Book binding processing apparatus and image forming system including same

Abstract

A book binding processing apparatus includes: a conveyance control device for controlling a conveyance device to feed a preceding sheet conveyed through a conveyance path to a buffer path; and the cache conveying control device is used for controlling the cache conveying device to convey the previous sheet from the cache path to the conveying path on the basis of the detection result of the detection device on the subsequent sheet after the previous sheet. The conveyance control device controls the conveyance device to feed a stack of the preceding sheet and the following sheet to a book binding process path.

Description

TECHNICAL FIELD

[0001] The present application relates to a bookbinding processing apparatus that performs a bookbinding processing on a sheet on which an image is formed, and an image forming system including the bookbinding processing apparatus. BACKGROUND

[0002] As an image forming system that performs a post-processing on a sheet, a known system includes an image forming apparatus and a post-processing apparatus that is connected to a discharge port of the image forming apparatus and stacks a sheet on which an image is formed, performs a post-processing, and loads the sheet on a loading section.

[0003] As a post-processing, a known bookbinding processing performs a binding processing at two points of a stacked sheet and folds the sheet in half to perform a bookbinding.

[0004] PTL 1 describes a configuration that receives a sheet from a main body discharge port 3 of an image forming apparatus A and transports the sheet to a second stacking unit 35 via a second turning conveyance path SP2 that branches downward from a sheet loading path PI.

[0005] Also disclosed is a configuration that, during a bookbinding processing in the second stacking unit 35, places a rear edge portion of a preceding sheet into a waiting path P3 provided in the sheet loading path PI, thereby inserting a following sheet to an underside of the preceding sheet.

[0006] However, PTL 1 does not mention a technical concept of aligning a position of the preceding sheet and a position of the following sheet. This is because, in the configuration of PTL 1, even if the following sheet is to be moved forward, it stops due to a frictional force generated when it is pinched between the stopped preceding sheet and the roller 30a, and in fact, it can not be possible to move the following sheet from Figure 12C to the state in FIG. 12D.

[0007] BIBLIOGRAPHIC LIST

[0008] PATENT LITERATURE

[0009] PTL 1: Japanese Patent Publication No. 2008-213971 SUMMARY

[0010] TECHNICAL PROBLEM

[0011] An object of the present application is to provide a bookbinding processing apparatus that is capable of aligning and feeding a stack of sheets to a bookbinding processing path.

[0012] SOLUTION TO PROBLEM

[0013] The bookbinding processing apparatus according to the present application includes: a conveying path configured to convey a sheet from a loading port to an unloading port; a bookbinding processing device provided on a lower side of the conveying path for performing a bookbinding process including binding and folding on a stack of sheets; a bookbinding processing path configured to convey the sheet from the conveying path to the bookbinding processing device; a conveying device provided in the conveying path for conveying the sheet; a detection device for detecting that the sheet conveyed by the conveying device reaches a predetermined position; a buffer path provided on an upper side of the conveying path and configured to buffer the sheet; a buffer conveying device provided in the buffer path for conveying the sheet; a conveying control device for controlling the conveying device to feed a preceding sheet conveyed through the conveying path to the buffer path; and a buffer conveying control device for controlling the buffer conveying device to convey the preceding sheet from the buffer path to the conveying path based on a detection result of a succeeding sheet subsequent to the preceding sheet by the detection device, wherein the conveying control device controls the conveying device to feed a stack of the preceding sheet and the succeeding sheet to the bookbinding processing path.

[0014] Advantages of the Invention

[0015] According to the present application, a stack of sheets can be aligned and then fed to a bookbinding processing path.

[0016] Other features and advantages of the present application will become apparent from the following description, taken in conjunction with the accompanying drawings, which illustrate, by way of example, the principles of the application. It should be noted that the same reference numerals are used throughout the several views to indicate the same or similar components. BRIEF DESCRIPTION OF DRAWINGS

[0017] The accompanying drawings incorporated in and forming a part of the specification illustrate embodiments of the present application and, together with the description, serve to explain the principles of the application.

[0018] Figure 1 A view showing the appearance of an image forming system;

[0019] Figure 2 A view showing the configuration of a sheet post-processing apparatus;

[0020] Figure 3 A view showing the configuration in the vicinity of a straight path;

[0021] Figure 4 A view showing the configuration of a punching unit;

[0022] Figure 5 A view for showing the configuration of the punching unit;

[0023] Figure 6 A view for explaining the shifting mechanism of the conveying roller;

[0024] Figure 7 A view for explaining the shifting mechanism of the conveying roller;

[0025] Figure 8 A view for explaining the binding processing mechanism;

[0026] Figure 9 A view for explaining the binding processing mechanism;

[0027] Figure 10 A view for explaining the binding processing mechanism;

[0028] Figure 11 A view for explaining the lifting mechanism of the tray;

[0029] Figure 12A A view for explaining the sheet unloading mechanism;

[0030] Figure 12B A view for explaining the sheet unloading mechanism;

[0031] Figure 12C A view for explaining the sheet unloading mechanism;

[0032] Figure 13 A view for showing the configuration of the stapling unit;

[0033] Figure 14 A view for showing the configuration of the control unit periphery;

[0034] Figure 15 A flowchart for showing the processing of the book binding processing discharge mode;

[0035] Figure 16A A view for explaining the sheet buffering operation in the sheet processing apparatus;

[0036] Figure 16B A view for explaining the sheet buffering operation in the sheet processing apparatus;

[0037] Figure 17A A view for explaining the sheet buffering operation in the sheet processing apparatus;

[0038] Figure 17B A view for explaining the sheet buffering operation in the sheet processing apparatus;

[0039] Figure 18A for explaining sheet buffering operations in a sheet handling apparatus;

[0040] Figure 18B for explaining sheet buffering operations in a sheet handling apparatus;

[0041] Figure 19A for explaining sheet buffering operations in a sheet handling apparatus;

[0042] Figure 19B for explaining sheet buffering operations in a sheet handling apparatus;

[0043] Figure 20A for explaining sheet buffering operations in a sheet handling apparatus;

[0044] Figure 20B for explaining sheet buffering operations in a sheet handling apparatus;

[0045] Figure 21A for explaining sheet buffering operations in a sheet handling apparatus;

[0046] Figure 21B for explaining sheet buffering operations in a sheet handling apparatus;

[0047] Figure 22A for explaining sheet buffering operations in a sheet handling apparatus;

[0048] Figure 22B for explaining sheet buffering operations in a sheet handling apparatus;

[0049] Figure 23 for explaining sheet buffering operations in a sheet handling apparatus;

[0050] Figure 16A to 23 for explaining lateral alignment adjustment;

[0051] Figure 24A to 33B for explaining lateral alignment adjustment;

[0052] Figure 24A to 33B for explaining lateral alignment adjustment;

[0053] Figure 16A to 23 for explaining lateral alignment adjustment;

[0054] Figure 24A to 33B for explaining lateral alignment adjustment;

[0055] Figure 24A to 33B Figure 1 1 is a view for explaining lateral alignment adjustment;

[0056] Figure 24A to 33B Figure 1 1 is a view for explaining lateral alignment adjustment;

[0057] Figure 24A Figure 1 1 is a view for explaining lateral alignment adjustment;

[0058] Figure 24B Figure 1 1 is a view for explaining lateral alignment adjustment;

[0059] Figure 25A Figure 1 1 is a view for explaining lateral alignment adjustment;

[0060] Figure 25B Figure 1 1 is a view for explaining lateral alignment adjustment;

[0061] Figure 26A Figure 1 1 is a view for explaining lateral alignment adjustment;

[0062] Figure 16B Figure 1 1 is a view for explaining lateral alignment adjustment;

[0063] Figure 26B Figure 1 1 is a view for explaining lateral alignment adjustment;

[0064] Figure 27A Figure 1 1 is a view for explaining lateral alignment adjustment;

[0065] Figure 27B Figure 1 1 is a view for explaining lateral alignment adjustment;

[0066] Figure 27B Figure 1 1 is a view for explaining lateral alignment adjustment;

[0067] Figure 18A Figure 1 1 is a view for explaining lateral alignment adjustment;

[0068] Figure 28A Figure 1 1 is a view for explaining lateral alignment adjustment;

[0069] Figure 28B Figure 1 1 is a view for explaining lateral alignment adjustment;

[0070] Figure 29A Figure 1 1 is a view for explaining lateral alignment adjustment;

[0071] Figure 29B Figure 1 1 is a view for explaining lateral alignment adjustment;

[0072] Figure 30A Figure 1 1 is a view for explaining lateral alignment adjustment;

[0073] Figure 21A a flowchart for illustrating the sheet buffering operation;

[0074] Figure 30B a flowchart for illustrating the sheet buffering operation;

[0075] Figure 31A a flowchart for illustrating the sheet buffering operation;

[0076] Figure 31B a flowchart for illustrating the sheet buffering operation;

[0077] Figure 21B a flowchart for illustrating the sheet buffering operation;

[0078] Figure 32A a view for explaining the operation in the case of a large-size sheet;

[0079] Figure 32B a view for explaining the operation in the case of a large-size sheet;

[0080] Figure 22B a view for explaining the operation in the case of a large-size sheet;

[0081] Figure 33A a view for explaining the operation in the case of a large-size sheet;

[0082] Figure 33B a view for explaining the operation in the case of a large-size sheet;

[0083] Figure 34A to 34D a view for explaining the operation in the case of a large-size sheet;

[0084] Figure 34A to 34D a view for explaining the operation in the case of a large-size sheet;

[0085] Figure 27A a view for explaining another embodiment; and

[0086] Figure 18A a view for explaining another embodiment. DETAILED DESCRIPTION

[0087] Hereinafter, embodiments will be described in detail with reference to the accompanying drawings. It should be noted that the following embodiments are not intended to limit the scope of the claimed invention. In the embodiments, a plurality of features are described, but the present invention is not limited to require inclusion of all such features, and a plurality of such features can be appropriately combined. Furthermore, in the drawings, the same reference numerals are given to the same or similar configurations, and redundant descriptions thereof are omitted.

[0088] [Image forming apparatus]

[0089] An image forming apparatus A in an image forming system shown in Figure 19B will be described. Figure 28A The image forming apparatus A shown in Fig. 1 represents an electrostatic printing mechanism, and is configured to include an image forming unit Al, a scanner unit A2, and a feeder unit A3. On the apparatus housing 1, a mounting leg 25 mounted on a mounting surface (e.g., a floor surface) is provided. Further, a feeder unit 2, an image forming unit 3, a discharge unit 4, and a data processing unit 5 are incorporated in the apparatus housing 1.

[0090] The feeder unit 2 is configured to include cassette mechanisms 2a to 2c that store sheets of a plurality of sizes to form an image, and to feed sheets of a size designated by a main body control unit 90 to a feeding path 6. Thus, a plurality of cassettes 2a to 2c are detachably arranged in the apparatus housing 1, and each cassette includes a separation mechanism that separates the sheets inside one by one, and a feeding mechanism that feeds the sheets. In the feeding path 6, a conveyance roller 7 that feeds the sheets supplied from the plurality of cassettes 2a to 2c to the downstream side is provided, and at a path end portion, an alignment roller pair 8 that aligns the leading edge of each sheet is provided.

[0091] It should be noted that a large capacity cassette 2d and a manual tray 2e are connected to the feeding path 6. The large capacity cassette 2d is configured to include an optional unit that stores sheets of a size that is consumed in a large amount. The manual tray 2e is configured to supply special sheets that are difficult to feed individually, such as thick sheets, coated sheets, or film sheets.

[0092] The image forming unit 3 is shown as an example of an electrostatic printing mechanism, provides a photosensitive member 9 (drum or belt), and a light emitting device 10 that emits a light beam to the photosensitive member 9, a developing device 11 (developer), and a cleaner (not shown) are arranged around the rotating photosensitive member. The example illustrated mechanism represents a monochrome printing mechanism in which a latent image is optically formed on the photosensitive member 9 by the light emitting device 10, and the developing device 11 attaches toner ink to the latent image. According to the time to form an image on the photosensitive member 9, a sheet is fed from the feeding path 6 to the image forming unit 3, and the image is transferred to the sheet by a transfer charger 12, and is fixed by a fixing unit (roller) 13 arranged in a discharge path 14. In the discharge path 14, a discharge roller 15 and a discharge port 16 are arranged, and the sheet is conveyed to a sheet post-processing apparatus B that will be described later.

[0093] The scanner unit A2 is configured to include a platen 17 on which an image original is placed, a carriage 18 that moves back and forth along the platen 17, a light source mounted to the carriage 18, and a reduction optical system 20 (a combination of a mirror and a lens) that guides reflected light from the original on the platen 17 to a photoelectric conversion unit 19. Figure 32B The reference numeral 21 in FIG. 1 indicates a second platen (a traveling platen) that performs image reading on a sheet fed from a feeder unit A3 by the carriage 18 and the reduction optical system 20. The photoelectric conversion unit 19 transfers image data that has undergone photoelectric conversion to the image forming unit 3.

[0094] The feeder unit A3 is configured to include a feeding tray 22, a feeding path 23 that guides a sheet fed from the feeding tray to the traveling platen 21, and a discharge tray 24 that stores an original that has undergone image reading by the platen.

[0095] The image forming apparatus A is not limited to the above-described mechanism, but can employ a printing mechanism such as a photolithography printing mechanism, an inkjet printing mechanism, or an ink ribbon transfer printing mechanism (thermal transfer ribbon printing, thermal sublimation ribbon printing, or the like).

[0096] [Sheet post-processing apparatus]

[0097] As an apparatus that performs post-processing on a sheet discharged from the discharge port 16 of the image forming apparatus A, the sheet post-processing apparatus B has, for example, (1) a function of loading and storing a sheet on which an image is formed (print-out mode), (2) a function of collating and storing a sheet on which an image is formed (jog sorting mode), (3) a function of aligning, stacking, and stapling a sheet on which an image is formed (stapling processing mode), and (4) a function of aligning and stapling a sheet on which an image is formed and then folding the sheet to perform bookbinding finishing (bookbinding processing mode).

[0098] It should be noted that, in this embodiment, the sheet post-processing apparatus B need not have all the functions described above, and is appropriately configured depending on the apparatus specifications (design specifications). In this embodiment, it is assumed, as an example, that the sheet post-processing apparatus B has the function of aligning and stapling a sheet on which an image is formed and then folding the sheet to perform bookbinding finishing.

[0099] Figure 22B The configuration of the sheet post-processing apparatus B is shown, Figure 20BA configuration near the straight path 28 is shown. The sheet post-processing apparatus B post-processes sheets loaded from the straight path entrance 26 connected to the discharge port 16 of the image forming apparatus A, and then stores the sheets in storage units (a first stack tray 49, a second stack tray 61, and a third stack tray 71, which will be described later). Figure 15 The apparatus shown in FIG. 8 transfers sheets conveyed from the processing unit Bl containing the stapling unit 47 to the straight path 28 to the first stack tray 49 (hereinafter referred to as "first tray") and the third stack tray 71 (hereinafter referred to as "third tray"). The apparatus shown also transfers sheets conveyed from the saddle stapling unit B2 to the straight path 28 to the second stack tray 61 (hereinafter referred to as "second tray"). Note that the straight path 28 is formed in a substantially linear shape, and thus even thick sheets can be transported.

[0100] The processing unit Bl is arranged at a path exit (straight path discharge port 35) of the straight path 28, and aligns, stacks, and staples sheets conveyed in sequence, and then stores the sheets in the first tray 49. The saddle stapling unit B2 is a post-processing unit arranged at a path exit (saddle stapling path discharge port) of the saddle stapling path 32 branched from the straight path 28, and aligns, stacks, and saddle-staples (sometimes does not saddle-staple) sheets conveyed in sequence, and then folds the sheets, and stores the sheets in the second tray 61. These components will be described in detail below.

[0101] 〈Apparatus housing〉

[0102] As Figure 34A to 34D shown in FIG. 8, the sheet post-processing apparatus B includes an apparatus housing 27, a straight path 28 included in the apparatus housing and including a straight path entrance 26 and a straight path discharge port 35, a processing unit Bl and a saddle stapling unit B2 that post-process sheets conveyed from the straight path 28, and a first tray 49, a second tray 61, and a third tray 71 that store sheets conveyed from each post-processing unit. Figure 35A to 35D The apparatus housing 27 shown in FIG. 8 is arranged at substantially the same height as the housing 1 of the image forming apparatus A located on the upstream side, and on a mounting surface, the discharge port 16 of the image forming apparatus A and the straight path entrance 26 of the sheet post-processing apparatus B are connected.

[0103] The housing 27 of the sheet post-processing apparatus is configured to include an apparatus frame 70. The apparatus frame 70 forms, for example, a box-shaped apparatus frame as shown in FIG. 9, and is configured to include, for example, a straight path 28 as shown in FIG. 8. Figure 35A to 35D Figure 35A to 35D ​The front-side side frame 70f located at the front, the rear-side side frame 70r located on the rear surface, and the brace member (connection reinforcing member) connecting the two side frames are located in the front in the state shown in FIG. 1. The straight path 28, the processing unit B1, the saddle mounting unit B2, and the like described later are attached between the left and right side frames. The device housing 27 is not limited to the illustrated shape, and of course can have a form preferred for design. The device frame 70 need not always have left and right side frames and a connecting brace structure, and various frame structures, such as a single-shell structure, can be employed.

[0104] <Sheet loading path>

[0105] As Figure 34A to 34D As shown in FIG. 1, the straight path 28 is formed of a substantially linear path passing through the device housing 27 in a substantially horizontal direction, and includes a straight path entrance 26 connected to the discharge port (main body discharge port) 16 of the image forming device A, and a straight path discharge port 35 on the opposite side of the straight path entrance 26 across the device from the loading port (straight path entrance 26). In the straight path 28, an entrance roller 29, a first conveyance roller 201, a second conveyance roller 202, and a third conveyance roller 203 are arranged in order from the straight path entrance 26 side as conveyance mechanisms that can convey a sheet from the straight path entrance 26 to the straight path discharge port 35, and also from the straight path discharge port 35 to the straight path entrance 26. Further, a discharge roller 36 (including a sheet conveyance mechanism such as a belt) is arranged in the straight path discharge port 35 as a conveyance mechanism. In the vicinity of the straight path entrance 26, an entrance sensor Se1 that detects one or both of the leading edge and the trailing edge of a sheet to be received, and a lateral alignment detection sensor S0 (detection unit) that detects the position of an end surface (side end) parallel to the sheet conveyance direction are arranged. Further, in the vicinity of the straight path discharge port 35, a discharge sensor Se2 that detects the leading edge and the trailing edge of a sheet is arranged. A sheet discharged from the straight path discharge port 35 is discharged to the first tray 49 via a first discharge path 31 connected to the straight path discharge port 35, or is guided to the processing unit B1. In the straight path 28, a punch unit 100 that punches a hole in a sheet is arranged. As the entrance sensor Se1 and the discharge sensor Se2, a photo interrupter or a combination of a sensor and a flag that comes into contact with a sheet can be employed.

[0106] <Layout of sheet loading path>

[0107] As Figure 36A to 39B and 3As shown in FIG. 6, in the straight path 28, a "saddle-stitching path 32", a "saddle-stitching buffer path P2", a "processing unit buffer path PI" and an "upper conveying path 30" are arranged in this order from the straight path entrance 26 to the straight path discharge port 35. At the branching portions of the paths, the saddle-stitching path damper 33b, the saddle-stitching buffer path damper 33a, the processing unit buffer path damper 200 and the upper conveying path damper 34 are arranged as conveying switching mechanisms (branching mechanisms) for the conveyed sheets. In this embodiment, the saddle-stitching buffer path P2 and the upper conveying path 30 are each formed as a return path for returning the sheets. Further, as shown in FIG. 6, the saddle-stitching unit B2 is provided on one side of the straight path 28, and the saddle-stitching buffer path P2 and the upper conveying path 30 are provided on the opposite side (the other side). This can further improve the conveying efficiency of the sheets in the return paths to the saddle-stitching unit B2. Figure 36A

[0108] In the above-described paths, the saddle-stitching path 32, the saddle-stitching buffer path P2 and the processing unit buffer path PI are each formed as a turnaround path that conveys the sheets in the direction opposite to the conveying direction from the straight path entrance 26 to the straight path discharge port 35, and loads the sheets to each path. Further, the upper conveying path 30 is configured to convey the sheets in the same direction as the conveying direction from the straight path entrance 26 to the straight path discharge port 35, thereby loading the sheets.

[0109] 〈Path branching mechanisms〉

[0110] The saddle-stitching path damper 33b, the saddle-stitching buffer path damper 33a and the processing unit buffer path damper 200 as sheet branching mechanisms are each formed of a damper guide that is movable to switch the conveying path of the sheet loaded from the straight path entrance 26, and is connected to a driving mechanism (not shown) such as an electromagnetic solenoid or a micro motor. The saddle-stitching path damper 33b guides the sheet conveyed from the straight path entrance 26 to the saddle-stitching path 32. The saddle-stitching buffer path damper 33a guides the sheet conveyed from the straight path entrance 26 to the saddle-stitching buffer path P2. The processing unit buffer path damper 200 guides the sheet conveyed from the straight path entrance 26 to the processing unit buffer path PI via the processing unit buffer rollers 301a and 301b. The upper conveying path damper 34 is configured to include a damper guide that is movable to switch the conveying path so as to convey the sheet conveyed from the straight path entrance 26 to one of the straight path discharge port 35 and the upper conveying path 30, and is connected to a driving mechanism (not shown) such as an electromagnetic solenoid or a micro motor.

[0111] 〈Upper conveying path〉

[0112] ​The upper conveying path 30 (print output discharge path) which loads the sheet except for the sheet to be discharged to the straight path discharge port 35 is connected to the straight path 28, and a path branching portion is provided with an upper conveying path damper 34 configured to guide the sheet to the upper conveying path 30. Further, the upper conveying path 30 contains upper conveying rollers 303 (303a and 303b) which guide the sheet to the third tray 71. The sheet guided to the upper conveying path 30 by these rollers is discharged from the upper conveying path discharge port 40 to the third tray 71 (overflow tray). It should be noted that, in this embodiment, the upper conveying path 30 is also used as a sheet return path.

[0113] 〈Saddle-stitching path〉

[0114] The saddle-stitching path 32 configured to load the sheet to the saddle-stitching element B2 is connected to the straight path 28, and a path branching portion is provided with a saddle-stitching path damper 33b configured to guide the sheet to the saddle-stitching path 32. The sheet guided from the saddle-stitching path 32 to the saddle-stitching element B2 via the saddle-stitching path discharge port undergoes a saddle-stitching stapling process and a folding process, and is then discharged in a substantially horizontal direction to the second tray 61 via the saddle-stitching discharge path 68. It should be noted that the saddle-stitching element B2 is preferably arranged on the lower side of the straight path 28, as it also utilizes gravity to align the sheet.

[0115] 〈Saddle-stitching buffer path〉

[0116] The saddle-stitching buffer path P2 configured to temporarily load the sheet which will undergo a saddle-stitching stapling process and a folding process in the saddle-stitching element B2 and to place the sheet in a standby state is connected to the straight path 28, and a saddle-stitching buffer path damper 33a configured to guide the sheet to the saddle-stitching buffer path P2 is formed. Further, the saddle-stitching buffer path P2 contains conveying rollers 302 (302a and 302b) which load the sheet and temporarily place the sheet in a standby state.

[0117] A fourth tray discharge port 305 is provided on the extension on the downstream side of the saddle-stitching buffer path P2, so that the sheet loaded into the saddle-stitching buffer path P2 can be discharged onto and loaded onto the fourth tray 310. In this case, the fourth tray 310 is vertically arranged above the saddle-stitching buffer path P2. It should be noted that the fourth tray 310 can be shared with an external member of the top surface of the sheet post-processing apparatus B, or can be fixed to the apparatus housing. The fourth tray 310 can be configured to contain a driving mechanism, and can be moved up / down in a substantially vertical direction.

[0118] It should be noted that the saddle stapling cache path P2 can be arranged at a vertically overlapping position above the punching unit 100 to make the apparatus more compact. However, if space is needed to make the punching unit 100 pop up to remove the sheet stuck in the punching unit 100, the saddle stapling cache path P2 can be arranged at a non-vertically overlapping position above the punching unit 100.

[0119] 〈Conveying roll displacement mechanism in loading path〉

[0120] A conveying displacement mechanism of the conveying rolls on the conveying path will be described herein with reference to Figure 17A and 7 The first conveying roll 201, the second conveying roll 202, the third conveying roll 203, and the conveying rolls 302a and 302b are configured to include a driving roll 111 and a driven roll 112, which are supported by the left side frame 70f and the right side frame 70r via bearings. A driving rotation shaft is connected to a driving roll shaft 113 via a transmission mechanism 116 (a gear transmission type is shown), and a driving motor (not shown) common to the discharge rolls 36 is connected to the driving rotation shaft 115. A driven roll shaft 114 is movably supported by the left side frame 70f and the right side frame 70r via bearings.

[0121] Each of the above-described conveying rolls is rotatably attached to a displacement member 117 that connects the driving roll shaft 113 and the driven roll shaft 114. The driving roll shaft 113 and the driven roll shaft 114 are connected by the displacement member 117 to move integrally in the axial direction (thrust direction) and can be independently rotated in the radial direction. The driving roll shaft 113 is supported by the left side frame 70f and the right side frame 70r via bearings, an end portion of the driving roll shaft 113 is located within a range on the front side of the side frame 70f indicated by an axial movement area of the conveying roll, and the other end portion is located on the rear side of the side frame 70r. The displacement member 117 (for example, a block-shaped member made of synthetic resin) is supported by the driving roll shaft 113 and the driven roll shaft 114 and integrally connects the two roll shafts.

[0122] A rack 117a is integrally formed on the displacement member 117 and engages with a displacement motor M9 and a transmission pinion 117b attached to the side frame 70r (apparatus housing: the same applies hereinafter). In this configuration, the displacement member 117 can be moved (displacement movement) in the axial direction of the conveying roll by the rotation of the displacement motor M9 (a step motor capable of rotating in the forward and reverse directions is shown).

[0123] A driven gear 118 is integrally formed on the driving rotation shaft 115, and the rotation of the driving motor is transmitted to the driven gear 118. In addition, the conveying roll pair (driving roll and driven roll) is in pressure contact with a driven rotation shaft 119 so as to be driven and rotated by the rotation of the driving rotation shaft 115.

[0124] In this embodiment, the driving rotary shaft 115 and the driven rotary shaft 119 are connected to each other and configured so that when one of the rotary shafts moves in the axial direction, the other rotary shaft is driven. In addition, one of the driving roller 111 and the driven roller 112 can be attached to the rotary shaft so that it can be slidably moved (slip) in the axial direction, and the other roller can move in the axial direction so that it is associated with the movement.

[0125] 〈Conveying displacement operation〉

[0126] Here, a displacement operation of the sheet loaded into the sheet post-processing device B (slow-sorting mode) will be described. The sheet conveyed from the image forming device A is sequentially conveyed to the straight path entrance 26, the entrance roller 29, the first conveying roller 201, the second conveying roller 202, and the third conveying roller 203. At this time, the transfer time of the sheet is synchronously detected by the entrance sensor Se1. When the sheet loaded by the entrance roller 29 passes through the straight path 28, the end position of the sheet is detected by the lateral alignment detection sensor S0. The lateral alignment detection sensor S0 detects the magnitude of the lateral alignment error X generated with respect to the center position of the sheet.

[0127] If the lateral alignment error X is detected by the lateral alignment detection sensor S0, the rollers of the first conveying roller 201, the second conveying roller 202, and the third conveying roller 203 are moved by a predetermined amount to the front side and the rear side while sequentially conveying the sheet, thereby performing the displacement operation of the sheet (also referred to as "lateral alignment detection processing"). Thereafter, the sheet is distributed by the upper conveying path damper 34 which is a branch mechanism and conveyed to the straight path discharge port 35 or the upper conveying path 30, and discharged onto the first tray 49 or the second tray 71.

[0128] 〈Processing unit〉

[0129] The processing unit B1 is a post-processing unit configured to include a processing tray 37 arranged on the downstream side of the straight path 28 and performing alignment and stacking of the sheet conveyed from the straight path discharge port 35, and a stapling processing mechanism performing stapling of the stacked sheet bundle. As shown in FIG. 1, the processing tray 37 is arranged on the downstream side of the straight path 28, and the straight path discharge port 35 is formed on the upstream side of the processing tray 37. The first discharge path (first turnaround path) 31 is formed between the straight path discharge port 35 and the processing tray 37, and reverses the conveying direction from the discharge port and guides the sheet onto the tray. Figure 37

[0130] ​A sheet loading mechanism that loads the sheet from the linear path discharge port to the tray is arranged between the linear path discharge port 35 and the processing tray 37. In the processing tray 37, a positioning mechanism that positions the sheet at a predetermined binding position and a sheet bundle unloading mechanism that discharges the bound sheet bundle to the first tray 49 on the downstream side are arranged. These components will be described later.

[0131] It should be noted that, Figure 18A The processing tray 37 shown in FIG. 8 bridges supports the sheet conveyed from the linear path discharge port 35 between it and the first tray 49 on the downstream side. That is, the processing tray 37 is configured so that the sheet conveyed from the linear path discharge port 35 is bridge supported with the front edge portion of the bridge supported sheet being on the uppermost sheet on the first tray 49 on the downstream side and the rear edge portion thereof being on the processing tray 37.

[0132] 〈Saddle binding unit〉

[0133] The saddle binding unit B2 is a post-processing unit that aligns and stacks the sheets conveyed from the linear path 28, binds the sheets at the center portion, and folds the sheets inward (hereinafter referred to as "magazine finish"). The second tray 61 is arranged on the downstream side of the saddle binding unit B2 to store the sheet bundle that has undergone the book binding process. It should be noted that the saddle binding unit can be configured to align and stack one or more sheets and fold the sheets inward at the center portion without performing the saddle stitch binding process.

[0134] The saddle binding unit B2 is configured to include a guide member 66 that stacks the sheets into a bundle, a front edge adjustment stopper 67 that positions the sheets at a predetermined position on the guide member 66, a tacking device 63 (saddle stitch binding tacking unit) that saddle stitch binds the sheets positioned by the front edge adjustment stopper 67 at the center portion, and a folding process mechanism (folding roller pair 64 and folding blade 65) that folds the sheet bundle at the center portion after the binding process.

[0135] As the saddle stitch binding tacking unit 63, a well-known mechanism that moves the sheet bundle clamped between a head unit and an anvil unit along the center portion (line) of the sheet and performs the binding process is employed. As shown in FIG. 9, the head unit 63a is arranged to be movable in the direction of the arrow A, and the anvil unit 63b is arranged to be movable in the direction of the arrow B. The head unit 63a is arranged to be movable in the direction of the arrow A by a head unit driving mechanism 63c, and the anvil unit 63b is arranged to be movable in the direction of the arrow B by an anvil unit driving mechanism 63d. Figure 38A As shown in FIG. 8, the folding process mechanism is configured so that the crease of the sheet bundle is inserted between the rollers of the folding roller pair 64 in pressure contact with each other by the folding blade 65, and the folding of the sheet bundle is achieved by the rolling of the roller pair.

[0136] Figure 22AThe processing unit B1 and the straight path 28 shown are arranged in a generally horizontal direction, the saddle binding path 32 that guides the sheet to the saddle binding unit B2 is arranged in a vertical direction, and the guide member 66 that aligns and stacks the sheet is arranged in a generally vertical direction. When the straight path 28 is arranged in a direction intersecting the device housing 27, and the saddle binding path 32 and the saddle binding unit B2 are arranged in a vertical direction, the device can be manufactured to be thinner. It should be noted that, according to this embodiment, the saddle binding unit B2 represents a tray supporting the sheet, the binding unit, and the folding unit, and is arranged such that when the guide member 66 supports the sheet of the largest size, the lower end is located downstream of the upper end in the conveying direction. Figure 39A (on the left side of the middle), thereby reducing the size in the conveying direction.

[0137] The second tray 61 is positioned downstream of the saddle-type order unit B2 and can store stacks of sheets folded into a magazine shape. The second tray 61 is positioned below the first tray 49. This is because it is assumed that the first tray 49 is used more frequently than the second tray 61, and the position of the first tray 49 is set at a height that facilitates easy access to the sheets on the tray.

[0138] <Punching Unit>

[0139] Reference Figure 32A A punching unit 100 is described, which is arranged in a straight path 28 and punches holes in a sheet conveyed from the straight path inlet 26. In the punching unit 100, a plurality of punching members 101a to 101e are arranged at predetermined intervals in a direction orthogonal to the sheet conveying direction of the straight path 28, and punch a selected number of holes in the sheet.

[0140] Figure 40 The overall configuration of the punching unit 100 is shown. The punching unit 100 is configured to include a unit frame 102, a plurality of punching members 101a to 101e arranged in the unit frame 102 to be movable in the vertical direction, a drive cam that moves each punching member in the vertical direction (that each punching member reciprocates in the punching direction), and a drive motor M7 that drives the drive cam.

[0141] Figure 40Reference numeral 104 in the figures indicates a scrap bin, which is arranged below the punching member 101 and stores punching fragments. The scrap bin 104 is attached to a guide rail (not shown) so that it can slide relative to the device frame 70 (different from the unit frame). Reference numeral 106 indicates a rotary operating member, which, in the event of jamming in the punching member 101 or malfunction of the drive motor M7, forces the drive cam to rotate, thereby disengaging (unengaging) the punching member 101 embedded in the sheet. Therefore, the rotary operating member 106 is formed by a manual knob connected to a rotation shaft 107 of the drive cam.

[0142] like Figure 41 As shown, the unit frame 102 is configured to include an upper frame 102a and a lower frame 102b, each frame having a predetermined length in a direction orthogonal to the sheet transport direction of the straight path 28. In the upper frame 102a, a plurality of punching members 101a to 101e are arranged at predetermined intervals in a direction orthogonal to the sheet transport direction (hereinafter referred to as the "transport orthogonal direction"), such that these punching members can reciprocate (move vertically) in the punching direction. In the lower frame 102b, a punching hole (die) is formed at a position facing the punching portion 101. In addition, a drive rotation shaft 107 is arranged in the unit frame 102, and a drive cam that moves the punching member 101 in the vertical direction is attached to the drive rotation shaft 107. A drive motor M7 is connected to the drive rotation shaft 107 via a transmission mechanism.

[0143] The drive cam is formed by a cylindrical cam member pivotally attached to the drive rotation shaft 107 and corresponding to a plurality of punching members 101, each punching member being connected to the cam member via a connecting pin. When the drive rotation shaft 107 rotates by a predetermined angle, the punching members 101 move vertically in the punching direction. At this time, the first group of punching members (e.g., double-hole punching) 101b and 101d move vertically in the punching direction at a first rotation angle of the drive rotation shaft 107. At different second rotation angles, the second group (e.g., triple-hole punching) of punching members 101a, 101c, and 101e move vertically in the punching direction.

[0144] Therefore, when the drive shaft 107 reciprocates within a preset angle range under the control of the motor M7, the binding processing control unit 95, which will be described later, causes the first set of punching members 101b and 101d to perform punching motion. When the drive shaft 107 reciprocates within different angle ranges, the second set of punching members 101a, 101c, and 101e can be made to perform punching motion.

[0145] The waste box 104 is disposed below the punching member 101 and is supported by a guide rail (not shown) provided in the apparatus frame, and can be detached from the front side of the apparatus.

[0146] The drive motor M7 is connected to the drive rotary shaft 107 via a reduction mechanism (a gear mechanism). In order to enable manual rotation by the operator, a rotary member is inserted into a hole provided in the side frame 70f, and is disposed at the front side of the side frame 70f. A front cover is openably and closably disposed at the front side of the apparatus, and in the open state, the rotary operation member 106 can be operated. It should be noted that in the cover open state, the supply of drive power of the drive motor M7 is cut off (prevented).

[0147] [Configuration of processing unit]

[0148] The configuration of the sheet loading mechanism, the sheet positioning mechanism, the stapling processing mechanism, and the sheet stack unloading mechanism of the processing unit B1 will be described next.

[0149] 〈Sheet loading mechanism〉

[0150] As shown in FIG. 1, the sheet loading mechanism is disposed at the front side of the apparatus, and is configured to load a sheet onto the processing tray 37. The sheet loading mechanism is provided with a sheet feeding mechanism 31, a sheet conveying mechanism 32, and a sheet reversing mechanism 33. ​ Between the straight path discharge port 35 and the processing tray 37, a reverse conveying mechanism that reversely conveys a sheet from the straight path discharge port 35 in the discharge direction and the opposite direction of the discharge, a guide mechanism (sheet guide member) 44 that guides the sheet to the tray side, and a rake-shaped rotary body 46 that guides the sheet to the rear edge adjustment portion are disposed.

[0151] The reverse conveying mechanism is configured to include a lift roller 41 that moves vertically between an operation position in which the lift roller engages with a sheet loaded onto the processing tray 37 and a waiting position in which the lift roller is separated from the sheet, and a paddle-shaped rotary body 42 that passes the sheet to the opposite direction of the discharge, and the lift roller 41 and the paddle-shaped rotary body 42 are attached to a swing bracket 43.

[0152] In the apparatus housing 27, the swing bracket 43 is disposed so as to be swingable about a rotary shaft (for example, a discharge roller shaft). The rotary shafts of the lift roller 41 and the paddle-shaped rotary body 42 are supported by the swing bracket 43 via bearings. A lift motor (not shown) is connected to the swing bracket 43, and the swing bracket 43 moves the lift roller 41 and the paddle-shaped rotary body 42 mounted thereon vertically between the operation position in which the lift roller 41 engages with a sheet and the waiting position in which the lift roller is separated from the sheet.

[0153] Further, a drive motor (not shown) is connected to the lift roller 41 and the paddle- shaped rotating body 42 to transmit a driving force so that the lift roller 41 rotates in a forward and reverse direction, and the paddle-shaped rotating body 42 rotates in a reverse direction (discharge opposite direction). The driven roller 48 in pressure contact with the lift roller 41 is arranged in the processing tray 37 to grip a single sheet or a stack of sheets and discharge it to a downstream side.

[0154] A guide mechanism is arranged between the lift roller 41 and a rake-shaped rotating body 46 which will be described later, which guides a rear edge of a sheet loaded onto the processing tray 37 toward the sheet end adjustment portion 38. The guide mechanism is configured to include a sheet guide member 44 which moves vertically from a dotted line state to a solid line state in ​ The sheet guide member 44 is withdrawn to the dotted line position when the sheet is discharged from the straight path discharge port 35, and guides the sheet rear edge onto the processing tray 37 after the sheet rear edge passes through the straight path discharge port 35. To this end, a driving mechanism (not shown) is connected to the sheet guide member 44, and the sheet guide member 44 moves vertically according to a time when the sheet rear edge is guided from the straight path discharge port 35 onto the processing tray 37.

[0155] 〈Sheet positioning mechanism〉

[0156] Positioning mechanisms 38 and 39 which position a sheet at a predetermined binding position are arranged on the processing tray 37, and ​ The positioning mechanisms shown in

[0157] As shown in ​ , the sheet end adjustment portion 38 is formed of a stopper member which adjusts the sheet rear edge by abutment. As for the side edge alignment member 39, as will be described later with reference to ​ , a sheet is discharged from the straight path 28 with a center reference, and the same center reference positioning or one-side reference positioning is performed according to a type of binding mode.

[0158] 〈Side edge alignment mechanism〉

[0159] As shown in ​As shown in FIG. 6, the side edge alignment plates 39F and 39R project upward from the sheet placement surface 37a of the processing tray 37, have adjustment surfaces 39x that engage with the side edges of the sheet, and are arranged as a pair of left and right components facing each other. The pair of side edge alignment portions 39 are arranged on the processing tray 37 so that they can be moved reciprocally in a predetermined stroke. The stroke is set based on the size difference between the largest size sheet and the smallest size sheet and the offset amount by which the sheet stack is moved (offset transported) in one of the left and right directions after alignment.

[0160] That is, the moving stroke of the left and right side edge alignment plates 39F and 39R is set based on the amount of movement for aligning sheets of different sizes and the offset amount of the sheet stack after alignment. Note that in corner stapling, the side edge alignment plates 39F and 39R move the sheet unloaded with the center reference to the right side by a predetermined amount in the case of right corner stapling or to the left side by a predetermined amount in the case of left corner stapling (offset movement). The offset movement is performed each time a sheet is loaded to the processing tray 37 (for each loaded sheet) or after the sheets are aligned into a stack to move the stack to perform the stapling process.

[0161] Therefore, as ​ As shown in FIG. 6, the side edge alignment portions 39 are configured to include a right side edge alignment member 39F (device front side) and a left side edge alignment member 39R (device rear side). For both of these side edge alignment members, adjustment surfaces 39x that engage with the side ends of the sheet are supported on the processing tray 37 so that these adjustment surfaces move in the approaching direction or the separating direction. A slit groove (not shown) that extends through the processing tray from the upper surface to the lower surface is provided in the processing tray 37. The side edge alignment portions 39 having the adjustment surfaces 39x that engage with the side edges of the sheet are slidably fitted in the slit groove.

[0162] The side edge alignment plates 39F and 39R are slidably supported by a plurality of guide rollers 80 on the tray rear surface, with a rack 81 integrally formed. The alignment motors M1 and M2 are connected to the left and right racks 81 via pinions 82. The left and right alignment motors M1 and M2 are each formed by a stepping motor and are configured to detect the positions of the left and right side edge alignment plates 39F and 39R by a position sensor (not shown) and, based on the detection values, move the alignment members by a specified movement amount in the left and right directions. Note that the configuration is not limited to the rack-pinion mechanism shown in FIG. 6, and the side edge alignment plates 39F and 39R can be fixed to a timing belt, and the timing belt can be connected by a pulley to a motor that reciprocally moves the timing belt in the left and right directions. ​

[0163] ​In the above configuration, the binding process control unit 95 described later causes the left and right side edge alignment plates 39F and 39R to wait at a predetermined waiting position (the width dimension of the sheet + position) based on the sheet size information provided from the image forming apparatus A. In "multi-binding", the sheet is loaded onto the process tray 37, and the alignment operation is started when the sheet end abuts against the sheet end adjustment portion 38. The alignment operation is performed by rotating the left and right alignment motors Ml and M2 in opposite directions (approaching direction) by the same amount. Then, the sheet loaded onto the process tray 37 is positioned with the center of the sheet as a reference, and stacked into a pile. The sheet loading operation and the alignment operation are repeated, thereby aligning and stacking the sheets into a pile on the process tray 37. At this time, sheets of different sizes are positioned with the center as a reference. In "corner binding", the sheet is loaded onto the process tray 37, and the alignment operation is started when the sheet end abuts against the sheet end adjustment portion 38. The alignment operation is performed by setting different movement amounts for the alignment plate on the binding position side and the alignment plate on the opposite side of the binding position. The movement amounts are set so that the corner of the sheet is located at the preset binding position.

[0164] 〈Binding process mechanism〉

[0165] On the process tray 37, a binding process mechanism 47 is arranged, which binds the pile of sheets stacked on the sheet placement surface 37a. The sheet placement surface 37a of the process tray 37 is positioned to the predetermined binding position by the positioning mechanism (the sheet end adjustment portion 38 and the side edge alignment portion 39). The binding process mechanism 47 is formed as a binding unit 47 that performs needle binding for the pile of sheets using a tacking needle ("tacking unit" as well below).

[0166] On the process tray 37, a binding process mechanism 47 is arranged, which binds the pile of sheets stacked on the sheet placement surface 37a. The sheet placement surface 37a of the process tray 37 is positioned to the predetermined binding position by the positioning mechanism (the sheet end adjustment portion 38 and the side edge alignment portion 39). The binding process mechanism 47 is formed as a binding unit 47 that performs needle binding for the pile of sheets using a tacking needle ("tacking unit" as well below). ​ The binding process mechanism 47 is formed of a tacking unit 47 that is movable along the rear end portion of the sheet placement surface 37a of the process tray 37.

[0167] ​ and 9 The tacking unit 47 arranged on the process tray 37 is shown. In ​ The binding position Cp1 is set at the sheet corner on the left side. The tacking unit 47 is moved along the first travel rail 53 and the second travel rail 54 formed on the apparatus frame 27b by the predetermined stroke SL1.

[0168] ​A moving stroke SL1 of the sheet and the binding member 47 loaded onto the processing tray 37 is shown. Sheets of different sizes including the largest size sheet to the smallest size sheet are loaded onto the processing tray 37 with a center reference. With respect to the left side edge of the sheet as a reference in the ​ binding process, the sheets are aligned by the pair of left and right side edge alignment plates 39F and 39R so that the sheets of different sizes can be matched. For this purpose, the left and right side edge alignment plates 39F and 39R are connected to different drive motors M1 and M2, and the binding process control unit 95 to be described later sets the moving amount of the left and right side edge alignment plates 39F and 39R according to the sheet size.

[0169] It should be noted that in the binding process other than the binding process of binding the corners of the sheet, for example, in the multiple binding mode to be described later, the binding process control unit 95 to be described later aligns the sheets with a center reference. In this case, the left and right side edge alignment plates 39F and 39R are moved by the same amount from the waiting position toward the center of the sheet, thereby positioning the sheet to the binding position.

[0170] This will be described with reference to ​ The binding member 47 moves in the stroke SL1 between the waiting position Wp1 (first waiting position) and the binding position Cp1. That is, the binding member 47 reciprocates between the waiting position Wp1 and the binding position Cp1 along the travel rails 53 and 54 (guide grooves or guide rods). The first waiting position Wp1 is set outside the largest size sheet to be bound on the processing tray 37.

[0171] ​ A configuration of the binding member 47 is shown. On the device frame 27b, a pair of left and right belt wheels 58a and 58b are arranged along the moving area of the binding member 47 in the left and right directions ​ in the

[0172] 〈Nail moving mechanism〉

[0173] As ​As shown in FIG. 6, the tacking unit 47 is mounted on the equipment frame (chassis frame) 27b fixed to the side frames 70f and 70r through an opening portion provided in the side frame 70f of the equipment frame 70. The first and second traveling rails 53 and 54 are arranged on the equipment frame 27b. The traveling rail surface 53x is formed on the first traveling rail 53, and the traveling cam surface 54x is formed on the second traveling rail 54. The traveling rail surface 53x and the traveling cam surface 54x cooperatively support the tacking unit 47 (hereinafter referred to as "moving unit") so that the tacking unit 47 can be reciprocally moved with a predetermined stroke and the angular attitude is synchronously controlled.

[0174] On the first and second traveling rails 53 and 54, the rail surface 53x and the traveling cam surface 54x are formed so that the moving unit is reciprocally moved within its moving range. As shown in FIG. 7, the rail surface 53x is formed in a linear shape, and the traveling cam surface 54x is formed in a cam shape. ​ As shown in FIG. 6, the timing belt 59 connected to the drive motor (traveling motor) M3 is fixed to the tacking unit 47. The timing belt 59 is wound around a pair of pulleys 58a and 58b axially supported on the equipment frame 27b, and the drive motor M3 is connected to one of the pulleys. Therefore, when the drive motor M3 is rotated in the forward and reverse directions, the tacking unit 47 is reciprocally moved with a stroke SL1.

[0175] The tacking unit 47 is engaged with the first and second traveling rails 53 and 54 by the following manner. As shown in FIG. 8, the tacking unit 47 is provided with a first rolling roller 83 (rail engaging member) engaged with the traveling rail surface 53x and a second rolling roller 84 (cam follower member) engaged with the traveling cam surface 54x. ​ As shown in FIG. 6, the tacking unit 47 is provided with a first rolling roller 83 (rail engaging member) engaged with the traveling rail surface 53x and a second rolling roller 84 (cam follower member) engaged with the traveling cam surface 54x. Further, the sliding rollers 47x (two sliding rollers in FIG. 6) having a spherical shape and engaged with the support surface of the frame 27b are formed on the tacking unit 47. In addition, the guide rollers 47y engaged with the bottom surface of the bottom frame are formed on the tacking unit 47, thereby preventing the tacking unit 47 from floating from the equipment frame 27b. ​ As shown in FIG. 6, the tacking unit 47 is provided with a first rolling roller 83 (rail engaging member) engaged with the traveling rail surface 53x and a second rolling roller 84 (cam follower member) engaged with the traveling cam surface 54x. Further, the sliding rollers 47x (two sliding rollers in FIG. 6) having a spherical shape and engaged with the support surface of the frame 27b are formed on the tacking unit 47. In addition, the guide rollers 47y engaged with the bottom surface of the bottom frame are formed on the tacking unit 47, thereby preventing the tacking unit 47 from floating from the equipment frame 27b.

[0176] By the above configuration, the tacking unit 47 is supported on the equipment frame 27b so that it can be moved by the sliding rollers 47x and the guide rollers 47y. Further, the first and second rolling rollers 83 and 84 travel according to the rail surface 53x and the cam surface 54x, respectively, while rotating along the traveling rail surface 53x and the traveling cam surface 54x.

[0177] 〈Stacked tray lifting mechanism〉

[0178] As shown in FIG. 6, the tacking unit 47 is provided with a first rolling roller 83 (rail engaging member) engaged with the traveling rail surface 53x and a second rolling roller 84 (cam follower member) engaged with the traveling cam surface 54x. Further, the sliding rollers 47x (two sliding rollers in FIG. 6) having a spherical shape and engaged with the support surface of the frame 27b are formed on the tacking unit 47. In addition, the guide rollers 47y engaged with the bottom surface of the bottom frame are formed on the tacking unit 47, thereby preventing the tacking unit 47 from floating from the equipment frame 27b. ​As shown in the figure, the sheet post-processing apparatus B includes a first tray 49. The first tray 49 is configured to move up and down according to the loading amount of the sheets. For this purpose, guide rollers 85 are provided at two points on the upper and lower sides of the proximal end portion of the first tray 49, and the guide rollers 85 are fitted and supported in a lifting guide 86 provided in the apparatus housing 27. A lifting gear 88 is provided at the proximal end portion of the first tray 49 and is connected to a lifting rack gear 87. Further, a lifting motor M4 is connected to the lifting gear 88. Thus, by controlling the rotation of the lifting motor M4, the first tray 49 is moved up and down according to the loading amount of the sheets.

[0179] 〈Sheet stack unloading mechanism〉

[0180] On the processing tray 37, a sheet stack unloading mechanism is arranged, which unloads the sheet stack that has undergone the stapling process to the first tray 49 on the downstream side. As a configuration for conveying the sheet stack to the downstream side, a method of conveying the sheet stack by rollers in pressure contact with each other (unloading roller mechanism), and a conveying mechanism that pushes the sheet trailing edge by a pushing member that moves from the upstream side to the downstream side along the tray surface are known. The apparatus shown in the figure employs both of these methods.

[0181] ​ The sheet stack unloading mechanism is shown. The conveying mechanism is configured to include a pushing protrusion 45 that passes the sheet stack from the stapling position (processing position) located on the upstream side to the stacking tray (first tray) 49 on the downstream side along the processing tray 37, a conveying belt 45v that moves the pushing protrusion, and a drive motor M6. On the processing tray 37, a driven roller 48 is arranged at the unloading port (boundary between the sheet placement surface 37a and the first tray 49), and a lifting roller 41 in pressure contact with the driven roller 48 is arranged to face the driven roller 48. The unloading roller mechanism is formed by the driven roller 48 and the lifting roller 41.

[0182] Thus, the conveying mechanism 45 and 45v that passes the sheet stack by pushing it from the upstream side to the downstream side, and the unloading roller mechanism 48 and 41 that grips the sheet stack and unloads it are arranged on the processing tray 37. ​ A state in which the sheet stack is located at the stapling position on the processing tray 37 is shown. At this time, the conveying mechanism 45 and 45v and the unloading roller mechanism 48 and 41 are set in an operating state. ​ A halfway state of passing the sheet stack to the downstream side from the processing position is shown. The sheet stack is conveyed to the downstream side by the movement of the pushing protrusion 45 and the rotation of the unloading roller mechanism 48 and 41. ​ A state immediately before unloading the sheet stack to the first tray 49 on the downstream side is shown. On the processing tray, the sheet stack is gradually (low speed) conveyed to the downstream side by the rotation of the unloading roller mechanism 48 and 41. At this time, the pushing protrusion 45 is in the​ at the position shown in the middle is in a standby state and returns (retracts) to the initial position.

[0183] <Configuration of the stapling unit>

[0184] The configuration of the above-described stapling unit will be described with reference to ​ The stapling unit 47 is formed as a unit separate from the sheet post-processing apparatus B. A unit frame 47a having a box shape, a drive cam 47d supported swingably axially on the unit frame 47a, and a drive motor M4 that pivots the drive cam 47d are installed in the unit frame 47a.

[0185] In the drive cam 47d, a stapling head 47b and an anvil member 47c are arranged facing each other at a stapling position. The stapling head 47b is biased by a biasing spring (not shown) of the drive cam 47d from an upper standby position to a lower stapling position (anvil member) and moves vertically. A needle pod 52 is detachably attached to the unit frame 47a.

[0186] The needle pod 52 stores linear staple needles, and the needles are supplied to the stapling head 47b by a needle feed mechanism. The stapling head portion 47b includes a forming member that bends the linear needle into a U-shaped shape, and a driver that presses the bent needle into a sheet stack. With this configuration, the drive cam 47d is rotated by the drive motor M4 to store energy of the biasing spring. When the rotation angle reaches a predetermined angle, the stapling head portion 47b is moved downward to the anvil member 47c side with a large force. By this operation, the stapling needle is bent into a U-shaped shape and then inserted into the sheet stack by the driver. The tip of the needle is bent by the anvil member 47c, thereby performing stapling stapling.

[0187] The needle feed mechanism is incorporated between the needle pod 52 and the stapling head 47b, and a sensor (empty sensor) that detects the presence or absence of a needle is arranged in the needle feed mechanism. Further, a pod sensor (not shown) that detects whether the needle pod 52 is inserted is arranged in the unit frame 47a.

[0188] The needle pod 52 adopts a structure that stacks staple needle layers connected in a band form and stored in a pod having a box shape, and a structure that stores staple needles in a roll form. The unit frame 47a is provided with a circuit that controls the above-described sensors and a circuit board that controls the drive motor M4, and is configured to generate an alarm signal when the needle pod 52 is not stored or lacks staple needles. The stapling control circuit is configured to control the drive motor M4 to perform a stapling operation by a staple needle signal, and to generate an "operation end signal" when the stapling head portion 47b moves from the standby position to the stapling position and returns to the standby position again.

[0189] <Explanation of the control configuration>

[0190] The image forming system shown in ​ will be described. ​ the control configuration in the image forming system shown in ​ The image forming system shown in includes a control unit 90 of the image forming apparatus A (hereinafter referred to as "main body control unit") and a control unit 95 of the sheet post-processing apparatus B (hereinafter referred to as "binding processing control unit"). The main body control unit 90 controls a print control unit 91, a feeding control unit 92, and an input unit 93 (control panel).

[0191] The "image forming mode" and the "post-processing mode" are set based on a user operation received via the input unit 93 (control panel). In the image forming mode, for example, a mode such as color / monochrome printing or double-sided / single-sided printing is set, and image forming conditions such as a sheet size, a sheet quality, a number of print-out copies, and a zoom print are set. Further, in the "post-processing mode", for example, a "print-out mode", a "book binding processing discharge mode", a "staple binding processing mode", or a "slow-moving sorting mode" is set.

[0192] Further, the main body control unit 90 transmits data indicating that the mode is the post-processing mode and data indicating a sheet number, a copy number information, and a paper thickness information of a sheet used to form an image to the binding processing control unit 95. Meanwhile, the main body control unit 90 transmits a job end signal to the binding processing control unit 95 every time the image forming ends.

[0193] The post-processing mode will be described. The "print-out mode" is a mode in which a sheet from the straight path discharge port 35 is stored in the stacking tray 49 via the processing tray 37 without performing a binding process. In this case, the sheets are stacked on the processing tray 37 in an overlapping state, and the sheet bundle is unloaded to the stacking tray 49 after the stacking according to the job end signal from the main body control unit 90.

[0194] The "product processing discharge mode" is a mode in which a sheet on which an image is formed is aligned and bound, and then folded to perform a book binding finish. The details will be described with reference to ​ to the details.

[0195] The "staple binding processing mode" is a mode in which a sheet from the straight path discharge port 35 is stacked and aligned on the processing tray 37, and a sheet bundle is bound, and then stored in the stacking tray 49. In this case, the operator needs to specify that the sheets on which images are to be formed have the same paper thickness and the same size. In the staple binding processing mode, one of "multiple binding", "right corner binding", and "left corner binding" is selected and specified.

[0196] In the "slow-moving classification mode", the sheet having the image formed by the image forming apparatus A is classified into a group that is subjected to the offset movement and the stacking and a group that is subjected to the stacking without the offset movement. The sheet stacks subjected to the offset movement and the sheet stacks not subjected to the offset movement are alternately stacked on the stacking tray.

[0197] <Binding processing control unit>

[0198] The binding processing control unit 95 causes the sheet post-processing apparatus B to operate in accordance with the post-processing mode set by the main body control unit 90. The binding processing control unit 95 is configured to include a control CPU. The ROM 96 and the RAM 97 are connected to the binding processing control unit 95, and the operation of the sheet post-processing apparatus B according to this embodiment is performed on the basis of a control program stored in the ROM 96 and control data stored in the RAM 97. Thus, the binding processing control unit 95 controls the drive circuits of all the drive motors described above, thereby starting / stopping the motors and controlling the forward / reverse rotation.

[0199] Reference will be made to ​ A book binding processing discharge mode as one of the post-processing modes will be described. Steps S101 and S102 indicate the processing in the image forming apparatus A, and steps S103 to S113 indicate the processing in the sheet post-processing apparatus B. That is, the processing of steps S101 and S102 is implemented, for example, by the main body control unit 90 reading a program stored in the ROM to the RAM and executing the program. The processing of steps S103 to S115 is implemented, for example, by the binding processing control unit 95 reading a program stored in the ROM 96 to the RAM 97 and executing the program.

[0200] The main body control unit 90 forms an image on a sheet in step S101, and discharges the sheet on which the image is formed in step S102. The sheet having the image formed by the image forming apparatus A is guided to the straight path 28.

[0201] In step S103, the binding processing control unit 95 controls the motor, thereby conveying the sheet discharged from the image forming apparatus A to the front edge adjustment stopper 67 through the path. The sheet conveying control in step S103 will be described later.

[0202] In step S104, the stapling process control unit 95 moves the position of the front edge adjustment stopper 67 to a position where the sheet can be loaded. At this time, the stapling process control unit 95 sets the position of the front edge adjustment stopper 67 based on the size of the sheet in the conveyance direction (received from the image forming apparatus A). In step S105, the stapling process control unit 95 loads the sheet to the front edge adjustment stopper 67 after the movement. The loaded sheet abuts against the receiving portion of the front edge adjustment stopper 67, and thus the front edge of the sheet is aligned.

[0203] In step S106, the stapling process control unit 95 determines whether the last sheet is loaded to the front edge adjustment stopper 67 based on the predetermined number of the post-process to be executed. The process starting from step S105 is repeated until it is determined that the last sheet is loaded to the front edge adjustment stopper 67. When it is determined that the last sheet is loaded to the front edge adjustment stopper 67, the process proceeds to step S107.

[0204] In step S107, the stapling process control unit 95 moves the position of the front edge adjustment stopper 67 loaded with the predetermined number of sheets to the lowest point. In step S108, the stapling process control unit 95 aligns the sheets in the width direction. The sheet alignment here is performed by a side end adjustment member (not shown).

[0205] In step S109, the stapling process control unit 95 rotates the folding roller 64. In step S110, the stapling process control unit 95 advances the folding blade 65 in the folding direction. In step S111, the stapling process control unit 95 determines whether the amount of rotation of the folding roller 64 reaches a predetermined amount. When it is determined that the amount of rotation of the folding roller 64 does not reach the predetermined amount, the process of step S111 is repeated. When it is determined that the amount of rotation of the folding roller 64 reaches the predetermined amount, the process proceeds to step S112. In step S112, the stapling process control unit 95 retreats the folding blade 65. In step S113, the stapling process control unit 95 conveys the folded sheet that has undergone the above-described folding process in the discharge direction by the downstream-side saddle stapling discharge roller. As a result, the folded sheet is stored in the second tray 61 via the saddle stapling discharge path 68.

[0206] The example in which the folding process is executed after moving the position of the front edge adjustment stopper 67 in step S107 has been described above, but the configuration is not limited to this. Another post-process can be executed after moving the position of the front edge adjustment stopper 67 and before executing the folding process. For example, a stapling process can be executed. For example, based on receiving a job end signal from the image forming apparatus A, a stapling unit (saddle stapling unit) (not shown) provided in the saddle stapling unit B2 can be caused to move to the center portion of the sheet, and a stapling process can be executed. At this time, the stapling process is executed at a defined position, for example, at one point or two points.

[0207] Even during the post-process in the saddle stapling unit B2, image formation is continuously executed by the image forming apparatus A. In this embodiment, in the sheet processing apparatus B, a cache operation of piling up the sheet transported from the image forming apparatus A is executed. This makes it possible to continuously execute the post-process without reducing the frequency of discharging the sheet from the image forming apparatus A, that is, without reducing the productivity of the image forming apparatus A.

[0208] Reference will be made to ​ An overview will be given of the sheet cache operation executed in step S103 in the sheet processing apparatus B. ​ A cross-sectional view of the sheet processing apparatus B as viewed from the side surface direction. Hereinafter, the first transport roller 201, the second transport roller 202, and the third transport roller 203 will be referred to as the displacement roller 201, the displacement roller 202, and the intermediate transport roller 203.

[0209] First, the cache operation of the sheet smaller in length in the sheet transport direction will be described. In this embodiment, as an example of the definition of the small size, a size suitable for the path length of the straight path 28 is defined as the small size.

[0210] ​ A state is shown in which, in the saddle stapling unit B2, a sheet S0 previously existing in the sheet processing apparatus B is subjected to the processes of steps S109 to S112 shown in ​ In addition, ​ A state is shown in which a sheet S1 discharged from the image forming apparatus A is transported to the entrance roller 29 and the displacement roller 201 via the straight path entrance 26. At this time, the entrance sensor Se1 executes front edge detection. In the state shown in ​ In the state shown in ​ A state is shown in which the front edge of the sheet S1 is further transported to a position beyond the displacement roller 202. At this time, lateral alignment adjustment is executed with respect to the sheet S1 (to be described later).

[0211] ​A state in which the front edge of the sheet S1 is further conveyed to a position beyond the discharge roller 36 is shown. ​ A state in which the position of the upper stopper 33a is moved to a cache path guide position is shown. The cache path guide position is set to a position in which the sheet can be fed into the saddle stitch cache path P2 based on the front edge detection result of the entrance sensor Se1 and the sheet length information. It should be noted that the detection result of Se2 can be used instead of or in combination with the detection result of Se1 if the sheet reaches the discharge sensor Se2.

[0212] ​ A state in which the position of the lower stopper 33b is moved to a cache path guide position is shown. By moving the upper stopper 33a and the lower stopper 33b, a path that conveys the sheet S1 to the saddle stitch cache path P2 is formed. ​ A state in which the sheet S1 is retracted to the saddle stitch cache path P2 is shown. Thus, in this embodiment, the sheet S1 is retracted to the saddle stitch cache path P2, so that a subsequent sheet discharged from the image forming apparatus A is continuously received in the straight path 28. In ​ In the state shown in FIG. 27, the post-processing (folding processing) of the sheet S0 is being performed. Here, "being performed" indicates not only that the folding processing is in progress, but also a state in which the folding processing itself has ended, but the sheet has not yet been discharged to the second tray 61.

[0213] ​ A state in which the sheet S1 is further conveyed toward the fourth tray discharge port 305 of the saddle stitch cache path P2 is shown. At this time, the post-processing of the sheet S0 is being performed. Further, ​ A state in which the position of the lower stopper 33b is moved is shown. The lower stopper 33b is moved so that a subsequent sheet S2 is received in the straight path 28.

[0214] ​ A state in which the sheet S1 is positioned at a predetermined position in the saddle stitch cache path P2 is shown. As ​ In the state shown in FIG. 27, the post-processing of the sheet S0 is being performed. Here, "being performed" indicates not only that the folding processing is in progress, but also a state in which the folding processing itself has ended, but the sheet has not yet been discharged to the second tray 61. ​ A state in which a subsequent sheet S2 discharged from the image forming apparatus A is conveyed to the entrance roller 29 and the displacement roller 201 via the straight path entrance 26 is shown. At this time, the front edge detection of the sheet S2 is performed by the entrance sensor Se1. In ​In the state shown in the middle, lateral alignment error detection is performed on the sheet S2 (to be described later). At this time, lateral alignment adjustment is performed so that the sheet S1 located in the saddle-stitch buffer path P2 is aligned according to the lateral alignment error of the sheet S2. The operation will be described later. At this time, post-processing of the sheet S0 is being performed.

[0215] ​ A state in which the sheets S1 and S2 are being synchronously conveyed to the displacement roller 202 is shown. The conveyance synchronization between the sheets is performed based on, for example, the detection result of the entrance sensor Se1 and the sheet length information and the sheet position information by the driving pulse of the stepping motor. By driving the buffer roller 302 based on the front edge detection result of the sheet S2 by the entrance sensor Se1, the front edges of the sheets S1 and S2 are aligned and fed into the straight path 28. At this time, post-processing of the sheet S0 is being performed. ​ A state before the sheets S1 and S2 are synchronously further conveyed to the intermediate conveyance roller 203 is shown. At this time, lateral alignment adjustment is performed so that the sheets S1 and S2 are center-aligned. The operation will be described later. At this time, post-processing of the sheet S0 is being performed.

[0216] ​ A state in which the sheets S1 and S2 are conveyed to the discharge roller 36 in an overlapping state is shown. At this time, the rear edges of the sheets S1 and S2 are away from the displacement roller 201. Further, at this time, post-processing of the sheet S0 is being performed. ​ A state in which the positions of the upper and lower flaps 33a and 33b are moved is shown. When the upper and lower flaps 33a and 33b are moved, a path for conveying the sheets S1 and S2 to the saddle-stitching element B2 is formed. At this time, the sheet S0 is discharged to the second tray 61, ​ A state in which the sheets S1 and S2 are loaded to the front edge adjustment stopper 67 is shown.

[0217] As described above, according to this embodiment, even when post-processing of the sheet in the saddle-stitching unit B2 is being performed, the sheet S1 can be caused to retreat to the buffer path P2 and the sheet S2 following it can be received from the image forming apparatus A. This makes it possible to perform post-processing of the sheet without reducing the productivity of the image forming apparatus A. In addition, since the leading edge is abutted against the leading edge adjustment stopper 67, the sheets S1 and S2 are sequentially stacked in the stacked state from the lower side, and the order of the plurality of sheets is maintained. Furthermore, since the buffered sheets S1 and S2 are fed into the saddle-stitching unit B2 in the aligned state, the buffered stack of sheets can be quickly retreated from the straight path 28, so that the time of receiving the next sheet can be advanced. It should be noted that the state in which the buffered sheets S1 and S2 are relatively aligned refers to a state in which the amount of deviation in the conveyance direction falls within a predetermined range (for example, a range of between 0 mm and +10 mm and a range of between 0 mm and -10 mm). In this embodiment, a state in which the sheet S1 that has entered the saddle-stitching buffer path P2, for example, about 2.5 mm in advance of the sheet S2 following it is located on the trailing edge side is used as a standard value for adjustment. This makes it possible to cause the sheet S1 located on the right side to abut against the leading edge adjustment stopper 67 first and facilitate alignment of the sheets when the stack of sheets S1 and S2 is fed into the saddle-stitching unit B2. Even considering various tolerances, when control is performed so that the trailing edge of the sheet S1 is located behind the sheet S2 within a predetermined range, the time of quickly retreating the sheets from the straight path 28 can be ensured, and the productivity can be improved by receiving the next sheet more quickly.

[0218] It should be noted that when the entrance of the saddle-stitching path 32 and the position at which the sheets are overlapped (the exit of the saddle-stitching buffer path P2) are disposed at close positions in the conveyance direction, the conveyance distance of the sheets from the straight path 28 to be retreated is short, and the productivity is improved. In addition, the saddle-stitching buffer path shutter 33a and the saddle-stitching path shutter 33b configured to feed the sheets from the straight path 28 to these paths can be shared. When the operation of feeding the sheets to the saddle-stitching buffer path P2 is performed two or more times, the buffer processing can be performed on three or more sheets.

[0219] In ​ part, lateral alignment error detection and lateral alignment adjustment are performed. Lateral alignment error detection and lateral alignment adjustment will be described below with reference to ​ . The upper part of ​ is a view showing a simplified configuration in the vicinity of the straight path 28 in ​ . The lower part of ​ is a view of the straight path 28 in the upper part as viewed from the upper side of the apparatus. Furthermore, ​the entry roller 29, the displacement roller 201, the displacement roller 202, the intermediate conveying roller 203, and the buffer rollers 302a and 302b shown in the lower portion of FIG. 10 correspond to ​ the entry roller 29, the displacement roller 201, the displacement roller 202, the intermediate conveying roller 203, and the buffer rollers 302a and 302b shown in the upper portion of FIG. 10. Further, as shown in the upper portion, among the rollers arranged on the straight path 28, the roller pairs look as if they overlap each other when viewed from the upper side. On the other hand, as for the rollers arranged on the saddle-stitch buffer path P2, the roller pairs look as if they are displaced from each other when viewed from the upper side because the conveying path is curved, and the state is shown.

[0220] ​ A state in which the sheet S1 is discharged from the image forming apparatus A is shown. At this time, the center axis of the sheet S1 is not normally located at the center in the width direction, and a lateral alignment error is generated. ​ A state in which the sheet S1 is conveyed to a position before the displacement roller 201 is shown. At this time, the alignment detection sensor 100 performs detection of the lateral alignment error of the sheet S1.

[0221] ​ A state in which the alignment detection sensor 100 ends detection of the lateral alignment error of the sheet S1 is shown. ​ A state in which the sheet S1 is conveyed to a position beyond the displacement roller 202 is shown. At this time, the gripping of the entry roller 29 is cancelled. In other words, the sheet S1 is gripped by the displacement roller 201 and the displacement roller 202. The displacement roller 201 and the displacement roller 202 can be displaced by the above-described conveying roller displacement mechanism.

[0222] In ​ the lateral alignment adjustment is performed by the displacement roller 201 and the displacement roller 202 so that the center axis of the sheet S1 in the conveying direction is aligned with the center. This corresponds to ​ the state shown in ​ A state in which the sheet S1 is conveyed to a position beyond the intermediate conveying roller 203 is shown. At this time, the entry roller 29 is in a gripped state, and can receive a sheet that follows.

[0223] ​ A state in which the position of the displacement roller 201 returns to the original position (receiving position) is shown. ​ A state in which the sheet S1 is reversely conveyed by the intermediate conveying roller 203, the displacement roller 202, and the buffer rollers 302a and 302b to the saddle-stitch buffer path P2 is shown. That is, in ​ the state shown in ​ the upper portion, the intermediate conveying roller 203 and the displacement roller 202 are controlled to reversely run. At this time, the upper baffle 33a and the lower baffle 33b are moved as shown in

[0224] ​ The state in which the position of the shift roller 202 returns to the original position (receiving position) is shown. ​ The state in which the sheet S2 is then discharged from the image forming apparatus A and is conveyed to a position beyond the shift roller 201 is shown. At this time, the center axis of the sheet S2 is not located at the center in the width direction, and a lateral alignment error is generated.

[0225] ​ The state in which the alignment detection sensor 100 performs detection of the lateral alignment error of the sheet S2 is shown. ​ The state in which the alignment detection sensor 100 ends detection of the lateral alignment error of the sheet S2, and the sheet S2 is further conveyed to a position before the shift roller 202 is shown.

[0226] ​ A view to show the state in which lateral alignment adjustment is performed on the sheet S1 located in the saddle-stitch buffer path P2 by the shift operation of the buffer rollers 302a and 302b in accordance with the lateral alignment error of the sheet S2. That is, a first shift operation is performed on the sheet S1. This corresponds to the state shown in FIG. 12B. The buffer rollers 302a and 302b can be shifted by the above-described conveyance roller shift mechanism. ​ A view to show the state in which lateral alignment adjustment is performed on the sheet S1 located in the saddle-stitch buffer path P2 by the shift operation of the buffer rollers 302a and 302b in accordance with the lateral alignment error of the sheet S2. That is, a first shift operation is performed on the sheet S1. This corresponds to the state shown in FIG. 12B. The buffer rollers 302a and 302b can be shifted by the above-described conveyance roller shift mechanism. ​ A view to show the state in which the sheet S1 and the sheet S2 are synchronously conveyed to the downstream side of the straight path 28 is shown.

[0227] ​ A view to show the state in which the sheet S1 and the sheet S2 are synchronously conveyed to a position beyond the shift roller 202 is shown. At this time, the clamping of the entrance roller 29 is cancelled. In other words, the sheet S2 overlaps the sheet S1 and is clamped by the shift roller 201 and the shift roller 2022. ​ A view to show the state in which lateral alignment adjustment is performed on the sheet S1 located in the saddle-stitch buffer path P2 by the shift operation of the buffer rollers 302a and 302b in accordance with the lateral alignment error of the sheet S2. That is, a first shift operation is performed on the sheet S1. This corresponds to the state shown in FIG. 12B. The buffer rollers 302a and 302b can be shifted by the above-described conveyance roller shift mechanism. ​ A view to show the state in which lateral alignment adjustment is performed on the sheet S1 located in the saddle-stitch buffer path P2 by the shift operation of the buffer rollers 302a and 302b in accordance with the lateral alignment error of the sheet S2. That is, a first shift operation is performed on the sheet S1. This corresponds to the state shown in FIG. 12B. The buffer rollers 302a and 302b can be shifted by the above-described conveyance roller shift mechanism.

[0228] ​ A view to show the state in which the sheet S1 and the sheet S2 are synchronously conveyed to the downstream side of the straight path 28 is shown. ​ A view to show the state in which the shift roller 201 moves to the original position (receiving position) is shown. At this time, as shown in FIG. 12A, the upper and lower flaps 33a and 33b move to a position at which a sheet can be guided to the saddle-stitch path 32. ​ A view to show the state in which the shift roller 201 moves to the original position (receiving position) is shown. At this time, as shown in FIG. 12A, the upper and lower flaps 33a and 33b move to a position at which a sheet can be guided to the saddle-stitch path 32.

[0229] ​ A view to show the state in which the sheet S1 and the sheet S2 are synchronously conveyed to the downstream side of the straight path 28 is shown.​ A view showing a state in which the shift roller 202 moves to the original position (receiving position).

[0230] As described above, according to this embodiment, the alignment error of each sheet discharged from the image forming apparatus A and continuously received by the straight path 28 can be adjusted.

[0231] ​ A flowchart showing the process of the sheet buffering operation performed by the sheet processing apparatus B. The process shown in FIG. 10 is implemented, for example, by the binding process control unit 95 reading a program stored in the ROM 96 to the RAM 97 and executing the program. ​ It should be noted that the binding process control unit 95 according to this embodiment is one control unit, but can be a combination of individual control units corresponding to the rollers.

[0232] In step S201, the sheet S1 is discharged from the image forming apparatus A. The process of step S201 is performed by the image forming apparatus A. In step S202, the binding process control unit 95 moves the sheet support to the operation position. The sheet support is a member configured to prevent the sheet conveyed on the straight path 28 from falling. In step S203, the binding process control unit 95 detects that the sheet S1 reaches the entrance roller 29. In step S204, the binding process control unit 95 detects the lateral alignment error of the sheet S1 by the alignment detection sensor 100.

[0233] In step S205, the binding process control unit 95 separates (clamping cancellation) the entrance roller 29. This is to perform the lateral alignment adjustment of the sheet S1 by the shift operation of the shift roller 201 and the shift roller 202 in the subsequent stage. In step S206, the binding process control unit 95 starts the shift operation of the shift roller 201 and the shift roller 202. Here, the shift direction is the direction to eliminate the lateral alignment error of the sheet S1. In step S207, the binding process control unit 95 accelerates the sheet S1 and conveys it to the downstream side of the straight path 28. In step S208, the binding process control unit 95 completes the shift operation of the shift roller 201 and the shift roller 202.

[0234] In step S209, the binding process control unit 95 again sets the entrance roller 29 in the clamped state. In step S210, the binding process control unit 95 returns the shift roller 201 to the original position (receiving position). This corresponds to the state shown in FIG. 8. ​

[0235] ​The binding process control unit 95 starts moving the upper flapper 33a to the cache path guide position in step S211, and starts moving the lower flapper 33b to the cache path guide position in step S212. In step S213, the binding process control unit 95 completes the movement of the upper flapper 33a to the cache path guide position, and in step S214, the binding process control unit 95 completes the movement of the lower flapper 33b to the cache path guide position. This corresponds to the state shown in FIG. 26. ​

[0236] In step S215, the binding process control unit 95 stops the shift rollers 202 and the intermediate conveyance rollers 203. In step S216, the binding process control unit 95 reversely operates the shift rollers 202 and the intermediate conveyance rollers 203, thereby reversely conveying the sheet S1. In step S217, the binding process control unit 95 starts moving the lower flapper 33b to the original position (receiving position). In step S218, the binding process control unit 95 causes the sheet S1 to retreat to the saddle binding cache path P2. In step S219, the binding process control unit 95 completes the movement of the lower flapper 33b to the original position. This corresponds to the state shown in FIG. 27. ​ ​

[0237] In step S221, the sheet S2 is discharged from the image forming apparatus A. The process of step S221 is performed by the image forming apparatus A.

[0238] In step S222, the binding process control unit 95 detects the lateral alignment error of the sheet S2 by the alignment detection sensor 100. In step S223, the binding process control unit 95 performs the lateral alignment adjustment by the shift operation of the cache rollers 302a and 302b, so that the sheet S1 located in the saddle binding cache path P2 is aligned according to the lateral alignment error of the sheet S2.

[0239] In step S224, the binding process control unit 95 separates the entry rollers 29 (clamping cancellation). This is to perform the lateral alignment adjustment of the sheet S1 and the sheet S2 by the shift operation of the shift rollers 201 and 202 and the cache rollers 302a and 302b in the subsequent stage.

[0240] In step S225, the binding process control unit 95 overlaps the sheet S1 and the sheet S2, and conveys them to the shift rollers 202.

[0241] ​​​In step S226, the binding processing control unit 95 performs alignment adjustment through the shifting operations of buffer rollers 302a and 302b and shift roller 202, so that the central axis of sheet S1 is aligned with the center. On the other hand, in step S227, the binding processing control unit 95 performs alignment adjustment through the shifting operations of shift rollers 201 and shift roller 202, so that the central axis of sheet S2 is aligned with the center. The processing in step S226 and the processing in step S227 are performed synchronously and in parallel.

[0242] In step S228, the binding processing control unit 95 again sets the inlet roller 29 to the clamping state. In step S229, the binding processing control unit 95 returns the shift roller 201 to its original position (receiving position). This corresponds to... ​ The state shown in the image.

[0243] In step S230, the binding processing control unit 95 begins moving the lower baffle 33b to the saddle-binding path guide position, and in step S231, it begins moving the upper baffle 33a to the saddle-binding path guide position. In step S232, the binding processing control unit 95 completes the movement of the lower baffle 33b to the saddle-binding path guide position, and in step S233, it completes the movement of the upper baffle 33a to the saddle-binding path guide position. This corresponds to... ​ The state shown in the image.

[0244] In step S234, the binding processing control unit 95 operates the intermediate conveying roller 203 and the shifting roller 202 in reverse, so that the sheets S1 and S2 overlap and are conveyed in reverse to the saddle binding path 32.

[0245] Detailed description ​ and 21A The diagram illustrates the operation of overlapping sheets S1 and S2. The leading edge of sheet S1 in the conveying direction is located upstream of the clamping point of the shift roller 202. If sheets S1 and S2 are to be merged at the clamping point where they overlap and are clamped, or downstream of the clamping point, sheet S1 may contact sheet S2, thus hindering conveying and preventing merging. This is particularly problematic in bookbinding processes, where high basis weights (e.g., 256 g / m²) are often used. 2 The cover uses a paper type with a lower grammage (g / m²) for the main page, while the inner pages use a paper type with a lower grammage. This is because the grammage typically used for inner pages is 52 to 82 g / m². 2 The thin paper is soft and easily bent, making it difficult to assemble.

[0246] After the sheet S1 and the sheet S2 are overlapped, the sheet S1 is buffered in the saddle-stitching buffer path P2 so that it can be gripped by the pair of rollers, the motor that drives the conveying roller and the motor that drives the buffer roller are adjusted so that the speed of the sheet S2 is substantially equal to the speed of the sheet S1, and the sheet S1 and the sheet S2 are merged.

[0247] More specifically, for example, using the detection result of the entrance sensor Se1 or the detection result of another sheet position sensor (not shown), the sheet is put in a standby state at a position at which the leading edge of the sheet S1 is pulled into the saddle-stitching buffer path P2 by about 3 mm from the straight path 28, i.e., at a position at which the leading edge of the sheet S1 is not exposed to the straight path 28, and the sheet S1 is accelerated to the conveying speed of the sheet S2 and merged in the straight path 28 before the leading edge of the sheet S2 reaches the displacement roller 202. Thus, defects due to contact between the sheets can be prevented, and the sheet S1 and the sheet S2 can be smoothly merged.

[0248] In step S235, the saddle-stitching processing control unit 95 moves the upper flap 33a to the original position (receiving position). In step S236, the saddle-stitching processing control unit 95 moves the lower flap 33b to the original position (receiving position).

[0249] In step S237, the saddle-stitching processing control unit 95 performs a saddle-stitching process on the sheet S1 and the sheet S2 loaded to the leading edge adjustment stopper 67. This corresponds to the processing of steps S109 to S111 in ​ In step S238, the saddle-stitching processing control unit 95 stores the sheet S1 and the sheet S2 that have undergone the saddle-stitching process in the second tray 61 via the saddle-stitching discharge path 68 (discharge portion). Thereafter. ​ The processing shown in

[0250] Regarding the buffering operation of a large-size sheet (whose length in the sheet conveying direction is larger than the length of a small-size sheet in the conveying direction), the differences from the small-size sheet will be described below.

[0251] ​ A flowchart showing the processing of the buffering operation of a large-size sheet performed by the sheet processing apparatus B. The processing shown in ​ is implemented, for example, by the saddle-stitching processing control unit 95 reading a program stored in the ROM 96 to the RAM 97 and executing the program. ​ The processing shown in ​The difference is that the processes of steps S303, S307, S311, S324, and S331 are executed. The processes of steps S301, S302, S304 to S306, S308 to S310, S312 to S323, S325 to S330, and S332 to S341 are the same as described with respect to steps S201, S202, S203 to S205, S206 to S208, S210 to S221, S222 to S227, and S229 to S238, and the description thereof will be omitted.

[0252] In step S303, the stapling process control unit 95 moves the upper conveying path damper 34 to the upper conveying path guide position. Thereby, a path that guides the sheet conveyed on the straight path 28 to the upper conveying path 30 is formed. When the trailing edge of the small-size sheet passes through the displacement roller 202, the leading edge of the sheet is located near the discharge roller 36. However, when the trailing edge of the large-size sheet passes through the displacement roller 202, the leading edge of the sheet can protrude outside the apparatus. In this case, the sheet can be twisted or damaged. In this embodiment, in the case of the large-size sheet, the sheet is conveyed on the upper conveying path 30 as shown in ​ , thereby preventing the sheet from being twisted or damaged as described above. It should be noted that the state shown in ​ and 36B corresponds to the state shown in ​ and 17B in the case of the small-size sheet. ​ The state shown in ​ corresponds to the state shown in ​ in the case of the small-size sheet. 38B The state shown in ​ and 22B corresponds to the state shown in ​ and 39B in the case of the small-size sheet. ​ The state shown in 32B corresponds to the state shown in It should be noted that, in the buffering operation of the large-size sheet, the position of the sheet can be detected using the detection result of a sensor (not shown) provided in the upper conveying path 30, or the position of the sheet can be detected using the entrance sensor Se1.

[0253] In steps S307 and S324, the stapling process control unit 95 separates the intermediate conveying roller 203 and the upper conveying roller 303. This makes it possible to perform the alignment adjustment of the large-size sheet by the displacement rollers 201 and 202.

[0254] In steps S311 and S331, the stapling process control unit 95 sets the intermediate conveying roller 203 and the upper conveying roller 303 again in the clamped state. This enables the conveyance of large-size sheets.

[0255] The straight path described in this embodiment is not necessarily an absolutely linear shape, and should allow the conveyance of coated paper having a grammage of greater than 500 g / m 2 at a speed of 1750 mm / sec without damage. More specifically, the curvature of the path is preferably set to a gentle curvature of not less than 100R (100 mm radius). Furthermore, the pair of conveying rollers sometimes protrude from the path surface, and the amount of protrusion is preferably about 1 mm to 2 mm with respect to the lower surface of the path. It should be noted that coated paper having a grammage of greater than 500 g / m 2 is so-called hard paper, and this paper type is used for paper packaging, magazine covers, and the like.

[0256] As described above, according to this embodiment, it is possible to buffer sheets continuously supplied from the image forming apparatus A, overlap the sheets, and then convey the sheets to the saddle stapling unit / folding process unit.

[0257] It should be noted that in another embodiment to be described below, it is possible to buffer sheets to be conveyed to the saddle stapling unit B2. Another embodiment will be described with reference to ​ and 41 Another embodiment will be described. ​ A state in which the first sheet (preceding sheet SA) and the second sheet (subsequent sheet SB) of the next sheet bundle are buffered before the completion of the saddle stapling process of the preceding sheet bundle is shown.

[0258] The preceding sheet SA is fed to the upper conveying path 30. When the trailing edge of the preceding sheet is withdrawn from the straight path 28, the sheet is temporarily stopped and enters a standby state. Next, the subsequent sheet SB is fed toward the straight path discharge port 35. When the trailing edge of the subsequent sheet SB passes to the branch portions (shelves 34a and 34b in the upper conveying path shutter 34) of the upper conveying path 30 in the conveying direction, the sheet is conveyed in a return direction.

[0259] When the return conveyance of the subsequent sheet SB is started, the conveyance of the preceding sheet SA to the straight path 28 is also started. ​ A state in which the subsequent sheet SB and the preceding sheet SA are aligned is shown. After the alignment of the sheets, the sheet bundle is supplied to the saddle stapling path 32.

[0260] Even in the operation according to the above-described another embodiment, it is possible to perform saddle stapling buffering for at most two sheets.

[0261] The present application is not limited to the above-described embodiments, and various changes and modifications can be made within the spirit and scope of the present application. Therefore, the following claims are presented to define the scope of the present application in order to inform the public of the scope of the present application.

[0262] This application claims priority to Japanese Patent Application No. 2023-142449, filed September 1, 2023, which is incorporated herein by reference.

[0263] List of Reference Signs

[0264] 28 straight path, 201 inlet roller, 202, 203 displacement roller, 203 intermediate conveying roller, 33a upper baffle (first baffle), 33b lower baffle (second baffle)

Claims

1. A bookbinding processing device, comprising: A conveying path configured to convey the sheet from a loading port to an unloading port; A bookbinding processing device, disposed below the conveying path, is used to perform bookbinding processing, including binding and folding, on a stack of sheets. A bookbinding processing path, the bookbinding processing path being configured to transport the sheet from the conveying path to the bookbinding processing device; A conveying device, disposed in the conveying path, is used to convey the sheet material; A detection device for detecting when the sheet conveyed by the conveying device reaches a predetermined position; A cache path is located above the transport path and configured to cache the sheet. A buffer conveying device is disposed in the buffer path for conveying the sheet; A conveying control device for controlling the conveying device to feed the preceding sheet conveyed through the conveying path to the buffer path; as well as A buffer conveying control device is configured to control the buffer conveying device to convey the preceding sheet from the buffer path to the conveying path based on the detection result of the detection device on the following sheet after the preceding sheet. The conveying control device controls the conveying device to feed the stack of the preceding sheet and the following sheet into the bookbinding processing path.

2. The bookbinding processing equipment according to claim 1, wherein, The buffer path is configured such that the preceding sheet is fed while moving in the direction from the unloading port to the loading port. The bookbinding process path is configured such that the stack of the preceding and following sheets is fed while moving in the direction from the unloading port to the loading port, and The cache path and the bookbinding processing path are arranged to face each other at least partially across the transport path.

3. The bookbinding processing equipment according to claim 1, wherein, The conveying device includes a pair of rollers capable of rotating in both the forward and reverse directions. The buffer path is configured such that the preceding sheet, conveyed from the loading port to the unloading port, is fed by reversing the rotation of the roller pair. The bookbinding process path is configured such that a stack of the rear sheet and the front sheet, conveyed from the loading port to the unloading port, is fed by reversing the rotation of the roller pair. The entry points of the cache path and the bookbinding process path are arranged on the upstream side of the roller pair in the direction from the loading port to the unloading port.

4. The bookbinding processing equipment according to claim 2 or 3, wherein, The bookbinding processing device includes: A stop, configured to stop the lower end of a stack of sheets fed through the bookbinding processing path; and A support device for supporting the stack of sheets stopped by the stop. The support device is arranged such that its lower end is positioned downstream of its upper end in the direction from the loading port to the unloading port. The buffer conveying control device controls the buffer conveying device such that when the preceding sheet and the following sheet are aligned, the rear edge of the preceding sheet is located upstream of the rear edge of the following sheet in the direction from the loading port to the unloading port.

5. The bookbinding processing equipment according to claim 1, further comprising: Position detection device for detecting the position of the sheet. The buffer conveying control device controls the buffer conveying device based on the detection result of the position detection device, so that buffering is performed at a position where the leading edge of the sheet conveyed to the buffer path is at a predetermined distance from the conveying path.

6. An image forming system, comprising: An image forming apparatus for forming an image on a sheet; A transport path configured to transport a sheet having an image formed by the image forming apparatus from the image forming apparatus to an unloading port; A bookbinding processing device, disposed below the conveying path, is used to perform bookbinding processing, including binding and folding, on a stack of sheets. A bookbinding processing path, the bookbinding processing path being configured to transport the sheet from the conveying path to the bookbinding processing device; A conveying device, disposed in the conveying path, is used to convey the sheet material; A detection device for detecting when the sheet conveyed by the conveying device reaches a predetermined position; A cache path is located above the transport path and configured to cache the sheet. A buffer conveying device is disposed in the buffer path for conveying the sheet; A conveying control device for controlling the conveying device to feed the preceding sheet conveyed through the conveying path to the buffer path; as well as A buffer conveying control device is configured to control the buffer conveying device to convey the preceding sheet from the buffer path to the conveying path based on the detection result of the detection device on the following sheet after the preceding sheet. The conveying control device controls the conveying device to feed the stack of the preceding sheet and the following sheet into the bookbinding processing path.

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