Sheet processing device, image formation device, and image formation system

Abstract

To provide a sheet processing apparatus that can improve both sheet alignment accuracy and binding strength while enabling miniaturization.SOLUTION: The sheet processing device includes: a tray for loading transported sheet-like media; a liquid application unit for applying liquid to a portion of the media loaded on the tray; a pressing unit for performing pressure binding on a portion of a media bundle consisting of a plurality of media loaded on the tray. And the controller operates the liquid application means as end pressing means for pressing an end of the media, and when media are loaded on the tray and a subsequent medium is transported in a first direction while in contact with a preceding medium loaded earlier, the end pressing means presses the downstream end of the preceding medium in a second direction.SELECTED DRAWING: Figure 29

Description

[Technical field]

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

[0002] 2. Description of the Related Art Sheet processing apparatuses that perform predetermined processing on sheet-like media on which images have been formed by an image forming apparatus are known, and image forming systems in which the sheet processing apparatuses and the image forming apparatuses are connected are also known.

[0003] There are several types of sheet processing (sometimes called "post-processing" since it corresponds to a post-process of image formation processing) that can be performed in a sheet processing apparatus, such as a sheet alignment process in which multiple media (sheets) are stacked and their edges are aligned, a binding process in which the edges of an aligned sheet stack are bound, and a folding process in which sheets are folded into a specified shape (e.g., a Z-fold, an outer tri-fold, a double fold, etc.).

[0004] When performing binding processing, which is one type of post-processing, post-processing devices are known that have a liquid application function that applies liquid to stacked sheets in order to improve the binding strength, and that improve the consistency of the sheets to which the liquid has been applied to prevent them from becoming misaligned (see, for example, Patent Document 1). Summary of the Invention [Problem to be solved by the invention]

[0005] The device disclosed in Patent Document 1 sets the angle of the sheet tray, which is a member for stacking sheets, at about 45° from the horizontal, so that the sheets stacked on the sheet tray are inclined and strike the edge alignment member. However, in the case of a so-called internal type sheet processing device in which a functional unit equivalent to the sheet processing device is provided inside the housing of the image forming device, the angle of the loading surface of the sheet tray cannot be increased in order to align the sheet edges, and there is a problem in improving the alignment accuracy of the sheet edges.

[0006] In addition, when a new sheet is placed on top of a sheet already placed on the sheet tray, there is a problem in that the sheet whose edge has already been aligned (the sheet that was previously placed) becomes misaligned due to friction between the sheets, reducing the alignment accuracy.

[0007] That is, in the conventional technology, the sheet processing apparatus tends to become large, and there is a problem in improving the alignment accuracy of the edges when a plurality of sheets are stacked.

[0008] SUMMARY OF THE PRESENT EMBODIMENT An object of the present invention is to provide a sheet folding device that can be made compact while improving both sheet alignment accuracy and binding strength. [Means for solving the problem]

[0009] In order to solve the above technical problems, one aspect of the present invention comprises a tray for loading transported sheet-like media, a liquid application unit for applying liquid to a portion of the media loaded on the tray, and a pressing unit for performing pressure binding on a portion of a media bundle consisting of a plurality of the media loaded on the tray, and is characterized in that when the media are loaded on the internal tray and a subsequent medium, which is the subsequent medium, is transported in a first direction while in contact with a preceding medium that has been previously loaded on the internal tray, the liquid application means or the pressure binding means, or both the liquid application means and the pressure binding means press the leading end of the preceding medium in the second direction. Effect of the Invention

[0010] According to the present invention, it is possible to improve the sheet alignment accuracy and the binding strength, while enabling miniaturization. [Brief description of the drawings]

[0011] [Figure 1] 1 is an external view showing an example of an MFP as an embodiment of an image forming apparatus according to the present invention. [Diagram 2]FIG. 11 is an external view showing another example of an MFP as an embodiment of an image forming apparatus according to the present invention. [Diagram 3] FIG. 2 is a functional block diagram of the MFP according to the embodiment. [Figure 4] FIG. 4 is a functional block diagram of the binding processing unit according to the embodiment. [Diagram 5] FIG. 2 is a cross-sectional configuration diagram of the binding processing unit according to the embodiment. [Figure 6] 6A to 6C are diagrams illustrating an example of an operation process of the binding processing unit according to the embodiment. [Figure 7] 6A to 6C are diagrams illustrating an example of an operation process of the binding processing unit according to the embodiment. [Figure 8] 6A to 6C are diagrams illustrating an example of an operation process of the binding processing unit according to the embodiment. [Figure 9] 6A to 6C are diagrams illustrating an example of an operation process of the binding processing unit according to the embodiment. [Figure 10] 6A to 6C are diagrams illustrating an example of an operation process of the binding processing unit according to the embodiment. [Figure 11] 6A to 6C are diagrams illustrating an example of an operation process of the binding processing unit according to the embodiment. [Figure 12] 6A to 6C are diagrams illustrating an example of an operation process of the binding processing unit according to the embodiment. [Figure 13] 6A to 6C are diagrams illustrating an example of an operation process of the binding processing unit according to the embodiment. [Figure 14] 6A to 6C are diagrams illustrating an example of an operation process of the binding processing unit according to the embodiment. [Figure 15] 6A to 6C are diagrams illustrating an example of an operation process of the binding processing unit according to the embodiment. [Figure 16] 6A to 6C are diagrams illustrating an example of an operation process of the binding processing unit according to the embodiment. [Figure 17] 6A to 6C are diagrams illustrating an example of an operation process of the binding processing unit according to the embodiment. [Figure 18] 6A to 6C are diagrams illustrating an example of an operation process of the binding processing unit according to the embodiment. [Figure 19] 6A to 6C are diagrams illustrating an example of an operation process of the binding processing unit according to the embodiment. [Figure 20] 6A to 6C are diagrams illustrating an example of an operation process of the binding processing unit according to the embodiment. [Figure 21] 6A to 6C are diagrams illustrating an example of an operation process of the binding processing unit according to the embodiment. [Figure 22] 6A to 6C are diagrams illustrating an example of an operation process of the binding processing unit according to the embodiment. [Figure 23] 6A to 6C are diagrams illustrating an example of an operation process of the binding processing unit according to the embodiment. [Figure 24] 6A to 6C are diagrams illustrating an example of an operation process of the binding processing unit according to the embodiment. [Diagram 25] 6A to 6C are diagrams illustrating an example of an operation process of the binding processing unit according to the embodiment. [Figure 26] 6A to 6C are diagrams illustrating an example of an operation process of the binding processing unit according to the embodiment. [Figure 27] 6A to 6C are diagrams illustrating an example of an operation process of the binding processing unit according to the embodiment. [Figure 28] 6A to 6C are diagrams illustrating an example of an operation process of the binding processing unit according to the embodiment. [Figure 29] 5 is a flowchart of a binding process of the binding processing unit according to the embodiment. [Diagram 30] 5 is a flowchart of a binding process of the binding processing unit according to the embodiment. [Diagram 31] FIG. 4 is a configuration diagram of a liquid providing unit included in the binding processing unit. [Diagram 32] FIG. 4 is a configuration diagram of a liquid providing unit included in the binding processing unit. [Diagram 33] FIG. 4 is a perspective view of a liquid deposition head included in the liquid deposition unit. [Diagram 34] 5 is an operation process diagram of the binding processing unit. [Diagram 35] 5 is an operation process diagram of the binding processing unit. [Diagram 36] 5 is an operation process diagram of the binding processing unit. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] [Embodiment of Image Forming Apparatus] Hereinafter, an MFP1 as an embodiment of an image forming apparatus according to the present invention will be described with reference to the drawings. Figures 1 and 2 are external views of the MFP1 according to this embodiment. The MFP1 is a device equipped with an image forming function for forming an image on a sheet S (typically, a sheet S) as a sheet-like medium, and a post-processing function for executing a predetermined sheet process (post-processing) on ​​the sheet S on which the image has been recorded.

[0013] As shown in Fig. 1, the MFP 1 mainly comprises a housing 31 and an image forming means 32 inside the housing 31. The housing 31 is a box-shaped member having an internal space formed therein for accommodating the components of the MFP 1. The housing 31 also has an internal space 33 formed therein that is accessible from outside the MFP 1. The internal space 33 is located, for example, slightly above the center of the housing 31 in the up-down direction. The internal space 33 is exposed to the outside by cutting out an outer wall of the housing 31.

[0014] Furthermore, in the internal space 33, a punch hole forming unit 200 and a binding processing unit 100 as an embodiment of a sheet processing device according to the present invention can be attached.

[0015] The image forming means 32 discharges the sheet S picked up from the sheet storage tray and conveyed to the punch hole punching unit 200 and the binding processing unit 100. The image forming means 32 may be of an inkjet type that forms an image using ink, or of an electrophotographic type that forms an image using toner. The configuration of the image forming means 32 is already known, so a detailed description will be omitted.

[0016] The punch hole punching unit 200 is attached to the internal space 33 of the MFP 1 downstream of the image forming means 32 and upstream of the binding processing unit 100 on the transport path of the sheet S from the image forming means 32 to the binding processing unit 100 (the path indicated by the dashed arrow in FIG. 1). That is, the sheet S on which an image is formed by the image forming means 32 is first handed over to the punch hole punching unit 200 where a predetermined punch hole forming process is performed, and then handed over to the binding processing unit 100 where a binding process described later is performed.

[0017] Furthermore, the punch hole punching unit 200 is configured to be detachable from the MFP 1. When the punch hole punching unit 200 is removed, as illustrated in Fig. 2, the sheet S on which an image has been formed by the image forming means 32 is directly delivered to the binding processing unit 100 for binding processing. Note that another processing unit that performs any processing on the sheet S can be attached to the position in the internal space 33 from which the punch hole punching unit 200 has been removed.

[0018] [Control configuration of sheet processing device including image forming device] Next, the control configuration of the MFP 1 including the binding unit 100 will be described with reference to Fig. 3. Fig. 3 is a diagram illustrating an example of the control configuration of the MFP 1 in a state in which the hole punching unit 200 is detached.

[0019] In FIG. 3, the transport path of the sheet S (flow of the sheet S) is indicated by dashed arrows, and the path of the communication signal (control signal) (signal flow) is indicated by solid arrows.

[0020] The MFP1 includes a display unit 301 for informing the user of the status of various devices and operation details, an operation unit 302 for the user to set the mode, number of copies, etc., and a paper feed unit 303 for stocking sheets S and separating and feeding the sheets one by one. The MFP1 also includes an image creation unit 304 for forming a latent image on a photoconductor, not shown in Fig. 3, and transferring the image to the sheet S, and a fixing unit 305 for fixing the image transferred to the sheet S. The MFP1 also includes an image formation control unit 306 for controlling the operation of each of the above units.

[0021] In the binding processing unit 100 as an embodiment of the sheet processing apparatus, a processing instruction is sent from the image formation control unit 306 of the MFP 1 to the post-processing control unit 102 via a communication line 307, and the post-processing unit 101 performs the specified processing on the sheets S.

[0022] The image forming control units 306 and post-processing control units 102 connected to each other are connected by a communication line 307, enabling the exchange of information. This enables the exchange of information regarding the post-processing operation mode, the size of the sheet S, the timing of delivery of the sheet S, and the like, enabling the system to operate.

[0023] [MFP1 hardware configuration] Next, the hardware configuration of the binding processing unit 100 included in the MFP 1 will be described with reference to Fig. 4. As shown in the figure, the binding processing unit 100 has a CPU 110 as a controller, and is connected to a plurality of motors that serve as power sources for the operation of each mechanism via an I / F (interface) 120. The CPU 110 is a calculation means, and controls the operation of the entire binding processing unit 100.

[0024] The CPU 110 in the binding processing unit 100 is connected to the image formation control unit 306 of the MFP 1 via the I / F 120, and controls the binding processing unit 100 in response to a processing signal from the MFP 1. The binding processing unit 100 is also an optional device, and therefore has a detachable hardware configuration.

[0025] Each motor is equipped with an encoder that can detect the motor drive amount in pulse number, and can stop at a position of a specific drive amount starting from a specific timing. Also, based on the timing when the sensor on the transport path is turned ON or OFF, the drive amount of each motor is calculated based on the encoder pulse, and the position of the edge of the transported sheet S can be detected based on the drive amount.

[0026] As illustrated in FIG. 4, the binding processing unit 100 is connected, via the I / F 120, to a conveying motor 151, a discharge motor 152, a binding unit moving motor 153, a liquid application unit moving motor 154, a liquid application motor 155, a pressing motor 156, a conveying sensor 157, a discharge sensor 158, a binding unit position sensor 159, a liquid application unit position sensor 160, a lifting sensor 161, a liquid amount sensor 162, a shift motor 163 for moving (shifting) the shift roller 13 in the main scanning direction, a tapping roller drive motor 164 for moving and rotating the tapping roller 15 up and down, a return roller drive motor 165 for driving the return roller 14, and a jogger motor 166 for moving the jogger fence 22 in the main scanning direction.

[0027] [Conveyance path configuration of binding processing unit 100] Next, a configuration of a conveying path for the sheet S provided in the binding processing unit 100 as one embodiment of the sheet processing device according to the present invention will be described. Fig. 5 shows a cross-sectional view of the conveying path provided in the binding processing unit 100. The binding processing unit 100 is configured to be able to set a plurality of operation modes and to operate appropriately based on the set operation mode. The operation modes provided in the binding processing unit 100 include, for example, a "shift discharge mode" in which the sheet S is conveyed and discharged from the upstream (image forming means 32) to the discharge tray 20 without being bound, and a "pressure binding mode" in which the sheet S is press-stitched by the pressing unit 19.

[0028] In the shift discharge mode, the sheet S transported from the MFP 1 is received by the inlet rollers 11, transported to the discharge rollers 16, and discharged onto the discharge tray 20. The inlet rollers 11, the transport rollers 12, the shift rollers 13, and the discharge rollers 16 constitute a first transport means. That is, when the sheet S is transported from the inlet rollers 11 to the discharge rollers 16, the transport direction corresponds to the first direction.

[0029] In the case of the pressure binding mode, the sheet S transported from the MFP 1 is received by the entrance rollers 11 and transported in a first direction to the shift rollers 13. When the sheet S leaves the shift rollers 13, the tapping rollers 15 are driven to place the sheet S on a stacking tray 17 serving as an internal tray. Thereafter, the sheet S is transported in a second direction different from the first direction by the operation of the tapping rollers 15 and the return rollers 14 serving as a second transport means. The second direction at this time is a transport toward a reference fence 18 for aligning the end of the sheet S, and corresponds to a transport opposite to the first direction, and therefore corresponds to a "switchback transport".

[0030] In the case of the pressure binding mode, the conveying operation of the sheets S in the second direction (the operation of conveying the sheets S along the stacking tray 17 to the reference fence 18) is repeated until the number of sheets to be bound is reached. Then, when the final sheet S is conveyed to the reference fence 18, the pressure bonding unit 19 as a pressure bonding means pressurizes and deforms the end of the stack of sheets S (sheet stack Sb), thereby executing a pressure binding process without using a binding member. The stapled sheet stack Sb is conveyed in the first direction by the discharge rollers 16 constituting the first conveying means, and is discharged to the discharge tray 20.

[0031] The sheet S or the sheet stack Sb discharged onto the discharge tray 20 is aligned by abutting an end of the sheet S or the sheet stack Sb against the end fence 21.

[0032] [Shift discharge mode operation process] Next, with reference to several drawings, an operational process of the shift discharge mode among the conveying process and binding process of the sheet S in the binding processing unit 100 will be described. First, as illustrated in Fig. 6, the process starts with the sheet S being received by the binding processing unit 100 and conveyed in the first direction. This state is the same regardless of the operation mode.

[0033] Next, the state shown in FIG. 7 is reached. FIG. 7(a) is a view of the binding processing unit 100 as viewed from the thickness direction, and is a plan view of the transport path. FIG. 7(b) is a view of the binding unit as viewed from the main scanning direction, and is a side view of the transport path. Note that the main scanning direction is a direction intersecting the first direction, and corresponds to the width direction of the sheet S when the sheet S is transported in the first direction. That is, in FIG. 7(a), the main scanning direction is the vertical direction in the drawing, and in FIG. 7(b), the main scanning direction is the direction between the rear and front sides of the drawing.

[0034] 7, when the sheet S is conveyed in the first direction and the leading edge in the conveying direction reaches the position of the discharge roller 16, the discharge driven roller 16b transitions from a nip state in which it is close to the discharge drive roller 16a to a nip pressure release state in which it is separated from the discharge drive roller 16a. Then, in a state in which the trailing edge of the sheet S has left the conveying roller 12, the shift roller 13 is moved in the width direction (main scanning direction) of the sheet S, whereby the sheet S is conveyed while shifting the conveying position in the main scanning direction.

[0035] In Fig. 7(a), the sheets are shifted from the center of the sheet conveyance to the rear side (upper side in Fig. 7). The shift roller 13 as a medium shifting means can shift the sheets to either the front side (lower side in Fig. 7) or the rear side, and by switching the shift direction for each sheet or for each set of sheets, a discharge process called a sort process in which the discharge position is shifted for each set of the sheet stack Sb can be performed.

[0036] Next, as shown in FIG. 8, when the shifting of the sheet S is completed, the discharge driven roller 16b is moved to the nip position, and the sheet S is conveyed toward the discharge tray 20.

[0037] Then, the sheet S is discharged onto a discharge tray 20 by discharge rollers 16, as shown in FIG.

[0038] As described above, when the binding processing unit 100 operates in the shift discharge mode, the sheet S is transported only in the first direction.

[0039] [Operation process of pressure binding mode] Next, with reference to several drawings, an operation process of the pressure binding mode among the conveying process and binding process of the sheet S in the binding processing unit 100 will be described. First, FIG. 10 is similar to FIG. 6 already described, and shows a state in which the sheet S is received by the binding processing unit 100.

[0040] Subsequently, as shown in FIG. 11, in the pressure binding mode, the sheet S is transported without being shifted, so that the discharge driven roller 16b remains in the nip pressure release position and the sheet S is transported in the first direction.

[0041] 12, the sheet S whose rear end has come out of the shift roller 13 falls by its own weight onto the stacking tray 17 serving as an internal tray. Then, the striking roller 15 comes into contact with the sheet S placed on the stacking tray 17 and conveys the sheet S in the second direction. As a result, the sheet S is switched back and conveyed toward the reference fence 18 while still placed on the stacking tray 17.

[0042] 13, the sheet S is conveyed by switchback conveyance by the striking roller 15 and the return roller 14 until the end of the sheet S (the end corresponding to the leading edge in the conveyance in the second direction) hits the reference fence 18. After the end of the sheet S hits the reference fence 18, the jogger fence 22 hits the side (width direction) end of the sheet S to pinch the sheet S. This operation aligns the width direction ends of the sheets S stacked on the stacking tray 17.

[0043] 10 to 13 are repeatedly performed, resulting in a state in which a plurality of sheets S are stacked on the stacking tray 17. Here, the number of repetitions corresponds to the number of sheets S for forming the sheet stack Sb. Next, as shown in FIG. 14, after the sheets S are stacked on the stacking tray 17, pressure binding is performed on a portion (a portion of an end portion) of the sheet stack Sb using the pressure bonding unit 19. When pressure binding is performed, the discharge driven roller 16b moves to the nip position.

[0044] Then, the sheet stack Sb is discharged onto the discharge tray 20 by the discharge rollers 16, as shown in FIG.

[0045] [Embodiment of the sheet processing device] Next, the binding processing unit 100 as an embodiment of the sheet processing device according to the present invention will be described in more detail. First, an outline of the operation of the pressure bonding unit 19 as the pressure binding means and the liquid application unit 26 as the liquid application means provided in the binding processing unit 100 will be described. The liquid application unit 26 applies liquid (e.g., water) stored in a liquid storage tank provided in the liquid application unit 26 to a portion (binding portion) of the sheet stack Sb to be bound by the pressure bonding unit 19. Hereinafter, applying liquid to the binding portion will be referred to as "liquid application".

[0046] Here, the liquid stored in the liquid storage tank for "liquid application" is, more specifically, a liquid compound of hydrogen and oxygen represented by the chemical formula HO as its main component. As long as it is in a liquid state, its temperature does not matter, and it may be so-called warm water or hot water. In addition, it is not limited to pure water, and it may be purified water, or may contain ionized salts. The metal ion content is also not limited to the hardness, from so-called soft water to ultra-hard water.

[0047] In addition to the main component, additives may be added. It may contain residual chlorine used in tap water, and it is also desirable to add colorants, penetrants, pH adjusters, preservatives such as phenoxyethanol, and drying inhibitors such as glycerin. Furthermore, inks used in inkjet printers and inks used in water-based pens also use water as an ingredient, so this may be used as "liquid application".

[0048] The liquid is not limited to those specifically mentioned here, and may be any "water" in the broad sense, such as hypochlorous acid water or an aqueous solution of ethanol diluted for disinfection, but if the only purpose is to function as a pressure binding, tap water, which is easy to obtain and manage, may be used. In addition, using a liquid whose main component is water, such as those exemplified above, can improve the binding strength of the sheet stack Sb more than using a liquid whose main component is not water.

[0049] 16, 17, and 18 are plan views of the binding processing unit 100. As shown in Fig. 16, when the sheets S are transported to the stacking tray 17 and the rear end thereof abuts against the reference fence 18, the liquid application unit 26 applies liquid to a portion (the bound portion) of the sheets S. At this time, the pressure bonding unit 19 is located on the rear side (upper part in the drawing) of the binding processing unit 100 relative to the liquid application unit 26.

[0050] After the liquid is applied, the liquid application unit 26 moves to the front side (lower side in the drawing) as shown in Fig. 17. Then, the pressure bonding unit 19 moves to the binding position to perform the pressure binding process. When the pressure bonding unit 19 moves to the binding position, the liquid application unit 26 may be moved to the front side (lower side in the drawing) to the end opposite the binding position as shown in Fig. 18.

[0051] The positional relationship between the pressure bonding unit 19 and the liquid deposition unit 26 is not limited to those exemplified in Figures 16, 17, and 18, and these may be arranged interchangeably. That is, as in Figure 16, when the liquid deposition unit 26 is located at the liquid deposition position (binding position), the pressure bonding unit 19 may be controlled to retreat downward (to the front side) in the drawing.

[0052] 19 is a cross-sectional view of the binding processing unit 100. As illustrated in FIG. 19, when the binding processing unit 100 is viewed from the main scanning direction, the pressure bonding unit 19 and the liquid application unit 26 are in positions where they can move along the rear end of the sheet S whose end is aligned by the reference fence 18, and each of them is movable in the main scanning direction. Therefore, when applying liquid, the pressure bonding unit 19 retreats to a position where it does not interfere with the operation of the liquid application unit 26. Also, when performing pressure binding processing, the liquid application unit 26 retreats to a position where it does not interfere with the operation of the pressure bonding unit 19. That is, each of them retreats to a position where they do not interfere with each other.

[0053] In the following description, the binding processing unit 100 is also provided with a pressing unit 19 and a liquid application unit 26. However, for ease of explanation, the pressing unit 19 or the liquid application unit 26 may be omitted from illustration in some figures.

[0054] [Operation process in pressure binding mode] Next, with reference to several drawings, an operation process when performing the operation of the pressure binding mode in the binding processing unit 100 will be described. First, the operation from Fig. 10 to Fig. 14 already described is the same in this embodiment, so a detailed description will be omitted.

[0055] 20 shows a process after the sheets S transported from the MFP 1 are aligned on the stacking tray 17, similar to the state shown in FIG. 14. The figure illustrates a state (pressing state) in which the liquid application head 27 of the liquid application unit 26 is closed to contact and press the rear end of the sheets S. In this state, as described with reference to FIG. 16, the rear end of the sheet stack Sb can be pressed by placing the liquid application unit 26 at the position of the end of the sheet stack Sb and operating the liquid application head 27 at that position to sandwich the sheet stack Sb between the liquid application unit 26 and the stacking tray 17.

[0056] Alternatively, as described using Figure 17, there is a method in which the liquid application head 27 is moved to near the widthwise center of the sheet stack Sb, and the liquid application head 27 is operated at that position to clamp the sheet stack Sb between itself and the stacking tray 17.

[0057] 18, the liquid application head 27 is moved to another end of the sheet bundle Sb, and the liquid application head 27 is operated at that position to clamp the end of the sheet bundle Sb between the stacking tray 17. In addition, the other end is clamped by the pressing unit 19, thereby pressing the end of the sheet bundle at multiple points.

[0058] 20, as shown in Fig. 21, the next sheet S is conveyed while pressing the end (rear end) of the sheet stack Sb stacked on the stacking tray 17. In the following description, the sheet S corresponding to the uppermost surface among the sheets S already stacked on the stacking tray 17 is referred to as the "preceding sheet Sf," and the sheet S newly conveyed to be placed on the preceding sheet Sf is referred to as the "subsequent sheet Sr."

[0059] When a subsequent sheet Sr as a subsequent medium is transported in a first direction relative to a preceding sheet Sf as a preceding medium, the subsequent sheet Sr moves in the first direction while contacting the preceding sheet Sf. When the subsequent sheet Sr moves in this manner while contacting the preceding sheet Sf, the preceding sheet Sf may be pushed and moved in the first direction, which is the transport direction of the subsequent sheet Sr, due to friction and static electricity generated between the preceding sheet Sf and the subsequent sheet Sr. The preceding sheet Sf, whose end has already been aligned in the sheet stack Sb, moves in the first direction, causing the end to become misaligned.

[0060] Therefore, the end (rear end) of the sheet stack Sb is pressed and held down by the liquid application head 27 in accordance with the timing at which the subsequent sheet Sr comes into contact with the preceding sheet Sf. This pressing can prevent the preceding sheet Sf from being pulled by the subsequent sheet Sr and pushed out in the first direction. In other words, by pressing (pressing) the end of the preceding sheet Sf by the liquid application head 27 in accordance with the transport timing of the subsequent sheet Sr, it is possible to prevent the preceding sheet Sf from becoming misaligned.

[0061] 22, with the rear end of the sheet stack Sb being released from the pressure applied by the liquid application unit 26, the succeeding sheet Sr is discharged toward the stacking tray 17. Then, the succeeding sheet Sr is struck by the action of the striking roller 15, and is switched back and conveyed toward the reference fence 18.

[0062] When the switchback transport is performed, the liquid application head 27 of the liquid application unit 26 is placed in a separated state, and the pressure on the end of the sheet stack Sb is released, so that even if friction or static electricity occurs between the preceding sheet Sf and the succeeding sheet Sr, the preceding sheet Sf is also transported in the second direction by the switchback transport (transport in the second direction) of the succeeding sheet Sr. As a result, the succeeding sheet Sr is transported together with the preceding sheet Sf to a position where the rear end abuts against the reference fence 18 and is aligned.

[0063] The timing for separating the liquid application head 27 of the liquid application unit 26 may be simultaneous with the start of the switchback transport, or may not be raised immediately after the start of the switchback transport, but may be immediately before the succeeding sheet Sr abuts against the reference fence 18. The timing immediately before abutting against the reference fence 18 may be determined by using the encoder of the discharge motor 152 that drives the discharge roller 16 as the medium detection means. Also, the position of the sheet S may be calculated by detecting the output from the encoder of the motor that drives the striking roller 15 and the return roller 14.

[0064] The output pulse of this encoder is constantly detected, and the transport distance of the succeeding sheet Sr in the switchback transport is calculated. In this case, the transport distance is the mechanical distance from the calculated end position of the sheet S (the end of the binding tray on the reference fence side) at the timing when the switchback transport starts to the reference fence 18. Then, based on the encoder pulse, it is calculated whether the transport distance reaches a distance equivalent to the distance obtained by subtracting from this distance a distance provided with a margin so that the sheet S switched back does not collide with the liquid deposition unit 26, and the timing to separate the liquid deposition head 27 is determined.

[0065] 23, the succeeding sheet Sr is switchback-conveyed by the action of the striking roller 15 and the return roller 14 until it hits the reference fence 18. After the succeeding sheet Sr hits the reference fence 18, the jogger fence 22 is operated to align the end of the sheet stack Sb in the width direction.

[0066] 20 to 23 are repeated to form a sheet bundle Sb consisting of a predetermined number of sheets. After the stacking and alignment of the predetermined number of sheets is completed, as shown in Fig. 24, the pressing unit 19 is moved to the rear side of the binding processing unit 100 (the rear side in Fig. 24), and the liquid application unit 26 is moved to the binding position (see Fig. 16). That is, after the liquid application unit 26 is moved in the main scanning direction to a position corresponding to the binding position, the liquid application head 27 is driven to apply liquid.

[0067] Thereafter, the liquid application unit 26 is moved to the front side (see FIG. 17 or 18), and the pressure bonding unit 19 is moved to the binding position. That is, after the pressure bonding unit 19 is moved in the main scanning direction, the pressure bonding process is performed. When the pressure bonding process is performed, the discharge driven roller 16b is moved to the nip position to hold the sheet bundle Sb so that it does not shift due to the pressure bonding.

[0068] After the compression binding process is completed, the sheet stack Sb is discharged onto the discharge tray 20 by the discharge rollers 16 as shown in FIG.

[0069] In the process illustrated in Figure 21, if the liquid application head 27 does not press the end of the sheet stack Sb and the subsequent sheet Sr abuts against the preceding sheet Sf, and the preceding sheet Sf is shifted in the first direction due to friction, static electricity, etc., the state illustrated in Figures 26 to 28 may result.

[0070] That is, the preceding sheet Sf is not displaced in the first direction, and is switched back and conveyed together with the succeeding sheet Sr to the reference fence 18. Then, in this state, pressure binding is performed, and the preceding sheet Sf is conveyed to the discharge tray 20 (conveyed in the first direction).

[0071] As a result, as shown in FIG. 28, the sheet stack Sb is discharged with its edges in the transport direction misaligned.

[0072] That is, according to the binding processing unit 100 of this embodiment, when multiple sheets S are stacked to form a sheet bundle Sb, at a timing when the multiple sheets S may be misaligned in the conveying direction due to friction or static electricity, the liquid application unit 26 presses the ends of the sheets S. This makes it possible to suppress misalignment of the sheet bundle Sb.

[0073] [First embodiment of binding process] Next, a binding process that can be performed in the binding processing unit 100 as an embodiment of the sheet processing device according to the present invention will be described with reference to the flowchart of Fig. 29. Note that the operations of Figs. 20 to 28 that have already been described are examples of operations that can be realized by the processing shown in the flowchart of Fig. 29.

[0074] In response to an image formation instruction input via a predetermined user input interface, the image formation control unit 306 causes the image forming means 32 to form an image on the sheet S, and outputs the sheet S on which the image has been formed to the binding processing unit 100. More specifically, the image formation control unit 306 discharges the sheet S until it reaches the inlet roller 11 of the binding processing unit 100. The image formation instruction includes the number of sheets S on which images are to be formed (hereinafter, referred to as the "predetermined number") and the binding position of the sheet bundle Sb. Therefore, the image formation control unit 306 forms images on the predetermined number of sheets S in order.

[0075] In addition, in response to the input of an image formation instruction, the CPU 110 executes the binding process shown in Fig. 24 in parallel with the process of the image forming means 32 by the image formation control unit 306. At the start of the binding process, the discharge drive roller 16a and the discharge driven roller 16b are separated from each other. Also, the pressing unit 19 and the liquid application unit 26 are in an open state and are disposed in the initial position (home position).

[0076] First, the CPU 110 drives the liquid application unit movement motor 154 as a liquid application movement means to move the liquid application unit 26 in the main scanning direction so as to face a position including the center in the main scanning direction of the sheets S or the sheet bundle Sb stacked on the stacking tray 17 (S2901). Note that the position to which the liquid application unit 26 is moved does not have to be approximately the center in the main scanning direction, but may be a position corresponding to the binding position where the pressure bonding unit 19 applies pressure and deforms in the subsequent binding process.

[0077] The process of step S2901 is executed before the first sheet S supplied from the image forming means 32 reaches the inlet rollers 11. Then, the CPU 110 waits to execute the processes of step S2903 and the following steps until the leading edge of the sheet S reaches the inlet rollers 11 (S2902: No).

[0078] CPU 110 can identify the position of liquid deposition unit 26 in the main scanning direction using liquid deposition unit position sensor 160 that detects the position of liquid deposition unit 26, a rotary encoder of liquid deposition unit movement motor 154, or a combination of these.

[0079] 10, in response to the first sheet S reaching the inlet rollers 11 (S2902: Yes & S2903: Yes), the CPU 110 maintains the liquid application head 27 of the liquid application unit 26 in a spaced state away from the sheet S rather than in a pressed state in contact with the sheet S (S2905), and rotates the inlet rollers 11, conveyance rollers 12, shift rollers 13, and discharge rollers 16 as the first conveying means (S2906). As a result, the sheet S is conveyed in the first direction as shown in FIG.

[0080] Furthermore, if the sheet S that has reached the inlet rollers 11 is not the first sheet (S2902: Yes & S2903: NO), the position of the liquid application head 27 of the liquid application unit 26 is set to a position (pressing position) where it contacts the end of the sheet S or the sheet stack Sb (S2904). At this time, the liquid application head 27 may press the end of the sheet stack Sb to prevent misalignment due to the influence of the succeeding sheet Sr, and at the same time, liquid may be applied in parallel. Below, the explanation will be continued assuming that the sheet S is not the first sheet (S2902: Yes & S2903: NO).

[0081] Next, the inlet roller 11, the conveying roller 12, the shift roller 13, and the discharge roller 16, which are a first conveying means composed of a plurality of conveying roller pairs, are rotated to convey the sheet S (S2906). As a result, as shown in FIG. 21, the sheet S is conveyed in the first direction.

[0082] Next, in response to the sheet S being placed on the stacking tray 17 (in other words, the trailing edge of the sheet S passing through the shift rollers 13), the CPU 110 stops the operations of the inlet rollers 11, the transport rollers 12, the shift rollers 13, and the discharge rollers 16 as the first transport means. With these operations stopped, the striking rollers 15 are brought into contact with the sheet S and rotated (S2907). As a result, as shown in FIG. 22, the sheet S is transported in the second direction along the stacking tray 17 (switchback transport).

[0083] Next, it is determined again whether the sheet S placed (conveyed) on the stack tray 17 is not the first sheet in the binding process currently being performed (S2908), and if the sheet S is the first sheet (S2908: Yes), the process proceeds to S2911. If the sheet S is not the first sheet (S2908: No), a process is executed to determine whether it is time to move the liquid application head 27 from the pressed state to the separated state (S2909).

[0084] In S2909, when it is time to transition the liquid dispensing head 27 to the separated state, the liquid dispensing head 27 is transitioned from the pressed state to the separated state (S2910), and the process proceeds to determine whether the loading of the newly placed sheet S (subsequent sheet Sr) on the stacking tray 17 is complete (S2911).

[0085] The period during which the liquid application head 27 presses the end of the sheet stack Sb starts at the latest before the succeeding sheet Sr contacts the preceding sheet Sf. As for the end, several variations can be assumed. One is a predetermined time before the succeeding sheet Sr reaches the liquid application head 27. In this case, the shorter the predetermined time, the longer the period during which the liquid application head 27 presses the end of the sheet stack Sb, so that the effect of preventing the sheet stack Sb from shifting is enhanced. It is sufficient to set it to just before the collision. Such a timing for transitioning the liquid application head 27 from the pressing state to the separating state may be based on a timing that can be derived from the correlation between the number of drive pulses of the motor that drives the tapping roller 15, which is specified in advance, and the moving distance in the switchback conveyance of the sheet S. Then, the position of the succeeding sheet Sr is specified in advance so that it can be calculated based on the number of drive pulses, and the timing for transitioning the liquid application head 27 from the pressing position to the separating position may be set to the time when the number of drive pulses corresponds to the number at which the succeeding sheet Sr collides with the liquid application head 27.

[0086] Alternatively, the timing for transitioning the liquid application head 27 to the separated state may be the timing when the operation of the striking roller 15 is started (S2907) and it is determined that the sheet S being switched back and transported is not the first sheet S of the sheet stack Sb (S2908: No).

[0087] Next, as shown in FIG. 23B, the CPU 110 loops the process until the trailing edge of the sheet S (the succeeding sheet Sr) reaches the reference fence 18 (S2911: No).

[0088] The CPU 110 can specify the position of the sheet S using a sheet sensor that detects the sheet S in the binding unit 100, a rotary encoder of a motor that rotates the inlet rollers 11, the conveying rollers 12, the shift rollers 13, the discharge rollers 16 and the striking rollers 15, or a combination of these. Therefore, the timing determination in S2909 may be performed based on the output of the sheet sensor.

[0089] Next, in response to the rear end of the sheet S reaching the reference fence 18 (S2911: Yes), the CPU 110 moves the jogger fence 22 in the main scanning direction as shown in Fig. 23(a). By this movement, the position of the sheet S accommodated in the stacking tray 17 in the main scanning direction is determined (S2912).

[0090] Next, the CPU 110 determines whether or not a predetermined number of sheets S are accommodated in the stacking tray 17 (S2913). If the CPU 110 determines that the predetermined number of sheets S are not accommodated in the stacking tray 17 (S2913: No), the CPU 110 executes the process from step S2902 onward for the next sheet S.

[0091] When the CPU 110 determines that a predetermined number of sheets S are stored in the stacking tray 17 (S2913: Yes), it drives the binding unit moving motor 153 as a pressing unit moving means, as shown in Fig. 17. This driving moves the pressing unit 19 to a position facing the binding position of the sheet stack Sb stacked on the stacking tray 17 (S2914). Next, as shown in Fig. 24, the CPU 110 drives the pressing motor 156 to close the pressing unit 19, and performs pressing and binding by pressing and deforming a part of the end of the sheet stack Sb.

[0092] Next, as shown in Fig. 25, the CPU 110 causes the return roller 14 to come into contact with the sheet stack Sb for which the binding process has been completed and rotates it, thereby causing the sheet stack Sb to enter between the discharge drive roller 16a and the discharge driven roller 16b. The CPU 110 also causes the sheet stack Sb to be sandwiched between the discharge drive roller 16a and the discharge driven roller 16b. Furthermore, the CPU 110 rotates the discharge roller 16 to discharge the sheet stack Sb onto the discharge tray 20 (S2916).

[0093] According to the binding processing unit 100 of the present embodiment described above, when a plurality of sheets S (sheet bundle Sb) are stacked on the stacking tray 17, if a subsequent sheet Sr is conveyed, it is possible to prevent misalignment of the sheet bundle Sb that occurs when the subsequent sheet Sr comes into contact with the preceding sheet Sf while being conveyed (moving). In other words, if the subsequent sheet Sr comes into contact with the preceding sheet Sf that has already been aligned while moving, it is possible to prevent the preceding sheet Sf that has already been aligned from shifting in the moving direction of the subsequent sheet Sr when friction or static electricity occurs between the preceding sheet Sf and the subsequent sheet Sr. As a result, one of the features of this embodiment is that it is possible to maintain the alignment accuracy of the sheet bundle Sb.

[0094] In order to prevent misalignment of the sheet stack Sb in the aligned state caused by the influence of a subsequent event as described above, before the subsequent sheet Sr contacts the preceding sheet Sf (before S2906), the liquid application head 27 presses the end of the sheet stack Sb including the preceding sheet Sf. This pressing allows the preceding sheet Sf, whose end is pressed, to obtain resistance to the external force caused by the contact of the subsequent sheet Sr, thereby preventing misalignment of the sheet stack Sb.

[0095] In addition, when the pressure binding mode and the shift discharge mode are used in combination, when the succeeding sheet Sr is conveyed relative to the preceding sheet Sf in S2906, the succeeding sheet Sr moves in the first direction relative to the preceding sheet Sf and further moves in the main scanning direction. Therefore, the binding processing unit 100 according to this embodiment can prevent misalignment of the sheet stack Sb, both in the first direction and in the main scanning direction.

[0096] [Second embodiment of binding process] Next, another binding process that can be performed in the binding processing unit 100 as an embodiment of the sheet processing apparatus according to the present invention will be described with reference to a flowchart of FIG.

[0097] In response to an image formation instruction input via a predetermined user input interface, the CPU 110 causes the image forming means 32 to form an image on the sheet S, and outputs the sheet S on which the image has been formed to the binding processing unit 100. More specifically, the CPU 110 causes the sheet S to be discharged until it reaches the inlet roller 11 of the binding processing unit 100. The image formation instruction includes the number of sheets S on which images are to be formed (hereinafter, referred to as the "predetermined number") and the binding position of the sheet bundle Sb. Therefore, the CPU 110 forms images on the predetermined number of sheets S in order.

[0098] In addition, in response to the input of an image formation instruction, the CPU 110 executes the binding process shown in Fig. 26 in parallel with the process of the image forming means 32. At the start of the binding process, the discharge drive roller 16a and the discharge driven roller 16b are separated from each other. Also, the pressing unit 19 and the liquid application unit 26 are in an open state and are disposed in the initial position (home position).

[0099] First, the CPU 110 drives the liquid application unit movement motor 154 as a liquid application movement means to move the liquid application unit 26 in the main scanning direction so that it faces one end position of the sheet S or sheet stack Sb stacked on the stacking tray 17 (S3001).

[0100] Further, the CPU 110 drives the binding unit moving motor 153 to move the pressing unit 19 in the main scanning direction so that the pressing unit 19 faces the other end of the sheet S or the sheet bundle Sb stacked on the stacking tray 17 (S3001).

[0101] The positions to which the liquid application unit 26 and the pressure bonding unit 19 are moved may not be the ends in the main scanning direction, but may be other positions. For example, the liquid application unit 26 may be located at a position that corresponds to the binding position where the pressure bonding unit 19 applies pressure and deforms the sheet in the subsequent binding process, as long as the position does not interfere with the pressure bonding unit 19.

[0102] The processes of steps S3001 and S3002 are executed before the first sheet S supplied from the image forming means 32 reaches the inlet rollers 11. Then, the CPU 110 waits to execute the processes of steps S3004 and onwards until the leading edge of the sheet S reaches the inlet rollers 11 (S3003: No).

[0103] The CPU 110 can identify the positions of the pressure bonding unit 19 and the liquid deposition unit 26 in the main scanning direction using a liquid deposition unit position sensor 160 that detects the position of the liquid deposition unit 26, a rotary encoder of the liquid deposition unit movement motor 154, or a combination of these.

[0104] Next, in response to the first sheet S reaching the inlet rollers 11 (S3003: Yes & S3004: Yes), the CPU 110 sets the liquid application head 27 of the liquid application unit 26 to a state where it maintains a spaced position away from the sheet S, rather than a pressing state where it contacts the sheet S (S3007). Also, the pressing unit 19 sets the binding teeth to an open state (open state), rather than a pressing state that does not pressurize and deform the sheet S (S3008).

[0105] Next, the inlet rollers 11, the conveying rollers 12, the shift rollers 13, and the discharge rollers 16, which serve as the first conveying means, are rotated (S3009). As a result, the sheet S is conveyed in the first direction.

[0106] If the sheet S that has reached the inlet rollers 11 is not the first sheet (S3003: Yes & S3004: NO), the liquid application head 27 of the liquid application unit 26 is brought into contact with the end of the sheet S or the sheet stack Sb (pressing state) (S3005). At this time, the liquid application head 27 may press the end of the sheet stack Sb to prevent misalignment due to the influence of the succeeding sheet Sr, and at the same time, liquid application may be performed in parallel.

[0107] In addition, the binding teeth of the crimping unit 19 are closed to press the end of the sheet stack Sb without causing deformation (S3006). The following description will be given assuming that the sheet S is not the first sheet (S3003: Yes & S3004: NO).

[0108] Next, the inlet roller 11, the conveying roller 12, the shift roller 13, and the discharge roller 16, which are a first conveying means composed of a plurality of conveying roller pairs, are rotated to convey the sheet S (S3009). As a result, the sheet S is conveyed in the first direction.

[0109] Next, in response to the sheet S being placed on the stacking tray 17 (in other words, the trailing edge of the sheet S passing through the shift rollers 13), the CPU 110 stops the operations of the inlet rollers 11, the transport rollers 12, the shift rollers 13, and the discharge rollers 16 as the first transport means. With these operations stopped, the striking rollers 15 are brought into contact with the sheet S and rotated (S3010). As a result, the sheet S is transported in the second direction along the stacking tray 17 (switchback transport).

[0110] Next, it is determined again whether the sheet S placed (conveyed) on the stack tray 17 is not the first sheet in the binding process currently being performed (S3011), and if the sheet S is the first sheet (S3011: No), the process proceeds to step S3014. If the sheet S is not the first sheet (S3011: Yes), a process is executed to determine whether it is time to transition the liquid application head 27 and the pressure bonding unit 19 from the pressed state to the separated state or released state (S3012).

[0111] In step S3012, when it is time to transition the liquid application head 27 to the separated state and the pressure bonding unit 19 to the open state, the liquid application head 27 is transitioned from the pressed state to the separated state, and the pressure bonding unit 19 is transitioned from the pressed state to the open state (S3013), and the process proceeds to determine whether loading of the sheet S (subsequent sheet Sr) newly placed on the stacking tray 17 is complete (S3014).

[0112] The period during which the liquid application head 27 and the pressure bonding unit 19 press the end of the sheet stack Sb is before the succeeding sheet Sr comes into contact with the preceding sheet Sf, and starts at the latest when the switchback transport of the succeeding sheet Sr begins. The end of the period during which the liquid application head 27 and the pressure bonding unit 19 press the end of the sheet stack Sb can be varied in several ways. One is until just before the succeeding sheet Sr collides with the liquid application head 27 and the pressure bonding unit 19. The timing at which the liquid application head 27 transitions from the pressing state to the separating state and the timing at which the pressure bonding unit 19 transitions from the pressing state to the releasing state may be based on a correlation between the number of drive pulses of the motor that drives the tapping roller 15 and the movement distance in the switchback transport of the sheet S, which is specified in advance. Then, the position of the subsequent sheet Sr is determined in advance so that it can be calculated based on the number of drive pulses, and the time when the number of drive pulses reaches the number at which the subsequent sheet Sr collides with the liquid application head 27 is determined as the timing for transitioning the liquid application head 27 from a pressed state to a separated state and for transitioning the pressure bonding unit 19 from a pressed state to an released state.

[0113] Alternatively, the timing at which the liquid application head 27 is transitioned to the separated state and the pressing unit 19 is set to the open state may be the timing at which the operation of the tapping roller is started (S3010) and it is determined that the sheet S being switched back and transported is not the first sheet S of the sheet stack Sb (S3011: Yes).

[0114] Next, the CPU 110 loops the process until the rear end of the sheet S (the succeeding sheet Sr) reaches the reference fence 18 (S3014: No).

[0115] The CPU 110 can specify the position of the sheet S using a sheet sensor that detects the sheet S in the binding unit 100, a rotary encoder of a motor that rotates the inlet rollers 11, the conveying rollers 12, the shift rollers 13, the discharge rollers 16, and the striking rollers 15, or a combination of these. Therefore, the timing determination in S3012 may be performed based on the output of the sheet sensor.

[0116] Next, in response to the rear end of the sheet S reaching the reference fence 18 (S3014: Yes), the CPU 110 determines the position of the sheet S stored in the stacking tray 17 in the main scanning direction by moving the jogger fence 22 in the main scanning direction (S3015).

[0117] Next, the CPU 110 determines whether or not a predetermined number of sheets S are accommodated in the stacking tray 17 (S3016). If the CPU 110 determines that the predetermined number of sheets S are not accommodated in the stacking tray 17 (S3016: No), the CPU 110 executes the process from step S3003 onward for the next sheet S.

[0118] When the CPU 110 determines that a predetermined number of sheets S have been stored in the stacking tray 17 (S3016: Yes), the CPU 110 drives the binding unit moving motor 153 as a pressing unit moving means to move the pressing unit 19 to a position facing the binding position of the sheet stack Sb stacked on the stacking tray 17 (S3017). Next, the CPU 110 drives the pressing motor 156 to close the pressing unit 19, and performs pressing and binding by pressurizing and deforming a part of the end of the sheet stack Sb (S3018).

[0119] Next, the CPU 110 causes the return roller 14 to come into contact with the sheet stack Sb for which the binding process has been completed and rotates it, thereby causing the sheet stack Sb to enter between the discharge drive roller 16a and the discharge driven roller 16b. The CPU 110 also causes the sheet stack Sb to be sandwiched between the discharge drive roller 16a and the discharge driven roller 16b. Furthermore, the CPU 110 rotates the discharge roller 16 to discharge the sheet stack Sb onto the discharge tray 20 (S3019).

[0120] According to the binding processing unit 100 of the present embodiment described above, when a plurality of sheets S (sheet bundle Sb) are stacked on the stacking tray 17, when a subsequent sheet Sr is conveyed, it is possible to prevent misalignment caused by the subsequent sheet Sr coming into contact with the preceding sheet Sf while being conveyed (moving). That is, the subsequent sheet Sr comes into contact with the preceding sheet Sf that has already been aligned while moving, thereby preventing the preceding sheet Sf from shifting from its aligned state in the movement direction of the subsequent sheet Sr due to friction with the subsequent sheet Sr or static electricity. This makes it possible to maintain the alignment accuracy of the sheet bundle Sb, which is one of the features of this embodiment.

[0121] In order to prevent the aligned sheet stack Sb from being displaced due to the influence of a subsequent event, before the subsequent sheet Sr comes into contact with the preceding sheet Sf (before S3009), the liquid application head 27 and the pressure bonding unit 19 press the edge of the sheet stack Sb including the preceding sheet Sf. This pressing allows the preceding sheet Sf, whose edge is pressed, to obtain resistance to an external force caused by contact with the subsequent sheet Sr, thereby preventing the sheet stack Sb from being displaced.

[0122] In addition, when the pressure binding mode and the shift discharge mode are used in combination, when the succeeding sheet Sr is conveyed relative to the preceding sheet Sf in S3009, the succeeding sheet Sr moves in the first direction relative to the preceding sheet Sf and further moves in the main scanning direction. Therefore, the binding processing unit 100 according to this embodiment can prevent misalignment of the sheet stack Sb, both in the first direction and in the main scanning direction.

[0123] As described above, the end of the sheet stack Sb may be pressed only by the liquid application unit 26, but the present invention is not limited to this. For example, the end may be pressed with a strength sufficient to prevent the end from moving, without being pressed, using the binding teeth (pressing portion) of the pressing unit 19 instead of the liquid application head 27. Also, the end of the sheet stack Sb may be pressed using both the liquid application unit 26 and the pressing unit 19.

[0124] That is, the CPU 110 as a controller according to the present embodiment operates the liquid application unit 26 and the pressure bonding unit 19 as an end pressing unit for suppressing misalignment of the end of the sheet stack Sb.

[0125] According to the binding processing unit 100 of the present embodiment described above, when a plurality of sheets S are stacked to form a sheet bundle Sb, the edge pressing means presses the edge of the sheet S according to the timing when the sheet (preceding sheet Sf) that has already been stacked and aligned is misaligned due to friction or static electricity caused by the conveyance of the newly stacked sheet S (subsequent sheet Sr), thereby suppressing misalignment. The binding processing unit 100 of the present embodiment may operate only the liquid application unit 26 as the edge pressing means, or may operate only the pressure bonding unit 19 as the edge pressing means. Alternatively, both the liquid application unit 26 and the pressure bonding unit 19 may be used to operate as the edge pressing means.

[0126] [Embodiment of liquid application unit 26] Next, a description will be given of the details of the liquid deposition unit 26. Fig. 31 is a schematic diagram of the inside of the liquid deposition unit 26 as viewed from the upstream side in the transport direction. Fig. 32 is a schematic diagram of the inside of the liquid deposition unit 26 as viewed from the main scanning direction side.

[0127] The liquid application unit 26 applies (hereinafter, referred to as "liquid application") a liquid (e.g., water) stored in a liquid storage tank 143 to the sheet S supported on the stacking tray 17. The liquid application unit 26 is configured to be movable in the main scanning direction by transmitting a driving force of a liquid application motor 155 (see FIG. 4).

[0128] 31 and 32, the liquid application unit 26 mainly includes a lower pressure plate 133, an upper pressure plate 134 (pressing portion), a lifting mechanism 135, and a liquid application mechanism 136. The liquid application head 27 is a portion excluding the lower pressure plate 133 from the entire assembly of these components.

[0129] The lower pressure plate 133 and the upper pressure plate 134 are disposed downstream of the stacking tray 17 in the conveying direction. The lower pressure plate 133 supports the sheet stack Sb supported by the stacking tray 17 from below. The upper pressure plate 134 is configured to be movable up and down above the sheet stack Sb supported by the stacking tray 17. That is, the lower pressure plate 133 and the upper pressure plate 134 are disposed opposite to each other in the thickness direction (hereinafter simply referred to as the "thickness direction") of the sheet stack Sb, sandwiching the sheet stack Sb supported by the stacking tray 17 therebetween. Furthermore, the upper pressure plate 134 has a through hole 134a penetrating in the thickness direction at a position facing the tip of the liquid application member 144 supported by the base plate 140.

[0130] The lifting mechanism 135 lifts and lowers the upper pressure plate 134, the base plate 140 (base member), and the liquid application member 144 in the thickness direction of the sheet stack Sb. The lifting mechanism 135 according to this embodiment lifts and lowers the upper pressure plate 134, the base plate 140, and the liquid application member 144 in a coordinated manner by a single lifting motor 137 (driving source). The lifting mechanism 135 mainly includes, for example, the lifting motor 137, a trapezoidal screw 138, a nut 139, a base plate 140, columnar members 141a, 141b, and coil springs 142a, 142b (urging members).

[0131] The lifting motor 137 generates a driving force for lifting and lowering the upper pressure plate 134, the base plate 140, and the liquid applying member 144. The trapezoidal screw 138 extends in the vertical direction. The trapezoidal screw 138 is connected to an output shaft of the lifting motor 137 via a pulley, a belt, or the like. The nut 139 is screwed into the trapezoidal screw 138. The driving force of the lifting motor 137 is transmitted to rotate the trapezoidal screw 138, causing the nut 139 to lift and lower.

[0132] The base plate 140 is a flat plate parallel to the sheet stack Sb supported on the stacking tray 17. The base plate 140 is disposed above the upper pressing plate 134. The base plate 140 supports the liquid application member 144 with the tip of the liquid application member 144 protruding downward. The base plate 140 is connected to a trapezoidal screw 138 and configured to be able to rise and fall together with the trapezoidal screw 138. The vertical position of the base plate 140 is detected by a lifting sensor 140a.

[0133] The columnar members 141a, 141b protrude downward from the base plate 140 around the tip of the liquid application member 144. The columnar members 141a, 141b are configured to be movable relative to the base plate 140 in the thickness direction. The columnar members 141a, 141b support the upper pressing plate 134 at their lower ends. The coil springs 142a, 142b are inserted around the columnar members 141a, 141b between the base plate 140 and the upper pressing plate 134. The coil springs 142a, 142b urge the upper pressing plate 134 and the columnar members 141a, 141b downward with respect to the base plate 140.

[0134] The liquid applying mechanism 136 applies liquid to the sheet stack Sb supported on the stacking tray 17 serving as an internal tray. More specifically, the liquid applying mechanism 136 applies liquid to at least one sheet S constituting the sheet stack Sb by bringing a tip of a liquid applying member 144 into contact with the sheet stack Sb. The liquid applying mechanism 136 mainly includes a liquid storage tank 143, a liquid applying member 144, a supply member 145, and a joint 146.

[0135] 33 is a diagram showing the liquid applicator 144 as viewed obliquely from below. A spray nozzle 149 is provided on the lower surface of the liquid applicator 144.

[0136] The liquid storage tank 143 stores water to be supplied to the sheet stack Sb. The amount of water stored in the liquid storage tank 143 is detected by a water amount sensor 143a. The liquid application member 144 sprays the liquid (e.g., "water") stored in the liquid storage tank 143 onto the sheet stack Sb. The liquid application member 144 is supported by the base plate 140 with its tip facing downward. By spraying the liquid, a small amount of liquid can be applied over a wide area.

[0137] The supply member 145 is a long member whose base end is immersed in the water stored in the liquid storage tank 143 and whose tip end is connected to the liquid applying member 144. The supply member 145 is made of a material with high water absorption. This allows water absorbed from the base end of the supply member 145 to be supplied to the liquid applying member 144 by capillary action. The protection member 145a is a long cylindrical body (for example, a tube) that is inserted around the supply member 145. This makes it possible to prevent the water absorbed by the supply member 145 from leaking or evaporating.

[0138] Moreover, the supply member 145 and the protective member 145a are formed of a flexible material. The joint 146 fixes the liquid applying member 144 to the base plate 140. As a result, even when the liquid applying member 144 is raised and lowered by the lifting mechanism 135, it protrudes downward from the base plate 140 and maintains a state in which its tip faces downward.

[0139] [End Pressing Operation by Liquid Application Unit 26] Next, the operation of pressing the end portion of the sheet stack Sb by the liquid application unit 26 will be described in detail with reference to FIGS.

[0140] Fig. 34 illustrates a state before the end of the sheet stack Sb is pressed by the liquid application unit 26. That is, in Fig. 34, the upper pressing plate 134 is not in contact with the sheet stack Sb.

[0141] FIG. 35 illustrates a state in which the liquid application unit 26 presses the end of the sheet stack Sb. That is, in FIG. 35, the upper pressing plate 134 is in contact with and pressing the sheet stack Sb. On the other hand, the liquid application member 144 and the spray nozzle 149 perform a pressing operation without coming into contact with the sheets S, which makes it possible to reduce the amount of liquid applied during pressing, or to press without applying any liquid at all. That is, a series of configurations that controls the operation so that only the upper pressing plate 134 is in contact with the sheets S without bringing the liquid application member 144 into contact with the sheets S corresponds to the liquid amount adjusting means. This makes it possible to suppress a decrease in the amount of liquid.

[0142] Fig. 36 illustrates a state in which liquid is being applied while pressing the sheet stack Sb by the liquid application unit 26. In Fig. 36, the liquid application member 144 and the spray nozzle 149 are in a state in which they are in contact with the sheets S (pressing state), and liquid is sprayed from the spray nozzle 149 to apply the liquid.

[0143] According to the embodiment of the present invention described above, when a plurality of sheets S are stacked to form a sheet bundle Sb, the liquid application unit 26 used in sheet processing can be used as a member for preventing misalignment of the edges of the sheets S due to friction between the sheets S and static electricity. This eliminates the need to provide a separate member for pressing the sheet bundle, and allows the number of parts to be reduced.

[0144] In addition, since the ends of the sheets S can be aligned using a driving mechanism such as a roller, there is no need to increase the inclination angle of the stacking tray 17. In other words, it can be made compact and can be applied to an internal unit.

[0145] The present invention is not limited to the above-described embodiments, and various modifications are possible without departing from the technical gist of the present invention. The present invention covers all technical matters included in the technical ideas described in the claims. The above-described embodiments are preferred examples, but a person skilled in the art can realize various modifications from the disclosed contents. Such modifications are also included in the technical scope described in the claims.

[0146] The contents of the present invention are, for example, as follows. <1> A discharge tray capable of holding a plurality of sheet-shaped media; an internal tray capable of loading the medium at a position different from the ejection tray; a first conveying means for conveying the medium in a first direction in which the medium is discharged onto a discharge tray; a second conveying means for conveying the medium in a second direction different from the first direction by moving the medium toward and away from the medium loaded on the internal tray; a pressure binding unit that is disposed downstream of the internal tray in the second direction and that performs pressure binding on the plurality of media loaded on the internal tray; A controller for controlling operations of the first conveying means, the second conveying means, and the pressure binding means; Equipped with the controller, when the media are loaded on the internal tray and a subsequent medium is transported in the first direction while in contact with the preceding medium previously loaded on the internal tray, causes the pressure binding means to press a downstream end of the preceding medium in the second direction; The sheet processing apparatus is characterized in that <2> A discharge tray capable of holding a plurality of sheet-shaped media; an internal tray capable of loading the medium at a position different from the ejection tray; a first conveying means for conveying the medium in a first direction in which the medium is discharged onto a discharge tray; a second conveying means for conveying the medium in a second direction different from the first direction by moving the medium toward and away from the medium loaded on the internal tray; a liquid applying unit that is disposed downstream of the internal tray in the second direction and applies liquid to the plurality of media loaded on the internal tray; a pressure binding unit that is disposed downstream of the internal tray in the second direction and that performs pressure binding on the plurality of media loaded on the internal tray; a controller for controlling operations of the first conveying means, the second conveying means, the liquid applying means, and the pressure binding means; Equipped with When the media are loaded on the internal tray, and a subsequent medium is transported in the first direction while in contact with a preceding medium previously loaded on the internal tray, the controller causes the liquid application means or the pressure binding means to press a downstream end of the preceding medium in the second direction. The sheet processing apparatus is characterized in that <3> the controller causes the liquid applying device and the pressure binding device to press the downstream end of the preceding medium in the second direction; The above <2> 2 is a sheet processing apparatus according to the first embodiment. <4> When the subsequent medium is being transported in the second direction, the liquid applying means or the pressure binding means releases the pressure on the end portion. The above <2> 2 is a sheet processing apparatus according to the first embodiment. <5> a medium detection means for detecting a position of the medium during transport; a reference fence against which an end of the trailing medium abuts when the trailing medium is stacked relative to the preceding medium; releasing the pressure on the end portion by the liquid applying means or the pressure binding means when the subsequent medium is transported in the second direction; The above <2> or the above <4> 13. The sheet processing apparatus according to claim 12, wherein the sheet is a sheet having a diameter of 100 mm or less. <6> a medium shifting means for shifting the position of the medium in a main scanning direction; When the movement is performed without performing the compression binding, pressing an edge of the medium with the liquid applying means or the pressure binding means; The above <2> or the above <5> 13. The sheet processing apparatus according to claim 12, wherein the sheet is a sheet having a diameter of 100 mm or less. <7> the liquid applying means includes a liquid amount adjusting means for adjusting the amount of liquid applied, When the end portion is pressed, the amount of liquid is reduced. The above <2> or the above <6> 13. The sheet processing apparatus according to claim 12, wherein the sheet is a sheet having a diameter of 100 mm or less. <8> The liquid applying means is a liquid deposition head that performs the liquid deposition; A pressing unit that performs the pressing; Equipped with while the end portion is being pressed as the end portion pressing means, the pressing portion presses the end portion, and the liquid dispensing head does not come into contact with the end portion; The above <2> or the above <7> 13. The sheet processing apparatus according to claim 12, wherein the sheet is a sheet having a diameter of 100 mm or less. <9> When the pressing position and the pressure-binding position are the same, the pressing is performed by the pressing unit and the liquid application head. The above <8> 2 is a sheet processing apparatus according to the first embodiment. <10> a liquid application / movement means for moving the liquid application means in a main scanning direction, pressing the end portion at a substantially central portion in a main scanning direction of the end portion; The above <2> or the above <9> 13. The sheet processing apparatus according to claim 12, wherein the sheet is a sheet having a diameter of 100 mm or less. <11> a pressure-bonding unit moving means for moving the pressure-bonding binding means in a main scanning direction, pressing the edge of the medium at different positions in a main scanning direction with the liquid applying means and the pressure binding means; The above <10> 2 is a sheet processing apparatus according to the first embodiment. <12> A housing and an image forming unit that is accommodated in the housing and that forms an image on a sheet-like medium; a pressure binding unit that is detachably supported by the housing and that performs pressure binding on the medium on which an image is formed by the image forming unit; <1> or the above <11> a sheet processing apparatus according to any one of the preceding claims; The image forming apparatus is characterized by comprising: <13> an image forming apparatus for forming an image on a sheet-like medium; The image forming apparatus connected to the <1> or the above <11> a sheet processing apparatus according to any one of the preceding claims; The image forming system includes: [Explanation of symbols]

[0147] 1:MFP 11: Entrance roller 12: Transport roller 13: Shift roller 14: Return roller 15: Coro 16: Discharge roller 16a: Discharge drive roller 16b: Discharge driven roller 17: Loading tray 18: Reference fence 18b: Discharge driven roller 19: Crimping unit 20: Output tray 26: Liquid application unit 27: Liquid application head 31: Housing 32: Image forming means 33:Inner body space 100: Binding processing unit 101: Post-processing section 102: Post-processing control unit 110: CPU 149: Spray nozzle 151: Transport motor 152: Discharge motor 153: Unit movement motor 154: Liquid application unit moving motor 155: Liquid application motor 156: Crimping motor 157: Transport sensor 158: Discharge sensor 159: Unit position sensor 160: Liquid application unit position sensor 161: Lift sensor 162: Liquid volume sensor 163: Shift motor 164: Roller drive motor 165: Return roller drive motor 166: Jogger motor 306: Image formation control unit [Prior art documents] [Patent documents]

[0148] [Patent Document 1] JP 2015-101009 A

Claims

1. A discharge tray capable of holding a plurality of sheet-shaped media; an internal tray capable of loading the medium at a position different from the ejection tray; a first conveying means for conveying the medium in a first direction in which the medium is discharged onto a discharge tray; a second conveying means for conveying the medium in a second direction different from the first direction by moving the medium toward and away from the medium loaded on the internal tray; a pressure binding unit that is disposed downstream of the internal tray in the second direction and that performs pressure binding on the plurality of media loaded on the internal tray; A controller for controlling operations of the first conveying means, the second conveying means, and the pressure binding means; Equipped with the controller, when the media are loaded on the internal tray and a subsequent medium is transported in the first direction while in contact with the preceding medium previously loaded on the internal tray, causes the pressure binding means to press a downstream end of the preceding medium in the second direction; A sheet processing apparatus comprising:

2. A discharge tray capable of holding a plurality of sheet-shaped media; an internal tray capable of loading the medium at a position different from the ejection tray; a first conveying means for conveying the medium in a first direction in which the medium is discharged onto a discharge tray; a second conveying means for conveying the medium in a second direction different from the first direction by moving the medium toward and away from the medium loaded on the internal tray; a liquid applying unit that is disposed downstream of the internal tray in the second direction and applies liquid to the plurality of media loaded on the internal tray; a pressure binding unit that is disposed downstream of the internal tray in the second direction and that performs pressure binding on the plurality of media loaded on the internal tray; a controller for controlling operations of the first conveying means, the second conveying means, the liquid applying means, and the pressure binding means; Equipped with When the media are loaded on the internal tray, and a subsequent medium is transported in the first direction while in contact with a preceding medium previously loaded on the internal tray, the controller causes the liquid application means or the pressure binding means to press a downstream end of the preceding medium in the second direction. A sheet processing apparatus comprising:

3. the controller causes the liquid applying device and the pressure binding device to press the end portion of the preceding medium on the downstream side in the second direction; The sheet processing apparatus according to claim 2 .

4. When the subsequent medium is transported in the second direction, the liquid applying means or the pressure binding means releases the pressure on the end portion. The sheet processing apparatus according to claim 2 .

5. a medium detection means for detecting a position of the medium during transport; a reference fence against which an end of the trailing medium abuts when the trailing medium is stacked relative to the preceding medium; releasing the pressure on the end portion by the liquid applying means or the pressure binding means when the subsequent medium is transported in the second direction; The sheet processing apparatus according to claim 2 .

6. a medium shifting means for shifting the position of the medium in a main scanning direction; When the movement is performed without performing the compression binding, pressing an edge of the medium with the liquid applying means or the pressure binding means; The sheet processing apparatus according to claim 2 .

7. the liquid applying means includes a liquid amount adjusting means for adjusting the amount of liquid applied, When the end portion is pressed, the amount of liquid is reduced. The sheet processing apparatus according to claim 2 .

8. The liquid applying means is a liquid deposition head that performs the liquid deposition; A pressing unit that performs the pressing; Equipped with While pressing the end portion, the pressing portion presses the end portion, and the liquid dispensing head does not come into contact with the end portion. The sheet processing apparatus according to claim 2 .

9. When the pressing position and the pressure-binding position are the same, the pressing is performed by the pressing unit and the liquid application head. The sheet processing apparatus according to claim 8 .

10. a liquid application / movement means for moving the liquid application means in a main scanning direction, pressing the end portion at a substantially central portion in a main scanning direction of the end portion; The sheet processing apparatus according to claim 2 .

11. a pressure-bonding unit moving means for moving the pressure-bonding binding means in a main scanning direction, pressing the edge of the medium at different positions in a main scanning direction with the liquid applying means and the pressure binding means; The sheet processing apparatus according to claim 10 .

12. A housing and an image forming unit that is accommodated in the housing and that forms an image on a sheet-like medium; 12. The sheet processing apparatus according to claim 1, wherein the sheet processing apparatus is detachably supported by the housing and performs pressure binding on the medium on which an image is formed by the image forming unit; An image forming apparatus comprising:

13. an image forming apparatus for forming an image on a sheet-like medium; The sheet processing apparatus according to claim 1 , which is connected to the image forming apparatus; An image forming system comprising:

Images