Sheet processing device and image forming system

Abstract

To provide a sheet processing device capable of executing binding processing along user's application, and of being reduced in size and weight.SOLUTION: A sheet processing device comprises a first binding processing unit for performing crimp binding processing, a second binding processing unit for performing needle binding processing, and a medium movement unit capable of moving a sheet bundle in both a conveyance direction for conveying a medium onto a tray and a direction opposite to the conveyance direction. When the number of media loaded on the tray exceeds the upper limit number of those subjected to the crimp binding processing by scheduling the crimp binding processing by the first binding processing unit, and when performing a processing switching operation for switching to the needle binding processing by the second binding processing unit, the second binding processing unit is switched according to a binding content for which the first binding processing unit is scheduled after moving the sheet bundle loaded on the tray, and after moving the second binding processing unit to a binding position at which the first binding processing unit is scheduled.SELECTED DRAWING: Figure 10

Description

Technical Field

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

Background Art

[0002] There is known a sheet processing apparatus that binds a sheet bundle in which sheet-like media are stacked. As binding processes applied to the sheet apparatus, there are known "needle binding process" in which a needle-like member (binding member) penetrating the sheet bundle is used for binding, and "pressure bonding binding process" in which pressure is applied to a part of the sheet bundle to deform and bind it without using a binding member.

[0003] In a sheet processing apparatus capable of selectively performing needle binding process and pressure bonding binding process, a technique for switching to needle binding process for the purpose of performing a binding process according to the user's application is disclosed. (For example, refer to Patent Document 1).

Summary of the Invention

Problems to be Solved by the Invention

[0004] When applying the technique disclosed in Patent Document 1, when switching between needle binding process and pressure bonding binding process, in order to move the binding unit for each process to the binding position, it is necessary to temporarily retract the other binding unit from the position where the binding process is performed. In this case, the space required for retraction needs to ensure a size where each binding unit can move relative to each other and do not interfere with each other, which leads to an increase in the overall size of the apparatus. That is, in the prior art, when configuring to switch the binding unit according to the user's application, there are problems in downsizing and weight reduction of the apparatus size.

[0005] An object of the present invention is to provide a sheet processing apparatus that can execute a binding process according to the user's application and can achieve downsizing and weight reduction.

Means for Solving the Problems

[0006] To solve the above problems, one aspect of the present invention relates to a sheet processing apparatus, comprising: a first binding processing unit that performs a crimping binding process by pressing and crimping a sheet bundle, which is made up of a plurality of sheet-like media loaded onto a tray; a second binding processing unit that performs a staple binding process by passing a needle-like member through the sheet bundle; and a media moving unit that allows the sheet bundle to be moved in either the direction of transport when the media is transported to the tray or in the opposite direction of the transport direction, wherein when the number of media loaded onto the tray for crimping binding by the first binding processing unit exceeds the upper limit of the crimping binding process, a processing switching operation is performed to switch to staple binding by the second binding processing unit, the media moving unit moves the sheet bundle loaded onto the tray in the opposite direction, then moves the second binding processing unit to the binding position planned by the first binding processing unit, and then moves the second binding processing unit according to the binding content planned by the first binding processing unit. The second binding processing unit is rotated relative to the medium. It is characterized by its ability to switch between modes. [Effects of the Invention]

[0007] According to the present invention, it is possible to perform binding processes according to the user's intended use, while also achieving miniaturization and weight reduction. [Brief explanation of the drawing]

[0008] [Figure 1] A diagram showing the overall configuration of the image forming system according to the present invention. [Figure 2] A diagram showing the internal structure of a post-processing device, which is an embodiment of the sheet processing device according to the present invention. [Figure 3] This is a perspective view showing a first example of a binding processing unit included in the above-mentioned post-processing device. [Figure 4] This is a perspective view illustrating the challenges that arise during switching operations in conventional binding processing units. [Figure 5] This diagram illustrates the problems that arise during switching operations in conventional binding processing units. [Figure 6] This diagram illustrates the problems that arise during switching operations in conventional binding processing units. [Figure 7]This diagram illustrates the problems that arise during switching operations in conventional binding processing units. [Figure 8] A sequence diagram showing the control triggers executed in the image forming system described above. [Figure 9] A flowchart showing a first example of the over-count control process performed by the post-processing unit described above. [Figure 10] This figure shows an example of the operation of the binding processing unit, which is executed by the above-mentioned over-page control process. [Figure 11] This figure shows an example of the operation of the binding processing unit, which is executed by the above-mentioned over-page control process. [Figure 12] This figure shows an example of the operation of the binding processing unit, which is executed by the above-mentioned over-page control process. [Figure 13] A flowchart showing a second example of the over-count control process performed by the post-processing unit described above. [Figure 14] This figure shows an example of the operation of the binding processing unit, which is executed by the above-mentioned over-page control process. [Figure 15] A flowchart showing a third example of the over-count control process performed by the post-processing unit described above. [Figure 16] This figure shows an example of the operation of the binding processing unit, which is executed by the above-mentioned over-page control process. [Figure 17] This is a perspective view showing a second example of a binding processing unit included in the above-mentioned post-processing device. [Figure 18] This figure shows the determination conditions in the second example of the binding processing unit described above. [Modes for carrying out the invention]

[0009] Embodiments of the present invention will be described below with reference to the drawings. Figure 1 is a diagram showing the overall configuration of a printer system 1 as an embodiment of the image forming system according to the present invention. The printer system 1 has the function of forming an image on a sheet of paper P, which is an example of a sheet-like medium, and performing post-processing on the sheet of paper P on which the image has been formed. As shown in Figure 1, the printer system 1 is configured to operate in cooperation with an image forming apparatus 2 and a post-processing device 3 as a sheet processing device. However, if all the functional configurations of the post-processing device 3 can be included in the image forming apparatus 2, it may be configured in that way.

[0010] The image forming apparatus 2 is a device that performs an image forming process to form an image on a sheet of paper P and a media discharge process to discharge the sheet of paper P with the image formed on it to a post-processing device 3. The image forming apparatus 2 mainly comprises a sheet storage tray for storing the sheets of paper P, a transport unit for taking the sheets of paper P out of the sheet storage tray and transporting them, and an image forming unit for forming an image on the sheets of paper P transported by the transport unit. The image forming unit may be an inkjet system that forms images using ink, or an electrophotographic system that forms images using toner. The configuration of the image forming apparatus 2 can be based on well-known standards, so a detailed explanation is omitted.

[0011] [Internal structure of the post-processing device 3] Figure 2 shows the internal structure of the post-processing device 3. The post-processing device 3 performs predetermined post-processing on the paper P on which an image has been formed by the image forming apparatus 2. The post-processing according to this embodiment corresponds to a "binding process" that fixes a stack of paper sheets (hereinafter referred to as a "sheet stack"), which is made by stacking a predetermined number of sheets P on which an image has been formed, into a single stack. As will be described later, the binding processes that can be performed in the post-processing device 3 according to this embodiment include a "pressure binding process" as a first binding process in which a part of the sheet stack is compressed and deformed to bind it, and a "stapling process" as a second binding process in which a "stapling needle" as a binding member is passed through a part of the sheet stack to bind it. The binding processes that can be performed in the post-processing device 3 also include an end binding process that binds the ends of the sheet stack and a saddle stitching process that binds the center of the sheet stack.

[0012] The post-processing device 3 includes conveyance roller pairs 10 to 19 as a post-processing conveyance unit and a switching claw 20 as a branch switching unit that selectively switches the conveyance direction in the post-processing conveyance unit. The conveyance roller pairs 10 to 19 convey the sheet P supplied from the image forming apparatus 2 inside the post-processing device 3. More specifically, the conveyance roller pairs 10 to 13 convey the sheet P along the first conveyance path Ph1. The conveyance roller pairs 14 to 15 convey the sheet P along the second conveyance path Ph2. The conveyance roller pairs 16 to 19 convey the sheet P along the third conveyance path Ph3.

[0013] Note that the conveyance roller pair 15 is composed of a driving roller 151 and a driven roller 152 as described later. The conveyance roller pair 15 also has a function of holding the sheet P stacked on the internal tray 22 by a nip formed by the driving roller 151 and the driven roller 152. Further, the conveyance roller pair 15 operates when conveying the sheet P to the internal tray 22 and when discharging a sheet bundle from the internal tray 22.

[0014] The first conveyance path Ph1 is a path from the supply port of the sheet P from the image forming apparatus 2 to the sheet discharge tray 21. The second conveyance path Ph2 branches from the first conveyance path Ph1 between the conveyance roller pairs 11 and 14 in the conveyance direction and reaches the sheet and sheet bundle discharge tray 31 via the internal tray 22. The third conveyance path Ph3 branches from the first conveyance path Ph1 between the conveyance roller pairs 11 and 14 in the conveyance direction and reaches the discharge tray 30.

[0015] The switching claw 20 is positioned at the branching point of the first transport path Ph1 and the second transport path Ph2. The switching claw 20 is configured to switch between a first position in which the paper P is discharged to the sheet discharge tray 21 via the first transport path Ph1, and a second position in which the paper P being transported along the first transport path Ph1 is guided to the second transport path Ph2. Furthermore, when the trailing end of the paper P that has entered the second transport path Ph2 passes the transport roller pair 11, the transport roller pair 14 is rotated in the reverse direction, thereby guiding the paper P to the third transport path Ph3. The post-processing device 3 is also equipped with multiple sensors that detect the position of the paper P on the first transport path Ph1, the second transport path Ph2, and the third transport path Ph3. The transport sensors for detecting the position of the paper P during transport are indicated by black-filled triangles (▲) in Figure 2.

[0016] The post-processing device 3 includes a sheet discharge tray 21, a discharge tray 30, and a sheet and sheet bundle discharge tray 31. The sheet discharge tray 21 supports the paper P discharged through the first transport path Ph1. The sheet discharge tray 21 discharges paper P supplied from the image forming apparatus 2 that has not undergone binding. The discharge tray 30 discharges paper P supplied from the image forming apparatus 2 that has undergone folding at the center position, and sheet bundles that have undergone saddle stitching at the center position. The sheet and sheet bundle discharge tray 31 discharges paper P supplied from the image forming apparatus 2 that has not undergone binding, and sheet bundles that have undergone binding.

[0017] Furthermore, the post-processing device 3 includes an internal tray 22 for stacking and aligning the edges of paper sheets P in order to form a state where multiple sheets are stacked and bound together. It also includes an end fence 23 for regulating and aligning the position of the edges of the paper sheets P in the direction from which they are being transported. In addition, it includes side fences 24 (consisting of a pair of left side fences 24L and right side fences 24R) for regulating and aligning the position of the edges of the paper sheets P in the width direction.

[0018] Furthermore, it is equipped with a release claw 26 for moving the paper P loaded in the internal tray 22 in the reverse direction from which it was transported. The end fences 23 are arranged at predetermined intervals in the width direction of the paper P. The release claw 26 is positioned between the end fences 23.

[0019] Furthermore, the post-processing device 3 includes a first binding processing unit 25 and a second binding processing unit 55, which function as sheet processing units. The internal tray 22, end fence 23, side fence 24, first binding processing unit 25, and second binding processing unit 55 perform edge binding on the paper P being transported along the second transport path Ph2.

[0020] Hereinafter, the direction from the transport roller pair 15 toward the end fence 23 will be defined as the "paper transport direction of P". Furthermore, the direction perpendicular to the surface of P and the transport direction of P will be defined as the "main scanning direction (width direction of P)". Note that the transport direction of P corresponds to the sub-scanning direction.

[0021] [Outline configuration of the first binding processing unit 25 and the second binding processing unit 55] Figure 3 is a perspective view showing the first binding processing unit 25 and the second binding processing unit 55, and the main configuration for performing the process of forming a sheet bundle by these units. As shown in Figure 3, the paper P, transported to the internal tray 22, is aligned by the end fence 23, which restricts the leading edge in the transport direction. Then, the first binding processing unit 25 or the second binding processing unit 55 performs a binding process on the end of the bundle of paper P that has been loaded into the internal tray 22 and whose ends have been aligned. In other words, the position where the leading edge in the transport direction is restricted by the end fence 23 corresponds to the position of the paper P when the binding process is performed.

[0022] Furthermore, release claws 26, which constitute the media movement section, are arranged in line with the end fence 23. A pair of transport rollers 15 are formed at the rear end of the internal tray 22 in the transport direction, and a drive roller 151 and a driven roller 152, which constitute the media movement section, are arranged there. The drive roller 151 and driven roller 152 also have the function of nipping and holding the sheet bundles loaded on the internal tray 22. In addition, a return roller 27 is arranged there as a media movement section that contacts the uppermost surface of the sheet bundles loaded on the internal tray 22 and functions when moving the sheet bundles in the transport direction or the opposite direction of transport.

[0023] The states of the first binding unit 25 and the second binding unit 55 shown in Figure 3 illustrate a state where the binding process for the paper P is selected as "stapleless binding" (pressure binding), according to the binding content determined by the user's pre-settings. Therefore, when the paper P is transported to the internal tray 22, the second binding unit 55 is already in a standby state at an initial position (home position) that is different from the binding position. In this case, the standby position of the second binding unit 55 is not limited to the initial position, but can be anywhere within the range that the second binding unit 55 can move when executing the binding process.

[0024] Furthermore, as illustrated in Figure 3, when the user has pre-configured the binding process for the paper P to be "stapleless binding" (pressure binding), the first binding processing unit 25, which performs the pressure binding process, is positioned appropriately for the binding type according to the setting when the paper P is transported to the internal tray 22.

[0025] Next, we will explain a conventional problem where the paper P may be damaged when switching the binding process to the second binding process (staple binding) from the state illustrated in Figure 3. Figure 4 is a perspective view illustrating a situation in which the paper P may be damaged when switching binding processes.

[0026] For example, in the first binding unit 25, which performs pressure binding, the number of sheets of paper P that can be bound is less than the number of sheets of paper P that can be bound in the second binding unit 55, which performs staple binding. In this case, if, as illustrated in Figure 3, the user has selected (set) "pressure binding" in the pre-settings, and the number of sheets of paper P discharged and transported by the operation of the image forming apparatus 2 executed thereafter may exceed the number of sheets that can be bound (upper limit) in the first binding unit 25. In this case, since pressure binding cannot be performed by the first binding unit 25, it is necessary to switch to the second binding unit 55 and perform staple binding.

[0027] For example, as illustrated in Figure 4, when switching from the first binding unit 25 to the second binding unit 55 with paper P stacked in the internal tray 22, it is necessary to move the second binding unit 55 to the binding position that was planned to be performed by the first binding unit 25 and change the binding orientation according to the binding content. Therefore, the first binding unit 25 is first moved from the position illustrated in Figure 3 back to its initial position. Then, the second binding unit 55 is moved to a position suitable for the binding type set by the user and changed to the binding orientation.

[0028] Here, if the position suitable for the binding type set by the user is the position where the orientation of the second binding processing unit 55 is rotated, there is a concern that the second binding processing unit 55 may come into contact with the edge of the paper P stacked in the internal tray 22 (the corner area R in Figure 4) during rotation. As a result, there is a concern that the edge of the paper P may be damaged, such as being bent or scratched, due to contact with the second binding processing unit 55.

[0029] To prevent damage to the paper P (such as folds or scratches on the edges) as illustrated above, the second binding unit 55 must be moved to a position away from the edges of the paper P, that is, closer to the initial position of the first binding unit 25, and before being rotated. Once the rotation is complete, the second binding unit 55 should be moved back to its binding position. In this case, the position to which the second binding unit 55 is returned is a position appropriate for the set binding type.

[0030] However, there are challenges in avoiding damage to the paper P as illustrated in Figure 4. Figures 5 to 7 illustrate the challenges that arise when the switching operation to the second binding processing unit 55 must be performed at a position sufficiently far from the edge of the paper P and at a position that does not interfere with the first binding processing unit 25.

[0031] Figure 5 shows an example of the initial position (home position) of the first binding unit 25, taking into account the distance the second binding unit 55 moves away from the edge of the paper P to avoid interference with the first binding unit 25 during the switching operation of the second binding unit 55. Note that the positional relationship between the first binding unit 25 and the second binding unit 55 shown in the example is relative. Similarly, the positional relationship between the second binding unit 55 and the paper P is also relative. Note that the configuration for stacking and holding the paper P, such as the internal tray 22, is omitted in Figures 5 to 7.

[0032] The "distance X" shown in Figure 5 exemplifies the travel distance assuming that the first binding unit 25 moves from its initial position to perform the binding operation on the paper P, without considering the second binding unit 55.

[0033] Furthermore, the "distance Y" exemplified in Figure 5 represents the distance between the initial position of the first binding unit 25 and the paper P, so that the second binding unit 55 can rotate without contacting the edge of the paper P, and so that the first binding unit 25, which is in its initial position, does not interfere. In other words, distance Y represents the distance that the first binding unit 25 needs to move during the binding process in order to avoid damaging the paper P when switching binding processes.

[0034] In other words, when the binding process is switched from pressure binding to staple binding due to an increase in the number of sheets of paper P, the first binding unit 25 needs to move a longer distance to avoid damaging the paper P. In the example, the movement distance of the first binding unit 25 needs to be increased by "distance Y - distance X".

[0035] Furthermore, as shown in Figure 6, following Figure 5, we will consider the operation in which, in the switching operation of the binding process, the first binding unit 25 retracts to its initial position, and then the second binding unit 55 rotates to change its angle with respect to the paper P. In this case, as shown in Figure 6, in the space obtained when the first binding unit 25 retracts to its initial position set as "distance Y" from the edge of the paper P, the second binding unit 55 moves to a position where it does not come into contact with the edge of the paper P even when it rotates. Then, at the destination position, the second binding unit 55 rotates so that it is at a predetermined angle with respect to the paper P. This space corresponds to a position "distance Z" which is near the binding position. Distance Z is in the relationship "distance 0 < distance Z < distance Y". Here, "distance 0" means the edge of the paper P.

[0036] As shown in Figure 7, following Figure 6, during the switching operation from the first binding unit 25 to the second binding unit 55, the rotated second binding unit 55 moves relative to the paper P to a position suitable for the set binding type. The distance the second binding unit 55 moves at this time corresponds to the "distance Z" described above.

[0037] As described above, when switching from the first binding processing unit 25 to the second binding processing unit 55, the distance traveled by the first binding processing unit 25 becomes longer, especially when the paper P is stacked in the internal tray 22. This increased distance ensures that there is space for the second binding processing unit 55 to rotate (switch over).

[0038] In other words, according to the conventional switching operation explained using Figures 5 to 7, it is difficult to complete the switching operation of the binding process without damaging the paper P unless the travel distance of the first binding processing unit 25 and the second binding processing unit 55 is increased. Furthermore, since the travel distance increases, the time required to complete the switching operation increases, which reduces the productivity of the sheet bundle. In addition, the need to secure space for operations such as the rotation of the second binding processing unit 55 leads to an increase in the size of the device.

[0039] [First embodiment of printer system 1] Next, a first embodiment of the operation of the printer system 1 as an embodiment of the image forming system according to the present invention will be described. Figure 8 is a command sequence diagram illustrating the control triggers for the image forming apparatus 2 and post-processing device 3 included in the printer system 1.

[0040] As shown in Figure 8, the image forming apparatus 2 notifies the post-processing device 3 of the printer system 1 startup trigger. When the startup is complete, the post-processing device 3 notifies the image forming apparatus 2 of the startup completion trigger (S801). This completes the startup of the printer system 1, and user setup, image forming, and post-processing begin.

[0041] Subsequently, when the paper P is ejected from the image forming apparatus 2 to the post-processing apparatus 3, a paper acceptance control trigger is notified (S802). After receiving the paper acceptance control trigger, the post-processing apparatus 3 transports the incoming paper P to the internal tray 22 and starts the configured binding process. For example, after transporting the paper P to the internal tray 22, the side fence 24 adjusts for variations in the main scanning direction of the paper P.

[0042] The image forming apparatus 2 compares the total number of sheets received with the maximum number of sheets that can be bound after the final paper is confirmed. If the number of sheets exceeds the maximum number of sheets that can be bound, it notifies the post-processing device 3 of an over-count control trigger according to a pre-set process (S803).

[0043] The post-processing device 3, for example, performs over-count control processing after receiving the final sheet into the internal tray 22. After all image forming processes and discharge processes to the post-processing device 3 are completed, if a changeover is necessary, the device performs a process changeover operation. By waiting for the final sheet discharged from the image forming apparatus 2 to the post-processing device 3 to be received before determining whether a changeover in the binding process is necessary and performing the process changeover, the time required to reheat the heater can be reduced (improving productivity), and the power used to reheat the heater can be suppressed, resulting in energy savings.

[0044] In Figure 8, the image forming apparatus 2 is shown to send a sheet count overload control trigger; however, the image forming apparatus 2 may not send the sheet count overload control trigger, and the post-processing device 3 may determine the number of sheets P. Furthermore, the timing of the sheet count overload control trigger notification is not limited to the timing exemplified in Figure 8.

[0045] [Second embodiment of printer system 1] Next, a second embodiment of the operation of the printer system 1 as an embodiment of the image forming system according to the present invention will be described. Since the command sequence in the second embodiment is the same as in the first embodiment, further illustration will be omitted, and the explanation will be given with reference to Figure 8.

[0046] In this embodiment, the image forming apparatus 2 compares the number of sheets P with the maximum number of sheets that can be bound each time it discharges paper P to the post-processing device 3 (S803). If the number of sheets exceeds the maximum number of sheets that can be bound, the image forming apparatus 2 notifies the post-processing device 3 of an over-number of sheets control trigger without waiting for the last sheet of paper P to be discharged, and the post-processing device 3 starts the binding process switching operation.

[0047] When the post-processing device 3 receives the sheet overload control trigger, it performs a processing switch operation from the first binding processing unit 25 to the second binding processing unit 55, and as will be described later, it moves the paper P in the opposite direction of the transport direction. In this case, the paper P loaded in the internal tray 22 can be moved without waiting for the last sheet. Generally, when moving a small amount of paper P compared to moving a large amount of paper P, moving a small amount of paper P results in less load (damage) to the paper P and less variation in the alignment of the paper P.

[0048] Therefore, the second embodiment, compared to the first embodiment, can perform a processing switch operation when the number of sheets of paper P loaded in the internal tray 22 is small, thereby reducing the load (damage) on the paper P and variations in the alignment of the paper P.

[0049] In the second embodiment, the image forming apparatus 2 may not send an over-count control trigger, and the post-processing device 3 may determine the number of sheets P. In this case, the amount of communication from the image forming apparatus 2 to the post-processing device 3 can be reduced, and the risk due to communication noise can be reduced. Furthermore, the timing of notification of the over-count control trigger is not limited to the timing exemplified in Figure 8.

[0050] [First embodiment of the post-processing device 3] Next, a first embodiment of the over-count control process executed in the post-processing device 3 will be described. Figure 9 is a flowchart of the over-count control process executed in the post-processing device 3 after receiving the over-count control trigger notification in S803.

[0051] First, the stack of paper P loaded in the internal tray 22 is moved in the opposite direction to the transport direction to the internal tray 22 by operating the moving member that constitutes the media moving unit (S901). This movement operation is called the "paper retraction operation". The relative positions of the first binding processing unit 25 and the second binding processing unit 55, and the relationship between the first binding processing unit 25 and the second binding processing unit 55 and the loaded paper P before S901 is executed are as illustrated in Figure 3.

[0052] Figure 10 illustrates the relative positional relationship between the first binding unit 25 and the second binding unit 55 after the media retraction operation of S901, and the relationship between the first binding unit 25 and the second binding unit 55 and the stacked paper P.

[0053] As shown in Figure 10, the paper P loaded in the internal tray 22 is moved away from the end fence 23 by moving the release claw 26 in the opposite direction of the transport direction while the paper P remains loaded in the internal tray 22. At this time, the leading edges of the paper P are aligned in the transport direction by the end fence 23, and the release claw 26 moves the aligned bundle of paper P away from the end fence 23.

[0054] Furthermore, the distance the paper P moves at this time is the distance required for the second binding processing unit 55 to reach a position where it does not come into contact with the paper P even when it rotates near a position suitable for the set binding type during the switching operation from the first binding processing unit 25 to the second binding processing unit 55.

[0055] Furthermore, the paper retraction operation is performed not only by movement by the release claw 26, but also by rotating the drive roller 151 in the opposite direction to that during transport while the paper is gripped by the drive roller 151 and the driven roller 152. By moving the paper while gripping it with the drive roller 151 and the driven roller 152, the alignment of the edges of the paper P can be suppressed while moving.

[0056] Subsequently, a processing switch operation is performed from the first binding processing unit 25 to the second binding processing unit 55 (S902). The processing switch operation (binding unit switching operation) of S902 is performed. Figure 11 illustrates the relative positional relationship between the first binding processing unit 25 and the second binding processing unit 55, and the relationship between the first binding processing unit 25 and the second binding processing unit 55 and the stacked paper P during the binding unit switching operation.

[0057] As shown in Figure 11, the first binding unit 25 has moved to its initial position, and the second binding unit 55 has moved to a position suitable for the set binding content. Then, near the position suitable for the binding content, it changes its orientation to a state suitable for the binding content (it is rotated relative to the paper P).

[0058] Subsequently, a paper recovery process is performed (S903) to return the paper P, which had been moved away from the end fence 23 by the paper retraction operation, to a position where it is in contact with the end fence 23. This recovery operation is performed by the rotational drive of the return roller 27, which is in contact with the upper surface of the topmost paper P loaded in the internal tray 22, and the drive roller 151 and driven roller 152. When the recovery operation is performed, the release claw 26 is returned from the position exemplified in Figure 11 to its original position (the position exemplified in Figure 12).

[0059] In the paper recovery process (S903), the paper P is moved toward the end fence 23 by a distance greater than the distance moved in the paper retraction operation (S902). This allows for correction of any disturbances in the stacking state of the paper P caused by slippage between the paper P and the movement mechanism. The distance the paper P moves in the paper recovery process can be controlled based on the drive amount of the motor that drives the drive roller 151. For example, if the motor that drives the drive roller 151 is a stepping motor, the amount of movement can be controlled by managing the number of pulses in its control pulse signal.

[0060] Subsequently, a staple stapling process is performed on the paper P, and the sheet bundle after stapling is discharged to the sheet and sheet bundle discharge tray 31 using the discharge claw 26, drive roller 151, and driven roller 152.

[0061] Furthermore, if the code includes processes S901 to S903, the processes before S901 and after S903 may be processes other than those exemplified above.

[0062] As explained above, the paper retraction operation performed in the over-sheet control process reduces the distance the first binding unit 25 needs to move to prevent the second binding unit 55 from contacting the paper P when the binding unit switching operation is performed, as illustrated in Figures 10 to 12. In other words, as explained using Figures 5 to 7, it becomes unnecessary to secure a switching location (distance Y - distance X), thus enabling miniaturization of the post-processing device 3.

[0063] Furthermore, since the travel distance of the first binding unit 25 and the second binding unit 55 can be shortened, the time required for switching binding units can be reduced, thereby improving the productivity of sheet bundles.

[0064] [Second embodiment of the post-processing device 3] Next, a second embodiment of the over-count control process executed in the post-processing device 3 will be described using the flowchart in Figure 13. This process is also an example of the over-count control process executed in the post-processing device 3 after receiving the over-count control trigger notification in S803.

[0065] The paper retraction operation (S1301), binding unit switching operation (S1302), and paper return operation (S1303) according to this embodiment are the same as S901, S902, and S903 described in the first embodiment, so a detailed explanation is omitted.

[0066] After the paper return operation (S1303) completes the movement of the paper P to a position where it contacts the end fence 23, the pair of side fences 24 are operated to perform a width alignment operation (S1304) to align the widthwise edges of the paper P.

[0067] Figure 14 illustrates the positional relationship between the pair of side fences 24 and the paper P when the paper width edge alignment operation is performed. As shown in Figure 14, the pair of side fences 24 are moved closer to or further away from the edges of the paper P. This allows the widthwise edges of the paper P, which have been returned to the binding position, to be realigned.

[0068] By performing realignment after returning the paper P, it is possible to correct paper variations in the main scanning direction even if they occur after the switching operation associated with retracting to the output side.

[0069] [Third embodiment of the post-processing device 3] Next, a third embodiment of the over-count control process executed in the post-processing device 3 will be described using the flowchart in Figure 15. This process is also an example of the over-count control process executed in the post-processing device 3 after receiving the over-count control trigger notification in S803.

[0070] First, a side fence retraction operation is performed to move the side fence 24 away from the position where it is in contact with the edge of the paper P (S1501). Figure 16 illustrates the positional relationship between the pair of side fences 24 and the paper P when the side fence retraction operation is performed.

[0071] As shown in Figure 16, after the paper P transported to the internal tray 22 is aligned along its width by the side fences 24, the pair of side fences 24 are moved to a position where they do not come into contact with the paper P before the binding unit switching operation. By moving the side fences 24 away from the paper P in this way before performing the paper retraction operation (S1502), paper resistance can be reduced.

[0072] Note that the paper retraction operation (S1502), binding unit switching operation (S1503), paper return operation (S1504), and paper width edge alignment operation (S1505) according to this embodiment are the same as those according to the paper retraction operation (S1301), binding unit switching operation (S1302), paper return operation (S1303), and paper width edge alignment operation (S1505) according to the second embodiment, so a detailed explanation is omitted.

[0073] [Fourth embodiment of the post-treatment device 3] Next, a fourth embodiment of the sheet count overload control processing performed in the post-processing device 3 will be described. In the paper retraction operation (S901) described in the first embodiment, the configuration used for the paper retraction operation of the paper P may be switched based on information indicating the size of the paper P loaded in the internal tray 22.

[0074] For example, when the paper size P is small, the release claw 26, the drive roller 151, and the driven roller 152 are used. When the paper size P is large, the release claw 26, the drive roller 151, the driven roller 152, and the return roller 27 are used.

[0075] By changing the paper retraction operation according to the size of the paper P, the return roller 27 is not used for small-sized paper P, thus reducing deterioration of the return roller 27. Furthermore, for large-sized paper P, the number of support points for transport can be increased, reducing variations during paper transport.

[0076] Furthermore, the paper retraction operation may be performed without using the release claw 26. In this case, the post-processing device 3 can be configured without the release claw 26, thus reducing the number of parts and lowering the manufacturing cost of the device.

[0077] [Fifth embodiment of the post-treatment device 3] Next, a fourth embodiment of the sheet count overload control processing performed in the post-processing device 3 will be described. In the paper return operation (S903) described in the first embodiment, the configuration used for the paper return operation of the paper P may be switched based on information indicating the size of the paper P loaded in the internal tray 22.

[0078] For example, when the paper size P is small, the drive roller 151 and the driven roller 152 are used. When the paper size P is large, the drive roller 151 and the driven roller 152, as well as the return roller 27, are used.

[0079] By changing the paper retraction operation according to the size of the paper P, the return roller 27 is not used for small-sized paper P, thus reducing deterioration of the return roller 27. Furthermore, for large-sized paper P, the number of support points for transport can be increased, reducing variations during paper transport.

[0080] Furthermore, the paper return operation may be performed without using the return roller 27, regardless of the size. In this case, the post-processing device 3 can be configured without the return roller 27, thus reducing the number of parts and lowering the manufacturing cost of the device.

[0081] [Sixth embodiment of the post-processing device 3] Next, a sixth embodiment of the post-processing device 3 will be described with reference to Figures 17 and 18. As shown in Figure 17, a first sensor 61 is provided at the end of the internal tray 22 in the direction of paper transport. In addition, a pair of second sensors 62 are provided at opposing positions at the ends of the internal tray 22 in the width direction of the paper P.

[0082] Figure 18 is a table showing the relationship between the state of the paper P and the cases when the first sensor 61 and the second sensor 62 are detecting the paper P (ON) or not detecting it (OFF).

[0083] As shown in Figures 17 and 18, when the first sensor 61 is ON and the second sensor 62 is also ON, it indicates that the paper P is in a position to contact the end fence 23.

[0084] On the other hand, when the first sensor 61 is OFF and the second sensor 62 is ON, it indicates that the paper P has been moved to a predetermined position by the paper retraction operation. That is, in this state, the binding unit switching operation (S902, etc.) is performed. In addition, in the paper retraction operation (S901, etc.), in order to determine that the paper P has moved to a predetermined retraction position, the time from when the first sensor 61 turns OFF until the second sensor 62 turns OFF may be predetermined, and the determination may be made by measuring the time difference between the ON / OFF states of each sensor.

[0085] Furthermore, by positioning the second sensor 62 opposite each other in the width direction of the paper P, detection of the paper P can be performed even if deformation such as bending occurs in the paper P.

[0086] According to each embodiment of the post-processing device 3 described above, the paper P loaded in the internal tray 22 is moved by a certain amount in a direction away from the end fence 23, and retracted to a position that does not interfere with the operation of either the first binding processing unit 25 or the second binding processing unit 55. This shortens the travel distance of the first binding processing unit 25 and the second binding processing unit 55 required for the processing switching operation from the first binding processing unit 25 to the second binding processing unit 55. Furthermore, the post-processing device 3 can be made smaller and lighter.

[0087] Furthermore, comparing the time it takes to move the paper P loaded in the internal tray 22 a certain amount away from the end fence 23 with the time it takes for the first binding processing unit 25 and the second binding processing unit 55 to move to a position where they do not interfere with the paper P, the paper P retraction operation is completed faster, thus improving the productivity of sheet stacks.

[0088] In each embodiment of the post-processing device 3 described above, the timing for comparing the number of sheets loaded in the internal tray 22 with the upper limit, and the timing for returning the sheet bundle after the processing switch operation from the first binding processing unit 25 to the second binding processing unit 55, are not limited to those exemplified. The timing can be appropriately selected as long as the sheet bundle does not interfere with the first binding processing unit 25 and the second binding processing unit 55 during the processing switch operation from the first binding processing unit 25 to the second binding processing unit 55, and the processing switch operation is completed faster than in the conventional method.

[0089] Furthermore, all of the embodiments described above are realized through the cooperation of the computer's hardware resources and computer software program provided by the control unit of the post-processing device 3. In other words, the control process is executed by the computer by having the arithmetic unit, memory device, input device, output device, and control device work together based on the program. The program may also be written to a memory device or storage medium and distributed, or distributed via telecommunication lines, etc.

[0090] Furthermore, the present invention is not limited to the embodiments exemplified above, and various modifications are possible without departing from its technical essence. All technical matters included in the technical concept described in the claims are covered by the present invention. The above embodiments are preferred examples, but those skilled in the art can realize various modifications from the disclosed content. Such modifications are also included in the technical scope described in the claims.

[0091] [Aspects of the present invention] The contents of this invention are, for example, as follows: <1> A first binding processing unit performs a crimping and binding process in which a sheet bundle, which consists of multiple sheet-like media stacked on a tray, is compressed and crimped together. A second binding processing unit that performs a staple binding process by passing a needle-shaped member through the aforementioned sheet bundle, A media moving unit that allows the sheet bundle to be moved in either the transport direction when the media is transported to the tray or in the opposite direction to the transport direction, Equipped with, When the number of sheets of media loaded onto the tray for crimping by the first binding unit exceeds the upper limit for the crimping process, the second binding unit performs a process switching operation to switch to staple binding. The media moving unit moves the sheet bundle loaded on the tray in the reverse direction, then moves the second binding unit to the binding position that the first binding unit had planned, The sheet processing device is characterized by switching the second binding processing unit according to the binding content planned by the first binding processing unit.

[0092] <2> The media moving unit, after the process switching operation has been performed, switches from the first binding processing unit to the second binding processing unit, and then returns the sheet bundle, which had been moved in the reverse direction, back to the transport direction. <1> This is the sheet processing device described above.

[0093] <3> When the above processing switching operation is performed, after the media moving unit moves the sheet bundle in the transport direction, a width-direction alignment operation is performed in which the width-direction ends of the sheet bundle are aligned by the side fences provided on the tray, <2> This is the sheet processing device described above.

[0094] <4> The distance traveled in the reverse direction and the distance traveled in the conveying direction are equal to or greater than the above. <2> or the above <3> This is the sheet processing device described above.

[0095] <5> The media moving unit is Distributed at the front end of the tray in the transport direction, and movable in both the transport direction and the opposite direction, A pair of conveying rollers is positioned at the rear end of the tray in the conveying direction and nip the sheet bundle, A return roller that contacts the uppermost surface of the sheet bundle loaded on the tray and rotates so that the sheet bundle can move in either the transport direction or the opposite direction, The above comprises one or more movable members. <1> or the above <4> It is a sheet processing device as described in any of the following.

[0096] <6> The media moving unit changes the number of moving members used to move the sheet bundle according to the size and thickness of the media forming the sheet bundle loaded on the tray. <5> This is the sheet processing device described above.

[0097] <7> The media moving unit moves the sheet bundle, which had been moving in the opposite direction, in the conveying direction, and then the sheet bundle is nipped and held by the conveying roller pair. <5> or the above <6> This is the sheet processing device described above.

[0098] <8> The distance the sheet bundle moves in the reverse direction by the media moving unit is the distance required for the sheet bundle to reach a position where it does not interfere with the second binding processing unit when switching from the first binding processing unit to the second binding processing unit according to the binding content. <1> or the above <7> It is a sheet processing device as described in any of the following.

[0099] <9> The switching operation from the first binding processing unit to the second binding processing unit is performed near the binding position corresponding to the binding content. <1> or the above <8> It is a sheet processing device as described in any of the following.

[0100] <10> The system comprises an image forming unit that forms an image on a sheet-like medium, and a sheet processing unit that performs a binding process on the medium, wherein the sheet processing unit is <1> or the above <9> This image forming system is characterized by being a sheet processing device as described in any of the above. [Explanation of Symbols]

[0101] 1: Printer System 2: Image forming apparatus 3: Post-processing equipment 15: Conveyor roller pair 22: Internal tray 23: End fence 24: Side fence 25: First Binding Processing Unit 26: Release claw 27: Return Roll 30: Output tray 31: Sheet and sheet bundle discharge tray 55: Second Binding Processing Unit 61: First Sensor 62: Second sensor 151: Drive roller 152: Driven roller [Prior art documents] [Patent Documents]

[0102] [Patent Document 1] Japanese Patent Publication No. 2016-026971

Claims

1. A first binding processing unit performs a crimping and binding process in which a sheet bundle, which consists of multiple sheet-like media stacked on a tray, is compressed and crimped together. A second binding processing unit that performs a staple binding process by passing a needle-shaped member through the aforementioned sheet bundle, The system includes a media moving unit that allows the sheet bundle to be moved in either the transport direction when the media is transported to the tray or in the opposite direction to the transport direction, When the number of sheets of media loaded onto the tray for crimping by the first binding unit exceeds the upper limit for the crimping process, the second binding unit performs a process switching operation to switch to staple binding. The media moving unit moves the sheet bundle loaded on the tray in the reverse direction, then moves the second binding unit to the binding position that the first binding unit had planned, A sheet processing apparatus characterized by switching the second binding processing unit to a state in which it is rotated relative to the medium, according to the binding content planned by the first binding processing unit.

2. The sheet processing apparatus according to claim 1, wherein the media moving unit returns the sheet bundle, which was moving in the reverse direction, back to the transport direction after the switching operation from the first binding processing unit to the second binding processing unit.

3. The sheet processing apparatus according to claim 2, wherein, when the processing switching operation is performed, after the sheet bundle is moved in the transport direction by the media moving unit, a width alignment operation is performed in which the ends of the sheet bundle in the width direction are aligned by the side fence provided on the tray.

4. The sheet processing apparatus according to claim 2 or 3, wherein the distance traveled in the reverse direction and the distance traveled in the conveying direction are equal to or greater than the distance traveled.

5. The media moving unit is Distributed at the front end of the tray in the transport direction, and movable in both the transport direction and the opposite direction, A pair of conveying rollers is positioned at the rear end of the tray in the conveying direction and nip the sheet bundle, The sheet processing apparatus according to claim 1, comprising one or more moving members: a return roller that contacts the uppermost surface of the sheet bundle loaded on the tray and rotates so that the sheet bundle can move in either the transport direction or the opposite direction.

6. The sheet processing apparatus according to claim 5, wherein the media moving unit changes the number of moving members used to move the sheet bundle according to the size and thickness of the media forming the sheet bundle loaded on the tray.

7. The sheet processing apparatus according to claim 5 or 6, wherein the media moving unit moves the sheet bundle, which had been moved in the opposite direction, in the conveying direction, and then nips and holds the sheet bundle with the conveying roller pair.

8. The sheet processing apparatus according to claim 1, wherein the distance the sheet bundle is moved in the reverse direction by the media moving unit is the distance required for the sheet bundle to reach a position where it does not interfere with the second binding processing unit when switching from the first binding processing unit to the second binding processing unit according to the binding contents.

9. The sheet processing apparatus according to claim 1, wherein the operation of switching the second binding processing unit to a state rotated with respect to the medium is performed near the binding position corresponding to the binding contents.

10. An image forming unit that forms an image on a sheet-like medium, The system comprises a sheet processing unit that performs binding processing on the medium, An image forming system characterized in that the sheet processing unit is the sheet processing unit described in claim 1.

Images