Sheet processing device and image formation system

Abstract

The present invention comprises a folding mechanism that folds a sheet, a pouch formation mechanism that presses an overlap portion of the sheet as folded by the folding mechanism between a pair of pressing teeth to interlace and bind the fibers of the sheet and thereby form a pouch from the sheet, an insertion mechanism that inserts an enclosure sheet into the sheet as folded by the folding mechanism such that the enclosure sheet is sandwiched inside the sheet, and a discharge mechanism that discharges an envelope that is the pouch formed by the pouch formation mechanism into which the enclosure sheet has been inserted by the insertion mechanism.

Description

Sheet processing apparatus and image forming system Field of application of the invention

[0001] The present invention relates to a sheet processing apparatus for folding sheets sent from an image forming apparatus, for example, and an image forming system including the same. 2. Description of Related Art

[0002] Conventionally, sheet processing devices that fold sheets have been provided as post-processing for sheets discharged from image forming devices such as copiers, printers, facsimiles, and combination devices thereof. For example, a sheet processing device is known that guides a predetermined position of a sheet conveyed from the image forming device to a sheet stacker into a nip portion of a pair of folding rollers, and folds the sheet in half or in thirds while conveying it with the pair of folding rollers.

[0003] The sheets folded by the sheet folding device are used, for example, by placing them in purchased envelopes and sending them as direct mail.

[0004] In addition, it has been desirable to be able to create envelopes from a single sheet rather than purchasing envelopes to store sheets. To address this, a device has been proposed that creates envelopes for pouches without using consumables, for example by folding a sheet and then crimping and binding the folded sheet using a crimping and binding mechanism (Patent Publication No. 2023-179184).

[0005] However, in the device of JP 2023-179184, the user must separately insert another sheet (enclosing sheet) into the envelope of the created bag body, and the enclosing operation is troublesome.

[0006] An object of the present invention is to provide a sheet processing apparatus that can automatically insert an insert sheet into an envelope sheet and form a bag by crimping and binding the envelope sheet, and an image forming system equipped with the same.

[0007] A typical configuration of the present invention for achieving the above-mentioned object includes a folding mechanism for folding sheets, a bag-making mechanism for making bags from sheets by a pressure-binding process in which the overlapping portions of the sheets folded by the folding mechanism are bitten by a pair of pressure-binding teeth to entangle the fibers of the sheets and bind them together, an insertion mechanism for inserting an enclosed sheet so that it is sandwiched inside the sheets folded by the folding mechanism, and a discharge mechanism for discharging envelopes made by the bag-making mechanism and into which the enclosed sheet has been inserted by the insertion mechanism.

[0008] According to the present invention, the process of inserting the insert sheet into the envelope sheet and crimping and binding the envelope sheet to form a bag can be carried out automatically, so that the insert sheet can be easily stored in the bag.

[0009] Further features of the present invention will become apparent from the following description of exemplary embodiments, which is to be taken in conjunction with the accompanying drawings.

[0010] FIG. 1 is an explanatory diagram of the overall configuration of an image forming system according to this embodiment; FIG. 1 is an explanatory diagram of the overall configuration of a sheet processing device in the image forming system; FIG. 2 is a cross-sectional view showing a folding processing device of the sheet processing device; (a) is a cross-sectional view showing a gripping state of a gripping means, and (b) is a perspective view thereof; (a) is a cross-sectional view showing a gripping state of the gripping means, and (b) is a perspective view thereof; Cross-sectional explanatory diagramCross-sectional explanatory diagram of the sheet's inward three-folding operationCross-sectional explanatory diagram of the sheet's inward three-folding operationCross-sectional explanatory diagram of the folding operation of an enclosed sheet and an envelope sheetCross-sectional explanatory diagram of the folding operation of an enclosed sheet and an envelope sheetCross-sectional explanatory diagram of the folding operation of an enclosed sheet and an envelope sheetExplanatory diagram showing the relationship between an enclosed sheet and an envelope sheetExplanatory diagram of the folding and gluing operation of the flap portion by a flap folding unitExplanatory diagram of the folding and gluing operation of the flap portion by a flap folding unitExplanatory diagram of the folding and gluing operation of the flap portion by a flap folding unitExplanatory diagram of the folding and gluing operation of the flap portion by a flap folding unitExplanatory diagram of the state after an enclosed sheet is placed in an envelope sheet and pressure-boundFlowchart showing the procedure for inserting an enclosed sheet before pressure-binding an envelope sheetFlowchart showing the procedure for inserting an enclosed sheet after pressure-binding an envelope sheet Description of the embodiment

[0011] [First Embodiment] Next, a sheet processing apparatus according to a preferred embodiment of the present invention and an image forming system including the same will be described with reference to the drawings. Fig. 1 shows a schematic diagram of the overall configuration of an image forming system including a sheet processing apparatus according to an embodiment of the present invention. As shown in the figure, the image forming system 100 is composed of an image forming apparatus A and a sheet processing apparatus B installed therewith.

[0012] <Image Forming Apparatus> The image forming apparatus A is made up of an image forming unit A1, a scanner unit A2, and a feeder unit A3. The image forming unit A1 includes a feeding section 2, an image forming section 3, a discharge section 4, and a data processing section 5 inside a device housing 1.

[0013] The feeding unit 2 is composed of multiple cassette mechanisms 2a, 2b, and 2c, each storing image-forming sheets of different sizes, and feeds sheets of a size specified by a main body control unit (not shown) to a feeding path 2f. Each cassette mechanism 2a, 2b, and 2c is detachably installed from the feeding unit 2 and includes a separation mechanism that separates the sheets stored therein one by one and a feeding mechanism that feeds the sheets. The feeding path 2f is provided with conveying rollers that feed sheets supplied from each cassette mechanism 2a, 2b, and 2c downstream, and a pair of registration rollers at the end of the path that aligns the leading edges of each sheet.

[0014] The feeding path 2f is connected to a large-capacity cassette 2d and a manual feed tray 2e. The large-capacity cassette 2d is an optional unit that stores sheets of a size that are consumed in large quantities. The manual feed tray 2e is configured to be able to feed special sheets that are difficult to separate and feed, such as cardboard sheets, coated sheets, and film sheets.

[0015] In this embodiment, the image forming unit 3 is configured using an electrophotographic system and includes a rotating photosensitive drum 3a, a light emitter 3b that emits an optical beam, a developing unit 3c, and a cleaner (not shown) arranged around the photosensitive drum 3a. The illustrated unit is a monochrome printing mechanism in which the photosensitive drum 3a, whose circumferential surface is uniformly charged, is irradiated with light by the light emitter 3b in accordance with an image signal to optically form a latent image, and the developing unit 3c attaches toner to this latent image to form a toner image.

[0016] In synchronization with the timing of image formation on the photosensitive drum 3a, a sheet is sent from the feeding path 2f to the image forming unit 3, and a transfer bias is applied from the transfer charger 3d to transfer the toner image formed on the photosensitive drum 3a onto the sheet. The sheet onto which the toner image has been transferred is heated and pressurized as it passes through the fixing device 6, whereby the toner image is fixed, and the sheet is discharged from the discharge opening 4b by the discharge rollers 4a and transported to the sheet processing device B, which will be described later.

[0017] The scanner unit A2 includes a platen 7a on which an original image is placed, a carriage 7b that reciprocates along the platen 7a, a photoelectric conversion means 7c, and a reduction optical system 7d that guides light reflected from the original image on the platen 7a by the carriage 7b to the photoelectric conversion means 7c. The photoelectric conversion means 7c photoelectrically converts the optical output from the reduction optical system 7d into image data and outputs it to the image forming unit 3 as an electrical signal.

[0018] The scanner unit A2 also has a traveling platen 7e to read sheets fed from the feeder unit A3. The feeder unit A3 is composed of a feed tray 8a on which original sheets are stacked, a feed path 8b that guides the original sheets fed from the feed tray 8a to the traveling platen 7e, and an ejection tray 8c that stores the original sheets that have passed the traveling platen 7e. The original sheets from the feed tray 8a are read by the carriage 7b and the reduction optical system 7d as they pass the traveling platen 7e.

[0019] <Sheet Processing Apparatus> Next, the overall configuration of the sheet processing apparatus B that processes the sheets sent from the image forming apparatus A will be described.

[0020] 2 is an explanatory diagram of the configuration of the sheet processing apparatus B according to this embodiment. The sheet processing apparatus B includes an apparatus housing 11 provided with an inlet 10 for introducing sheets from the image forming apparatus A. The apparatus housing 11 is positioned in alignment with the housing 1 of the image forming apparatus A so that the inlet 10 communicates with the discharge outlet 4b of the image forming apparatus A.

[0021] The sheet processing apparatus B includes a sheet carry-in path 12 for transporting a sheet introduced from a carry-in entrance 10, a first discharge path 13a, a second discharge path 13b, and a third discharge path 13c branching off from the sheet carry-in path 12, a first path switching means 14a, and a second path switching means 14b. The first path switching means 14a and the second path switching means 14b are each configured with a flapper guide for changing the transport direction of a sheet transported through the sheet carry-in path 12.

[0022] The first path switching means 14a is switched by a driving means (not shown) between a mode in which the sheet from the carry-in entrance 10 is guided to the first discharge path 13a, which transports the sheet horizontally as is, and the second discharge path 13b, which transports the sheet downward, and a mode in which the sheet is guided to the third discharge path 13c, which transports the sheet upward. The first discharge path 13a and the second discharge path 13b are connected so that a sheet once introduced into the first discharge path 13a can be reversed in its transport direction and switched back to be transported to the second discharge path 13b.

[0023] The second path switching means 14b is disposed downstream of the first path switching means 14a in the conveying direction of the sheet conveyed through the sheet carry-in path 12. The second path switching means 14b is switched by a driving means (not shown) between a mode in which the sheet that has passed through the first path switching means 14a is introduced into the first discharge path 13a and a mode in which the sheet that has once been introduced into the first discharge path 13a is switched back and conveyed to the second discharge path 13b.

[0024] The sheet processing apparatus B includes a first processing section B1, a second processing section B2, and a third processing section B3, each of which performs a different post-processing operation. Furthermore, a punch unit 15 is disposed in the sheet carrying-in path 12 to punch holes in the carried-in sheets.

[0025] The first processing unit B1 is a binding processing unit that accumulates, collates, and binds multiple sheets discharged from a discharge opening 16a at the downstream end of the first discharge path 13a in the conveying direction of the sheets conveyed through the sheet carry-in path 12, and discharges the sheets to a stacking tray 16b provided outside the device housing 11. The first processing unit B1 also includes a sheet conveying device 16c that conveys sheets or a sheet stack, and a binding processing unit 16d that binds the sheet stack. A pair of discharge rollers 16e is provided at the downstream end of the first discharge path 13a to discharge the sheets from the discharge opening 16a and to switchback-convey the sheets from the first discharge path 13a to the second discharge path 13b.

[0026] The second processing unit B2 is a folding processing unit that folds a sheet or multiple sheets conveyed in a switchback manner from the second discharge path 13b into a sheet bundle, or that binds the sheet bundle and then folds it. As will be described later, the second processing unit B2 includes a folding processing device F that folds the conveyed sheet or sheet bundle, and a binding processing unit 17a that is disposed immediately upstream of the folding processing device F in the sheet conveyance direction of the sheets conveyed to the second discharge path 13b and binds the sheet bundle. The folded sheet or sheet bundle is discharged by a pair of discharge rollers 17b to a stacking tray 17c provided outside the device housing 11.

[0027] The third processing section B3 performs jog sorting to separate sheets sent from the third discharge path 13c into a group that is accumulated by offsetting the sheets by a predetermined amount in the sheet width direction perpendicular to the conveying direction, and a group that is accumulated without offsetting the sheets. The jog sorted sheets are discharged onto a stacking tray 18 provided outside the device housing 11, and the offset sheet bundles and the non-offset sheet bundles are stacked.

[0028] 3 is a schematic diagram of the overall configuration of the second processing section B2. As described above, the second processing section B2 includes a folding device F that folds in half the sheets conveyed from the second discharge path 13b or the sheet bundle collated by collecting and setting sheets, and a binding unit 17a that binds the sheet bundle before folding. The binding unit 17a shown in the figure is a stapler device that staples the sheet bundle.

[0029] A sheet transport path 20 is connected to the second discharge path 13b in order to transport sheets into the folding processing device F. With respect to the transport direction of the sheets transported from the second discharge path 13b to the intermediate tray 21, an intermediate tray 21 constituting a part of the sheet transport path 20 is provided downstream of the sheet transport path 20 to position and stack the sheets to be folded.

[0030] <Folding Device> A pair of folding rollers 22 serving as a pair of folding rotors is disposed on one side of the intermediate tray 21 so as to face one side of the sheet or sheet stack transported to the intermediate tray 21. The pair of folding rollers 22 consists of a pair of folding rollers 22a, 22b whose roller surfaces are pressed against each other, with a nip portion 22c, which is the pressure contact portion, facing the intermediate tray 21. The folding rollers 22a, 22b are arranged upstream and downstream along the transport direction of the sheet transported from the upstream side to the downstream side of the intermediate tray 21, with approximately equal spacing from the intermediate tray 21. Note that in the present invention, the rotating portion of the pair of folding rotors is not limited to the folding rollers 22a, 22b of this embodiment and can be composed of a rotating belt or the like. Furthermore, the pair of folding rollers 22 can be configured by continuously arranging multiple folding rollers (rotating bodies) in series along the axial direction of each folding roller 22a, 22b.

[0031] (Folding Roller Pair) As shown in FIG. 3 , each of the folding rollers 22a, 22b of the folding roller pair 22 of this embodiment has a roller circumferential surface including a first roller surface 22a2, 22b2 and a second roller surface 22a3, 22b3. The first roller surfaces 22a2, 22b2 have a constant radius R1 centered on the rotational axis of the rotation shafts 22a1, 22b1, respectively. The distance of the second roller surfaces 22a3, 22b3 from the rotational axis of the rotation shafts 22a1, 22b1, respectively, is smaller than the radius R1 of the first roller surface. The first roller surfaces 22a2, 22b2 are formed of a rubber material or the like with a relatively high coefficient of friction, similar to a typical roller surface. In contrast, the second roller surfaces 22a3, 22b3 are formed of a plastic resin material or the like with a lower coefficient of friction than the first roller surfaces 22a2, 22b2.

[0032] The rotation shafts 22a1 and 22b1 of the folding rollers 22a and 22b are driven to rotate by a common drive means such as a drive motor, thereby allowing the rotation positions of the first roller surfaces 22a2 and 22b2 and the second roller surfaces 22a3 and 22b3 to be always synchronized with each other.

[0033] A folding blade 23 serving as a protruding member is disposed on the opposite side of the folding roller pair 22 across the intermediate tray 21. The folding blade 23 is supported by a blade carrier 24 with its tip pointing toward the nip portion 22c of the folding roller pair 22. The blade carrier 24 is provided so as to be movable by a moving means formed of a cam member or the like in a direction that crosses the intermediate tray 21 at a substantially right angle, that is, in a direction that intersects with the conveying direction of the sheet conveyed from the second discharge path 13b to the intermediate tray 21.

[0034] (Folding Blade) A pair of cam members 25 (only one of which is shown in the figure) consisting of mirror-symmetrical eccentric cams are provided on both sides of the blade carrier 24 in the front-to-rear direction in Figure 3, i.e., in the axial direction of the folding rollers. The cam members 25 rotate around a rotation shaft 25a provided at an eccentric position by a driving means such as a drive motor. A cam groove 25b is formed in the cam member 25 along its outer periphery.

[0035] The blade carrier 24 is provided with a cam pin 24c as a cam follower that is slidably fitted into the cam groove 25b.

[0036] When the drive motor rotates the cam member 25, the blade carrier 24 moves back and forth in a direction approaching or moving away from the intermediate tray 21. As a result, as shown in Figure 3, the folding blade 23 can be freely moved back and forth linearly along a protruding path connecting an initial position where the tip of the folding blade 23 does not enter the sheet conveying path 20 formed by the intermediate tray 21, and a maximum protruding position where the tip of the folding blade 23 is sandwiched between the nip portion 22c of the pair of folding rollers 22.

[0037] (Pressing Guide Member) As shown in FIG. 3 , an L-shaped pressing guide member 30, which is a direction-changing member, is disposed above the folding blade 23 and is rotatable about a rotation shaft 30a. This pressing guide member 30 changes the orientation of the sheet S, which is folded by the forward rotation (first direction) of the folding roller pair 22 and then switchback-conveyed by the reverse rotation (second direction) of the folding roller pair 22, to return the sheet to the intermediate tray 21. By rotating about the rotation shaft 30a, the pressing guide member 30 can move between a standby position (see FIG. 15A ) where it does not affect the change in the sheet conveyance orientation and a guide position (see FIG. 17A ) where it guides the conveyed sheet to change its orientation. The standby position of the pressing guide member 30 is located on the opposite side of the intermediate tray 21 across the guide surface 21a of the intermediate tray 21. Because the sheet is conveyed along the guide surface 21a, the pressing guide member 30 does not come into contact with the sheet when it is positioned at the standby position.

[0038] (Regulation Stopper) A regulation stopper 26 is disposed at the lower end of the intermediate tray 21. The regulation stopper 26 serves as a position adjustment means that abuts against the leading edge of the conveyed sheet in the conveying direction to regulate the sheet and adjust the position of the sheet in the sheet conveying path 20. The regulation stopper 26 is provided so as to be able to rise and fall along the intermediate tray 21 by a sheet lifting mechanism 27.

[0039] The sheet lifting mechanism 27 in this embodiment is disposed below the blade carrier 24 when the folding blade 23 is in its initial position behind the intermediate tray 21, where the leading edge of the folding blade 23 does not enter the sheet transport path 20 formed by the intermediate tray 21. The sheet lifting mechanism 27 is a conveyor belt mechanism including a pair of pulleys 27a, 27b disposed near the upper and lower ends of the intermediate tray 21 along the tray, and a transmission belt 27c wound around the pulleys. The regulating stopper 26 is fixed on the transmission belt 27c. By rotating the drive pulley 27a or 27b by a driving means such as a drive motor, the regulating stopper 26 moves up and down between the lower end position shown in FIG. 3 and a desired height position, thereby moving the sheet or sheet stack along the intermediate tray 21 and positioning it at the desired height.

[0040] As described above, the regulating stopper 26 can move up and down along the intermediate tray 21, and the gripping means 50 is attached to the regulating stopper 26, so that the regulating stopper 26 can move up and down integrally with the regulating stopper 26. The gripping means 50 grips the sheet conveyed to the intermediate tray 21, and ensures the sheet movement in accordance with the movement of the regulating stopper 26.

[0041] (Gripping Means) Next, the configuration of the gripping means 50 will be described with reference to Figures 4 and 5. Figure 4(a) is a cross-sectional view of the gripping means 50 in a state where it is able to grip a sheet, and Figure 4(b) is a perspective view thereof. Figure 5(a) is a cross-sectional view of the gripping means 50 in a state where it has released its grip on the sheet, and Figure 5(b) is a perspective view thereof.

[0042] As shown in Figure 4, the gripping means 50 is attached to the regulating stopper 26. The regulating stopper 26 has a base 26a that is movable along the guide surface 21a of the intermediate tray 21 by the drive power transmitted from the transmission belt 27c, and a contact portion 26b is provided on the base 26a. The contact portion 26b positions the sheet when the lower end of the sheet conveyed to the intermediate tray 21 comes into contact with the contact portion 26b, and during folding processing, the position of the contact portion 26b is adjusted to move the sheet to the folding position. The contact portion 26b is formed with a rising portion 26c that is continuously bent upward in the vertical direction, so that the sheet that comes into contact with the contact portion 26b can be stored so as not to fall out.

[0043] The gripping means 50 is attached to the base 26a and moves integrally with the base 26a when the base 26a moves along the guide surface 21a. The gripping means 50 has a support portion 50a attached to the base 26a so as to be slidable in a direction along the thickness of the sheet perpendicular to the conveying direction of the sheet conveyed to the intermediate tray 21. An upright portion 50b is formed integrally with the support portion 50a, and a gripping portion 50c is formed on the inner surface of the upright portion 50b. Furthermore, a facing portion 50d is provided integrally with the base 26a at a position facing the gripping portion 50c across the sheet conveying path 20 to the intermediate tray 21.

[0044] The support portion 50a is drivingly connected to a gripper motor 72e (see Figure 11) provided on the regulating stopper 26, and can be moved by driving the gripper motor 72e between a grip position (see Figure 4) where the gripping portion 50c abuts against the opposing portion 50d and a grip release position (see Figure 5) where the gripping portion 50c moves away from the opposing portion 50d.

[0045] The support portion 50a is disposed below the contact portion 26b of the restriction stopper 26, i.e., at a position far from the pair of folding rollers 22, so that the support portion 50a can grip the sheet that has been positioned by contacting the contact portion 26b without interfering with the positioning of the sheet that contacts the contact portion 26b. The gripping portion 50c that grips the sheet is disposed above the contact portion 26b, i.e., at a position close to the pair of folding rollers 22. This allows the support portion 50a to reliably grip the sheet whose end portion contacts the contact portion 26b.

[0046] The gripping means 50 is provided with an envelope sheet abutment 50e, which abuts the lower end of the envelope sheet, at a position above the abutment 26b of the regulating stopper 26. In Figures 4 and 5, the reference numeral 51 denotes a sheet pressing member. The envelope sheet abutment 50e may be provided at the same height as the abutment 26b in the vertical direction.

[0047] (Side Alignment Mechanism) The folding device F of this embodiment further includes a sheet side alignment mechanism for aligning the sides of sheets conveyed to the intermediate tray 21. As shown in FIG. 6 , this sheet side alignment mechanism has a pair of sheet side alignment members 28a, 28b symmetrically arranged on both sides of the intermediate tray 21 in the sheet width direction (the direction along the surface of the sheet perpendicular to the sheet conveyance direction). Note that FIG. 6 is a schematic plan view of the folding device F viewed from above. The sheet side alignment members 28a, 28b are held movably so as to be able to move relatively close to and away from each other in the sheet width direction. When a sheet is conveyed to the intermediate tray 21 and its leading edge abuts against the regulating stopper 26, the sheet side alignment members 28a, 28b are moved to align the widthwise position of the sheet relative to the center.

[0048] <Sheet Storage Device> The sheet processing device B of this embodiment not only folds and discharges sheets, but also includes a sheet storage device G that can crimp and bind both widthwise sides of the folded sheets to form an envelope. This sheet storage device G can store and discharge other sheets that have been folded when forming the envelope.

[0049] Next, the sheet storage device G will be described. Figure 7 is an explanatory diagram of the entire sheet storage device G. The sheet storage device G is disposed downstream of the discharge roller pair 17b (see Figure 2), and a flapper member 40 that changes the conveying direction of the sheet conveyed by the discharge roller pair 17b is provided in the sheet carry-in section. In the envelope mode in which the folded sheet is stored in an envelope, the tip of the flapper member 40 rotates downward to guide the sheet conveyed by the discharge roller pair 17b to the sheet storage device G. On the other hand, in the normal mode in which the folded sheet is discharged as is, the tip of the flapper member 40 rotates upward to discharge the sheet onto the stacking tray 17c.

[0050] 7, the sheet storage device G of this embodiment is provided with a flap folding unit G1 and a sheet pressure binding unit G2 downstream thereof. The flap folding unit G1 folds back and adheres the flap portions formed on the envelope sheets, and the sheet pressure binding unit G2 pressure binds the envelope sheets to form envelopes.

[0051] The envelope sheet transported to the sheet storage device G in the envelope mode is sealed by folding and pasting the flap portion by the flap folding unit G1 while being transported by pairs of transport rollers 41a, 41b, 41c, and when being transported to the sheet pressure binding unit G2, both widthwise sides of the doubled envelope sheet are bound to form an envelope.

[0052] (Flap folding unit) In the flap folding unit G1, a tape adhesive member 60 is provided downstream of the pair of conveying rollers 41b, and a creasing plate 61 is provided downstream of that. The tape adhesive member 60 is provided with a roll of tape adhesive, and adhesive can be applied by pressing it against the sheet and moving it. The tape adhesive member 60 and the creasing plate 61 are arranged with a gap shorter than the length of the flap portion formed on the envelope sheet in the conveying direction.

[0053] An upper guide member 62 that guides the upper surface of the sheet being conveyed is provided above the tape adhesive member 60 and the creasing plate 61, and this upper guide member 62 is formed with a linear groove 62a along the sheet width direction at a position opposite the creasing plate 61. The sheet can be creased by pressing the sheet against the groove 62a with the creasing plate 61.

[0054] The tape glue member 60 is attached to a glue moving table 60a, which is movable in the sheet width direction. Therefore, when the glue moving table 60a is moved by the drive of the glue moving motor connected to it, the tape glue member 60 moves in the sheet width direction.

[0055] Similarly, the creasing plate 61 is fixed to a creasing plate moving base 61a, which is movable in the sheet width direction. Therefore, when the creasing plate moving base 61a is driven by the creasing motor connected to it, the creasing plate 61 moves along the groove 62a.

[0056] The glue moving table 60a and the creasing plate moving table 61a are configured to move along a cam groove (not shown). This cam groove is configured so that the tape glue member 60 and the creasing plate 61 are spaced apart from the upper guide member 62 in the regions near both ends in the sheet width direction, and are pushed upward in the central region other than the regions near the both ends, so that the tape glue member 60 and the creasing plate 61 come into contact with the upper guide member 62 and move in this state in the sheet width direction.

[0057] The area where the tape adhesive member 60 contacts the upper guide member 62 is the area inside the crimp binding lines formed on both sides of the envelope sheet in the sheet width direction, as will be described later. Also, the area where the creasing plate 61 contacts the upper guide member 62 is the entire width of the flap portion formed on the envelope sheet.

[0058] A folding guide 63 that folds back the flap portion formed on the envelope sheet is provided upstream of the tape adhesive member 60. The folding guide 63 has a slightly curved upper surface and an acutely angled downstream end. The folding guide 63 is configured to be movable parallel to the sheet conveyance direction by the drive of a folding guide motor connected to it.

[0059] A lower guide member 64 that guides the lower surface of the sheet being conveyed is provided downstream of the creasing plate 61. The lower guide member 64 is also configured to be movable parallel to the sheet conveying direction by the drive of a lower guide motor that is drive-connected to the lower guide member 64.

[0060] (Sheet pressure binding unit) Next, the sheet pressure binding unit G2, which is a bag making mechanism, will be described. As shown in Figure 8, the sheet pressure binding unit G2 has binding units 80 for binding the widthwise edge of the sheet provided on both sides of the sheet width direction as it is conveyed, and pressure binds the folded sheet being conveyed by sandwiching and biting it between the pair of binding units 80. Each binding unit 80 has the same configuration and is arranged in a mirror symmetrical manner.

[0061] As shown in Fig. 9, the binding unit 80 is configured with a pair of crimping teeth 80a, 80b (hereinafter referred to as "crimping tooth pair"), each of which is made up of a drive tooth 80a and a driven tooth 80b meshing together. The drive tooth 80a and the driven tooth 80b each have alternating convex and concave portions, and each convex portion fits into the concave portion and rotates while being pressed against the other. The drive tooth 80a and the driven tooth 80b bite into the folded sheet, entangling the fibers of the sheet and binding it.

[0062] The drive teeth 80a are fixed to a drive shaft 82 supported by a bearing 81a, and the drive teeth 80a rotate when the drive shaft 82 is driven to rotate. The bearing 81a is attached to a fixed portion 83a.

[0063] The driven teeth 80b are rotatably mounted on a bearing 81b attached to a support portion 83b and mesh with the drive teeth 80a. The driven teeth 80b are rotated by the rotation of the drive teeth 80a. The support portion 83b is movably mounted on a shaft 84 fixed to the fixed portion 83a and is biased downward from above by a pressure spring 85. Therefore, when a sheet is sandwiched between the drive teeth 80a and the driven teeth 80b, the driven teeth 80b press the sheet against the drive teeth 80a. When the drive teeth 80a rotate in this state, the convex portion of one of the drive teeth 80a and the driven teeth 80b enters the concave portion of the other, gripping the sheet and conveying it while crimping and binding it. The pressing force of the driven teeth 80b can be adjusted by changing the position of an adjustment nut 87 attached to a bolt member 86 that attaches the pressure spring 85. The pair of crimping teeth 80a, 80b can be separated by a separation mechanism (not shown).

[0064] The pair of binding sections 80 are configured so that the spacing between each pair of crimping teeth 80a, 80b is approximately the same as the widthwise length of the envelope sheet being transported, and when the envelope sheet is transported through the sheet crimping binding unit G2, both widthwise ends of the envelope sheet are positioned so that they are bitten by the pair of crimping teeth 80a, 80b.

[0065] <Control Unit> Next, the control unit configuration of the drive system when folding a sheet will be described. As shown in the block diagram of Fig. 10, in image forming apparatus A, a first control unit 70a controls the driving of each member of image forming unit 3 based on information received at an input unit 71 that inputs information from an operation panel, an external personal computer, etc., to form an image on a sheet. On the other hand, sheet processing apparatus B is controlled by a second control unit 70b that cooperates with the first control unit 70a and a third control unit 70c that cooperates with these control units.

[0066] In addition to image data for performing image formation processing on sheets, information regarding the folding mode is input to the input unit 71. In this embodiment, the folding modes available are a first folding mode (normal mode) in which the folded sheets are discharged without being stored in the sheet storage device G, and a second folding mode (envelope mode) in which the folded sheets are stored in an envelope sheet by the sheet storage device G and then discharged. Information regarding which mode to execute is input to the input unit 71 by an external device such as a personal computer or smartphone connected directly or via a network, or by an operation panel provided on the image forming apparatus A.

[0067] The second control unit 70b receives detection signals and processing signals from various detection sensors and controls the driving of various drive motors and the like of the sheet processing device B according to the input signals. For example, the second control unit 70b receives detection signals from a regulating stopper HP sensor that detects whether the regulating stopper 26 is in the home position, a folding blade HP sensor that detects whether the folding blade 23 is in the home position, a glue moving cam HP sensor that detects whether the glue moving cam 41 is in the home position, and a sheet detection sensor 42 (see FIG. 7) that detects whether the sheet transported to the sheet storage device G has passed a predetermined position upstream of the transport roller pair 41a.

[0068] 11 to 13 in accordance with the input signal (folding mode information input to the input unit 71), the second control unit 70b drives and controls a restriction stopper motor 72a that drives the sheet lifting mechanism 27 that lifts and lowers the restriction stopper 26, a cam motor 72b that drives the cam member 25 that operates the blade carrier 24, and a folding roller motor 72c that drives and rotates the folding roller pair 22. The second control unit 70b also drives and controls a gripper motor 72e that drives the gripping means 50, a pressure guide motor 72f that operates the pressure guide member 30, an alignment motor 72g that operates the alignment members 28a and 28b, and a conveyance roller motor 72h that drives conveyance rollers and the like that convey the sheet to the intermediate tray 21.

[0069] The third control unit 70c controls the drive of each motor for driving the sheet storage device G in accordance with the procedure of the flowchart shown in Fig. 14 in accordance with the folding mode information input from the input unit 71. Specifically, the third control unit 70c controls the drive of an envelope sheet transport motor 73a for driving the transport roller pairs 41a, 41b, and 41c, a glue moving motor 73b for moving the glue moving table 60a, a creasing motor 73c for moving the creasing plate moving table 61a, a folding guide motor 73d for moving the folding guide 63, a lower guide motor 73e for moving the lower guide member 64, and a crimping tooth motor 73f for rotating the drive tooth 80a of the sheet crimping binding unit G2.

[0070] The second control unit 70b and the third control unit 70c may be directly provided in the sheet processing apparatus B, or the second control unit 70b and the third control unit 70c may be provided in the image forming apparatus main body, and these control units may control the driving of the sheet processing apparatus B connected to the image forming apparatus A. In the following description, expressions such as "the second control unit 70b rotates the pair of folding rollers 22a" and "the second control unit 70b moves the regulating stopper 26" are used. However, these expressions are used to omit explanations, and actually indicate that the second control unit 70b controls the driving of the respective driving members such as motors, as described above. The same applies to the third control unit 70c.

[0071] <Folding process control> The folding process is controlled by the control unit, and the folding processing device F of this embodiment is capable of performing normal folding processing and envelope folding processing in which an envelope sheet made by folding a sheet in half is crimped and bound by a sheet storage device G to form an envelope, and the sheet is stored in the envelope.

[0072] The operation of the folding processing device F of this embodiment when performing folding processing will be described below with reference to the flowcharts of Figures 11 to 14 and the cross-sectional schematic diagrams of Figures 15 to 29 which show the movement of each part along the flow of the sheet S when the folding processing is performed.

[0073] As shown in Figure 11, when a job is accepted (S1), it is determined whether or not folding processing is required (S2), and if folding processing is not required, the sheet on which an image has been formed by the image forming device A is processed by the first processing section B1, the third processing section B3, etc., and then discharged.

[0074] On the other hand, if it is determined in step S2 that a folding process is to be performed, it is determined whether the folding process is a first folding process (first folding mode) in which the sheet is folded by the sheet storage device G without being stored in an envelope, or a second folding process (second folding mode) in which the sheet is folded into an envelope by the sheet storage device G and then stored (S5). The second control unit 70b and the third control unit 70c determine which folding mode to use based on information input from the input unit 71. Then, the first folding process or the second folding process is performed according to the selected mode (S6, S7).

[0075] (First Folding Process) The first folding process is performed as shown in the flowchart of Fig. 12. Fig. 12 shows an example of folding a sheet in three. Here, the first folding process refers to a process in which a sheet is folded in half in a first folding process, and then the sheet is folded a second time at a position different from the initial folding position, so that one edge of the sheet folded in the first folding process is folded inside the sheet to be folded in the second folding process, thereby folding the sheet in three.

[0076] When a sheet on which an image has been formed in the image forming apparatus A is conveyed to the sheet processing apparatus B (S11), the regulating stopper 26 moves to the "sheet receiving position" (S12). At this time, the gripping means 50 is in a released state, i.e., the gripping portion 50c is separated from the opposing portion 50d, and the regulating stopper 26 is in a state where it can receive a sheet (FIG. 15A).

[0077] 15A, the intermediate tray 21 of this embodiment is formed at an angle with respect to the vertical direction, and when a sheet S is conveyed to the intermediate tray 21, one side of the sheet S is guided by a guide surface 21a that forms the intermediate tray 21, and the sheet S is conveyed so that the sheet leading edge E1 is downward and the sheet trailing edge E2 is upward, and the sheet leading edge E1 hits the abutment portion 26b of the regulating stopper 26 and stops. When two or more sheets are to be folded in a stack, a predetermined number of sheets are conveyed to the intermediate tray 21 in the same manner. Note that an example of folding a single sheet will be described here.

[0078] When the sheet S after image formation is conveyed to the intermediate tray 21, the alignment members 28a and 28b operate to align the sheet widthwise position (S13, S14), and then the gripping means 50 operates to grip the lower end of the sheet S (S15). In this state, the regulating stopper 26 is raised to move the sheet S to the "first folding position" (S16). This first folding position is a position where the folding position of the sheet S faces the folding blade 23. The folding blade 23 is positioned to push the sheet S from the side of the guide surface 21a of the intermediate tray 21 toward the folding roller pair 22. In other words, the guide surface 21a of the intermediate tray 21 and the folding roller pair 22 are positioned to sandwich the sheet S therebetween.

[0079] Then, the gripping of the sheet by the gripping means 50 is released, and the first folding process is performed (S17). When the folding process is performed, as shown in FIG. 15B, the cam motor 72b is driven to move the blade carrier 24 toward the pair of folding rollers 22, and the folding blade 23 contacts the first folding position of the sheet S and protrudes into the nip portion 22c. At the same time, the folding roller motor 72c and the discharge roller motor 68 are driven to rotate the pair of folding rollers 22 and the pair of discharge rollers 17b forward. When pulse motors are used for the motors, the number of drive pulses is counted by a counter when the motor is driven. When DC motors are used for the motors, a sensor reads the slits in a code wheel (slit plate) attached to the rotation shaft of the motor, and the number of pulses is counted by a counter. The count value can be used to detect the transport amount of the sheet S, the protrusion amount of the folding blade 23, and the like.

[0080] When the sheet S protruded by the folding blade 23 is nipped by the nip portion 22c of the pair of folding rollers 22, the regulating stopper 26 moves to the "switchback receiving position." The switchback receiving position is a position where, when the folded sheet that has been subjected to the first folding process by the pair of folding rollers 22 is switched back and conveyed to the intermediate tray 21 by the pair of folding rollers 22 rotating in the reverse direction, the sheet end E1 on the side farther from the folding position abuts against the abutting portion 26b of the regulating stopper 26 when sheet conveyance stops.

[0081] When the folding blade 23 that has protruded the sheet protrudes a predetermined amount to protrude the first folded portion of the sheet S up to the nip portion 22c of the folding roller pair 22, the direction of travel is reversed by the rotation of the cam member 25, and the blade moves in the return direction to return to the home position.

[0082] As a result of the protrusion of the folding blade 23, the first fold of the sheet S is protruded into the nip portion 22c of the folding roller pair 22, and is pressed with a predetermined pressing force while being sandwiched and transported by the folding roller pair 22, thereby undergoing a folding process, and is then transported as is by the discharge roller pair 17b, which together with the folding roller pair 22 constitutes a sheet transport means.

[0083] 16A, when the sheet S is nipped by the discharge roller 17b and the second roller surfaces 22a3 and 22b3 of the folding rollers 22a and 22b face each other, the folding roller motor 72c stops. This causes the pair of folding rollers 22 to no longer nip the sheet, and the sheet is conveyed by the discharge roller 17b. At this time, the sheet is conveyed by the discharge roller 17b while being guided by the second roller surfaces 22a3 and 22b3, which have a small coefficient of friction. In this embodiment, whether the sheet has been conveyed to the discharge roller 17b and whether the second roller surfaces 22a3 and 22b3 of the pair of folding rollers face each other is determined by counting pulses of the motor. However, other configurations may also be used, such as detecting the sheet S with a sensor and controlling the drive of the motor based on the detection result.

[0084] Next, to perform the second folding process, as shown in Figure 16(b), sheet conveyance is stopped when the trailing edge E2 of the sheet that has been folded the first time reaches a predetermined position. The predetermined position is a position where the trailing edge E2 of the sheet S, which is closer to the fold, is conveyed into the sheet conveyance path 20 formed by the intermediate tray 21. From this state, the folding roller pair 22 and the discharge roller pair 17b are driven in reverse to perform the switchback conveyance process. When the sheet is folded inward in three, the trailing edge E2 of the sheet becomes the edge that is folded inward in the second folding process (hereinafter referred to as the "folded edge E2").

[0085] When the switchback conveying process is performed, the L-shaped pressure guide member 30, which is located in the home position (standby position), is rotated about the rotation shaft 30a to move to the switchback guide position, as shown in FIG. 17A. The rotation of the guide member 30 pushes the folded end E2 downward (toward the intermediate tray 21 where the sheet leading edge E1 is located). In this state, as shown in FIG. 17B, the gripping means 50 grips the sheet end E1 on the side farther from the fold of the sheet (S18). Then, as shown in FIG. 18A, the folding roller pair 22 and the discharge roller pair 17b are driven in the reverse direction to switchback convey the sheet, and the regulating stopper 26 is lowered to match the speed and move to the "reversal position."

[0086] The sheet whose folding end E2 has been guided to the intermediate tray 21 as described above moves downward as the regulating stopper 26 gripping the sheet end E1 moves to the "reversal position." As shown in FIG. 18B, the reversal position is a position where the sheet has been moved to a position where the pressing guide member 30 can rotate without interfering with the sheet S. The amount of sheet transport to the reversal position is determined according to the sheet size and folding position. Then, as shown in FIG. 19A, the pressing guide member 30 is returned to the standby position.

[0087] Next, as shown in Fig. 19(b), the regulating stopper 26 is moved to the "second folding position" (S19). This second folding position is a position where the second folding position of the sheet conveyed by the movement of the regulating stopper 26 faces the folding blade 23. At this position, as shown in Figs. 20(a) and 20(b), the grip of the sheet is released and the folding blade 23 pushes the sheet into the nip portion 22c of the folding roller pair 22, so that the folding roller pair 22 performs the second folding process (S20), and the sheet folded in three is discharged (S21).

[0088] The first folding process of this embodiment may be a double folding process in which the sheet is only folded in half and then discharged, instead of a triple folding process.

[0089] (Second Folding Process) The second folding process, which results in an envelope fold, is performed as shown in the flowcharts of Figures 13 and 14. The second folding process in this embodiment has two modes: a first storage mode (enclosing mode) in which the folded insert sheet (first sheet) and the envelope sheet (second sheet) are overlapped and folded simultaneously to store the insert sheet in an envelope, and then the flap portion formed on the envelope sheet is folded and glued to store and enclose the insert sheet in the envelope; and a second storage mode (enclosing mode) in which the insert sheet is stored in the envelope but the flap portion is not glued. This mode is also performed based on mode information input to the input unit 71.

[0090] In the second folding process for enclosing an insert sheet in an envelope sheet, the first folding process is performed on the insert sheet S1 on which an image has been formed, and the process is the same as the first folding process described above (S32-S39) until the sheet is switched back and the regulating stopper 26 is lowered to the "reversal position" (the state shown in FIG. 19(a)). Note that when the first folding process of the insert sheet S1 is performed, an image is formed on the envelope sheet S2 (S40).

[0091] 21(a), after the first folding process of the enclosed sheet S1, as shown in FIG. 21(b), the envelope sheet S2 is transported to the intermediate tray 21 (S41) as shown in FIG. 21(b). This envelope sheet S2 is transported to the outside of the enclosed sheet S1 (opposite the folding roller) until its leading edge abuts against the envelope sheet abutment portion 50e located a predetermined distance above the abutment portion 26b of the regulating stopper 26.

[0092] Next, while the enclosing sheet S1 is gripped by the gripping means 50, the sheet side alignment members 28a, 28b are operated to align the envelope sheet S2 in the width direction (S42). The envelope sheet S2 is a sheet wider in width than the enclosing sheet S1 (see FIG. 24(a)). When the envelope sheet S2 is aligned in the width direction by the sheet side alignment members 28a, 28b, a predetermined amount of the envelope sheet S2 is exposed on both sides of the overlapping enclosing sheet S1 in the width direction. This exposed portion becomes the pressure-bonded binding area 90, which will be described later.

[0093] After aligning the envelope sheet S2 as described above, as shown in Figure 22 (a), the regulating stopper 26 is moved to the "second folding processing position" where the second folding position of the sheet faces the folding blade 23 (S43).

[0094] Next, the grip on the enclosed sheet S1 is released, and the pair of folding rollers 22 is rotated while the folding blade 23 is thrust out to perform folding (S44). During this folding process, the enclosed sheet S1 and the envelope sheet S2 are transported so as to be drawn into the nip portion of the pair of folding rollers 22, as shown in Fig. 22(b). Then, as the envelope sheet S2 passes through the nip portion of the pair of folding rollers 22, the enclosed sheet S1, which has been folded in three, is transported by the pair of discharge rollers 17b with the enclosed sheet S1 inside the envelope sheet S2, which has been folded in half, as shown in Fig. 23, and is transported to the sheet storage device G for pressure binding (S45).

[0095] As described above, the bottom edge of the envelope sheet S2 transported to the intermediate tray 21 is positioned above the bottom edge of the enclosed sheet S1 (see FIG. 21(b)), and the edges of both sheets are transported to the second folding position with a misalignment and folded. Therefore, as shown in FIG. 24(b), the enclosed sheet S1 discharged in the envelope is slightly exposed from the envelope edge S2a formed by one side edge of the envelope sheet S2. This makes it easy to remove the enclosed sheet S1 from the envelope when checking it.

[0096] 24(b), the folded insert sheet S1 and envelope sheet S2 are conveyed with the folded end E3 of the envelope sheet S2 at the front in the conveying direction, with the insert sheet S1 sandwiched between the folded envelope sheet S2. A flap portion S2c is formed on the rear side of the envelope sheet S2 in the conveying direction, with the folding line S2b as the boundary.

[0097] (Press-binding Process) The envelope sheet S2 with the insert sheet S1 sandwiched therebetween as described above is guided by the flapper member 40 and transported to the sheet storage device G, where the press-binding process is executed according to the procedure of the flowchart shown in FIG.

[0098] When the envelope sheet S2 is transported to the sheet storage device G, the envelope sheet transport motor 73a and the crimping tooth motor 73f are driven to transport the envelope sheet S2, and the crimping tooth pairs 80a and 80b rotate (S51, S52). Then, as shown in Figure 25(a), when the envelope sheet S2 passes through the crimping tooth pairs 80a and 80b, the crimp binding area 90 (see Figure 24(a)) of the envelope sheet S2 is bitten by the crimping tooth pairs 80a and 80b, whereby both widthwise sides of the folded envelope sheet S2 are crimp-bound.

[0099] Here, as described above, the pressure binding process of this embodiment has an enclosing mode in which the flap portion S2c is folded and glued, and a storage mode in which the flap portion S2c is not glued (S53).

[0100] In the case of the enclosing mode in which the adhesive process of the flap portion S2c is performed, when the flap portion S2c of the envelope sheet S2 being transported reaches the flap folding unit G1, specifically after the leading edge of the envelope sheet S2 is detected by the sheet detection sensor 42 (see Figure 7) (S54), the sheet is transported a predetermined distance and the folding line S2b (see Figure 24(b)) of the flap portion S2c is transported to a position opposite the creasing plate 61 (S55), the drive of the transport roller pairs 41a, 41b, 41c and the crimping tooth pairs 80a, 80b is stopped to stop the sheet transport (S56).

[0101] Next, the glue moving motor 73b and the creasing motor 73c are driven to move the tape glue member 60 and the creasing plate 61 in the sheet width direction (S57). As a result, the tape glue member 60 and the creasing plate 61, which were in the home position and separated from the upper guide member 62, move upward as shown in Fig. 25(b), so that the tape glue member 60 contacts the flap portion S2c of the envelope sheet S2, and the creasing plate 61 presses the envelope sheet S2 into the recessed groove 62a of the upper guide member 62. In this state, the glue moving table 60a and the creasing plate moving table 61a move in the sheet width direction, so that the tape glue 60b adheres to the flap portion S2c, and a fold is made along the folding line S2b of the flap portion S2c, as shown in Fig. 26(a).

[0102] As described above, the area where the tape glue adheres to the flap portion S2c as the tape glue member 60 moves is inside the pressure-bonded binding area formed on both sides of the envelope sheet S2. The creasing plate 61 is configured to move in the width direction at a timing delayed from that of the tape glue member 60. This allows the tape glue 60b to adhere to the flap portion S2c before the creasing plate 61 creates a crease. The tape glue member 60 and the creasing plate 61 are then separated from the envelope sheet S2 and moved to their home positions.

[0103] Next, as shown in Figure 26(b), the folding guide 63 is moved downstream (S58). At this time, because the flap portion S2c is inclined due to the crease formed as described above, the folding guide 63, whose tip is bent at an acute angle, enters above the flap portion S2c and acts to fold the flap portion S2c. At this time, the lower guide member 64 is in the home position, and its upstream end is in approximately the same position as the crease formed in the flap portion S2c. Therefore, the flap portion S2c, which is folded by the movement of the folding guide 63, is folded back by the lower guide member 64 pressing down on the crease.

[0104] As described above, the folding guide 63 is moved a predetermined distance to fold back the flap portion S2c, and the lower guide motor 73e is driven to move the lower guide member 64 downstream to move the flap portion S2c away from the flap attachment area of ​​the envelope sheet S2 (S59), as shown in Figure 27(a). As a result, the tape adhesive 60b adheres the folded back flap portion S2c to the envelope sheet S2.

[0105] After the flap portion S2c is folded back and adhered, as shown in Fig. 27(b), the envelope sheet conveying motor 73a and the crimping tooth motor 73f are driven to convey the envelope sheet S2 containing the enclosed sheet S1 (S60), and the envelope sheet S2 is crimped and bound on both widthwise sides by passing through the crimping tooth pairs 80a and 80b, and then discharged (S61). Then, as shown in Fig. 28, the folding guide 63 and the lower guide member 64 are returned to their home positions, and the process is completed.

[0106] As a result, as shown in Figure 29 (a), the enclosed sheet S1 is enclosed inside the folded envelope sheet S2, both widthwise sides are bound by the pressure-bonded binding section S2d, and the envelope is discharged with the flap section S2c folded back and glued.

[0107] On the other hand, if a storage mode that does not perform the gluing process on the flap portion S2c is selected in step S53, the flap portion S2c is not folded back and glued in steps S54 to S60 as described above, and the enclosed sheet S1 is sandwiched between the folded envelope sheet S2 and conveyed through the pair of crimping teeth 80a, 80b, whereby both widthwise sides of the envelope sheet S2 are crimped and bound and then discharged (S61).

[0108] As a result, as shown in Figure 29 (b), the enclosed sheet S1 is stored inside the folded envelope sheet S2, both widthwise sides are bound by the crimped binding section S2d, and the envelope is discharged with the flap section S2c open.

[0109] As described above, the envelope is discharged with the enclosed sheet S1 inside the envelope sheet S2 and both sides bound, so there is no need to widen the insertion opening of the envelope to insert the enclosed sheet as in the past, and there is no risk of the pressure-bound portion coming off.

[0110] In addition, in the enclosing mode, the flap portion S2c formed on the envelope sheet S2 is folded back and adhered, allowing the envelope to be formed with the enclosing sheet S1 completely enclosed. On the other hand, in the storage mode, the flap portion S2c is not adhered, making it easy to pull out and check the enclosing sheet S1. In this case, as shown in Figure 29(b), the edge of the enclosing sheet S1 is slightly exposed beyond the opening edge E4 of the envelope sheet, making it easy to pull out the enclosing sheet S1. Furthermore, the pressure-sealed binding portion S2d is formed to extend beyond the opening edge E4 and over the flap portion S2c, so the opening edge E4 is securely bound, making the pressure-sealed binding portion less likely to peel off.

[0111] <Variations of the embodiment> In the above-described embodiment, an example was shown in which the enclosed sheet S1 and the envelope sheet S2 were folded at the same time and the pressure binding process was performed with the enclosed sheet S1 stored in the envelope sheet S2, but it is also possible to fold the envelope sheet S2 first and then insert the enclosed sheet into the folded envelope sheet S2 later.

[0112] For example, when inserting an enclosed sheet S1 before crimping and binding an envelope sheet S2, as shown in the flowchart of Fig. 30, first, the envelope sheet S2 is folded in half and transported to the sheet storage device G, and the envelope sheet transport motor 73a is driven to transport the envelope sheet S2 (S71). Then, when the envelope sheet S2 reaches a position where the enclosed sheet S1 can be inserted, specifically, when the envelope end S2a (see Fig. 24(b)), which is the overlapping end of the envelope sheet S2, reaches a predetermined position downstream of the folding guide 63 (S72), the transport of the envelope sheet S2 is stopped (S73).

[0113] Next, an expansion process is performed to expand the opening of the folded envelope sheet S2 (S74). This expansion process widens the opening side of the overlapping envelope sheets S2 so that the insert sheet S1 can enter between the folded envelope sheets S2. In this embodiment, the folding guide 63 is moved downstream so that the downstream tip of the folding guide 63 enters the inside of the folded sheets from the envelope end S2a, which becomes the opening of the envelope, and widens the opening of the envelope.

[0114] After the envelope opening is expanded as described above, the folded insert sheet S1 is transported to the sheet storage device G. As a result, the insert sheet S1 is inserted into the inside of the folded envelope sheet (S75).

[0115] Thereafter, the conveyance of the envelope sheet S2 with the inserted enclosed sheet S1 is resumed, and at the same time, the crimping tooth motor 73f is driven to rotate the crimping tooth pairs 80a and 80b (S76, S77). As a result, both widthwise sides of the envelope sheet S2 containing the enclosed sheet S1 pass through the crimping tooth pairs 80a and 80b, whereby the envelope sheet S2 is crimp-bound and discharged (S78).

[0116] The above procedure is for inserting an enclosed sheet before the envelope sheet S2 is pressure-sealed and bound, but as shown in the flowchart of Figure 31, it is also possible to perform a pressure-sealing and binding process on the envelope sheet S2 to form a bag body, and then insert the enclosed sheet S1 into this bag body.

[0117] The procedure shown in the flowchart of Figure 31 will be explained as follows: the envelope sheet S2 that has been folded in half is transported to the sheet storage device G, the envelope sheet transport motor 73a and the pressure tooth motor 73f are driven to transport the envelope sheet S2 to a predetermined position, and then the drive of the transport motor 73a and the pressure tooth motor 73f is stopped (S81-S84).

[0118] The predetermined position is the position where the overlapping end S2a of the envelope sheet S2 passes through the pair of crimping teeth 80a, 80b, and where the overlapping area of ​​the envelope sheet is completely crimped. As a result, both widthwise sides of the folded envelope sheet S2 are crimped and bound to form a pouch that will become an envelope.

[0119] Next, the pair of crimping teeth 80a, 80b are separated (S85), and the envelope sheet conveying motor 73a is driven in the reverse direction to return the envelope sheet S2 by a predetermined distance (S86) until the envelope end S2a of the envelope sheet S2 reaches a position downstream of the folding guide 63. Then, in the same manner as above, the folding guide 63 is moved downstream to execute the envelope opening widening process (S87), widening the envelope opening.

[0120] Next, the folded insert sheet S1 is transported to the sheet storage device G, and the insert sheet S1 is inserted into the formed envelope (S88). Thereafter, the transport of the envelope sheet S2 is resumed, and the envelope with the inserted insert sheet S1 is discharged (S89). At this time, the pair of crimping teeth 80a, 80b are separated, so the envelope sheet S2 is not subjected to the crimp binding process again.

[0121] In addition, the flowcharts shown in Figures 30 and 31 show an example in which the enclosed sheet S1 is inserted into the envelope sheet S2 and then discharged as is, but it is also possible to configure the envelope sheet S2 so that after the enclosed sheet S1 is inserted inside the envelope sheet S2, the flap portion bonding process described in the above-mentioned embodiment (S54-S61 in the flowchart in Figure 14) is performed to seal the flap portion and then discharge the envelope sheet S2.

[0122] The crimp binding process for the envelope sheet S2 described above is performed in the area where the envelope sheets S2 folded in half by the folding mechanism overlap each other and where the enclosed sheet S1 does not overlap, thereby turning the envelope sheet S2 into a pouch. Therefore, the envelope sheet S2 must be longer in width than the enclosed sheet S1, and the crimp binding process cannot be performed on an envelope sheet S2 that is narrower than the enclosed sheet S1.

[0123] Therefore, the input unit 71, which serves as a setting unit for setting the sheet sizes of the enclosed sheet S1 and the envelope sheet S2, may be configured so that when setting the sheet size of the envelope sheet S2, a sheet whose width direction is shorter than the set length of the enclosed sheet S1 cannot be set. For example, if a value for the width direction of the envelope sheet S2 shorter than the size of the enclosed sheet S1 is input into the input unit 71, the control unit may perform error processing and display an error message on the display unit. This prevents folding and binding processes from being performed on sheets of incompatible sizes.

[0124] In the above-described embodiment, images are formed on the enclosed sheet S1 and the envelope sheet S2 in the image forming unit 3, and the sheets are then folded and pressure-stitched. However, the above-described folding and stitching processes may be performed on the enclosed sheet S1 and the envelope sheet S2 on which images have already been formed. In this case, for example, the enclosed sheet S1 and the envelope sheet S2 on which images have already been formed are set on the manual feed tray 2e (see FIG. 1), and the sheets are transported to the folding processing device F for the above-described folding process without image formation in the image forming unit 3, and then transported to the sheet storage device G for the pressure-stitching process. This allows the image formation process, folding process, and stitching process to be performed independently on the sheets. Furthermore, a manual feed tray (not shown) may be provided in the sheet processing device B, and the enclosed sheet S1 and the envelope sheet S2 on which images have already been formed may be fed without going through the image forming device A, and the above-described folding and stitching processes may be performed.

[0125] Furthermore, in the above-described embodiment, a configuration was shown in which a folding blade 23 was used to clamp the sheet between the folding roller pair 22, but it is also possible to provide pairs of conveying rollers upstream and downstream of the folding roller pair 22 in the conveying direction, and while the sheet is being conveyed by the upstream conveying roller pair and the downstream conveying roller pair, to reduce the rotational speed of the downstream conveying roller pair to cause a flexure in the sheet, and then to draw the sheet into the folding roller pair and clamp it.

[0126] In addition, in the above-described embodiment, a sheet folding device is shown as using a pair of folding rollers 22 and a folding blade 23 to perform folding processing on a sheet, but it may also be configured to use three folding rollers to perform a third fold.

[0127] Although the present invention has been described with reference to exemplary embodiments, it is not intended that the invention be limited to the disclosed exemplary embodiments, and the scope of the following claims is to be accorded the broadest interpretation encompassing all modifications, equivalent structures, and functions.

[0128] This application claims priority based on Japanese Patent Application No. 2024-144430, filed August 26, 2024, the entire contents of which are incorporated herein by reference.

Claims

1. A sheet processing device comprising: a folding mechanism that folds sheets; a bag making mechanism that forms bags from the sheets by a pressure binding process in which overlapping portions of the sheets folded by the folding mechanism are clamped with a pair of crimping teeth to entangle the fibers of the sheets and bind them together; an insertion mechanism that inserts an enclosed sheet so that it is sandwiched inside the sheets folded by the folding mechanism; and a discharge mechanism that discharges envelopes that have been formed by the bag making mechanism and have had the enclosed sheet inserted by the insertion mechanism.

2. A sheet processing device as described in claim 1, comprising: a conveying mechanism that conveys an envelope sheet to be made into an envelope and an enclosed sheet contained in the envelope in a conveying direction; and a stacking mechanism that stacks the enclosed sheet and the envelope sheet so that both side areas of the envelope sheet do not overlap with the enclosed sheet in a sheet width direction that intersects the conveying direction, wherein the folding mechanism wraps the enclosed sheet with the envelope sheet by folding the enclosed sheet and the envelope sheet stacked by the stacking mechanism, and the bag making mechanism performs the pressure binding process on both side areas of the envelope sheet that has wrapped the enclosed sheet by the folding mechanism.

3. The sheet processing device described in claim 2, characterized in that the overlapping mechanism has a transport mechanism that transports the enclosed sheet and the envelope sheet, and an alignment mechanism that performs width alignment processing on the enclosed sheet and the envelope sheet based on a center reference in the sheet width direction, and performs the width alignment processing on the enclosed sheet whose length in the sheet width direction is a first length, then transports the envelope sheet whose length in the sheet width direction is longer than the first length so that it is overlapped with the enclosed sheet, and performs the width alignment processing on the envelope sheet in a state where the enclosed sheet and the envelope sheet are overlapped.

4. The sheet processing device according to claim 1, characterized in that the folding mechanism has a pair of folding rollers that crease the sheet, and performs the folding process while transporting the sheet in the folding transport direction with the pair of folding rollers, and also has a flap folding mechanism that folds back and adheres a flap portion formed at the downstream end of the envelope sheet in the folding transport direction that becomes an envelope folded by the folding mechanism.

5. A sheet processing apparatus as described in claim 4, characterized in that when transporting the envelope sheet wrapped around the insert sheet, the flap folding mechanism performs a folding and gluing process on the flap portion, and the bag making mechanism performs the pressure binding process on the envelope sheet.

6. A sheet processing apparatus according to claim 5, characterized in that it has a first discharge mode in which the flap folding mechanism performs a folding and gluing process on the flap portion, and a second discharge mode in which the flap folding mechanism does not perform a folding and gluing process on the flap portion.

7. An image forming system comprising: an image forming unit that forms an image on a sheet; a folding mechanism that folds the sheet on which the image has been formed by the image forming unit; a bag making mechanism that forms a bag from the sheets by a pressure binding process in which the overlapping portions of the sheets folded by the folding mechanism are clamped together with a pair of pressure teeth to entangle the fibers of the sheets and bind them together; an insertion mechanism that inserts an enclosed sheet so that it is sandwiched inside the sheets folded by the folding mechanism; and a discharge mechanism that discharges the envelope that has been formed by the bag making mechanism and into which the enclosed sheet has been inserted by the insertion mechanism.

8. An image forming system as described in claim 7, comprising an input unit capable of inputting a first folding mode in which, when a sheet is folded, the folded sheet is discharged, and a second folding mode in which an envelope sheet to be made into an envelope and an enclosed sheet to be contained in the envelope are folded and the enclosed sheet is stored in the envelope sheet.

9. An image forming system as described in claim 8, further comprising a setting means for setting the sheet sizes of the enclosed sheet and the envelope sheet, wherein the setting means prevents the setting of a sheet whose width direction length is shorter than the width direction length of the enclosed sheet when setting the sheet size of the envelope sheet.

Images