Sheet processing device, sheet processing method, and image formation 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] There is known a sheet processing apparatus capable of performing a "binding process" for binding a sheet bundle obtained by bundling sheet-like recording media. There are several types of binding processes that are performed by the sheet processing apparatus. For example, there is known an "end binding process" for binding an end of a sheet bundle, and a "saddle stitching process" for folding a sheet bundle in half and binding the vicinity of the folding position. The saddle stitching process is a binding method that is mainly used when producing a book such as a pamphlet.

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

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

[0005] Also, a staple saddle stitching device that folds the spine of a booklet into a square shape has been disclosed that has a groove in a 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 pressure stitches the center of a booklet and then performs center folding processing, with the aim of providing a staple-free bound booklet (see, for example, Patent Document 4).

[0007] Also, a bookbinding device has been disclosed that uses an electrophotographic image forming apparatus to form an adhesive toner layer on the edges of sheets, and then heats and pressurizes the 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 performing pressure saddle stitching and folding the corners of the booklet spine. However, when forming a saddle stitched booklet using these conventional techniques, there are problems such as the feeling of discomfort in the spread portion when turning the pages, or the pressure bonded portion being peeled off due to the load placed on the pressure bonded portion by the page turning operation. In other words, the conventional techniques have problems with the quality and binding strength of the finished product when pressure stitching 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 problems, the spine forming process of the present invention includes a center folding means for performing a center fold on a sheet bundle consisting of a plurality of sheet materials, and a spine crimp binding means for forming a spine on the sheet bundle on which the center fold has been performed and performing a crimp binding on the spine, and is characterized in that the spine crimp binding means has a spine forming section for forming the spine on the sheet bundle on which the center fold has been performed, and a crimp binding section for performing the crimp binding on the sheet bundle on which the center fold has been performed. Effect of the Invention

[0011] According to the present invention, it is possible to form a press-stitched saddle-stitched booklet that can be easily opened without the press-stitched binding coming undone by page-turning operations. [Brief description of the drawings]

[0012] [Figure 1] 1 is a diagram showing the overall configuration of an image forming system according to a first embodiment. [Diagram 2] FIG. 2 is a diagram showing the internal structure of the post-processing device according to the first embodiment. [Diagram 3] FIG. 4 is a schematic diagram of the edge stitching processing section as viewed from the discharge port side. [Figure 4] FIG. 4 is a schematic diagram showing a configuration of crimping teeth of a crimped-end binding processing section. [Diagram 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] 11 is a cross-sectional view showing the operation of the pressure-bonding saddle stitching processing unit. FIG. [Figure 8] FIG. 13 is a schematic diagram showing the pressing state of the pressure-bonding saddle stitching processing section. [Figure 9] FIG. 2 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. 13 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 unit. FIG. [Figure 13] 13A and 13B are cross-sectional views showing the operation of the second modified example of the pressure-bonding saddle-stitching processing unit. [Figure 14] 13A and 13B are cross-sectional views showing the operation of the pressure-bonding saddle-stitching processing unit according to the third modified example. [Figure 15] 13A and 13B 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 compression 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] 13 is a cross-sectional view showing the operation of the seventh modified example of the pressure-bonding saddle stitching processing section. FIG. [Figure 21]FIG. 13 is a schematic diagram showing Modification 8 of the pressure-bonding saddle-stitching processing section. [Figure 22] 13 is a cross-sectional view showing the operation of the pressure-bonding saddle stitching processing unit according to Modification 8. FIG. [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 the pressure-bonding saddle-stitching processing unit according to Modification 9. [Diagram 25] FIG. 13 is a diagram showing the overall configuration of an image forming system according to a second embodiment. [Figure 26] FIG. 11 is a diagram showing the internal structure of a post-processing device according to a second embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[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 a 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 on which the image has been formed to a post-processing apparatus 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 executing a known image forming method. For example, it may be an inkjet method in which liquid ink is ejected toward 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 detailed description will be given of a post-processing device 110 as an embodiment of a sheet processing device according to the present invention. Fig. 2 is a diagram showing an 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 paper P on which an image has been formed by the image forming device 101, and receives paper P on which an image has been formed from an entrance 1100 that receives paper P from the image forming device 101, and performs binding processing to bind a paper stack Pb of multiple sheets bound together.

[0016] More specifically, the binding process according to this embodiment includes "pressure binding" in which pressure is applied to the binding position of a paper stack Pb formed by stacking multiple sheets of paper P to deform the paper stack Pb, and "staple binding" in which a staple is used to bind the paper stack Pb at the binding position. Furthermore, pressure binding includes an end binding process in which an end of the paper stack Pb is bound, and a saddle binding process in which the center of the paper stack Pb is bound.

[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 from an 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 section 117 and a crimp end binding processing section 118 as end binding processing sections, 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 by the return transport rollers 113 is different from the transport direction by the first transport roller pair 111 and the second transport roller pair 112. In other words, the transport direction by the return transport rollers 113 is a direction that switches back from the transport direction by 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 the 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 stacking a plurality of sheets of paper P that are sequentially transported. The sheets of paper P stacked on the internal tray 114 are switchback-transported by the return transport rollers 113 to a position where they collide with an 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 by the switchback transport. The ends of the sheets of paper P stacked on the internal tray 114 are aligned by the end fence 115, and a sheet bundle Pb is formed.

[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 conveying direction of the paper P by the switchback conveyance, i.e., in the direction perpendicular to the conveying 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 fence 116 performs a "jogging motion" in which it repeatedly comes into contact with and separates from the widthwise ends of multiple sheets of paper P loaded on the internal tray 114. This jogging motion also aligns the widthwise ends of multiple sheets of paper P. In other words, the side fence 116 constitutes an alignment member for aligning both widthwise ends (both ends perpendicular to the transport 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 paper stack Pb aligned by the end fence 115 and the side fence 116.

[0026] After the stapling process is performed, the return transport rollers 113 come into contact with the paper 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 transport is performed. Therefore, the return transport rollers 113 discharge the paper stack Pb that has been subjected to the edge stitching process from the first discharge port 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, there are "parallel binding processes" that perform binding processes along one side parallel to the main scanning direction (see FIG. 3) of the paper stack Pb, "diagonal binding processes" that perform binding processes at corners of the paper stack Pb, and "two-point binding processes" that perform binding processes at multiple points spaced apart in the width direction along one side parallel to the transport direction of the paper stack Pb.

[0028] 3 is a schematic diagram of the end binding processing unit 1110 including the staple end binding processing unit 117 and the crimp end binding processing unit 118, viewed from the first discharge port 1101 in the direction of the end fence 115. As shown in FIG. 3, the end binding processing unit 1110 is attached to an end 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 the end 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 movably along the guide shaft 152.

[0029] The staple end binding processing unit 117 includes a staple end binding main scanning movement motor 161, a driving 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 driving 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 stapling processing unit 117 includes a staple-end stapling posture rotation motor 164 and rotates about a staple-end stapling rotation shaft 165 as a rotation center relative to the staple-end stapling processing unit base member 163 .

[0032] The staple-end stapling processing unit 117 is provided with a staple-end stapling clinch motor 166, and performs stapling processing 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 driving 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 driving 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 a pulley 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 with respect to the crimp-end binding processing section base member 173 about a crimp binding rotation shaft 175 as a rotation center.

[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 stack Pb to be sandwiched between the uneven upper crimping teeth 177 and the lower crimping teeth 178 and deformed by pressure. This pressure deformation causes the fibers of the sheets P that make up the paper stack Pb to become entangled, and a single bundle of paper stacks Pb is formed from a plurality of sheets P. This binding process using pressure deformation is referred to as "pressure binding."

[0037] FIG. 4 is a schematic diagram showing the configuration of the upper and lower crimping teeth 177 and 178 as the crimping section provided in the crimp end binding processing section 118. As shown in FIG. 4, the crimping section 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 paper stack Pb so that the paper stack Pb placed on the internal tray 114 can be sandwiched. The upper and lower crimping teeth 177 and 178 are formed in an uneven shape with concave and convex portions alternately formed. In addition, the upper and lower crimping teeth 177 and 178 are formed with the concave and convex portions shifted so as to mesh with each other. The crimping section is configured so that the upper and lower crimping teeth 177 are opened and closed (approach and separate) relative to the lower crimping teeth 178 by the driving force of the crimp end binding clinch motor 176.

[0038] In the process in which a plurality of sheets P constituting the sheet bundle Pb are supplied to the internal tray 114, the upper pressure teeth 177 and the lower pressure teeth 178 are separated from each other, as shown in FIG. 4(a). Then, when all sheets P constituting the sheet bundle Pb are placed on the internal tray 114 and a predetermined alignment operation (operation of aligning the ends) is completed, the pressure-end binding processing unit 118 moves to the binding position, and the upper pressure teeth 177 and the lower pressure teeth 178 approach and mesh with each other, as shown in FIG. 4(b). That is, the upper pressure teeth 177 and the lower pressure teeth 178 sandwich the predetermined binding position for the sheet bundle Pb, and pressurize and deform the sheet bundle Pb from the thickness direction. As a result, the sheet bundle Pb placed on the internal tray 114 is pressure-bound and bound. Then, the pressure-bound sheet bundle Pb is discharged from the first discharge port 1101 to the discharge tray 120 by the discharge roller pair 119.

[0039] In addition, since the crimp end binding processing unit 118 only needs to exert a function of pressing the paper stack Pb to press a specific position, it is sufficient that the upper and lower crimping teeth 177 and 178 mesh and press when the paper stack Pb is sandwiched between them and bound. Therefore, the configuration capable of executing the operation of closing the upper and lower crimping teeth 177 and 178 is not limited to the configuration example disclosed in this embodiment. For example, it may be a crimping mechanism of a link mechanism type (for example, one disclosed in Japanese Patent No. 6057167) that performs the operation of approaching (crimping) and separating the upper and lower crimping teeth 177 and 178 using a drive source and a link mechanism that rotates forward or backward only. It may also be a linear type crimping mechanism that performs the operation of pressing and separating the upper and lower crimping teeth 177 and 178 linearly by a screw mechanism that converts the rotational motion of the drive source into linear motion.

[0040] 3, the crimping unit includes a binding tooth slide mechanism for moving the upper crimping teeth 177 and the lower crimping teeth 178 relative to the frame of the crimped 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 and lower crimping teeth 177 and 178 is, for example, equal to the length of the crimp mark. The upper and lower crimping teeth 177 and 178 perform multiple crimp binding operations before and after the slide movement. That is, when the length of the crimp mark by the upper and lower crimping teeth 177 and 178 is 10 mm, by setting the amount of slide movement to 10 mm, the length of the crimp mark can be set to 20 mm by combining the crimping operation before the slide movement (first stroke) and the crimping operation after the slide movement (second stroke), and the binding force is improved by about two times.

[0042] [Binding process overview] 5 is a diagram 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. 5(a) illustrates a standby state (standby state) for the binding process. As shown in FIG. 5(a), in the standby state, the staple end binding processing unit 117 is located at a staple standby position HP1. And the crimp end binding processing unit 118 is located at a crimp standby position HP2.

[0043] 5(b) and 5(c) show an example of the oblique binding process performed by the crimp-end binding processing unit 118. As shown in Fig. 5(b), before the first sheet P1 of the paper stack Pb is supplied to the internal tray 114, the crimp-end binding processing unit 118 is moved in the main scanning direction and obliquely rotated 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 as a control means, which will be described later in Fig. 10.

[0044] 5(c), the controller 19, with the crimp-end binding processing unit 118 positioned at a position facing the first binding position B1, executes a jogging operation every 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. 5C, 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 stack 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 stapling processing unit 118 to the press-stapling standby position HP2 shown in FIG.

[0048] 5(d) and 5(e) illustrate the state in which the two-point stapling process is performed by the staple-end stapling processing unit 117. The second stapling position B2 and the third stapling position B3 are spaced apart from each other in the main scanning direction. Before the first sheet P1 constituting the paper stack Pb is supplied to the internal tray 114, the controller 19 moves the staple-end stapling processing unit 117 in the main scanning direction so that the staple-end stapling processing unit 117 can face the second stapling position B2. Next, as shown in FIG. 5(d), in a state in which the staple-end stapling processing unit 117 has been moved to a position where it can face the second stapling 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 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 stapling processing unit 117 to face the third stapling position B3, and executes the stapling operation on the paper stack Pb placed on the internal tray 114 at the third stapling position B3.

[0052] In the example of FIG. 5, in the two-point binding, the binding process is performed for the second binding position B2, and then the binding process for the third binding position B3. However, the order of performing the two-point binding is not limited to this. That is, two-point binding may be performed by binding the third binding position B3 and then the second binding position B2. In the case where the number of bound copies is consecutive, the third binding position B3 is bound after the second binding position B2 for odd-numbered copies, and the second binding position B2 is bound after the third binding position B3 for even-numbered copies. In this way, the efficiency of the binding process can be improved by performing the binding process by switching the order of the binding positions according to the order of the entire number of bound copies.

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

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

[0055] [Outline of the pressure-bonding saddle stitching processing unit] Returning to Fig. 2, a detailed description will be given of the portion of the post-processing device 110 that performs the pressure saddle stitching process. As shown in Fig. 2, the post-processing device 110 includes a return conveying roller 113, an internal tray 114, a side fence 116 (not shown), a movable end fence 131, a folding blade 132, a folding roller pair 133, a folding blade engagement roller 134, a half-folded booklet discharge roller pair 135, and a half-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 portion in the transport direction of the paper P placed on the internal tray 114 to align the center-folding position, which is set near the center of the paper P in the transport 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 and adjusts the center folding position of the sheet bundle Pb to a position facing the folding blade 132. Alternatively, at the stage of stacking the predetermined number N of sheets P constituting the sheet bundle Pb, the position of the movable fence may be moved so that the center folding position of the sheet bundle Pb is a position facing the folding blade 132, and then the sheets P may be stacked on the internal tray 114. In either case, the center folding 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, in a state where these adjustments have been 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, at the timing when the paper P carried in from the image forming apparatus 101 passes through the second conveying roller pair 112 and is placed on the internal tray 114, the return conveying roller 113 causes the paper P to be switched back and conveyed toward the movable end fence 131. A series of steps leading up to this switchback conveyance corresponds to a conveying step. At this time, the movable end fence 131 may have already moved to a position corresponding to the 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 in sequence. A movable end fence 131 that is movable toward the conveying direction side of the end fence 115 is provided for the internal tray 114. The movable end fence 131 is a member that is movable in the conveying direction of the sheets P along the internal tray 114. The movable end fence 131 corresponds to a configuration that moves under the control of the controller 19 according to the conveying direction length of the sheets P placed on the internal tray 114 (which also has the same meaning as the conveying direction length in switchback conveyance), and changes the position of the sheets P. The position of the movable end fence 131 is set so that the center position of the conveying direction length of the sheets P faces 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 stitch processing unit performs pressure saddle stitching on the sheet stack Pb aligned by the movable end fence 131 and the side fence 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 the crimping saddle stitching means] Next, the operation of the pressure saddle stitching means will be described with reference to FIG. 6 and the like. FIG. 6 is a schematic diagram showing an outline of the saddle stitching process by mainly showing the folding blade 132 as a folding plate member constituting the pressure saddle stitching means, the folding roller pair 133 as a folding roller pair member, and the folding blade engagement roller 134 as a folding plate engagement member. FIG. 6(a) illustrates a state in which the paper stack Pb is loaded on the internal tray 114 after the conveying process and the loading process, the ends of the paper P are aligned, and the positions of all the paper 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 at the initial positions.

[0063] The initial position of the folding blade 132 is a position separated from the surface of the paper stack Pb in a direction substantially perpendicular to the paper stack Pb. In the initial position, the folding blade 132 faces a folding position where the paper stack Pb is folded in the middle, and is configured to move forward and backward in the thickness direction of the paper stack Pb by a folding blade moving motor 141 (FIG. 10) constituting a folding plate member moving mechanism. The folding blade 132 moves forward and backward with respect to the paper stack Pb between a pushing position for forming a fold in a center folding process for folding the central portion of the paper stack Pb in the conveying direction length as part of the paper stack Pb, and a retreat position for removing the folding blade 132 from the paper stack Pb after folding the center of the paper stack Pb. The retreat position of the folding blade 132 corresponds to the initial position (HP position).

[0064] The folding roller pair 133 is disposed symmetrically with respect to the center line of the folding blade 132. That is, the folding roller pair 133 is disposed in 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 folding roller pair 133 is configured to be rotated by a folding roller pair rotation motor 142 (see FIG. 10). The folding roller pair 133 is also configured to be capable of approaching and separating from each other by a folding roller pair contact / separation motor 143 (see FIG. 10) constituting 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 paper 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" where the nip position is spaced apart according to a predetermined separation amount under the control of the controller 19. 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 paper stack Pb is also a standby position during the center folding and binding process, and therefore corresponds to a standby position.

[0066] The folding blade engagement roller 134 constituting the back pressure 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 supported so as to be rotatable about the rotation axis. The folding blade engagement roller 134 has an engagement pressure tooth portion 134a having a concave-convex shape on the outer periphery of the cylindrical portion (cylindrical outer periphery surface). The folding blade engagement roller 134 also has flange portions 134b on both ends of the cylindrical portion, the outer diameter of which is larger than that of the engagement pressure tooth portion 134a. The flange portions 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. The irregularities are formed parallel to the rotation axis of the folding blade engagement roller 134.

[0068] In the press-fit saddle-stitching process according to the present embodiment, first, a center-folding process is performed. In the center-folding process, first, the controller 19 adjusts the position of a pair of rollers constituting the folding roller pair 133 by the folding roller pair approaching and separating motor 143 to make it possible to receive the paper stack Pb. The folding roller pair approaching and separating motor 143 adjusts the gap at the nip position of the folding roller pair 133, and the adjustment amount (separation amount) at this time is for forming a gap that allows the folding blade 132 to push the vicinity of the center of the paper stack Pb in the conveying direction (length direction) into the nip position (gap) of the folding roller pair 133 and for the folding blade 132 to proceed through the nip position while pushing the paper stack Pb. Therefore, the adjustment amount of the gap at the receiving position of the folding roller pair 133 is changed according to the predetermined number N of sheets P constituting the paper stack Pb, size information including the size and thickness of the paper stack P, and the like.

[0069] That is, as a preliminary step to the center folding process, when the folding blade 132 guides the sheet stack Pb to the gap (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 stack Pb to pass between the rollers. At this time, in the "receiving position" which is the position of the rollers constituting the folding roller pair 133, for example, the outer circumferences of the rollers are slightly separated from each other.

[0070] 6(b), the folding blade 132 guides the sheet stack Pb toward the nip position of the folding roller pair 133. At this time, the folding roller pair 133 is pressed toward the sheet stack Pb by the elastic force of the folding roller pair pressure member 144 (see FIG. 8). That is, the degree to which the sheet stack Pb is pressed against the folding blade 132 is determined by the elastic force of the folding roller pair pressure member 144. At this time, the pressing of the folding roller pair 133 against the sheet stack Pb and the advancement of the folding blade 132 form a fold in the sheet stack Pb.

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

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

[0073] 6(c), the tip of the folding blade 132 continues to move to a position sufficiently beyond the nip position of the pair of folding rollers 133, and the center folding process of the sheet stack Pb proceeds. In this center folding process, a portion of the sheet stack Pb (a portion substantially at the center in the conveying direction) becomes a fold portion Fp (see FIG. 9). When the center folding process shown in FIG. 6(b) and FIG. 6(c) is being performed, the folding blade engagement roller 134 is located in a retracted position spaced apart from the tip of the 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 retreated position toward the folding blade 132. The destination of the movement at this time is an engagement position where the folding blade engagement roller 134 and the folding blade 132 come into contact with each other via the stack of paper Pb. When the folding blade engagement roller 134 moves to the engagement position, the folding blade 132 and the folding blade engagement roller 134 are in a pressing state in which the stack of paper Pb is sandwiched between them. In this pressing state, the stack of paper Pb is pressed from both sides so that the folding pressure tooth portion 132a formed as a concave-convex shape at the tip of the folding blade 132 and the engagement pressure tooth portion 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] Also, while pressure binding is being performed on the fold portion Fp of the paper stack Pb, the action of the flange portion 134b of the folding blade engagement roller 134 and the folding blade 132 folds the paper stack Pb 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 paper stack Pb is formed with a spine Cb (see FIG. 9) having a width equivalent to the distance between the flanges 134b of the folding blade engagement rollers 134 that face each other starting from the center of the conveyance direction length. 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. That is, this process corresponds to a spine pressure binding process in which the spine Cb is formed while forming two parallel creases f, and pressure binding is performed on the spine Cb at the same time or after the formation of the spine Cb.

[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 portion 132a of the folding blade 132 and the engagement pressure teeth portion 134a of the folding blade engagement roller 134 form a plurality of binding marks (pressure marks) approximately perpendicular to the fold f, that is, a pressure mark group Ct shown in FIG. 9.

[0078] That is, in a state in which the folding blade 132 and the folding blade engagement roller 134 press and pinch the paper stack Pb, the controller 19 causes the folding blade engagement roller 134 to scan in the width direction (main scanning direction) of the paper stack Pb. Then, when the folding blade engagement roller 134 moves in the width direction, the folding blade engagement roller 134 moves while rotating. In other words, the folding blade engagement 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 wraps and pinches the paper 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 paper stack Pb while simultaneously or after the spine Cb is formed, and 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 paper stack 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 paper stack Pb through between the pair of folding rollers 133, and discharges the pressure-bonded saddle-stitched booklet with the spine Cb pressure-bonded to a center-folded booklet discharge tray 136 (see FIG. 2).

[0081] As described above, the post-processing device 110 according to the present embodiment performs a compression saddle stitching process on the paper stack Pb, first performing a center folding process, and then performing a spine folding process to form the spine Cb of the center folded paper stack Pb. Then, either at the same time or after the spine Cb is formed, compression stitching is performed on the spine Cb to complete the compression saddle stitching process. That is, in the compression saddle stitching process method as an embodiment of the sheet processing method according to the present invention, a center folding process is followed by a spine forming process, and either at the same time or after the spine Cb is formed, a compression stitching process (spine compression stitching process) is performed on the spine Cb. This makes it possible to form a compression saddle stitched booklet that is easy to open without the compression stitching coming off due to folding and page turning operations, unlike the conventional method.

[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 folding blade engaging roller 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, it is possible to perform the spine forming process and the pressure binding process in any order.

[0083] 7 is a cross-sectional view showing the operation of the pressure saddle stitch processing unit, as viewed from the paper conveying 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 center line 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 described, 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 paper stack 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 paper stack Pb in the booklet form when the center folding process is performed on the paper stack Pb. The waiting position at this time 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 paper stack Pb that is pushed into the nip position of the folding roller pair 133 and advances, and corresponds to a position in which it is separated from the paper stack Pb. Note that, of the components of the folding blade engagement roller 134, only the engagement and pressing teeth portion 134a are shown in FIG. 7.

[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 stitch 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 engagement roller guide rail 146 has a dimension longer than the dimension of the stack of paper Pb in the main scanning direction, and the portion outside the end of the stack of paper Pb in the main scanning direction is separated from the fold of the stack of paper Pb that has passed the nip position of the folding roller pair 133. Also, the engagement roller guide rail 146 is adapted to approach the fold of the stack of paper Pb that has passed the nip position of the folding roller pair 133 at the portion inside the end of the stack of paper Pb in the main scanning direction.

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

[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 to pressurize and deform the paper stack Pb sandwiched between the folding blade 132. When the folding blade engagement roller 134 is at the fold of the paper 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 paper stack Pb so that the paper stack Pb is not pushed back. The control for maintaining the pressurized state of the folding roller pair 133 is executed by the controller 19. That is, when the pressurized saddle stitching process is executed for the paper 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, by pressing the folding blade engagement roller 134 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 with each other so as to sandwich the paper stack Pb. As a result, the spine Cb of the paper stack Pb is pressurized and deformed in the main scanning direction, and the spine crimp binding process is performed.

[0091] The folding pressure tooth portion 132a has a concave portion and a convex portion arranged at a predetermined interval in the main scanning direction, like the rack tooth profile 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 tooth portion 134a of the folding blade engagement roller 134 and the folding pressure tooth portion 132a of the folding blade moves in the main scanning direction. This movement of the meshing position (engagement position) executes pressure binding for the spine Cb of the paper stack Pb. Then, while pressure binding is being executed, the folding roller pair 133 is maintained in a state of being pressed toward the nip position so that the folding blade engagement roller 134 can reciprocate in the main scanning direction while maintaining the engagement position. This prevents the paper 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 approaches the spine Cb formed on the paper stack Pb, it moves obliquely from the outside in the width direction of the paper stack Pb toward the spine Cb. As a result, the engagement and crimping teeth 134a of the folding blade engagement roller 134 approaches from a direction that does not collide with the end in the width direction of the spine Cb of the paper stack Pb, and the position of engagement with the folding and crimping teeth 132a of the folding blade 132 starts from the inside of the end in the width direction of the paper stack Pb. This makes it possible to prevent the end from being turned up when the folding blade engagement roller 134 passes over the end of the paper stack Pb.

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

[0094] When the next sheet bundle Pb is successively pressure-stitched, it moves in the opposite direction in the main scanning direction, that is, from left to right in FIG. 7B for odd-numbered copies and from right to left in FIG. 7B for even-numbered copies.

[0095] Although the folding blade engagement roller contact / separation mechanism according to the present embodiment is exemplified by 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 in the center-folding discharge direction so as to be able to advance and retreat may be further provided.

[0096] 8 is a schematic diagram showing a state when the pressure-bonding saddle-stitching processing unit presses the paper 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 transport direction of the paper stack Pb placed and stacked on the internal tray 114 toward the nip position of the folding roller pair 133 as a predetermined direction.

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

[0098] That is, the folding roller pair 133 is biased toward the folding blade 132 by the folding roller pair pressure member 144 so that the folding roller pair 133 pinches the folding blade 132 and the paper stack Pb at the nip position. This biasing causes the folding roller pair 133 to press the folding blade 132 passing through the nip position. Note that since the folding roller pair pressure member 144 is an elastic member such as a spring, 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 elasticity 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 by the end of the folding blade 132 in the moving direction pressing the fold portion while the sheet stack Pb passes between the pair of folding rollers 133. 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 engagement roller 134 is pressed toward the folding blade 132 with the paper stack Pb sandwiched therebetween by a folding blade engagement roller pressure member 147. The folding blade engagement roller 134 is a roller-shaped member and is supported on a shaft. The rotation shaft of the folding blade engagement 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 serving as a cylindrical portion having a predetermined width in the rotation axis direction, and flange portions 134b serving 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 paper stack Pb interposed between the folding blade 132 by the force of the folding blade engagement roller pressure member 147, and performs pressure binding. Then, by being pressed toward the folding blade 132 by the engagement pressure tooth portion 134a, the part of the paper stack Pb sandwiched between the end of the folding blade 132 in the thickness direction and the flange portion 134b is directed in the direction along the folding blade 132, and the part of the paper stack Pb sandwiched between the flange portion 134b and the folding blade 132 is folded. This folding direction is the opposite direction to the direction of entry of the folding blade 132. At this time, the folded parts are formed at two places with a predetermined interval in the thickness direction of the folding blade 132, so that two fold lines are formed on the paper stack Pb by the pressure binding operation. As a result, a square spine is formed at the folded part of the paper stack Pb, and a spine Cb that is a substantially flat part is formed between the fold lines. That is, the spine is folded at a square shape by the spine compression binding process.

[0103] [Booklet Bk] FIG. 9 is a perspective view illustrating a booklet Bk formed by the above-described press saddle stitching operation. As shown in FIG. 9, the booklet Bk is formed by folding the paper stack Pb at the crease Fp by the center folding process, and a square spine is formed on the spine Cb. Then, on the spine Cb, a group of pressure marks Ct, which are deformed by the engagement pressure teeth 134a and the folding blade 132, are formed at a predetermined interval in the longitudinal direction of the spine Cb. This group of pressure marks Ct can be formed at a position that overlaps with the position (crease Fp) where the paper stack Pb is folded in the center folding process. In addition, the booklet Bk has two creases f that form the spine Cb as movable parts when a page is turned over. The two creases f are formed near both sides of the group of pressure marks Ct.

[0104] Therefore, the booklet Bk by the pressure saddle stitching process according to this embodiment has a structure in which the load is not applied to the pressure bonded portion when a page is turned at the fold f, and therefore does not induce peeling of the bound portion due to the page turning operation. In addition, since the fold f is formed at two places on either side of the spine Cb, the fold f that moves during the page turning operation is one of the two places. This fold f is at 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 is the binding position of the pressure binding.

[0105] Therefore, when a page is turned over, the page is turned over at the fold f, and the fold portion Fp, which corresponds to the center of the booklet Bk when it is open, is bound, so that the page is not turned over 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] Fig. 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 calculation means and controls the operation of the entire 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 working 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 capable of reading and writing information and has a large storage capacity, and stores an OS (Operating System), various control programs, application programs, etc.

[0108] The post-processing device 110 processes a control program stored in the ROM 13, an information processing program (application program) loaded from a storage medium such as the HDD 14 to the RAM 12, and the like, by using a calculation function provided in the CPU 11. A software control unit including various functional modules of the post-processing device 110 is configured by this processing. A combination of the software control unit configured in this manner and hardware resources mounted on the post-processing device 110 configures functional blocks that realize the functions of the post-processing device 110. That is, the CPU 11, the RAM 12, the ROM 13, and the HDD 14 configure 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 approach / 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 teeth slide motor 179, the crimp roller moving motor 188, and the operation panel 102 to the common bus 16.

[0110] Through the I / F 15, the controller 19 operates 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 approach / 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 teeth 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, and the like. The operation panel 102 obtains information from the user through the operation unit, and provides the information to the user through the display. Note that a specific example of the notification unit is not limited to a display, and may be an LED lamp, a speaker, or the like. 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 with 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 the same reference numbers are used for components common to the pressure-bonding saddle stitching processing unit according to the first embodiment, and detailed descriptions thereof will be omitted.

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

[0114] The folding blade engagement die 181 is provided with a die crimping portion 181a including a concave and convex shape as a group of multiple engaging crimping teeth in the longitudinal direction on the surface facing the folding blade 132. The folding blade 132 is provided with a folding crimping tooth portion 132a as a group of folding plate crimping teeth that engages with the die crimping portion 181a as a group of engaging crimping teeth on the surface facing the folding blade engagement die 181. When the folding blade 132 pushes the paper stack Pb into the pair of folding rollers 133 and the fold of the paper 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 to perform 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 that 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 pressure binding. As a result, a pressure mark group Ct including a plurality of pressure marks is formed on the spine Cb along the longitudinal direction of the spine Cb. The direction of the pressure marks included in the pressure 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 stack Pb.

[0116] Fig. 12 is a cross-sectional view showing the operation of the first modified example of the pressure-bonding saddle-stitching processing unit. It is a cross-sectional view taken along the BB line as seen from the paper transport 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. Fig. 12(a) corresponds to the state of Fig. 6(c). The folding blade 132 pushes the paper stack Pb to a position beyond the nip position of the pair of folding rollers 133, and the folding blade engagement die 181 is in the standby position (HP position) and is separated 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] Fig. 12(b) corresponds to the state of Fig. 6(d). The folding blade engagement die 181 is pressed against the folding blade 132, sandwiching the paper stack Pb, and the concave and convex teeth of the die pressure bonding portion 181a of the folding blade engagement die 181 and the folding pressure bonding tooth portion 132a provided on the pushing surface of the folding blade 132 engage with each other, sandwiching the paper stack Pb. The folding blade engagement die 181 is pressed by the folding blade engagement die pressure member 183, so that the spine of the paper stack Pb is pressure-bound.

[0119] [Variation 2] Next, a second modified example of the pressure saddle stitch processing unit will be described with reference to FIG. 13. The difference from the first modified example is that the folding blade 184 does not have uneven pressure teeth uniformly arranged in the width direction, but has a plurality of partial (intermittent) pressure teeth as a folding plate pressure teeth group. Also, in the folding blade engagement die 185, a pressure tooth group as an engagement pressure tooth group is arranged at a position facing the folding plate pressure teeth group. The portion where the engagement pressure tooth group is not arranged is a substantially flat portion. The same reference numbers are used for the components common to the pressure saddle stitch processing unit according to the first embodiment, and detailed description thereof will be omitted.

[0120] Fig. 13 is a cross-sectional view showing the operation of modified example 2 of the pressure-bonding saddle-stitching processing unit. It is a cross-sectional view seen from the paper transport direction side at the center line of the center fold, in other words, the center position of the thickness of the folding blade 132. Fig. 13(a) corresponds to the state of Fig. 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 at the standby position (HP position) and is separated from the paper stack Pb in the center fold discharge direction.

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

[0122] Fig. 13(b) corresponds to the state of Fig. 6(d). The folding blade engagement die 185 is pressed against the folding blade 184, sandwiching the paper stack Pb, and the concave and convex teeth of the pressure-bonding portion 185a of the folding blade engagement die 185 and the concave and convex teeth of the folding pressure-bonding portion 184a provided on the pushing surface of the folding blade 184 engage with each other, sandwiching the paper stack 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 paper stack Pb is pressure-bonded and bound.

[0123] [Variation 3] Next, a third modified example of the pressure-bonding saddle stitching processing section will be described with reference to Fig. 14. The difference from the first modified example 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 are sequentially engaged with each other. Note that the same reference numbers are used for components common to the first embodiment of the pressure-bonding saddle stitching processing section, and detailed descriptions thereof will be omitted.

[0124] Fig. 14 is a cross-sectional view showing the operation of the third modified example of the pressure-bonding saddle-stitching processing unit. It is a cross-sectional view seen from the paper transport direction side at the center line of the center fold, in other words, the center position of the thickness of the folding blade 132. Fig. 14(a) corresponds to the state of Fig. 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 at 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] Fig. 14(b) corresponds to the state of Fig. 6(d). The folding blade engagement die 186 is pressed against the folding blade 132, sandwiching the paper stack Pb, and the uneven teeth of the pressure-bonding portion 186a of the folding blade engagement die and the uneven teeth of the folding pressure-bonding portion 132a provided on the pushing surface of the folding blade 132 sandwich and engage the paper stack Pb. The folding blade engagement die 186 is pressed by the folding blade engagement die pressure member 183, so that the spine of the paper stack Pb is pressure-bonded and bound.

[0127] In addition, the crimping portion 186a of the folding blade engagement die 186 is not flat but a curved surface, and concave and convex teeth of the crimping portion 186a are provided on the curved surface, and the folding blade engagement die 186 may be moved in a rotational trajectory so that the concave and convex teeth of the crimping portion 186a of the folding blade 132 sequentially mesh 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 sequentially mesh with the concave and convex teeth of the folding crimping tooth portion 132a of the folding blade 132, thereby reducing the pressure force during crimping binding and making it possible to miniaturize the device.

[0129] [Variation 4] Next, a fourth modified example 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 arranged on its outer periphery that moves in the main scanning direction. Note that the same reference numbers are used for components common to the pressure saddle stitching processing unit according to the first embodiment, and detailed descriptions thereof will be omitted.

[0130] Figure 15 is a cross-sectional view showing the operation of the fourth modified example of the pressure saddle stitch processing unit. It is a cross-sectional view seen from the paper transport 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 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 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 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] FIG. 15(b) corresponds to the state of FIG. 6(d). The folding blade engagement roller 134 as the 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 through the paper stack 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 pushing surface of the pressure roller 187 are engaged with the paper stack 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 paper stack Pb, so that the spine Cb of the paper stack Pb is pressure-bound.

[0133] [Variation 5] Next, a fifth modified example of the pressure-bonding saddle stitching processing unit will be described with reference to Fig. 16. The difference from the pressure-bonding 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 numbers are used for the components common to the pressure-bonding 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 the pressure saddle stitch processing unit of the fifth modified example. It is a cross-sectional view seen from the paper transport 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 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 in the standby position (HP position) and is separated from the paper stack Pb in the center fold discharge direction.

[0135] Fig. 16(b) corresponds to the state of Fig. 6(d). The folding blade engagement roller 134 is pressed against the folding blade 184, sandwiching the paper stack Pb, and the uneven teeth of the engagement pressure-bonding teeth portion 134a of the folding blade engagement roller 134 and the uneven teeth of the folding pressure-bonding teeth portion 184a provided on the pushing surface of the folding blade 184 mesh with each other, sandwiching the paper stack 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-bonding teeth portion 134a of the folding blade engagement roller 134 and the uneven teeth of the folding pressure-bonding teeth portion 184a of the folding blade 184 press and deform the paper stack Pb, so that the spine Cb of the paper stack Pb is pressure-bonded and bound.

[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 a predetermined interval, and a group of press marks Ct is formed at a predetermined interval in the longitudinal direction of the spine Cb (the width direction of the paper stack Pb).

[0137] [Variation 6] Next, a sixth modified example of the pressure saddle stitch processing unit will be described with reference to Figs. 18 and 19. The difference from the first embodiment is that the concave and convex teeth of the engagement pressure tooth 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 inclined to the main scanning direction. Here, the inclination angle of the concave and convex teeth of the engagement pressure tooth portion 134a is, for example, 15 degrees. The same reference numbers are used for the components common to the first embodiment of the pressure saddle stitch processing unit, and detailed description thereof will be omitted.

[0138] Fig. 19 is a schematic diagram of a press-stitched booklet bound in Modification 6. As illustrated in Fig. 19, the spine Cb of the booklet Bk is formed with a square spine. The spine Cb is press-stitched, and the pressure marks included in the pressure mark group Ct are formed in a line at an angle 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 section will be described with reference to Fig. 20. The difference from the pressure-bonding saddle stitching processing section 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 the same reference numerals are used for the components common to the pressure-bonding saddle stitching processing section according to the first embodiment, and detailed description thereof will be omitted.

[0140] Figure 20 is a cross-sectional view showing the operation of Variation 7 of the pressure saddle stitch processing unit. It is a cross-sectional view seen from the paper transport 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 at 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 separated 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] Fig. 20(b) corresponds to the state of Fig. 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 paper stack Pb, from a first predetermined position in the width direction of the paper stack Pb. At this time, the uneven 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 paper stack 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 paper stack 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 retreat position past the end of the paper stack, and press-staples approximately half of the width of the paper stack Pb.

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

[0146] Next, as shown in FIG. 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 until it passes through the other end of the paper stack Pb while again pressing the paper stack Pb.

[0147] The folding blade engagement roller 134 is guided by the engagement roller guide rail 146a and moves along a trajectory that draws a figure eight, whereby the paper stack Pb is pressure-bound over the entire longitudinal area of ​​the spine Cb.

[0148] The folding blade engagement roller 134 presses and deforms the spine Cb of the paper stack Pb, thereby performing pressure binding and folding the spine. Since pressure binding and folding the spine are performed sequentially while moving in the main scanning direction, the pressing force can be concentrated at the processing point, reducing the pressing force and realizing a compact device. However, on the other hand, if unintended deformation of the paper stack Pb (e.g., paper wrinkles) occurs, this may lead to the paper wrinkles accumulating and expanding 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 figures of eight, the front half of the paper width can be processed first from the center toward one end, and then the rear half can be processed from the center toward the other end. This makes it possible to reduce the accumulation of paper wrinkles by half even if unintended deformation (e.g., paper wrinkles) occurs in the paper stack Pb.

[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 is not provided with a concave-convex pressure-bonding tooth portion, and the folding blade engagement roller is not provided with a configuration such as the folding and compression tooth portion 132a as a concave-convex folding and compression tooth portion, but is configured with a heating portion provided on the cylindrical outer periphery of the folding blade engagement roller 191. Note that the same reference numbers 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-bonding saddle-stitching processing section. The pair of folding rollers 133 sandwich the folding blade 132 and the stack of paper sheets Pb, and are pressed against each other by a pressure member 144 for the pair of folding rollers.

[0152] Moreover, the folding blade engagement roller 191 as the folding plate engagement heating member according to this modification is pressed against the folding blade 132 with the paper stack Pb sandwiched therebetween by the folding blade engagement roller pressure member 147. 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, the flange portions 191b formed on both ends of the cylindrical portion of the folding blade engagement roller 191 can execute a spine forming process for folding the paper stack Pb into a square spine.

[0153] The folding blade engagement roller 191 constituting 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 about the rotation axis. The folding blade engagement roller 191 has a heat pressing 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 pressing portion 191a. The flange portions 191b have the same diameter on both ends of the cylindrical outer periphery surface.

[0154] The folding blade engagement roller 191 has a heat pressing portion 191a which is heated by a heater mounted inside the folding blade engagement roller 191.

[0155] Figure 22 is a cross-sectional view showing the operation of Variation 8 of the pressure-bonding saddle-stitching processing unit. It is a cross-sectional view taken along the BB line in Figure 21, seen from the paper transport 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 of Figure 6(c). The folding blade 132 has pushed the paper stack Pb to a position beyond the nip position of the pair of folding rollers 133, and the folding blade engagement roller 191 is in the standby position (HP position) and is separated from the paper stack Pb in the center fold discharge direction.

[0156] The folding blade engaging roller 191 (heat bonding section 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 pressure saddle stitch processing section is provided with an engaging roller guide rail 146 as a folding blade engaging roller contact / 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 sandwiched and heated and pressurized, whereby the spine Cb of the paper stack Pb is pressure-bonded and bound.

[0158] FIG. 22C illustrates a state in which the folding blade engagement roller 191 is separated from the sheet bundle Pb in the center-folding discharge direction after pressure-binding the entire area in the longitudinal direction of the spine Cb of the sheet bundle Pb.

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

[0160] Fig. 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. In the spine Cb, the adhesive toner image tn is reheated, so that the toner image tn in the overlapping portion of the multiple sheets P that form the flat portion of the square spine (spine Cb) exerts adhesive force, and the toner pressure binding is performed.

[0161] [Variation 9] Next, a ninth modified example of the pressure-bonding saddle stitching processing section will be described with reference to Fig. 24. The difference from 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 with 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 the same reference numbers are used for components common to the pressure-bonding saddle stitching processing section according to the first embodiment, and detailed descriptions thereof will be omitted.

[0162] Figure 24 is a cross-sectional view showing the operation of Variation 9 of the pressure saddle stitch processing unit. It is a cross-sectional view taken along the BB line as seen from the paper transport 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 pair of folding rollers 133, and the folding blade engagement die 192 is in the standby position (HP position) and is separated 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 a 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 composed 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 on which the image has been formed to a post-processing apparatus 210. The image forming apparatus 201 includes a tray in which the sheet P is stored, a transport unit that transports the sheet P stored in the tray, and an image forming unit that forms 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. Other configurations 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 an internal structure of a post-processing device 210 according to the second embodiment. The post-processing device 210 performs post-processing on the 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 for binding a stack of multiple sheets P on which images have been formed (hereinafter referred to as a "sheet bundle Pb"). More specifically, the binding process according to this embodiment includes so-called "pressure binding" in which the sheet bundle Pb is pressurized and deformed at a press binding position, and "staple binding" in which the sheet bundle Pb is stapled. Furthermore, pressure binding includes end binding in which an end of the sheet bundle Pb is stapled, and saddle binding in which the center of the sheet bundle Pb is stapled.

[0168] The same components as those in the compression saddle stitching processing section according to the first embodiment are given the same reference numerals, and detailed description thereof will be omitted.

[0169] [Press-stitching process] As shown in FIG. 26, the post-processing device 210 includes a folding blade 232 , a pair of folding rollers 233 , a folding blade engagement 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 a plurality of sheets P which 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 P, and aligns the position of the sheets so that the folding blade 232 faces the center position of the length of the sheets in the transport direction according to the sheet size. The side fences align the position of the sheets P or the sheet stack Pb placed on the saddle stitching internal tray 237 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 238 and the side fence. The sheet stack Pb which has been pressure saddle stitched is discharged by a pair of centerfold booklet discharge rollers 235 and loaded onto a centerfold booklet discharge tray 236.

[0172] The present invention is not limited to the above-described embodiments, and various modifications are possible without departing from the technical gist of the present invention. The present invention covers all technical matters included in the technical ideas 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 contents. 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 means for performing center folding on a sheet bundle made up of a plurality of sheet materials; a spine pressure binding means for forming a spine on the folded sheet bundle and pressure binding the spine; Equipped with The back crimp binding means is a spine forming section for forming the spine of the folded sheet bundle; a pressure binding unit that performs pressure binding on the center-folded sheet bundle; having The sheet processing apparatus is characterized in that <2> The center folding means is A folding plate member that guides the sheet stack in a predetermined direction; a pair of folding rollers for sandwiching the sheet stack guided by the folding plate member and advancing the sheet stack in the direction; Equipped with The above <1> 2 is a sheet processing apparatus according to the first embodiment. <3> The back crimp 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 above <2> 2 is a sheet processing apparatus according to the first embodiment. <4> The folding plate engaging member is biased toward the folding plate member and sandwiches and presses the spine of the sheet stack between the folding plate member and the folding plate member. The above <3> 2 is a sheet processing apparatus according to the first embodiment. <5> The folding plate engaging member is a roller-shaped member supported by a shaft, and moves back and forth in the longitudinal direction of the spine of the sheet bundle to perform a spine forming process for forming a spine in the sheet bundle and the pressure binding. The above <4> 2 is a sheet processing apparatus according to the first embodiment. <6> The folding plate member has a folding plate pressing tooth having a concave-convex shape on a surface facing the folding plate engagement member, The fold plate engagement member has engagement crimping teeth having a concave-convex shape that engage with the fold plate crimping teeth. The above <3> or the above <5> 13. The sheet processing apparatus according to claim 12, wherein the sheet is a sheet having a diameter of 100 mm or less. <7> The folding plate engagement member simultaneously performs a spine forming process for forming a spine in the sheet bundle by moving the spine of the sheet bundle in the longitudinal direction and the pressure binding. The above <3> or the above <6> 13. The sheet processing apparatus according to claim 12, wherein the sheet is a sheet having a diameter of 100 mm or less. <8> The folding plate member has a plurality of spaced apart unevenly shaped folding plate pressing teeth on a surface facing the folding plate engagement member, The fold plate engagement member has a plurality of spaced apart engagement crimping teeth having a concave-convex shape that engage with the fold plate crimping teeth, The compression binding is performed by moving the folding plate member toward the folding plate engagement member. The above <6> or the above <7> 2 is a sheet processing apparatus according to the first embodiment. <9> The folding plate engaging member is a plate-shaped blade member facing the folding plate member, and the pressure binding is performed by moving the blade member toward the folding plate member. The above <3> 2 is a sheet processing apparatus according to the first embodiment. <10> The back crimp binding means is A first roller member having uneven teeth; a second roller member that engages with the first roller member via the sheet stack; Consists of: The above <1> or the above <9> 13. The sheet processing apparatus according to claim 12, wherein the sheet is a sheet having a diameter of 100 mm or less. <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 being larger in diameter than the cylindrical portion. The above <6> 2 is a sheet processing apparatus according to the first embodiment. <12> The flange portion abuts against the sheet stack sandwiched between the folding plate member and the folding plate engagement member from both sides of the cylindrical portion. The above <11> 2 is a sheet processing apparatus according to the first embodiment. <13> The spine pressure binding means forms two parallel folds in the longitudinal direction on the spine of the sheet stack. The above <1> or the above <12> 13. The sheet processing apparatus according to claim 12, wherein the sheet is a sheet having a diameter of 100 mm or less. <14> The spine of the sheet stack is a substantially flat portion formed between the two parallel creases. <13> 2 is a sheet processing apparatus according to the first embodiment. <15> 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 above <6> 2 is a sheet processing apparatus according to the first embodiment. <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 above <6> 2 is a sheet processing apparatus according to the first embodiment. <17> The folding plate member has a plurality of unevenly shaped folding plate pressing teeth on a surface facing the folding plate engagement member, and has a substantially flat portion on a portion of the facing surface other than the uneven portion. The above <6> 2 is a sheet processing apparatus according to the first embodiment. <18> an image forming apparatus for forming an image on a sheet material; The image forming apparatus includes an internal paper discharge unit, <1> or the above <17> The sheet processing apparatus according to any one of claims 1 to 4, The image forming system is characterized in that: <19> an image forming apparatus for forming an image on a sheet material; a sheet processing device that performs a predetermined process on the sheet material on which an image has been formed by the image forming device; An image forming system comprising: The sheet processing device <1> or the above <17> The sheet processing apparatus according to any one of claims 1 to 5, The image forming system is characterized in that: <20> A sheet processing method that can be performed in a sheet processing apparatus that includes a center folding unit that performs center folding on a sheet bundle made of a plurality of sheet materials, and a spine pressure binding unit that forms a spine on the sheet bundle that has been center folded and pressure binds the spine, comprising: In the back compression binding means, a spine forming step of forming the spine on the folded sheet bundle; a pressure binding process for performing the pressure binding on the sheet bundle that has been subjected to the center folding; Execute The sheet processing method is characterized in that <21> The back crimp binding means is The folding plate member; A folding plate engagement and heating member includes a heating portion that presses the sheet stack toward the folding plate member and heats the sheet stack; Equipped with The folding plate engagement heating member heats an adhesive medium formed in the adhesive portion of the sheet stack. <2> 2 is a sheet processing apparatus according to the first embodiment. <22> The adhesive medium is a toner that forms a visible image. The above <21> 2 is a sheet processing apparatus according to the first embodiment. <23> The folding plate engaging and heating member is a roller-shaped member supported by a shaft, and moves back and forth in the longitudinal direction of the spine of the sheet bundle to perform a spine forming process for forming the spine of the sheet bundle and the pressure binding. The above <21> 2 is a sheet processing apparatus according to the first embodiment. <24> The folding plate engaging and heating member is a plate-shaped blade member facing the folding plate member, and the pressure binding is performed by moving the blade member toward the folding plate member. The above <21> 2 is a sheet processing apparatus according to the first embodiment. <25> an image forming apparatus for forming 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 by the image forming device, the adhesive medium is formed by the image forming device; The sheet processing device <21> 25. A sheet processing apparatus according to any one of claims 1 to 24, The image forming system is characterized in that: [Explanation of symbols]

[0174] 19: Controller 100: Image forming device system 101: Image forming apparatus 102: Operation panel 110: Post-processing device 117: Staple end binding processing section 118: Crimp end binding processing section 119: Discharge roller pair 120: Output tray 131: Movable end fence 132: Folding blade 132a: Folding crimping teeth 132b: Pressure roller rail 133: Pair of folding rollers 134: Folding blade engagement roller 134a: Engagement crimp teeth 134b: Flange part 135: Booklet ejection roller pair 136: Booklet ejection 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 engagement roller pressure member 177: Upper crimping teeth 178: Lower crimping teeth 181: Folding blade engagement die 181a: Die crimping section 181b: Flange part 182: Folding blade engagement die moving motor 183: Folding blade engagement die pressure member 184: Folding blade 184a: Folding crimping teeth 185: Folding blade engagement die 185a: Crimping section 186: Folding blade engagement die 186a: Crimping section 187: Pressure roller 187a: Crimping section 188: Pressure roller movement motor 191: Folding blade engagement 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] JP 2014-031268 A [Patent Document 2] Patent No. 6089675 [Patent Document 3] JP 2004-168012 A [Patent Document 4] Patent No. 5361858 [Patent Document 5] JP 2004-209858 A

Claims

1. A center folding means for performing center folding on a sheet bundle made up of a plurality of sheet materials; a spine pressure binding means for forming a spine on the folded sheet bundle and pressure binding the spine; Equipped with The back crimp binding means is a spine forming section for forming the spine of the folded sheet bundle; a pressure binding unit that performs pressure binding on the center-folded sheet bundle; having A sheet processing apparatus comprising:

2. The center folding means is A folding plate member that guides the sheet stack in a predetermined direction; a pair of folding rollers for sandwiching the sheet stack guided by the folding plate member and advancing the sheet stack in the direction; Equipped with The sheet processing apparatus according to claim 1 .

3. The back crimp 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 2 .

4. The folding plate engaging member is biased toward the folding plate member and sandwiches and presses the spine of the sheet stack between the folding plate member and the folding plate member. The sheet processing apparatus according to claim 3 .

5. The folding plate engaging member is a roller-shaped member supported by a shaft, and moves back and forth in the longitudinal direction of the spine of the sheet bundle to perform a spine forming process for forming a spine in the sheet bundle and the pressure binding. The sheet processing apparatus according to claim 4 .

6. The folding plate member has a folding plate pressing tooth having a concave-convex shape on a surface facing the folding plate engagement member, The fold plate engagement member has engagement crimping teeth having a concave-convex shape that engage with the fold plate crimping teeth. The sheet processing apparatus according to claim 3 .

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

8. The folding plate member has a plurality of spaced apart unevenly shaped folding plate pressing teeth on a surface facing the folding plate engagement member, The fold plate engagement member has a plurality of spaced apart engagement crimping teeth having a concave-convex shape that engage with the fold plate crimping teeth, The compression binding is performed by moving the folding plate member toward the folding plate engagement member. The sheet processing apparatus according to claim 6 .

9. The folding plate engaging member is a plate-shaped blade member facing the folding plate member, and the pressure binding is performed by moving the blade member toward the folding plate member. The sheet processing apparatus according to claim 3 .

10. The back crimp binding means is A first roller member having uneven teeth; a second roller member that engages with the first roller member via the sheet stack; Consists of: The sheet processing apparatus according to claim 1 .

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 being larger in diameter than the cylindrical portion. The sheet processing apparatus according to claim 6 .

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

13. The spine pressure binding means forms two parallel folds in the longitudinal direction on the spine of the sheet stack. The sheet processing apparatus according to claim 1 .

14. The sheet processing apparatus according to claim 13 , wherein the spine of the sheet stack is a substantially flat portion formed between the two parallel creases.

15. 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 6 .

16. The engaging and crimping teeth are inclined in the longitudinal direction of the spine of the sheet stack and have a repeatedly formed uneven shape. The sheet processing apparatus according to claim 6 .

17. The folding plate member has a plurality of unevenly shaped folding plate pressing teeth on a surface facing the folding plate engagement member, and has a substantially flat portion on a portion of the facing surface other than the uneven portion. The sheet processing apparatus according to claim 6 .

18. an image forming apparatus for forming 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.

1. An image forming system comprising:

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

1. An image forming system comprising:

20. A sheet processing method that can be performed in a sheet processing apparatus that includes a center folding unit that performs center folding on a sheet bundle made of a plurality of sheet materials, and a spine pressure binding unit that forms a spine on the sheet bundle that has been center folded and pressure binds the spine, comprising: In the back compression binding means, a spine forming step of forming the spine on the folded sheet bundle; a pressure binding process for performing the pressure binding on the sheet bundle that has been subjected to the center folding; Execute A sheet processing method comprising:

21. The back crimp binding means is The folding plate member; A folding plate engagement and heating member includes a heating portion that presses the sheet stack toward the folding plate member and heats the sheet stack; Equipped with The sheet processing apparatus according to claim 2 , wherein the folding plate engagement and heating member heats an adhesive medium formed in the adhesive portion of the sheet stack.

22. The adhesive medium is a toner that forms a visible image. The sheet processing apparatus of claim 21 .

23. The folding plate engaging and heating member is a roller-shaped member supported by a shaft, and moves back and forth in the longitudinal direction of the spine of the sheet bundle to perform a spine forming process for forming the spine of the sheet bundle and the pressure binding. The sheet processing apparatus of claim 21 .

24. The folding plate engaging and heating member is a plate-shaped blade member facing the folding plate member, and the pressure binding is performed by moving the blade member toward the folding plate member. The sheet processing apparatus of claim 21 .

25. an image forming apparatus for forming 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 by the image forming device, the adhesive medium is formed by the image forming device; The sheet processing apparatus according to any one of claims 21 to 24, be, 1. An image forming system comprising:

Images