding blade 132, sandwiching the sheet bundle Pb, and the concave and convex teeth of the die crimping portion 181a of the folding blade engagement die 181 and the folding crimping teeth portion 132a provided on the pushing surface of the folding blade 132 engage with each other, sandwiching the sheet bundle Pb. The folding blade engagement die 181 is pressed by the folding blade engagement die pressure member 183, so that the spine of the sheet bundle Pb is crimped and bound.

[0119] [Variation 2] Next, a second modified example of the crimping saddle stitching processing section will be described with reference to Fig. 13. The difference from the first modified example of the crimping saddle stitching processing section is that the folding blade 184 does not have uneven crimping teeth uniformly arranged in the width direction, but has crimping teeth arranged partially (intermittently) at multiple locations as a folding plate crimping tooth group. Also, the folding blade engaging die 185 has crimping teeth arranged as an engaging crimping tooth group at a position opposite the folding plate crimping tooth group. The portion where the engaging crimping tooth group is not arranged is a substantially flat portion. Note that the same reference numerals are used for components common to the crimping saddle stitching processing section according to the first embodiment, and detailed description thereof will be omitted.

[0120] Figure 13 is a cross-sectional view showing the operation of Variation 2 of the pressure-bonding saddle-stitch processing unit. It is a cross-sectional view seen from the paper conveyance direction side at the center line of the center fold, in other words, the center position of the thickness of the folding blade 132. Figure 13(a) corresponds to the state of Figure 6(c). The folding blade 184 pushes the paper stack Pb to a position beyond the nip position of the folding roller pair 133, and the folding blade engagement die 185 is located in the standby position (HP position) and is separated from the paper stack Pb in the center-fold discharge direction.

[0121] The folding blade engaging die 185 is moved toward the folding blade by a folding blade engaging die moving motor 182 (see FIG. 10).

[0122] Figure 13(b) corresponds to the state of Figure 6(d). The folding blade engagement die 185 is pressed against the folding blade 184, sandwiching the sheet bundle Pb, and the concave and convex teeth of the crimping portion 185a of the folding blade engagement die 185 and the concave and convex teeth of the folding crimping tooth portion 184a provided on the pushing surface of the folding blade 184 engage with each other, sandwiching the sheet bundle Pb. The folding blade engagement die 185 is pressed by the folding blade engagement die pressure member 183, so that the spine Cb of the sheet bundle Pb is crimped and bound.

[0123] [Variation 3] Next, a third modified example of the pressure saddle stitching processing section will be described with reference to Fig. 14. The difference from the first modified example of the pressure saddle stitching processing section is that the folding blade engaging member (folding blade engaging die 186) does not move linearly facing the folding blade 132 to engage with it, but moves along a rotational trajectory so that the concave and convex pressure teeth sequentially engage with it. Note that the same reference numerals are used for components common to the first modified example of the pressure saddle stitching processing section, and detailed description thereof will be omitted.

[0124] Figure 14 is a cross-sectional view showing the operation of Variation 3 of the pressure-bonding saddle-stitch processing unit. It is a cross-sectional view seen from the paper conveyance direction side at the center line of the center fold, in other words, the center position of the thickness of the folding blade 132. Figure 14(a) corresponds to the state of Figure 6(c). The folding blade 132 pushes the paper stack Pb to a position beyond the nip position of the folding roller pair 133, and the folding blade engagement die 186 is located in the standby position (HP position) and is separated from the paper stack Pb in the center-fold discharge direction.

[0125] The folding blade engagement die 186 is moved toward the folding blade 132 by the folding blade engagement die moving motor 182 (see Figure 10), and moves in a rotational trajectory so that the concave and convex teeth of the crimping portion 186a of the folding blade engagement die 186 sequentially engage with the concave and convex teeth of the folding crimping tooth portion 132a of the folding blade 132.

[0126] Figure 14(b) corresponds to the state of Figure 6(d). The folding blade engagement die 186 is pressed against the folding blade 132, sandwiching the sheet bundle Pb, and the concave and convex teeth of the crimping portion 186a of the folding blade engagement die and the concave and convex teeth of the folding crimping tooth portion 132a provided on the pushing surface of the folding blade 132 engage with each other, sandwiching the sheet bundle Pb. The folding blade engagement die 186 is pressed by the folding blade engagement die pressure member 183, so that the spine of the sheet bundle Pb is crimped and bound.

[0127] In addition, the crimping portion 186a of the folding blade engaging die 186 is not flat but has a curved surface, and the curved surface may be provided with concave and convex teeth of the crimping portion 186a, and the folding blade engaging die 186 may be moved along a rotational trajectory so that the concave and convex teeth of the crimping portion 186a of the folding blade 132 sequentially engage with the concave and convex teeth of the folding crimping tooth portion 132a of the folding blade 132.

[0128] In this way, the concave and convex teeth of the crimping portion 186a of the folding blade engagement die 186 and the concave and convex teeth of the folding crimping tooth portion 132a of the folding blade 132 sequentially mesh with each other, thereby reducing the pressure force during crimping binding and making it possible to make the device more compact.

[0129] [Variation 4] Next, a fourth variation of the pressure saddle stitching processing unit will be described with reference to Fig. 15. The difference from the pressure saddle stitching processing unit according to the first embodiment is that the folding blade 132 is provided at its tip with a pressure roller 187 having uneven teeth on its outer periphery that moves in the main scanning direction. Note that components common to the pressure saddle stitching processing unit according to the first embodiment are given the same reference numerals, and detailed descriptions thereof will be omitted.

[0130] Figure 15 is a cross-sectional view showing the operation of Variation 4 of the pressure saddle stitching processing unit. It is a cross-sectional view seen from the paper conveyance direction side at the center line of the center fold, in other words, the center position of the thickness of the folding blade 132. Figure 15(a) corresponds to the state of Figure 6(c). The folding blade 132 has pushed the paper stack Pb to a position beyond the nip position of the folding roller pair 133, and the folding blade engagement roller 134 and the pressure roller 187 are in the standby position (HP position) and are separated from the paper stack Pb in the center fold discharge direction.

[0131] A pressure roller 187 serving as a first roller member is supported so as to be guided by a pressure roller rail 132b. The pressure roller rail 132b is disposed in the longitudinal direction (main scanning direction) of the folding blade 132. The pressure roller 187 is moved in the main scanning direction of the paper stack Pb by a pressure roller movement motor 188 (see FIG. 10).

[0132] 15(b) corresponds to the state of FIG. 6(d). The folding blade engagement roller 134, which serves as a second roller member, is guided by the engagement roller guide rail 146 to approach the pressure roller 187 and is pressed against the pressure roller 187 via the stack of sheets Pb. The uneven teeth of the engagement pressure tooth portion 134a of the folding blade engagement roller and the uneven teeth of the pressure portion 187a provided on the pressing surface of the pressure roller 187 intermesh with each other, sandwiching the stack of sheets Pb. At this time, the folding blade engagement roller 134 is pressed by the folding blade engagement roller pressure member 147. As a result, the uneven teeth of the engagement pressure tooth portion 134a of the folding blade engagement roller 134 and the uneven teeth of the pressure portion 187a of the pressure roller 187 press and deform the stack of sheets Pb, thereby pressure-binding the spine Cb of the stack of sheets Pb.

[0133] [Variation 5] Next, a fifth variation of the pressure saddle stitching processing unit will be described with reference to Fig. 16. The difference from the pressure saddle stitching processing unit according to the first embodiment is that the concave and convex pressure teeth of the folding blade are not uniformly arranged in the main scanning direction, but are arranged partially (intermittently). Note that the same reference numerals are used to designate components that are common to the pressure saddle stitching processing unit according to the first embodiment, and detailed descriptions thereof will be omitted.

[0134] Figure 16 is a cross-sectional view showing the operation of Variation 5 of the pressure-bonding saddle-stitch processing unit. It is a cross-sectional view seen from the paper conveyance direction side at the center line of the center fold, in other words, the center position of the thickness of the folding blade 184. Figure 16(a) corresponds to the state of Figure 6(c). The folding blade 184 has pushed the paper stack Pb to a position beyond the nip position of the folding roller pair 133, and the folding blade engagement roller 134 is in the standby position (HP position) and is separated from the paper stack Pb in the center-fold discharge direction.

[0135] Figure 16(b) corresponds to the state of Figure 6(d). The folding blade engagement roller 134 is pressed against the folding blade 184, sandwiching the sheet bundle Pb, so that the concave and convex teeth of the engagement crimping teeth portion 134a of the folding blade engagement roller 134 and the concave and convex teeth of the folding crimping teeth portion 184a provided on the pushing surface of the folding blade 184 mesh with each other, sandwiching the sheet bundle Pb. At this time, the folding blade engagement roller 134 is pressed by the folding blade engagement roller pressure member 147. As a result, the concave and convex teeth of the engagement crimping teeth portion 134a of the folding blade engagement roller 134 and the concave and convex teeth of the folding crimping teeth portion 184a of the folding blade 184 press and deform the sheet bundle Pb, thereby crimping and binding the spine Cb of the sheet bundle Pb.

[0136] Fig. 17 is a schematic diagram of a booklet Bk formed in Modification 5. As illustrated in Fig. 17, the spine Cb of the booklet Bk is formed with a square spine. The spine Cb is press-bound at predetermined intervals, and groups of press marks Ct are formed at predetermined intervals in the longitudinal direction of the spine Cb (the width direction of the paper stack Pb).

[0137] [Variation 6] Next, a sixth variation of the pressure saddle stitching processing unit will be described with reference to Figures 18 and 19. The difference from the pressure saddle stitching processing unit according to the first embodiment is that the concave and convex teeth of the engagement pressure teeth portion 134a of the folding blade engagement roller 134 are not arranged parallel to the main scanning direction, but are arranged in a "helical tooth" shape, for example, inclined relative to the main scanning direction. Here, the inclination angle of the concave and convex teeth of the engagement pressure teeth portion 134a is, for example, 15 degrees. Note that the same reference numerals are used for components common to the pressure saddle stitching processing unit according to the first embodiment, and detailed description thereof will be omitted.

[0138] Fig. 19 is a schematic diagram of a crimped saddle-stitched booklet bound in Modification Example 6. As illustrated in Fig. 19, the spine Cb of the booklet Bk is formed with a square spine. The spine Cb is crimped and the crimp marks included in the crimp mark group Ct are formed in a slanted line in the longitudinal direction of the spine Cb (the width direction of the paper stack Pb).

[0139] [Variation 7] Next, a seventh modified example of the pressure-bonding saddle stitching processing unit will be described with reference to Fig. 20. The difference from the pressure-bonding saddle stitching processing unit according to the first embodiment is that the scanning trajectory of the folding blade engagement roller 134 is configured to draw a figure eight. Note that components common to the pressure-bonding saddle stitching processing unit according to the first embodiment are given the same reference numerals, and detailed description thereof will be omitted.

[0140] Figure 20 is a cross-sectional view showing the operation of Variation 7 of the pressure-bonding saddle-stitch processing unit. It is a cross-sectional view seen from the paper conveyance direction side at the center line of the center fold, in other words, the center position of the thickness of the folding blade 132. Figure 20(a) corresponds to the state of Figure 6(c). The folding blade 132 pushes the paper stack Pb to a position beyond the nip position of the folding roller pair 133, and the folding blade engagement roller 134 is located in the standby position (HP position) and is separated from the paper stack Pb in the center-fold discharge direction.

[0141] The folding blade engaging roller 134 is supported on an engaging roller guide rail 146a. The folding blade engaging roller 134 is moved along the engaging roller guide rail 146a by a folding blade engaging roller scanning motor 145 (see FIG. 10). The movement of the folding blade engaging roller 134 is controlled by a controller 19 (FIG. 10).

[0142] The engagement roller guide rail 146a is arranged to connect between a position where the engagement crimping teeth 134a of the folding blade engagement roller 134 engage with the folding crimping teeth 132a of the folding blade 132, and a position where the engagement crimping teeth 134a are spaced apart from the folding blade 132. The engagement roller guide rail 146a brings the folding blade engagement roller 134 close to each other in a predetermined section in the longitudinal direction of the folding blade 132, and separates them in other sections.

[0143] Figure 20(b) corresponds to the state of Figure 6(d). The folding blade engagement roller 134 is guided by the engagement roller guide rail 146a and is pressed toward the folding blade 132, sandwiching the bundle of sheets Pb, from a first predetermined position in the width direction of the bundle of sheets Pb. At this time, the concave and convex teeth of the engagement pressure tooth portion 134a of the folding blade engagement roller and the folding pressure tooth portion 132a provided on the pushing surface of the folding blade 132 engage with each other, sandwiching the bundle of sheets Pb. The folding blade engagement roller 134 is pressed by the folding blade engagement roller pressure member 147, so that the spine Cb of the bundle of sheets Pb is pressure-bound.

[0144] As shown in FIG. 20(b), the folding blade engagement roller 134 is guided by the engagement roller guide rail 146a and moves in the main scanning direction to a retracted position past the end of the paper stack, and press-stitches approximately half of the width of the paper stack Pb.

[0145] Subsequently, as shown in FIG. 20(c), the folding blade engaging roller 134 is guided by the engaging roller guide rail 146a, moves away from the sheet stack Pb again at the retreat position, and moves in the opposite direction in the main scanning direction.

[0146] Next, as shown in Figure 20(d), the folding blade engagement roller 134 is guided by the engagement roller guide rail 146a and moves in the main scanning direction from the second predetermined position, again pressing the paper stack Pb, until it passes the other end of the paper stack Pb.

[0147] The folding blade engaging roller 134 is guided by the engaging roller guide rail 146a and moves along a locus that draws a figure eight, whereby the entire area in the longitudinal direction of the spine Cb of the paper-sheet bundle Pb is crimp-bound.

[0148] The folding blade engagement roller 134 presses and deforms the spine Cb of the paper stack Pb, thereby crimping and folding the paper squares. Since the folding blade engagement roller 134 sequentially crimps and folds the paper squares while moving in the main scanning direction, the pressure can be concentrated at the processing point, reducing the pressure and enabling the device to be more compact. However, if unintended deformation of the paper stack Pb (for example, paper wrinkles) occurs, the paper wrinkles may accumulate and expand as the paper stack moves in the main scanning direction.

[0149] Therefore, by moving the folding blade engagement roller 134 in a trajectory that draws a series of figure eights, it is possible to process the front half of the paper width from the center toward one end, and then process the rear half from the center toward the other end. As a result, even if unintended deformation (for example, paper wrinkles) occurs in the paper stack Pb, the accumulation of paper wrinkles can be reduced by half.

[0150] [Variation 8] Next, an eighth modified example of the pressure-bonding saddle stitching processing unit will be described with reference to Fig. 21. The difference from the pressure-bonding saddle stitching processing unit according to the first embodiment is that the pressing surface of the folding blade 132 does not have a concave-convex pressure-bonding tooth portion, and the cylindrical outer periphery of the folding blade engaging roller does not have a configuration such as the folding pressure-bonding tooth portion 132a as a concave-convex pressure-bonding tooth portion, but a heating unit is provided on the cylindrical outer periphery of the folding blade engaging roller 191. Note that the same reference numerals are used for components common to the pressure-bonding saddle stitching processing unit according to the first embodiment, and detailed description thereof will be omitted.

[0151] 21 is a schematic diagram showing Modification 8 of the pressure saddle stitching processing section. The pair of folding rollers 133 sandwich the folding blade 132 and the sheet stack Pb, and are pressed against each other by a folding roller pair pressure member 144.

[0152] Furthermore, the folding blade engagement roller 191 serving as the folding plate engagement and heating member according to this modification is pressed by the folding blade engagement roller pressure member 147 toward the folding blade 132, sandwiching the paper stack Pb. By utilizing this pressing force and heat, the heating and pressing portion 191a of the folding blade engagement roller 191 and the folding blade 132 perform toner pressure binding on the paper stack Pb. Then, flange portions 191b formed on both ends of the cylindrical portion of the folding blade engagement roller 191 can perform a spine forming process to fold the paper stack Pb into a square spine.

[0153] The folding blade engagement roller 191, which constitutes the toner pressure binding means, is a cylindrical roller-shaped member. A rotation axis is set in a direction penetrating both ends of the folding blade engagement roller 191 that sandwich the cylindrical outer periphery. The folding blade engagement roller 191 is supported so as to be rotatable around this rotation axis. The folding blade engagement roller 191 has a heat-pressure bonding portion 191a on the cylindrical outer periphery (cylindrical outer periphery surface). The folding blade engagement roller 191 also has flange portions 191b on both ends of the cylindrical outer periphery surface, the flange portions 191b having an outer diameter larger than that of the heat-pressure bonding portion 191a. The flange portions 191b have the same diameter on both ends of the cylindrical outer periphery surface.

[0154] The heat-pressure bonding portion 191a of the folding blade engaging roller 191 is a portion that is heated by a heater installed inside the folding blade engaging roller 191.

[0155] Figure 22 is a cross-sectional view showing the operation of Variation 8 of the pressure-bonding saddle-stitch processing unit. It is a cross-sectional view taken along the BB line in Figure 21, as seen from the paper conveyance direction side at the center line of the center fold, in other words, the center position of the thickness of the folding blade 132. Figure 22(a) corresponds to the state in Figure 6(c). The folding blade 132 has pushed the paper stack Pb to a position beyond the nip position of the folding roller pair 133, and the folding blade engagement roller 191 is in the standby position (HP position) and is spaced apart from the paper stack Pb in the center-fold discharge direction.

[0156] The folding blade engaging roller 191 (heat pressing unit 191a) is moved in the main scanning direction (width direction of the paper P) by a folding blade engaging roller scanning motor 145 (see FIG. 10). The pressing saddle stitching processing unit is provided with an engaging roller guide rail 146 as a folding blade engaging roller contact and separation mechanism, and the folding blade engaging roller 191 is configured to move in the main scanning direction along the engaging roller guide rail 146.

[0157] Fig. 22(b) corresponds to the state of Fig. 6(d). The folding blade engagement roller 191 is pressed against the folding blade 132 with the paper stack Pb sandwiched therebetween, and the heat and pressure bonding portion 191a of the folding blade engagement roller is pressed against the pushing surface of the folding blade 132, and the paper stack Pb is heated and pressurized with the paper stack Pb sandwiched therebetween, whereby the spine Cb of the paper stack Pb is pressure-bound.

[0158] FIG. 22(c) illustrates a state in which the folding blade engagement roller 191 separates from the sheet bundle Pb in the center-fold discharge direction after crimping and binding the entire area of ​​the spine Cb of the sheet bundle Pb in the longitudinal direction.

[0159] FIG. 23(a) is a schematic diagram of the sheet stack Pb before pressure saddle stitching (center folding and pressure binding) in Modification 8. Note that FIG. 23(a) corresponds to the state of FIG. 6(a). As illustrated in FIG. 23(a), the image forming apparatus 101 forms a toner image tn at a position corresponding to the fold of the booklet Bk, using toner that forms a visible image as an adhesive. The toner image corresponds to an adhesive medium formed at the adhesive portion of the sheet stack Pb. Note that the details of the method for forming the adhesive toner image tn by the image forming apparatus 101 are well known technology, as disclosed in JP 2004-209858 A and the like.

[0160] 23(b) is a schematic diagram of a booklet Bk formed by center folding and pressure binding in Modification Example 8. As illustrated in FIG. 23(b), a square spine is formed in the spine Cb of the booklet Bk. Then, in the spine Cb, the adhesive toner image tn is reheated, causing the toner image tn in the overlapping portion of the multiple sheets P that form the flat portion of the square spine (spine Cb) to exert adhesive force, resulting in toner pressure binding.

[0161] [Variation 9] Next, a ninth modified example of the pressure saddle stitching processing unit will be described with reference to Fig. 24. The difference from the pressure saddle stitching processing unit according to the eighth modified example is that the folding blade engaging member is not a roller member that moves while rotating in the main scanning direction, but is configured as a folding blade engaging die 192 as a blade member that extends in the width direction (main scanning direction) of the paper stack Pb. Note that components common to the pressure saddle stitching processing unit according to the first embodiment are given the same reference numerals, and detailed description thereof will be omitted.

[0162] Figure 24 is a cross-sectional view showing the operation of Variant 9 of the pressure saddle stitching processing unit. It is a cross-sectional view taken along the BB line as seen from the paper conveyance direction side at the center line of the center fold, in other words, the center position of the thickness of the folding blade 132. Figure 24(a) corresponds to the state of Figure 6(c). The folding blade 132 pushes the paper stack Pb to a position beyond the nip position of the folding roller pair 133, and the folding blade engagement die 192 is in the standby position (HP position) and is spaced apart from the paper stack Pb in the center fold discharge direction.

[0163] The folding blade engagement die 192 is moved toward the folding blade by the folding blade engagement die movement motor 182 (see FIG. 10).

[0164] Fig. 24(b) corresponds to the state of Fig. 6(d). The folding blade engagement die 192 is pressed against the folding blade 132 with the paper stack Pb sandwiched therebetween, and the heat and pressure bonding portion 192a of the folding blade engagement roller is pressed against the pushing surface of the folding blade 132, and the paper stack Pb is heated and pressurized with the paper stack Pb sandwiched therebetween, whereby the spine of the paper stack Pb is pressure-bound.

[0165] [Second embodiment] Next, a second embodiment of the image forming system according to the present invention will be described. Fig. 25 is a diagram showing the overall configuration of an image forming system 200 as the second embodiment of the image forming system. 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 on which the image has been formed. As shown in Fig. 25, the image forming system 200 is made up of an image forming apparatus 201 and a console-type post-processing apparatus 210 arranged adjacent to the image forming apparatus.

[0166] The image forming apparatus 201 forms an image on a sheet P and discharges the sheet P with the image formed thereon to a post-processing apparatus 210. The image forming apparatus 201 includes a tray for storing the sheet P, a transport unit for transporting the sheet P stored in the tray, and an image forming unit for forming an image on the sheet P transported by the transport unit. The image forming unit may be an inkjet type that forms an image using ink, or an electrophotographic type that forms an image using toner. The image forming apparatus 201 also includes an operation panel 202 and a controller 203 for controlling the operation of the image forming apparatus 201. The operation panel 202 is similar to the operation panel 102 in FIG. 1, and therefore a description thereof will be omitted. The controller 203 is similar to the controller 103 in FIG. 1, and therefore a description thereof will be omitted. The other components of the image forming apparatus 201 are already known, and therefore a detailed description thereof will be omitted.

[0167] FIG. 26 is a diagram showing the internal structure of a post-processing device 210 according to the second embodiment. The post-processing device 210 performs post-processing on sheets P on which images have been formed by the image forming device 201. The post-processing according to this embodiment is a binding process that binds a stack of multiple sheets P on which images have been formed (hereinafter referred to as a "sheet stack Pb"). More specifically, the binding process according to this embodiment includes so-called "pressure binding," in which the sheet stack Pb is pressurized and deformed at a press binding position, and "staple binding," in which the sheet stack Pb is stapled. Furthermore, press binding includes end binding, in which the end of the sheet stack Pb is bound, and saddle binding, in which the center of the sheet stack Pb is bound.

[0168] The same components as those of the pressure-bonding saddle-stitching processing unit according to the first embodiment are given the same reference numerals, and detailed description thereof will be omitted.

[0169] [Clamming saddle stitching processing] As shown in FIG. 26, the post-processing device 210 includes a folding blade 232, a pair of folding rollers 233, a folding blade engaging roller 234, a pair of half-folded booklet discharge rollers 235, and a half-folded booklet discharge tray 236.

[0170] The conveying rollers switch back and convey the paper P toward the movable end fence 238 while placing the paper P on the saddle stitching inner tray 237.

[0171] The saddle stitching internal tray 237 temporarily holds multiple sheets of paper P that are transported in sequence. The movable end fence 238 is movable along the saddle stitching internal tray 237 in the transport direction of the sheets of paper P, and aligns the positions of the sheets of paper so that the folding blade 232 faces the center position of the length in the paper transport direction according to the paper size. The side fences align the position in the main scanning direction (width direction) of the sheets of paper P or the stack of sheets Pb placed on the saddle stitching internal tray 237. The pressure saddle stitching processing unit performs pressure saddle stitching on the stack of sheets Pb aligned by the movable end fence 238 and the side fences. The stack of sheets Pb that has been pressure saddle stitched is discharged by a pair of centerfold booklet discharge rollers 235 and stacked on a centerfold booklet discharge tray 236.

[0172] The present invention is not limited to the above-described exemplary embodiments, and various modifications are possible without departing from the technical gist thereof. The present invention covers all technical matters included in the technical concept described in the claims. The above-described embodiments are preferred examples, but a person skilled in the art can realize various modifications from the disclosed content. Such modifications are also included in the technical scope described in the claims.

[0173] For example, aspects of the present invention are as follows. <1> a center folding unit for performing center folding on a sheet bundle made up of a plurality of sheet materials; The sheet bundle that has been subjected to the center-folding process Pressure-sealed binding process a crimp binding means; Equipped with before Recording pressure The binding means is The aforementioned The sheet stack Centerfold In a state of being clamped by a means The pressure binding process conduct, The sheet processing apparatus is characterized by the above. <2> The center folding means is a folding plate member that guides the sheet stack in a predetermined direction; a pair of folding rollers that sandwich the sheet stack guided by the folding plate member and advance the sheet stack in the direction; Equipped with The aforementioned <1> 2. The sheet processing apparatus according to claim 1, wherein the sheet processing apparatus is a sheet processing apparatus. <3> before Recording pressure The binding means is The folding plate member; a folding plate engaging member that engages with the folding plate member via the sheet bundle; Equipped with The aforementioned <2> 2. The sheet processing apparatus according to claim 1, wherein the sheet processing apparatus is a sheet processing apparatus. <4> the folding plate engagement member is biased toward the folding plate member; The aforementioned The folding plate engaging member and the folding plate member press the sheet stack. The back Form , The aforementioned <3> 2. The sheet processing apparatus according to claim 1, wherein the sheet processing apparatus is a sheet processing apparatus. <5> The folding plate engaging member is a roller-shaped member supported by a journal, The sheet stack is moved back and forth in the longitudinal direction of the spine. The aforementioned A spine forming process for forming a spine and a pressure binding process are performed. The aforementioned <4> 2. The sheet processing apparatus according to claim 1, wherein the sheet processing apparatus is a sheet processing apparatus. <6> the folding plate member has a folding plate pressing tooth having a concave-convex shape on a surface facing the folding plate engaging member, The folding plate engaging member has engagement crimping teeth having a concave-convex shape that engage with the folding plate crimping teeth. The aforementioned <3> and the above <5> 10. The sheet processing apparatus according to claim 9, wherein the sheet processing apparatus is a sheet processing apparatus having a plurality of nozzles. <7> The folding plate engaging member is adapted to engage with the sheet stack by moving the spine in the longitudinal direction. The aforementioned The spine forming process and the pressure binding process are performed simultaneously. The above< 4 The sheet processing apparatus is described in the above. <8> The folding plate member has a plurality of spaced apart, concave-convex folding plate pressing teeth on a surface facing the folding plate engaging member, the folding plate engaging member has a plurality of spaced apart engaging crimping teeth having a concave-convex shape that engage with the folding plate crimping teeth, The crimp binding process is performed by moving the folding plate member toward the folding plate engaging member. The aforementioned <6> or the above <7> 2. The sheet processing apparatus according to claim 1, wherein the sheet processing apparatus is a sheet processing apparatus. <9> The folding plate engaging member is a plate-shaped blade member that faces the folding plate member, and the pressure binding process is performed by moving the blade member toward the folding plate member. The aforementioned <3> 2. The sheet processing apparatus according to claim 1, wherein the sheet processing apparatus is a sheet processing apparatus. <10> before Recording pressure The binding means is a first roller member having concave and convex teeth; a second roller member that engages with the first roller member via the sheet stack; It consists of The aforementioned <1> and the above <9> 10. The sheet processing apparatus according to claim 9, wherein the sheet processing apparatus is a sheet processing apparatus having a plurality of nozzles. <11> The folding plate engagement member includes a cylindrical portion having the engagement crimping teeth, and flange portions on both sides of the cylindrical portion, the flange portions having a diameter larger than that of the cylindrical portion. The aforementioned <6> 2. The sheet processing apparatus according to claim 1, wherein the sheet processing apparatus is a sheet processing apparatus. <12> the flange portions abut against the sheet stack sandwiched between the folding plate member and the folding plate engaging member from both sides of the cylindrical portion; The aforementioned <11> 2. The sheet processing apparatus according to claim 1, wherein the sheet processing apparatus is a sheet processing apparatus. <13> before Recording pressure The binding means forms two parallel creases in the longitudinal direction on the spine of the sheet bundle. The above< 4 The sheet processing apparatus is described in the above. <14> the spine of the sheet stack is a substantially flat portion formed between the two creases; The aforementioned <13> 2. The sheet processing apparatus according to claim 1, wherein the sheet processing apparatus is a sheet processing apparatus. <15> The engaging crimping teeth have a concave-convex shape that is repeatedly formed in the longitudinal direction of the spine of the sheet stack. The aforementioned <6> 2. The sheet processing apparatus according to claim 1, wherein the sheet processing apparatus is a sheet processing apparatus. <16> The engaging and crimping teeth are inclined in the longitudinal direction of the spine of the sheet stack and have a repeatedly formed concave and convex shape. The aforementioned <6> 2. The sheet processing apparatus according to claim 1, wherein the sheet processing apparatus is a sheet processing apparatus. <17> The folding plate member has a surface facing the folding plate engaging member, the surface having concave and convex folding plate pressing teeth at a plurality of locations, and the surface facing the folding plate engaging member has a flat portion other than the concave and convex portions. The aforementioned <6> 2. The sheet processing apparatus according to claim 1, wherein the sheet processing apparatus is a sheet processing apparatus. <18> an image forming device that forms an image on a sheet material; The image forming apparatus includes an internal paper discharge unit. <1> and the above <17> a sheet processing apparatus according to any one of The image forming system is characterized by the above. <19> an image forming device that forms an image on a sheet material; a sheet processing device that performs a predetermined process on a sheet material on which an image has been formed in the image forming device; An image forming system comprising: The sheet processing apparatus <1> and the above <17> The sheet processing apparatus according to any one of the above items, The image forming system is characterized by the above. <20> a center folding unit for performing center folding on a sheet bundle made up of a plurality of sheet materials; The aforementioned The sheet bundle that has been subjected to center folding processing Pressure-sealed binding process A sheet processing method that can be performed in a sheet processing apparatus that includes a pressure binding unit, before Recording pressure In the binding means, The aforementioned The sheet stack Centerfold In a state of being clamped by a means The pressure binding Perform processing , The sheet processing method is characterized by the above. [Explanation of symbols]

[0174] 19: Controller 100: Image forming device system 101: Image forming device 102: Operation panel 110: Post-processing device 117: Staple end binding processing unit 118: Crimped end binding processing section 119: Discharge roller pair 120: Output tray 131: Movable end fence 132: Folding blade 132a: Folding and crimping teeth 132b: Pressure roller rail 133: Pair of folding rollers 134: Folding blade engaging roller 134a: Engagement crimp teeth 134b: flange part 135: Pair of center-folded booklet discharge rollers 136: Center-fold booklet output tray 141: Folding blade movement motor 142: Folding roller pair rotation motor 143: Folding roller pair contact / separation motor 144: Folding roller pair pressure member 145: Folding blade engagement roller scanning motor 146: Engagement roller guide rail 147: Folding blade engaging roller pressure member 177: Upper crimping teeth 178: Lower crimping teeth 181: Folding blade engagement die 181a: Die crimping part 181b: Flange part 182: Folding blade engagement die moving motor 183: Folding blade engagement die pressure member 184: Folding blade 184a: Folding and crimping teeth 185: Folding blade engagement die 185a: Crimping part 186: Folding blade engagement die 186a: Crimping part 187: Pressure roller 187a: Crimping part 188: Pressure roller movement motor 191: Folding blade engaging roller 191a: Heat pressing section 191b: Flange part 192: Folding blade engagement die 192a: Heat pressing section [Prior art documents] [Patent documents]

[0175] [Patent Document 1] Japanese Patent Application Laid-Open No. 2014-031268 [Patent Document 2] Patent No. 6089675 [Patent Document 3] Japanese Patent Application Laid-Open No. 2004-168012 [Patent Document 4] Patent No. 5361858 [Patent Document 5] Japanese Patent Application Laid-Open No. 2004-209858

Claims

1. a center folding unit for performing center folding on a sheet bundle made up of a plurality of sheet-like media; a pressure binding unit for performing a pressure binding process on the sheet bundle that has been subjected to the center-folding process; A sheet processing apparatus comprising: The center folding means is a folding plate member that guides the sheet stack in a predetermined direction; a pair of folding rollers that convey the sheet stack guided by the folding plate member in the predetermined direction while sandwiching the sheet stack therebetween, The sheet bundle is sandwiched between the pair of folding rollers, and the pressure binding process is performed in a state where the sheet bundle is stopped. A sheet processing apparatus characterized by:

2. The pressure binding means is The folding plate member; a folding plate engaging member that engages with the folding plate member via the sheet bundle; Equipped with The sheet processing apparatus according to claim 1 .

3. the folding plate engagement member is biased toward the folding plate member; the folding plate engaging member and the folding plate member press the sheet stack to form a spine; The sheet processing apparatus according to claim 2 .

4. The folding plate engaging member is a roller-shaped member supported by a journal, a spine forming process for forming the spine of the sheet bundle by reciprocating in the longitudinal direction of the spine and a pressure binding process; The sheet processing apparatus according to claim 3 .

5. the folding plate member has a folding plate pressing tooth having a concave-convex shape on a surface facing the folding plate engaging member, The folding plate engaging member has engagement crimping teeth having a concave-convex shape that engage with the folding plate crimping teeth. The sheet processing apparatus according to claim 2 .

6. the folding plate engaging member simultaneously performs a spine forming process for forming the spine in the sheet bundle and the pressure binding process by moving the folding plate engaging member in the longitudinal direction of the spine. The sheet processing apparatus according to claim 3 .

7. The folding plate member has a plurality of spaced apart, concave-convex folding plate pressing teeth on a surface facing the folding plate engaging member, the folding plate engaging member has a plurality of spaced apart engaging crimping teeth having a concave-convex shape that engage with the folding plate crimping teeth, The crimp binding process is performed by moving the folding plate member toward the folding plate engaging member. The sheet processing apparatus according to claim 5 .

8. The folding plate engaging member is a plate-shaped blade member that faces the folding plate member, and the pressure binding process is performed by moving the blade member toward the folding plate member. The sheet processing apparatus according to claim 2 .

9. The pressure binding means is a first roller member having concave and convex teeth; a second roller member that engages with the first roller member via the sheet stack; It consists of The sheet processing apparatus according to claim 1 .

10. The folding plate engagement member includes a cylindrical portion having the engagement crimping teeth, and flange portions on both sides of the cylindrical portion, the flange portions having a diameter larger than that of the cylindrical portion. The sheet processing apparatus according to claim 5 .

11. the flange portion abuts against the sheet stack sandwiched between the folding plate member and the folding plate engaging member from both sides of the cylindrical portion; The sheet processing apparatus according to claim 10 .

12. The crimping binding means forms two parallel creases in the longitudinal direction on the spine of the sheet bundle. The sheet processing apparatus according to claim 3 .

13. the spine of the sheet stack is a substantially flat portion formed between the two creases; The sheet processing apparatus according to claim 12 .

14. The engaging and crimping teeth have a concave and convex shape repeatedly formed in the longitudinal direction of the spine of the sheet stack. The sheet processing apparatus according to claim 5 .

15. The engaging and crimping teeth are inclined in the longitudinal direction of the spine of the sheet stack and have a repeatedly formed concave and convex shape. The sheet processing apparatus according to claim 5 .

16. The folding plate member has a surface facing the folding plate engaging member, the surface having concave and convex folding plate pressing teeth at a plurality of locations, and the surface facing the folding plate engaging member has a flat portion other than the concave and convex portions. The sheet processing apparatus according to claim 5 .

17. an image forming device that forms an image on a sheet material; The image forming apparatus is provided with the sheet processing apparatus according to claim 1 in an internal paper discharge section. An image forming system comprising:

18. an image forming device that forms an image on a sheet material; a sheet processing device that performs a predetermined process on a sheet material on which an image has been formed in the image forming device; An image forming system comprising: The sheet processing apparatus is the sheet processing apparatus according to claim 1. An image forming system comprising:

19. A sheet processing method that can be performed in a sheet processing apparatus that includes a center folding unit that performs a center folding process on a sheet bundle made up of a plurality of sheet-like media, and a pressure binding unit that performs a pressure binding process on the sheet bundle that has been center folded, In the pressure binding means, The sheet bundle is sandwiched by the center folding means, and the pressure binding process is performed in a state where the sheet bundle is stopped. A sheet processing method comprising:

Images