JP7530820B2 - Sheet processing apparatus and image forming system - Google Patents

Description

The present invention relates to a sheet processing device for folding sheets sent from an image forming device, for example, and an image forming system equipped with the same.

Conventionally, sheet processing devices have been provided that fold a stack of sheets into a booklet as post-processing for sheets discharged from image forming devices such as copiers, printers, facsimiles, and combination devices of these. For example, a sheet processing device is known that folds a specific position of a sheet conveyed from an image forming device to a sheet stacker with a butting plate, pushes the sheet into the nip between a pair of folding rollers, and folds the sheet in half as it is conveyed by the pair of folding rollers.

Among sheet processing devices that perform folding processes on sheets, there are some that not only fold in half, but also fold the sheet in two different places and perform an inner triple fold process in which one edge of the sheet is on the inside of the folded sheet.

When performing the above-mentioned inner triple fold process, when the abutment pushes the sheet into the nip between the pair of folding rollers for the second fold process, the edge of the sheet that was folded in half in the first fold process may curl up.

To prevent this, a configuration has been proposed in which a curl prevention member having a shape that follows the outer diameter of the folding roller is integrally provided on the abutment plate, and when the sheet is poked with the abutment plate to perform the second folding process, the curl prevention member guides the edge of the sheet to be folded into the nip portion, thereby preventing the edge from curling (Patent Document 1).

Patent Publication 2012-056674

However, in the configuration of Patent Document 1, when the abutment plate protrudes near the nip between the pair of folding rollers, it is necessary to ensure a distance between the tip of the abutment plate and the curl-up prevention member so that it does not come into contact with the outer circumference of the folding roller. This distance becomes longer as the diameter of the folding roller increases.

If the distance between the tip of the abutment plate and the curl prevention member becomes long, the timing at which the curl prevention member guides the edge of the sheet to be folded when the abutment plate begins to push the sheet will be delayed. This can result in loss of sheet transport until the curl prevention member comes into contact with the edge of the sheet to be folded, which can cause the sheet to crease.

The present invention has been made in consideration of the above problems, and its purpose is to provide a sheet processing device and an image forming system equipped with the same that can accurately guide the edge of a sheet to a nip portion when performing multiple folding processes.

A typical configuration according to the present invention for achieving the above object is a sheet processing apparatus that performs a first folding process on a sheet, and then performs a second folding process at a position different from the crease formed by the first folding process, so that one end of the sheet folded by the first folding process is on the inside of the folded sheet, the sheet processing apparatus includes a conveying path having a guide surface that guides a sheet conveyed in a predetermined conveying direction, a pair of rotating bodies that clamp the sheet conveyed to the conveying path in a nip portion and rotate to pull in the sheet and perform a folding process, a pushing member that pushes the sheet into the nip portion of the pair of rotating bodies, and when the pushing member pushes the sheet into the nip portion when performing the second folding process, The folding device includes a protruding guide member having a guide portion that pushes the one end of the sheet folded by the first folding process so as to approach the pair of rotating bodies, a moving means that moves the protruding member and the protruding guide member in a protruding direction that protrudes toward the nip portion and a return direction that is the opposite direction, and an angle changing means that changes the angle of the guide portion in conjunction with the movement of the protruding guide member, the protruding guide member is configured to be rotatable by a rotating shaft provided at one end of the guide portion that is closer to the protruding member, and the angle changing means rotates the other end of the guide portion so as to approach the movement trajectory of the rotating shaft when the protruding guide member moves in the protruding direction.

The present invention also relates to a sheet processing apparatus that performs a first folding process on a sheet, and then performs a second folding process at a position different from the crease formed by the first folding process, so that one end of the sheet folded by the first folding process is on the inside of the folded sheet. The sheet processing apparatus includes a conveying path having a guide surface that guides a sheet conveyed in a predetermined conveying direction, a pair of rotating bodies that clamp the sheet conveyed to the conveying path in a nip portion and rotate to pull in the sheet and perform a folding process, a pushing member that pushes the sheet into the nip portion of the pair of rotating bodies, and a pushing member that pushes the sheet into the nip portion of the pair of rotating bodies when performing the second folding process. The apparatus includes a protruding guide member having a guide portion that pushes the one end of the sheet folded by the first folding process toward the pair of rotating bodies when protruding, a moving means that moves the protruding member and the protruding guide member in a protruding direction toward the nip portion and a return direction that is the opposite direction, and an angle changing means that changes the angle of the guide portion in conjunction with the movement of the protruding guide member, and the angle changing means changes the angle of the guide portion so that the portion of the guide portion farther from the protruding member is tilted toward the upstream side of the protruding direction when the protruding guide member moves in the protruding direction.

In the present invention, when the sheet is pushed out by the pushing member for folding, the guide portion of the pushing guide member guides the sheet edge to prevent it from curling up, and further, the angle of the guide portion relative to the pushing direction decreases in conjunction with the pushing out of the pushing guide member, so that the sheet edge can be guided close to the nip portion of the pair of rotating bodies that performs the folding process. This allows the sheet to be pushed out into the nip portion and the sheet edge to be guided accurately.

1 is an explanatory diagram of an overall configuration of an image forming system according to an embodiment of the present invention. FIG. 1 is an explanatory diagram of an overall configuration of a sheet processing apparatus in an image forming system. FIG. 2 is a cross-sectional view showing a folding processing device of the sheet processing device. FIG. 4A and 4B are cross-sectional views illustrating an inward three-folding operation of a sheet. 4A and 4B are cross-sectional views illustrating an inward three-folding operation of a sheet. 4A and 4B are cross-sectional views illustrating an inward three-folding operation of a sheet. 4A and 4B are cross-sectional views illustrating an inward three-folding operation of a sheet. 4A and 4B are cross-sectional views illustrating an inward three-folding operation of a sheet. 4A and 4B are cross-sectional views illustrating an inward three-folding operation of a sheet. 4A and 4B are cross-sectional views illustrating an inward three-folding operation of a sheet. FIG. 4 is an explanatory diagram of the arrangement of a pair of folding rollers, a folding blade, and a pressing guide member. FIG. (a), (b), and (c) are explanatory diagrams of the operation of the pressing guide member. 5A and 5B are cross-sectional views illustrating the operation of a folding blade and a blade guide member. 5A and 5B are cross-sectional views illustrating the operation of a folding blade and a blade guide member. 5A and 5B are cross-sectional views illustrating the operation of a folding blade and a blade guide member. 5A and 5B are cross-sectional views illustrating the operation of a folding blade and a blade guide member. 5A and 5B are cross-sectional views illustrating the operation of a folding blade and a blade guide member. FIG. 4 is a control block diagram of a folding operation in the sheet folding processing device. 4 is a flowchart of a folding operation in the sheet folding processing device. 4 is a flowchart of a folding operation in the sheet folding processing device. FIG. 5A, 5B, and 5C are top view explanatory diagrams of the operation of the folding blade and the blade guide member. 11A to 11C are cross-sectional explanatory views of the operation of the folding blade and the blade guide member. 11A to 11C are cross-sectional explanatory views of the operation of the folding blade and the blade guide member. 11A to 11C are cross-sectional explanatory views of the operation of the folding blade and the blade guide member. 11A to 11C are cross-sectional explanatory views of the operation of the folding blade and the blade guide member. 11A to 11C are cross-sectional explanatory views of the operation of the folding blade and the blade guide member. 4A and 4B are cross-sectional explanatory views of a deflection guide member. 4A and 4B are cross-sectional explanatory views of a deflection guide member. 4A and 4B are cross-sectional explanatory views of a deflection guide member. FIG.

Next, a sheet processing apparatus according to a preferred embodiment of the present invention and an image forming system equipped with 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 equipped with 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 attached thereto.

<Overall Configuration of 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 paper feed section 2, an image forming section 3, a paper discharge section 4, and a data processing section 5 inside a device housing 1.

The paper feed section 2 is composed of multiple cassette mechanisms 2a, 2b, and 2c that store image formation sheets of different sizes, and feeds sheets of a size specified by a main body control unit (not shown) to a paper feed path 2f. Each cassette mechanism 2a, 2b, and 2c is installed detachably from the paper feed section 2, and each has a built-in separation mechanism that separates the internal sheets one by one, and a paper feed mechanism that feeds the sheets. The paper feed path 2f is provided with a transport roller that feeds the 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 edge of each sheet.

The paper feed 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 such as cardboard sheets, coated sheets, and film sheets that are difficult to separate and feed.

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. What is shown 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 response to 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.

In accordance with the timing of image formation on the photosensitive drum 3a, a sheet is sent from the paper feed path 2f to the image forming unit 3, and the toner image formed on the photosensitive drum 3a is transferred onto the sheet by applying a transfer bias from the transfer charger 3d. The sheet onto which the toner image has been transferred is heated and pressurized as it passes through the fixing device 6 to fix the toner image, and is discharged from the paper discharge port 4b by the paper discharge rollers 4a and transported to the sheet processing device B described below.

Scanner unit A2 includes a platen 7a on which an image document is placed, a carriage 7b that reciprocates along the platen 7a, a photoelectric conversion means 7c, and a reduction optical system 7d that guides the light reflected from the document 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.

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

<Overall Configuration of Sheet Processing Apparatus>
Next, the overall configuration of the sheet processing apparatus B that performs post-processing on the sheets sent from the image forming apparatus A will be described.

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

The sheet processing device B includes a sheet input path 12 that transports a sheet introduced from an input entrance 10, a first discharge path 13a, a second discharge path 13b, and a third discharge path 13c that branch off from the sheet input 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 composed of a flapper guide that changes the transport direction of a sheet transported through the sheet input path 12.

The first path switching means 14a is switched by a driving means (not shown) between a mode in which the sheet from the 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 switched back and transported to the second discharge path 13b by reversing the transport direction.

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

The sheet processing device B includes a first processing device B1, a second processing device B2, and a third processing device B3, each of which performs different post-processing. In addition, a punch unit 15 is disposed in the sheet entrance path 12, which punches holes in the sheets that are entered.

The first processing section B1 is a binding processing section that accumulates, collates, and staples a plurality of sheets discharged from the discharge port 16a at the downstream end of the first discharge path 13a in relation to the conveying direction of the sheets conveyed through the sheet conveying path 12, and discharges the sheets to a stacking tray 16b provided outside the device housing 11. The first processing section B1 also includes a sheet conveying device 16c that conveys a sheet or a sheet stack, and a binding processing unit 16d that staples the sheet stack. At the downstream end of the first discharge path 13a, a pair of discharge rollers 16e is provided for discharging the sheets from the discharge port 16a and for switchback conveying from the first discharge path 13a to the second discharge path 13b.

The second processing section B2 is a folding processing section that forms a sheet bundle from multiple sheets conveyed in a switchback manner from the second discharge path 13b, binds the sheet bundle, and then folds it. As described below, the second processing section B2 includes a folding processing section F that folds the sheets or sheet bundle that have been conveyed, and a binding processing section 17a that is disposed immediately upstream of the folding processing section F along the sheet conveying direction of the sheets conveyed to the second discharge path 13b and binds the sheet bundle. The folded sheet bundle is discharged by discharge rollers 17b to a stacking tray 17c provided outside the device housing 11.

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

Figure 3 shows a schematic diagram of the overall configuration of the second processing section B2. As described above, the second processing section B2 includes a folding processing device F that folds in half the stack of sheets that is fed in from the second discharge path 13b and that has been accumulated and collated, and a binding processing unit 17a that binds the stack of sheets before folding. The binding processing unit 17a shown in the figure is a stapler device that drives staples into the stack of sheets to bind them.

A sheet transport path 20 is connected to the second discharge path 13b to transport sheets to the folding processing device F. In the transport direction of the sheet transported from the second discharge path 13b to the sheet stacking tray 21, a sheet stacking tray 21 that constitutes a part of the sheet transport path is provided downstream of the sheet transport path 20 to position and stack the sheets to be folded. Immediately upstream of the sheet stacking tray 21, a binding processing unit 17a and its staple receiving portion 17d are provided in opposing positions across the sheet transport path 20.

On one side of the sheet stacking tray 21, a pair of folding rollers 22 as a pair of folding rotating bodies are arranged so as to face one surface of the sheet or sheet bundle loaded on the sheet stacking tray. The pair of folding rollers 22 consists of a pair of folding rollers 22a, 22b whose roller surfaces are pressed against each other, and the nip portion 22c, which is the pressing portion, is arranged facing the sheet stacking tray 21. The folding rollers 22a, 22b are arranged in parallel with the sheet stacking tray 21 at approximately equal intervals on the upstream side and the downstream side along the conveying direction of the sheet conveyed from the upper upstream side to the lower downstream side of the sheet stacking tray 21. In addition, in the present invention, the rotating portion of the pair of folding rotating bodies 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.

As shown in FIG. 3, each of the folding rollers 22a, 22b of the pair of folding rollers 22 in this embodiment has a first roller surface 22a2, 22b2 whose roller periphery has a constant radius R1 centered on the rotation axis of the rotation shaft 22a1, 22b1, and a second roller surface 22a3, 22b3 whose distance from the rotation axis of the rotation shaft is smaller than the radius R1 of the first roller surface. The first roller surface 22a2, 22b2 is formed of a rubber material or the like having a relatively high friction coefficient, like a normal roller surface. In contrast, the second roller surface 22a3, 22b3 is formed of a plastic resin material or the like having a smaller friction coefficient than the first roller surface 22a2, 22b2.

The rotation shafts 22a1 and 22b1 of the folding rollers 22a and 22b are rotated by a common drive means such as a drive motor. This allows 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.

A folding blade 23 is disposed on the opposite side of the folding roller pair 22 across the sheet stacking tray 21 as a protruding member. The folding blade 23 is supported by a blade carrier 24 with its tip facing the nip portion 22c of the folding roller pair 22. The blade carrier 24 is provided so that it can travel in a direction that crosses the sheet stacking tray 21 at a substantially right angle by a moving means constituted by a cam member or the like, that is, in a direction that intersects with the conveying direction of the sheet conveyed from the second discharge path 13b to the sheet stacking tray 21.

Cam members 25 (only one of which is shown in the figure) are made up of a pair of mirror-symmetric eccentric cams, and are provided on both sides of the blade carrier 24 in the front-to-rear direction in FIG. 3, i.e., in the axial direction of the folding rollers. The cam members 25 rotate around a rotation shaft 25a provided at the eccentric position by a driving means such as a drive motor. The cam member 25 has a cam groove 25b formed along its outer periphery.

The blade carrier 24 is provided with a cam pin 24c that acts as a cam follower and slides freely into the cam groove 25b.

When the drive motor rotates the cam member 25, the blade carrier 24 travels back and forth in a direction approaching or receding from the sheet stacking tray 21. As a result, as shown in FIG. 3, the folding blade 23 can be moved back and forth in a straight line along a protruding path connecting an initial position where the tip of the folding blade 23 does not enter the sheet transport path formed by the sheet stacking tray 21 and a maximum protruding position where the tip is sandwiched between the nip portion 22c of the pair of folding rollers 22.

A regulating stopper 26 is disposed at the bottom end of the sheet stacking tray 21 to abut against and regulate the leading edge of the conveyed sheet in the transport direction. The regulating stopper 26 is arranged so that it can be raised and lowered along the sheet stacking tray 21 by a sheet lifting mechanism 27.

The sheet lifting mechanism 27 of this embodiment is a conveyor belt mechanism that is arranged below the blade carrier 24 when the tip of the folding blade 23 is in an initial position behind the sheet stacking tray 21, which is a position where it has not entered the sheet transport path formed by the sheet stacking tray 21, and is composed of a pair of pulleys 27a, 27b arranged near the upper and lower ends along the sheet stacking tray 21, and a transmission belt 27c wound around both pulleys. The regulating stopper 26 is fixed on the transmission belt 27c. By rotating the drive side pulley 27a or 27b by a driving means such as a driving 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 a sheet or a sheet stack along the sheet stacking tray 21.

In addition, the folding processing device F of this embodiment further includes a sheet side alignment mechanism for aligning the side edges of the sheets fed into the sheet stacking tray 21. As shown in FIG. 4, this sheet side alignment mechanism has a pair of sheet side alignment members 28a, 28b arranged symmetrically on both sides of the sheet width direction (direction perpendicular to the sheet conveying direction) of the sheet stacking tray 21. Note that FIG. 4 is a schematic plan view of the folding processing device F seen from above. The sheet side alignment members 28a, 28b are held so that they can move relatively close to and away from each other in the sheet width direction. When a sheet is conveyed to the sheet stacking tray 21 and its leading edge hits the regulating stopper 26, the sheet's widthwise position is aligned by moving the sheet side alignment members 28a, 28b.

<Inner triple folding process>
The sheet processing device B of this embodiment is capable of folding a sheet in three after it has been conveyed to the sheet stacking tray 21, which serves as the sheet conveying path, by the folding device F. The folding in three is a process in which a sheet is folded in two by a first folding process, and then the sheet is folded a second time at a position different from the first folding position, so that one end of the sheet folded in the first folding process is folded inside the sheet folded in the second folding process, thereby folding the sheet in three. Here, the outline of the operation of the folding device F of this embodiment when folding in three will be described with reference to Figs. 5 to 11. Figs. 5 to 11 are schematic cross-sectional views showing the movement of each part along the flow of the sheet S when folding in three is performed.

The sheet stacking tray 21 of this embodiment is formed at an angle to the vertical direction, and the sheet S is conveyed so that it falls with the sheet leading edge S1 at the bottom and the sheet trailing edge S2 at the top while being guided by the guide surface 21a that forms the sheet stacking tray 21 on one side, and the sheet leading edge hits the regulating stopper 26 and stops (FIG. 5(a)). At this time, the position of the regulating stopper 26 is arranged so that the first folding position of the sheet S against which the sheet leading edge S1 hits is a position facing the folding blade 23. The folding blade 23 is arranged at a position that pushes the sheet S from the guide surface 21a side of the sheet stacking tray 21 toward the folding roller pair 22. In other words, the guide surface 21a of the sheet stacking tray 21 and the folding roller pair 22 are arranged at corresponding positions with the sheet S sandwiched therebetween.

In this state, the sheet side alignment members 28a and 28b align the sheet widthwise position, and then the folding blade 23 is operated to fold the sheet S in half and push the folded portion into the nip portion 22c of the folding roller pair 22 (FIG. 5B). In synchronization with the pushing operation of the folding blade 23, the folding roller pair 22 and the discharge roller 17b are driven in the forward direction to pull the sheet S into the folding roller pair 22 and the discharge roller 17b. As a result, the sheet S is pressed by the nip portion of the folding roller pair 22, and the first folding process is performed (FIG. 6A).

Next, in order to perform the second folding process, the sheet conveyance is stopped when the rear end S2 of the sheet after the first folding process reaches a predetermined position (FIG. 6(b)), and the pair of folding rollers 22 and the discharge roller 17b are driven in the reverse direction to perform the switchback conveyance process. The rear end S2 of the sheet becomes the end (hereinafter referred to as the "folded end") that is folded inside the sheet folded by the second folding process when the sheet is folded in three. Then, when performing the switchback conveyance process, the folded end S2 is pushed down (toward the sheet stacking tray 21 where the sheet tip S1 is located) by the L-shaped pressing guide member 30 (FIG. 7(a)), and the pressing guide member 30 guides the sheet S conveyed in the direction where the regulating stopper 26 of the sheet stacking tray 21 is located again (FIG. 7(b)). The configuration and operation of this pressing guide member 30 will be described in detail later.

When the leading edge of the sheet S reaches the regulating stopper 26, which has been moved to the sheet receiving position in advance by the switchback transport (FIG. 8(a)), the pressing guide member 30 is returned to the retracted position and then moved to the reverse transport guide position (FIG. 8(b)), and the regulating stopper 26 is moved to a position where the second folding position faces the folding blade 23 (FIG. 9(a)). After the movement is completed, the pressing guide member 30 is moved to a guide position parallel to the guide surface 21a of the sheet stacking tray 21 (FIG. 9(b)).

Next, the folding blade 23 is operated again to push the sheet S into the nip portion 22c of the pair of folding rollers 22 (FIG. 10(a)). At this time, the blade guide member 40, which is a push-out guide member arranged above the folding blade 23, protrudes to guide the folded end S2 of the sheet so that it is pushed into the nip portion 22c (FIG. 10(b)). The configuration and operation of this blade guide member 40 will be described in detail later.

The sheet S is sent to the pair of folding rollers 22 by the protrusion of the folding blade 23, and is folded a second time by passing through the nip portion 22c (Figure 11(a)), and the sheet S folded in three is discharged by the discharge rollers 17b (Figure 11(b)).

<Pressing guide member>
Next, the pressing guide member 30, which is the pressing member, will be described with reference to Figs. 12 to 14. Fig. 12 is a perspective view of the folding processing device F with the pressing guide member 30 exposed, and Fig. 13 is a diagram showing the rotation trajectory of the pressing guide member 30 and its relationship with other members. Fig. 14 is an explanatory diagram of the operation of the pressing guide member 30.

(Shape of the pressing guide member)
The pressing guide member 30 presses the folded end S2 of the sheet downward when the sheet on which the first folding process has been performed is switched back and conveyed, and guides the sheet so as to be conveyed to the sheet stacking tray 21. In other words, the pressing guide member 30 is also a direction changing member that changes the orientation of the folded end S2 of the sheet to the direction of the sheet tip S1 of the sheet stacking tray 21 when the sheet on which the first folding process has been performed is switched back and conveyed.

As shown in FIG. 12 (and FIG. 4), the pressing guide members 30 are arranged on the side opposite the folding roller pair 22, sandwiching the sheet S guided by the guide surface 21a of the sheet stacking tray 21. In this embodiment, three pressing guide members 30 are attached to a rotating shaft 31, which is a support member arranged in the sheet width direction, at approximately equal intervals. The two on both sides are positioned so that they can abut against both ends of the sheet S being transported on the sheet stacking tray 21, and the central one is positioned so that it can abut against the approximately center in the width direction of the sheet being transported.

The pressing guide member 30 can be moved by a moving means. In this embodiment, the rotating shaft 31 is connected to the pressing guide motor 33 via a drive transmission member 32 such as a drive belt, and the rotating shaft 31 rotates when driven by the pressing guide motor 33, and the three pressing guide members 30 are configured to rotate integrally with the rotating shaft 31.

As shown in FIG. 13, the pressing guide member 30 has a rotating portion 30a that can rotate around a rotating shaft 31, and a guide portion 30b that serves as a first guide surface that guides the sheet S being conveyed in a switchback manner, and is composed of a member with an L-shaped cross section in which the guide portion 30b is connected to the rotating portion 30a at a substantially right angle. The corner of the L-shape between the rotating portion 30a and the guide portion 30b, i.e., the tip of the rotating portion 30a, is formed as a pressing portion 30c that presses the sheet S.

The pressing guide member 30 is provided so as to be exposed from a notch formed in the guide surface 21a. When the sheet S is transported to the sheet stacking tray 21, the pressing guide member 30 is retracted to a retracted position (see FIG. 5A). When in this retracted position, the rotating portion 30a is provided so as to be substantially flush with the guide surface 21a. Therefore, the rotating portion 30a functions as part of the guide surface 21a and acts as a guide surface (second guide surface) that guides the sheet transported to the sheet stacking tray 21. When the pressing guide member 30 is in the retracted position, it is sufficient that the guide portion 30b does not protrude from the guide surface 21a, so that the storage space for the pressing guide member 30 in the retracted state can be reduced.

(Position of rotation center)
13, the rotation shaft 31 which is the rotation center of the pressing guide member 30 of this embodiment is disposed upstream of the nip line L1 connecting the nip portion 22c of the folding roller pair 22 and the tip of the folding blade 23 in the conveying direction in which the sheet S is carried into the sheet stacking tray 21, and is disposed on the opposite side to the side on which the folding roller pair 22 is disposed across the guide surface 21a of the sheet stacking tray 21. Furthermore, the rotation shaft 31 of this embodiment passes through the rotation shaft 22a1 of the folding roller 22a, which is disposed upstream of the nip line L1 in the sheet conveying direction among the folding rollers 22a and 22b, i.e., the folding roller 22a which is closer to the rotation shaft 31, and is disposed downstream of the axis L2 parallel to the nip line L1 in the conveying direction.

The rotating portion 30a is set to rotate in a direction in which the pressing portion 30c presses the sheet S toward the side where it is to be switched back and transported.

Therefore, when the sheet S on which the first folding process has been performed is conveyed in a switchback manner, as shown in FIG. 14(a), the pressing guide member 30 in the retreated position rotates, and as shown in FIG. 14(b), the pressing portion 30c presses the folded end S2 of the sheet downward from above the folded end S2. As a result, the folded end S2 is guided to the downstream side (downward) of the sheet conveying direction in which the sheet S was received on the sheet stacking tray 21 before the first folding process of the sheet stacking tray 21 while being conveyed in a switchback manner. In other words, the pressing portion 30c changes the orientation of the folded end S2 of the sheet to the direction of the sheet tip S1 of the sheet stacking tray 21. After changing the orientation of the folded end S2, the pressing guide member 30 remains in that position, thereby being able to guide the folded end S2 to the downstream side of the sheet conveying direction in which the sheet S was received on the sheet stacking tray 21 before the first folding process.

Furthermore, as shown in FIG. 14(c), when the pressing portion 30c rotates to the guide position where it is positioned on the guide surface 21a, the pressing portion 30c abuts against the sheet and then presses down so as to pull the folded end S2 of the sheet from the nip portion 22c side toward the guide surface 21a side, and guides the sheet in the direction in which the regulating stopper 26 of the sheet stacking tray 21 is located. Therefore, even if the folded end S2 of the sheet is curled upward, the sheet will not proceed upward on the sheet stacking tray 21, but will be reliably transported downward.

(Rotation area of the rotating part)
The length of the rotating portion 30a of the pressing guide member 30 in this embodiment, i.e., the length from the rotating shaft 31, which is the rotation fulcrum, to the pressing portion 30c, is set to be longer than the shortest distance to the first roller surface 22a2 of the folding roller 22a closer to the rotating shaft 31 of the two folding rollers 22a, 22b, as shown in Figure 13, and shorter than the shortest distance to the second roller surface 22a3.

As described above, even if the length of the rotating portion 30a is set longer than the shortest distance to the first roller surface 22a2, the folding roller pair 22 stops so that the second roller surfaces 22a3, 22b3 face the rotating portion 30a when the sheet switches back, so that the rotating portion 30a does not interfere with the folding roller pair 22 even when it is rotated. Furthermore, because the rotating portion 30a can be set longer than the shortest distance to the first roller surface 22a2, which is the large diameter portion of the folding roller 22a, the pressing portion 30c presses the sheet being switched back at a position closer to the nip portion 22c, so that the sheet is more reliably guided to the sheet stacking tray 21.

When the rotating portion 30a is lengthened, the rotating shaft 31 must be positioned away from the folding blade 23 in the sheet conveying direction to prevent the rotated pressing guide member 30 from interfering with the folding blade 23. As a result, the rotating shaft 31 must also be positioned away from the pair of folding rollers 22. In this regard, in this embodiment, as described above, the rotating shaft 31 is configured to be positioned between the nip line L1 and the rotation axis L2 in the sheet conveying direction, so that the position where the pressing portion 30c presses the sheet being switched back and conveyed can be brought closer to the nip portion 22c without unnecessarily lengthening the length of the rotating portion 30a.

Here, in addition to using different diameter rollers having first roller surfaces 22a2, 22b2 and second roller surfaces 22a3, 22b3 with different diameters as in this embodiment, it is also possible to use a pair of rollers with a constant roller diameter, but in that case, the length of the rotating part 30a needs to be shorter than the shortest distance to the outer periphery of the folding roller closer to the rotating axis.

In addition, as shown in FIG. 13, the pressing guide member 30 of this embodiment has a shape in which the guide portion 30b is inside the rotation trajectory L3 of the rotating portion 30a and does not protrude outside that area. This means that even if the rotating portion 30a, which is configured to be long as described above, is rotated, the guide portion 30b will not interfere with the folding roller pair 22.

When the sheet that has been folded the first time as described above is transported in a switchback manner, it is returned to the sheet stacking tray 21 while being guided by the pressure guide member 30. After the sheet abuts against the regulating stopper 26 and the switchback transport is completed, the pressure guide member 30 is returned to the retracted position. At this time, the rotating portion 30a, which serves as the second guide surface of the pressure guide member 30, moves the sheet stacking tray 21 to a reverse transport guide position that protrudes slightly toward the sheet transport path from the guide surface 21a so as to guide the sheet S transported in the reverse direction (see FIG. 8(b)).

After the pressure guide member 30 moves to the reverse transport guide position, the regulating stopper 26 is raised to reverse transport the sheet so that the second folding position faces the folding blade 23. At this time, the sheet S is guided by the rotating portion 30a of the pressure guide member 30, so it is transported without getting caught in the notches for attaching the pressure guide member formed on the guide surface 21a (see FIG. 9(a)).

<Blade guide member>
After the second folding position of the sheet conveyed in the switchback manner as described above moves to a position facing the folding blade 23, the pressing guide member 30 is moved to the retracted position and the folding blade 23 is operated to perform the second folding operation. At this time, the blade guide member 40 provided above the folding blade 23 is configured to guide the folded end S2 of the sheet (see FIG. 10(b)).

Next, the configuration and operation of the blade guide member 40 will be specifically described with reference to Figures 15 to 19. Note that Figure 15 is an explanatory diagram of the rotation of the blade guide member 40, and Figures 16 to 19 are diagrams showing the operation of the folding blade 23 and the blade guide member 40 when performing a second folding process on the sheet.

(Configuration of Blade Guide Member)
When the second folding process is performed on the sheet S, the blade guide member 40 moves in the protruding direction of the folding blade 23 to guide the sheet end on the crease side formed by the first folding process, i.e., the folded end S2 of the sheet, in the protruding direction relative to the folding blade 23 to the nip portion 22c of the pair of folding rollers 22. For this purpose, as shown in FIG. 15, the blade guide member 40 has an abutment portion 40a that abuts against the rear end of the sheet, and a fitting hole portion 40b with a partial cutout is formed at one end of the abutment portion 40a, and this fitting hole portion 40b is rotatably fitted into a shaft portion 40f formed in the base portion 40e. In addition, an arm portion 40c is integrally provided at the other end of the abutment portion 40a, and an engagement protrusion portion 40d is formed at the end of this arm portion 40c. The engagement protrusion portion 40d is slidably engaged with a long hole 50 formed in the frame of the sheet processing device B. The long hole 50 is formed in the vicinity of the upper part of the blade carrier 24 and generally parallel to the guide surface 21 a of the sheet stacking tray 21 .

The base portion 40e is attached to the blade carrier 24 so that it can slide in a direction parallel to the movement direction of the blade carrier 24. A tension spring 51 is attached between the locking portion 40e1 formed on the base portion 40e and the locking portion 24a formed on the blade carrier 24.

The blade carrier 24 is provided with a pressing protrusion 24b that can come into contact with and press the base portion 40e. This pressing protrusion 24b is provided rotatably on the blade carrier 24 and is biased counterclockwise in FIG. 15 by a coil spring 52 attached to the rotation shaft. As a result, when the blade carrier 24 moves in the blade protruding direction, the pressing protrusion 24b comes into contact with the base portion 40e and presses the base portion 40e, and the blade guide member 40 moves integrally with the blade carrier 24. The coil spring 52 provided on the pressing protrusion 24b acts as a so-called torque limiter, and when a clockwise force of a predetermined value or more is applied to the pressing protrusion 24b, it rotates clockwise.

(Angle change of the contact part relative to the moving direction of the folding blade)
In the above configuration, as shown in Fig. 15(a), when the blade carrier 24 is in the home position, the blade guide member 40 is pulled by the tension spring 51 and is in a position where the abutment portion 40a abuts against the rotation shaft 31 which serves as the rotation fulcrum of the pressing guide member 30. This state is the home position of the blade guide member 40. At this time, the abutment portion 40a stands up so as to be substantially flush with the guide surface 21a. When the blade carrier 24 moves from the home position in the blade protruding direction, the blade guide member 40 is pressed by the pressing protrusion 24b and moves together with the blade carrier 24, and moves until the abutment portion 40e2 formed in an upright position at the rear end of the base portion 40e abuts against the rotation shaft 31, as shown in Fig. 15(b).

As described above, when the blade guide member 40 moves in the blade protruding direction, the engaging protrusion 40d slides downward while being guided by the long hole 50, and the abutment portion 40a rotates around the shaft portion 40f. The shaft portion 40f is provided at one end of the abutment portion 40a closer to the folding blade 23. This one end refers to the area between the center of the abutment portion 40a and the end closer to the folding blade 23. In other words, the shaft portion 40f is provided in any area on the folding blade 23 side from the center of the abutment portion 40a. Therefore, when the blade guide member 40 is in the home position as shown in FIG. 15(a), the abutment portion 40a is at an angle of approximately right angles to the movement direction of the blade carrier 24, i.e., the movement direction of the folding blade 23, and is in an upright state. As the blade carrier 24 moves in the direction in which the folding blade 23 is protruding, as shown in FIG. 15(b), the other end of the abutment 40a moves closer to the path of the axis 40f, which is the center of rotation, i.e., it rotates so as to fall toward the upstream side of the protruding direction of the folding blade 23, and the angle of the abutment 40a with respect to the moving direction of the blade carrier 24 changes to an acute angle (the angle on the upstream side of the protruding direction becomes smaller) as the blade carrier 24 moves. As described above, one end of the abutment 40a is configured to be rotatable around the axis, and the end of the arm 40c, which is provided by extending the other end of the abutment 40a, is configured to be slidable along the long hole 50, so that the blade guide member 40 can change its angle with respect to the moving direction in conjunction with the movement of the blade guide member 40 without providing a special driving means.

As shown in FIG. 15(a), a protrusion 40f1 is formed on the shaft 40f, which serves as the rotation axis of the abutment portion 40a. On the other hand, the notch formed in the fitting hole 40b that fits with the shaft 40f is formed wider than the width of the protrusion 40f1, and the blade guide member 40 can rotate within the range of the notch.

In the above configuration, when the blade carrier 24 moves to the home position, the base portion 40e is pulled by the tension spring 51, and at this time the cutout surface of the fitting hole portion 40b abuts against the protrusion 40f1, restricting further rotation of the abutment portion 40a. Therefore, with the abutment portion 40a abutting against the rotation shaft 31, further movement of the blade guide member 40 is restricted, and the abutment portion 40a maintains an upright state at the home position.

In addition, in the blade guide member 40 of this embodiment, the abutment portion 40a and the arm portion 40c are composed of linear members when viewed in cross section, and the arm portion 40c is formed at a predetermined angle with respect to the abutment portion 40a. As a result, even if the abutment portion 40a is configured to be approximately flush with the guide surface 21a when the blade guide member 40 is in the home position, the end portion on the side where the engagement protrusion 40d of the arm portion 40c is provided is located away from the guide surface 21a on the opposite side to the side where the folding roller pair 22 is located. In other words, it is located on the side of the guide surface 21a in the direction of returning the folding blade 23 from the nip portion 22c side to the home position. Therefore, the long hole 50 with which the engagement protrusion 40d engages can be located away from the guide surface 21a on the opposite side to the side where the folding roller pair 22 is located, and can be located in a position that does not interfere with the guide surface 21a. Therefore, when the blade guide member 40 is in the home position, the contact portion 40a can be configured to function as a guide portion for the sheets being transported through the sheet stack tray 21.

(Operation of the folding blade and blade guide member)
Next, the operation of the blade guide member 40 when the folding blade 23 is operated to perform a second folding operation on the sheet will be described with reference to FIGS.

Figure 16 (a) shows the blade carrier 24 in the home position, and the blade guide member 40 is also in the home position at this time. In the following explanation, the direction in which the blade carrier 24 protrudes the folding blade 23 from the home position into the nip portion 22c of the pair of folding rollers 22 is referred to as the "protruding direction," and the direction in which the blade carrier 24 returns the folding blade 23 from the nip portion 22c side to the home position is referred to as the "returning direction."

When in the home position, the tip of the folding blade 23 is approximately flush with the guide surface 21a or is on the return direction side of the guide surface 21a (first position) and is separated from the sheet S on the sheet stacking tray 21. Therefore, the sheet guided by the guide surface 21a and transported to the sheet stacking tray 21 does not get caught on the tip of the blade. Even if the tip of the folding blade 23 protrudes toward the folding roller 22 side from the guide surface 21a, if the sheet transported to the sheet stacking tray 21 by another guide member does not get caught on the tip of the blade, it can be said that the tip of the blade is retracted from the sheet transport path, and this state may be the first position. Also, when the blade guide member 40 is in the home position, the abutment portion 40a of the blade guide member 40 is in a position abutting the pivot shaft 31. At this time, the pressing protrusion 24b is separated from the base portion 40e.

Next, to protrude the folding blade 23, the cam drive motor is driven, causing the cam member 25 to rotate and move the blade carrier 24 in the protruding direction. Then, the pressing protrusion 24b comes into contact with the base portion 40e, and the blade guide member 40 moves in the protruding direction together with the blade carrier 24 and the folding blade 23 (Figure 16 (b)). At this time, the tip of the folding blade 23 is configured to protrude in the protruding direction further than the tip of the blade guide member 40.

When the blade carrier 24 moves further in the protruding direction, the tip of the folding blade protrudes a predetermined amount, and as shown in FIG. 17(a), the first folding process is performed, the second folding position faces the folding blade 23, and the tip of the folding blade 23 abuts against the sheet S stopped in the sheet stacking tray 21 (second position). At this time, as described above, since the tip of the folding blade 23 protrudes in the protruding direction further than the blade guide member 40, the folding blade 23 abuts against the folding position of the sheet S before the blade guide member 40. Therefore, due to the protrusion of the folding blade 23, the tip of the folding blade facing the folding position of the sheet abuts accurately without shifting from the folding position of the sheet, and the folding process is performed at the correct folding position.

The tip of the folding blade does not necessarily have to protrude beyond the blade guide member 40. As long as it is in the same position as the blade guide member 40 in the protruding direction, it is possible to prevent the tip of the blade from shifting when it comes into contact with the folding position of the sheet.

When the blade carrier 24 moves in the protruding direction in the above state, the folding blade 23 protrudes the second folding position of the sheet S toward the nip portion 22c of the pair of folding rollers 22. At the same time, the contact portion 40a of the blade guide member 40 contacts the folded end portion S2 of the sheet that has been folded once, and guides the folded end portion S2 so as to push it toward the nip portion 22c (Figure 17(b)).

As described above, the blade guide member 40 guides the folded end S2 of the sheet to the nip portion 22c, so that the folded end S2 of the sheet moves toward the nip portion 22c without turning over. In addition, when the protruding blade guide member 40 approaches the nip portion 22c, there is a risk that it may interfere with the outer circumference of the folding rollers 22a and 22b. At this time, as described above, the blade guide member 40 of this embodiment moves in the protruding direction, and the angle of the abutment portion 40a with respect to the protruding direction changes to an acute angle (changing from the state in FIG. 17(a) to the state in FIG. 17(b)). Therefore, the abutment portion 40a can enter closer to the nip portion 22c, and the folded end S2 of the sheet can be reliably guided to the nip portion.

When the blade carrier 24 moves further in the protruding direction and the abutment portion 40e2 abuts against the pivot shaft 31 as shown in FIG. 17(b), the blade guide member 40 is restricted from moving further in the protruding direction. When the blade guide member 40 moves to the furthest protruding direction, the tip of the blade guide member 40 (the end on the folding roller pair 22 side in the protruding direction) protrudes toward the nip portion 22c from the tangent line (of the two folding rollers 22a and 22b) connecting the outer circumference of the folding roller 22a and the folding roller 22b on the sheet stacking tray 21 side. On the other hand, when the blade carrier 24 is pushed out in the protruding direction by the rotation of the cam member 25, as shown in FIG. 18(a), the pressing protrusion 24b rotates clockwise against the biasing force of the coil spring 52 because a certain amount of force or more is applied to the coil spring 52, and it slides into the lower part of the base portion 40e. As a result, the pressing protrusion 24b no longer presses the blade guide member 40, and the blade guide member 40 remains stationary, and only the folding blade 23 moves in the protruding direction, moving to a position (third position) where the blade tip protrudes to the maximum and protrudes the sheet S into the nip portion 22c. At this time, the tip of the folding blade 23 protrudes farther than the tip of the abutting portion 40a of the blade guide member 40. That is, the distance from the blade tip to the abutting portion tip in the third position is greater than the distance from the blade tip to the abutting portion tip in the second position. As a result, the sheet is reliably drawn into the nip portion 22c of the pair of folding rollers 22 that rotates in a state where it is folded at the second folding position, and the sheet tip S1 is also drawn into the nip portion 22c to be folded in three.

When the folding blade 23 is protruding the sheet, that is, when the tip of the folding blade is moving from the second position to the third position, if a large load is applied to the blade guide member 40 in the return direction, for example, when folding multiple sheets stacked together and the sheets have high rigidity, a large load is applied to the blade guide member 40 during folding. In this case, when a certain load or more is applied, the blade guide member 40 can move in the return direction relative to the folding blade 23 against the frictional force with the pressing protrusion 24b, which is pressed against the bottom surface of the base portion 40e by the biasing force of the coil spring 52. This prevents the blade guide member 40 from being damaged when a large load is applied to the blade guide member 40 during folding of the sheet.

When the cam member 25 rotates further after the tip of the folding blade reaches the third position, the blade carrier 24 moves in the return direction together with the folding blade 23 (Figure 18 (b)). At this time, as described above, the pressing protrusion 24b is pressed against the base portion 40e of the blade guide member 40 by the biasing force of the coil spring 52, so that the frictional force between the pressing protrusion 24b and the bottom surface of the base portion 40e causes the blade guide member 40 to move in the return direction together with the blade carrier 24, i.e., simultaneously with the folding blade 23.

When the cam member 25 rotates further and the blade carrier 24 moves in the return direction, the abutment portion 40a of the blade guide member 40 abuts against the pivot shaft 31, and the blade guide member 40 returns to the home position. The blade guide member 40 is then restricted from moving further in the return direction (Figure 19(a)). When the cam member 25 rotates further, the blade guide member 40 does not move, and only the folding blade 23 moves in the return direction and returns to the home position (Figure 19(b)).

As described above, when the blade carrier 24 moves in the return direction, the folding blade 23 and the blade guide member 40 simultaneously move in the return direction, and the blade guide member 40 returns to its home position before the blade carrier 24 and the folding blade 23 return to their home positions. In other words, the blade guide member 40 retreats from the sheet drawn in by the folding roller pair 22 and the discharge roller 17b earlier than the folding blade 23. This reduces the transport load of the sheet S drawn in by the discharge roller 17b, etc., caused by the blade guide member 40.

(Arrangement Relationship Between Blade Guide Member and Pressing Guide Member)
In this embodiment, as shown in Fig. 4, which is a schematic plan view of the folding processing device F, two blade guide members 40 are arranged at predetermined positions in the sheet width direction. The folding blade 23 in this embodiment has six protruding tips 23a formed at approximately equal intervals in the sheet width direction on the protruding side. When the protruding tips 23a protrude the sheet, the sheet is protruded into the nip portion 22c of the folding roller pair 22, and folding processing is performed. The blade guide member 40 is arranged above the protruding tip 23a1 of the six protruding tips 23a, that is, on the upstream side in the conveying direction of the sheet conveyed to the sheet stacking tray 21. Therefore, the folding end S2 of the sheet S protruded by the folding blade 23 is guided by the blade guide members 40 on both sides in the width direction.

In order to guide the folded end S2 of the sheet to the nip portion 22c, it is desirable to place the blade guide member 40 above all six of the thrust tips 23a (23a1), but placing them at all of them would increase the number of parts. In contrast, in this embodiment, as described above, the blade guide member 40 is placed at the positions of the two thrust tips 23a1 formed on both ends of the sheet width direction, so the number of parts can be reduced. Furthermore, the folded end S2 of the sheet pushed out by the folding blade 23 during the second folding process is more likely to curl up near the ends than the center in the sheet width direction, so by guiding this portion toward the nip portion with the blade guide member 40, the curling can be effectively prevented.

The two blade guide members 40 are positioned above the protruding tip 23a1, which is formed slightly toward the center rather than at either end in the sheet width direction of the smallest width sheet that can be transported to the sheet stacking tray 21. This is because, when protruding a sheet with the protruding tip 23a, it is more effective to protrude the sheet slightly toward the center rather than at the ends in the sheet width direction, and the blade guide members 40 are positioned to correspond to the position of the protruding tip 23a1.

The pressing guide member 30 of this embodiment is disposed outside the two blade guide members 40 in the sheet width direction relative to the position of the blade guide member 40. Specifically, the two pressing guide members 30 are disposed at intervals approximately equal to the width of the smallest size sheet that can be processed by the folding processing device F, and are disposed at positions where they can press and guide both ends of the sheet width direction when folding the smallest size sheet. In this embodiment, in addition to the two pressing guide members 30 that can press and guide both ends of the sheet, a pressing guide member 30 that can press and guide the center of the sheet width direction is provided, for a total of three pressing guide members 30. More specifically, the smallest size sheet that can be processed by the folding processing device F in this embodiment is A4, and the width of a typical A4 size sheet in the short side direction is 210 mm. The two pressing guide members 30 capable of pressing and guiding both ends of the sheet in the width direction are formed to a length of 18 mm in the sheet width direction, and the length of a straight line connecting the outer ends of each of the two pressing guide members 30 is 226 mm, which is longer than the width of an A4 size sheet, and the width direction ends of an A4 size sheet extend 10 mm on each side to a part near the center of the width direction of the face of the pressing guide members 30. The maximum size of sheet that can be processed by the folding device F is A3, and the width in the short direction of a typical A3 size sheet is 297 mm. By setting the length of a straight line connecting the outer ends of each of the two pressing guide members 30 capable of pressing and guiding both ends of the sheet in the width direction to be longer than the width of the smallest size sheet, it is possible to provide a guide effect even for the ends of the largest size sheet.

When feeding back the sheet that has undergone the first folding process, as described above, the pressing guide members 30 press the folded end S2 of the sheet to guide it back to the sheet stacking tray 21, and pressing both ends in the sheet width direction to guide it is effective in preventing curling. For this reason, the two pressing guide members 30 are positioned outside the blade guide members 40 in the sheet width direction. In this embodiment, the pressing guide members 30 on both sides in the sheet width direction are positioned at a distance approximately equal to the width of the minimum size sheet, and the blade guide members 40 are positioned further inward, at a distance shorter than the width of the minimum size sheet.

In this embodiment, the poking tip 23a2 is arranged on the outside of each pressing guide member 30. The poking tip 23a2 is intended to prevent wrinkles from occurring in the sheet when a large size sheet is poked in the sheet width direction, and is arranged inside both ends of the maximum size sheet (it is not necessary to provide it in a device that handles only the minimum size sheets described above). In other words, it is desirable to arrange the pressing guide member 30 and the blade guide member 40 according to the minimum size sheet, but if necessary, the poking tip 23a2 may be arranged separately on the outside of the pressing guide member 30. In other words, the blade guide member 40 is arranged inside the two pressing guide members 30 in the sheet width direction, and the poking tip 23a1 is arranged corresponding to the position of the blade guide member 40, and the poking tip 23a2 may be further arranged on the outside of the two pressing guide members 30 according to the sheet size to be handled. In this embodiment, two thrusting tips 23a1 with blade guide members 40 are provided on either side of the center of the sheet S, but it may be configured with one thrusting tip 23a1 and one blade guide member 40.

In addition, if there is a large difference between the minimum and maximum sizes that the device can handle, it is possible to provide a blade guide member 40 corresponding to the minimum size, a thrust tip 23a1 provided with the blade guide member 40, and two pressing guide members 30, and a blade guide member 40 corresponding to the maximum size, a thrust tip 23a2 provided with the blade guide member 40, and two pressing guide members 30.

In this embodiment, the pressing guide member 30 is disposed between the thrusting tip portion 23a1 and the thrusting tip portion 23a2 so that the pressing guide member 30 does not interfere with the thrusting tip portions 23a1 and 23a2 when the pressing guide member 30 moves to the guide position. This allows each component to be disposed in a space-saving manner.

<Drive control>
Next, the control configuration of the drive system when folding a sheet will be described. As shown in the block diagram of Fig. 20, the control unit 60 controls the drive of a folding roller motor 61 which drives and rotates the folding roller pair 22, a discharge roller motor 62 which drives and rotates the discharge roller 17b, and a regulating stopper motor 63 which operates the sheet lifting mechanism 27 for lifting and lowering the regulating stopper 26, in accordance with the procedures of the flowcharts shown in Figs. 21 and 22. Similarly, the control unit 60 also controls the drive of a cam motor 64 which drives a cam member 25 for operating the blade carrier 24, and a pressing guide motor 33 which rotates the pressing guide member 30.

Figures 21 and 22 are flowcharts showing the drive control procedure when a sheet S is transported to the sheet stacking tray 21, the leading edge of the sheet hits the regulating stopper 26 that is stopped at a predetermined position, and the first folding position is in a position opposite the folding blade 23, and then a folding process is performed.

When the folding process is performed, the cam motor 64 is driven to move the blade carrier 24 in the protruding direction, and the folding blade 23 contacts the first folding position of the sheet S and protrudes into the nip portion 22c (S1). At the same time, the folding roller motor 61 and the discharge roller motor 62 are driven to rotate the folding roller pair 22 and the discharge roller 17b in the forward direction (S2). Each of the motors uses a pulse motor, and when the motor is driven, the number of drive pulses is counted.

When the cam member 25 rotates, the folding blade 23 protrudes a predetermined amount to push the first fold of the sheet S into the nip portion 22c of the pair of folding rollers 22, then it reverses its direction of travel and moves back to the home position (S3).

The sheet S protruded into the nip portion 22c of the pair of folding rollers 22 by the protrusion of the folding blade 23 is folded while being sandwiched and transported by the pair of folding rollers 22, and is then transported by the discharge roller 17b, which constitutes the sheet transport means together with the pair of folding rollers 22. When the sheet is sandwiched and transported by the discharge roller 17b (S4), the folding roller motor 61 stops when the second roller surfaces 22a3 and 22b3 of the folding rollers 22a and 22b face each other (S4, S5). As a result, the pair of folding rollers 22 no longer nip the sheet, and the sheet is transported by the discharge roller 17b. At this time, the sheet is transported 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, 22b3 of the pair of folding rollers 22 have come into contact with each other is determined by counting the pulses of the motor, but other configurations are also possible, such as detecting the sheet S with a sensor and controlling the drive of the motor according to the detection results.

When the folded end S2 of the conveyed sheet S reaches a position within a predetermined area (S7), the driving of the discharge roller motor 62 is stopped to stop the sheet conveyance (S8). This predetermined area is the area between the folded end S2 of the sheet and the rotation trajectory L3 of the pressing guide member 30 and the guide surface 21a of the sheet stacking tray 21 (see FIG. 14(a)). By stopping the sheet so that the folded end S2 is within the area, when the pressing guide member 30 is rotated, the pressing portion 30c can reliably press the sheet S in the switchback conveying direction (see FIG. 14(b)), and further the folded end S2 being switched back can be guided by the guide portion 30b (see FIG. 14(c)).

After the folded end S2 of the sheet S is stopped within the area, the pressing guide motor 33 is driven to rotate the pressing guide member 30 so that the guide portion 30b of the pressing guide member 30 reaches a position (the position shown in FIG. 14(c)) where it can guide the sheet S being switched back (S9). In addition, together with the rotation of the pressing guide member 30, the regulating stopper motor 63 is driven to move the regulating stopper 26 to a position where it can accept the sheet S being switched back.

After the pressure guide member 30 rotates as described above, the discharge roller motor 62 and the folding roller motor 61 are driven in the reverse direction (S10). This causes the discharge roller 17b and the folding roller pair 22 to rotate in the reverse direction, causing the sheet S to be conveyed in a switchback manner. At this time, since the sheet is guided by the pressure guide member 30 as described above, the sheet is conveyed in a switchback manner in the direction in which the regulating stopper 26 of the sheet stacking tray 21 is located without causing any conveyance problems.

The discharge roller motor 62 and the folding roller motor 61 are driven to perform a switchback transport of the sheet S, and when the sheet S that has passed through the nip portion 22c of the folding roller pair 22 falls until it abuts against the regulating stopper 26 and the switchback transport is completed (S11), the drive of the discharge roller motor 62 and the folding roller motor 61 is stopped (S12). Here, the completion of the switchback transport of the sheet S may be determined by counting the number of drive pulses of the discharge roller motor 62 and the folding roller motor 61 and determining that the sheet S has been transported a predetermined amount.

Next, the pressing guide motor 33 is driven to return the pressing guide member 30 to the retracted position. At this time, the speed at which the pressing guide member 30 is returned from the guide position (see FIG. 14(c)) to the retracted position (see FIG. 14(a)) is set to a speed faster than when the pressing guide member 30 is moved from the retracted position to the guide position. When the pressing guide member 30 is moved from the retracted position to the guide position, the speed is reduced to press and rotate the stopped sheet S for switchback transport to change its orientation, whereas when the pressing guide member 30 is moved from the guide position to the retracted position, the speed is returned quickly, thereby making it possible to advance the timing for executing the next operation.

Then, after the pressing guide member 30 is moved to the reverse conveyance guide position (see FIG. 9A) (S13), the regulating stopper motor 63 is driven to move the second folding position of the sheet S to a position facing the folding blade 23 (S14). In this state, the cam motor 64, the folding roller motor 61, and the discharge roller motor 62 are driven to perform the second folding operation (S15 to S17).

In this embodiment, a separate motor is provided to drive each component, but it is also possible to use a common motor and drive each component by switching the drive using a clutch or the like.

<Other embodiments>
In the above-described embodiment, when the folding blade 23 and the blade guide member 40 are moved, the blade guide member 40 moves together with the folding blade 23 up to a predetermined region while changing the angle of the contact portion 40a with respect to the protruding direction, and once the predetermined region is exceeded, the blade guide member 40 does not move and only the folding blade 23 moves relatively. However, for example, the base portion 40e may be fixed to the blade carrier 24, and the folding blade 23 and the blade guide member 40 may move integrally with each other as the blade carrier 24 moves.

Even in the above case, by using the link mechanism described above, the angle of the abutment portion 40a relative to the protruding direction can be changed in conjunction with the movement of the blade guide member 40, and the blade guide member 40 can guide the folded end portion S2 of the sheet to the vicinity of the nip portion 22c.

In the above-described embodiment, the folding rollers 22a, 22b are configured as rollers having a first roller surface 22a2, 22b2 with a constant circular outer diameter and a second roller surface 22a3, 22b3 with a smaller outer diameter. However, the folding rollers 22a, 22b may be configured as rollers with a constant outer diameter, such as circular rubber rollers. In this case, when the sheet passes through the pair of folding rollers, it is always sandwiched in the nip portion of the pair of folding rollers, so the conveying amount of the sheet can be managed by the rotation of the pair of folding rollers. Therefore, when the folded end of the sheet is stopped at a predetermined position (see FIG. 7(a)), it can be controlled by the driving amount of the folding rollers.

In the above-described embodiment, a regulating stopper 26 is disposed at the lower end of the sheet stacking tray 21 to abut against and regulate the leading edge of the conveyed sheet in the conveying direction, and the regulating stopper 26 is arranged so as to be movable up and down along the sheet stacking tray 21 by the sheet lifting mechanism 27. In other embodiments, a pair of rollers may be disposed to convey the sheet to the upstream side or downstream side in the sheet conveying direction, sandwiching the folding blade 23 and folding roller pair 22 of the sheet stacking tray 21. In this case, when the sheet S that has been subjected to the first folding process is switched back and conveyed, it can be returned to either the upstream side or downstream side in the sheet conveying direction, sandwiching the folding blade 23 and folding roller pair 22 of the sheet stacking tray 21.

<Modification>
23 to 29 show modified examples of the blade guide member 40 and the blade carrier 24 (blade guide member 140 and blade carrier 124). The function of the blade guide member 140 is the same as in the above-mentioned embodiment, and the same reference numerals are used to designate the same components as in the above-mentioned embodiment, and the description thereof will be omitted. Fig. 23 is a perspective view showing the state in which the blade guide member 140 has moved in the protruding direction. Note that a pressing guide member 30 is provided on the right side of the blade guide member 140 in Fig. 23, but is not shown for convenience.

The blade guide member 140 is composed of an abutment portion 140a, an arm portion 140c, an engagement protrusion 140d, a locking portion 140e, a pivot fulcrum 140f, a pressed portion 140g, and a locking protrusion 140h. The abutment portion 140a is a member that abuts against the sheet to guide it, and one end of the abutment portion 140a is provided with a pivot fulcrum 140f, and the other end is provided with an arm portion 140c, an engagement protrusion 140d that slidably engages with a long hole 50 formed in the frame of the sheet processing device B, and a locking portion 140e formed to tension a tension spring 151 between the engagement protrusion 140d that slidably engages with a long hole 50 formed in the frame of the sheet processing device B, and a locking portion 124a formed in the frame of the sheet processing device B. The blade guide member 140 is biased in the upward direction of FIG. 25 by this tension spring 151. 25, a pressed portion 140g against which a pressing protrusion 124b1 (described later) abuts is provided on the back side of the abutting portion 140a (upstream side in the protruding direction), and the pressed portion 140g is pushed out in the protruding direction by the pressing protrusion 124b1, so that the abutting portion 140a rotates clockwise in Fig. 25 around the rotation fulcrum 140f. In other words, the abutting portion 140a is configured to be angle-changeable from an upright position substantially perpendicular to the folding blade 23a as shown in Fig. 25 to a position on the opposite side of the abutting portion 140a from the rotation fulcrum 140f toward the upstream side in the protruding direction as shown in Fig. 26. In addition, the locking protrusion 140h that is bent from the pivot point 140f is a stopper that prevents the pressed portion 140g from coming off the pressing protrusion 124b1 when the pressing protrusion 124b1 is pressing the pressed portion 140g.

The blade carrier 124 holds the folding blade 23 and the slide rail 124c, and is configured to be movable together in the protruding direction and the return direction by the cam 25 (as in the above-mentioned embodiment). The slide rail 124c holds the pressing member 124b so that it can slide in the protruding direction and the return direction. The pressing member 124b has a pressing protrusion 124b1 formed at the downstream end of the pressing member 124b in the protruding direction, a locking portion 124b2 formed at the upstream end of the protruding direction and engaged with the spring 124e, and an abutment portion 124d formed between the pressing protrusion 124b1 and the locking portion 124b2.

Figure 24 is a top view of the blade guide member 140 and the blade carrier 124. Figure 24(a) shows the blade carrier 124 in the home position (thrust tip 23a1 is in the first position), Figure 24(b) shows the blade carrier 124 moved a predetermined amount in the protruding direction by the cam 25 (thrust tip 23a1 is in the second position), and Figure 24(c) shows the blade carrier 124 moving further in the protruding direction so that the protruding tip 23a1 protrudes to the maximum extent and protrudes the sheet S into the nip portion 22c (thrust tip 23a1 is in the third position).

The blade carrier 124 is provided with a locking portion 124f to which one end of a spring 124e is attached. The other end of the spring 124e is attached to a locking portion 124b2 of the pressing member 124b, and the pressing member 124b is biased in the protruding direction (downward in FIG. 24) on the slide rail 124c by the spring 124e.

Referring now to FIG. 25, the pressing member 124b and the slide rail 124c are provided with protrusions 124b3 and 124c1, respectively. The engagement between the protrusions 124b3 and 124c1 restricts the movement of the pressing member 124b in the protruding direction even when the spring 124e urges the pressing member 124b in the protruding direction at the home position. When the blade carrier 124 moves in the protruding direction in this state, the slide rail 124c moves in the protruding direction, and the protrusion 124c1 provided on the slide rail 124c also moves in the protruding direction. As the protrusion 124c1 moves, the pressing member 124b urged by the spring 124e also moves in the protruding direction at the same time.

When the pressing member 124b moves in the protruding direction from the state shown in FIG. 25, the pressing protrusion 124b1 presses the pressed portion 140g of the blade guide member 140, moving the abutting portion 140a of the blade guide member 140 in the protruding direction. At this time, the blade guide member 140 rotates clockwise around the rotation fulcrum 140f while the engagement protrusion 140d slides downward through the long hole 50 against the biasing force of the tension spring 151.

When the blade carrier 124 moves to the state shown in FIG. 26 (the thrust tip 23a1 is in the second position), the abutment portion 124d of the pressing member 124b abuts against the pivot shaft 31 of the pressing guide member 30, restricting the movement of the pressing member 124b in the thrust direction. This prevents the pressing member 124b from moving any further in the thrust direction, even if the spring 124e urges the pressing member 124b in the thrust direction. At this position, the abutment portion 140a of the blade guide member 140 guides the sheet toward the folding roller pair 22, and the thrust tip 23a abuts against the sheet to thrust it toward the folding roller pair.

When the blade carrier 124 moves further in the protruding direction, the state shown in FIG. 27 is reached. In FIG. 27, the blade guide member 140 remains stopped in the position shown in FIG. 26, and only the blade carrier 124, the folding blade 23 (protruding tip 23a), and the slide rail 124c move in the protruding direction, and the protruding tip 23a1 protrudes to the maximum and moves to a position (third position) where the sheet S is protruded into the nip portion 22c. At this time, the protruding tip 23a1 of the folding blade 23 protrudes farther than the tip of the abutting portion 140a of the blade guide member 140. That is, the distance from the blade tip to the abutting tip at the third position is greater than the distance from the blade tip to the abutting tip at the second position. As a result, the sheet is reliably drawn into the nip portion 22c of the pair of folding rollers 22 that rotates in a state where it is folded at the second folding position, and the sheet tip S1 is also drawn into the nip portion 22c to be folded in three.

Then, the blade carrier 124 moves in the return direction. At this time, the pressing member 124b is stopped at the position shown in FIG. 26. FIG. 28 shows the state where the thrust tip 23a1 has returned to the second position. Here, the protrusion 124c1 on the slide rail 124c engages with the protrusion 124b3 on the pressing member 124b. When the blade carrier 124 is further moved in the return direction in this state, the slide rail 124c and the pressing member 124b move in the return direction at the same time against the biasing force of the spring 124e. When the pressing member 124b moves in the return direction from the position shown in FIG. 28, the pressing protrusion 124b1 moves in a direction away from the pressed portion 140g of the blade guide member 140, and the blade guide member 140 changes its angle to the upright position shown in FIG. 29 due to the biasing force of the tension spring 151.

When the folding blade 23 is protruding the sheet, that is, when the protruding tip 23a1 is moving from the second position to the third position, if a large load is applied to the blade guide member 140 in the return direction, for example, when folding multiple sheets in a stacked state and the sheets have high rigidity, a large load is applied to the blade guide member 140 during folding. In this case, when a certain load or more is applied, the blade guide member 140 can move in the return direction relative to the folding blade 23 against the spring 124e. As described above, the blade guide member 140 is biased in the protruding direction by the spring 124e via the pressing member 124b, so when a load greater than the biasing force of the spring 124e is applied to the blade guide member 140, the blade guide member 140 is configured to be able to move in the return direction along the slide rail 124c. This prevents the blade guide member 140 from being damaged when a large load is applied to the blade guide member 140 during folding of the sheet.

Figures 30 to 33 are diagrams explaining the deflection guide 170 provided between the folding roller 22a and the guide surface 21a of the sheet stacking tray 21. The deflection guide 170 has a flexible guide member 170a (such as Mylar) that contacts the sheet S to guide the sheet S, and one end of the guide member 170a is fixed to a bracket 172. The bracket 172 has an engagement piece 171 that protrudes toward the folding roller 22a, and this engagement piece 171 is positioned by engaging with the engagement portion 22d (see Figure 33) of the folding roller 22a. The engagement portion 22d of the folding roller 22a has a first roller surface 22a2 with a constant radius R1 centered on the rotation axis of the rotation shaft 22a1, and a second roller surface 22a3 whose distance from the rotation axis of the rotation shaft is smaller than the radius R1 of the first roller surface 22a2. When the folding roller 22a rotates with the engagement piece 171 engaged with the engagement portion 22d, the bracket 172 holding the guide member 170a is configured to be rotatable around the pivot shaft 173. The surface of the engagement portion 22d with which the engagement piece 171 engages is made of a plastic resin material or the like with a low coefficient of friction.

In this embodiment, the guide member 170a is provided with a guide area capable of guiding the transported sheet S, and the lower end of the guide area in FIG. 30 is called the first end 170a1, and the upper end is called the second end 170a2. If the bracket 172 is also capable of guiding the sheet S, the sheet guide area of the bracket 172 is also considered to be part of the guide member 170a, and the second end 170a2 is the upper end of the guide area of the bracket 172.

In addition, in this embodiment, the space sandwiched between the first transport guide member 181 and the second transport guide member 182 that form the sheet transport path 20 is called the guide space 180, and the space sandwiched between the first stacking guide member 184 and the second stacking guide member 185 that form the sheet stacking tray 21 is called the storage space 183.

Figure 30 shows how the sheet S is transported from the guide space 180 toward the storage space 183 (this direction is called the first transport direction) with the engagement piece 171 engaged with the first roller surface 22a2 and the guide member 170a positioned at the first guide position. Figure 31 shows how the sheet S (in this figure, a sheet S that has been folded once) is transported from the storage space 183 toward the guide space 180 (this direction is called the second transport direction) with the engagement piece 171 engaged with the second roller surface 22a3 and the guide member 170a positioned at the second guide position.

Figure 32(a) shows the state where the guide member 170a is positioned at the first guide position, and Figure 32(b) shows the state where the guide member 170a is positioned at the second guide position. The dashed dotted line 186 in the figure is a line (hereinafter referred to as the virtual line 186) that connects the transport guide end 181a, which is the downstream end of the first transport guide member 181 in the first transport direction, and the loading guide end 184a, which is the downstream end of the first loading guide member 184 in the second transport direction.

As shown in FIG. 32(a), when the guide member 170a is positioned at the first guide position, the first end 170a1 of the guide member 170a is positioned on the opposite side of the folding roller 22a (the guide surface 21a side) from the imaginary line 186 in the thickness direction of the sheet S being transported. The second end 170a2 is positioned on the folding roller 22a side from the imaginary line 186 in the thickness direction of the sheet S. This allows the leading edge of the sheet S (the downstream end in the first transport direction) to be guided from the guide space 180 to the storage space 183 when the sheet S is transported in the first transport direction as shown in FIG. 30(a) and (b).

On the other hand, as shown in FIG. 32(b), when the guide member 170a is positioned at the second guide position, the first end 170a1 of the guide member 170a is positioned closer to the folding roller 22a side than the imaginary line 186 in the thickness direction of the sheet S being transported. The second end 170a2 is positioned on the opposite side of the folding roller 22a side (guide surface 21a side) than the imaginary line 186 in the thickness direction of the sheet S. This allows the leading edge of the sheet S (the downstream end in the second transport direction) to be guided from the storage space 183 to the guide space 180 when the sheet S is transported in the second transport direction as shown in FIG. 31(a) and (b).

As shown in FIG. 33, multiple guide members 170a are provided in the width direction of the sheet S. In this embodiment, two guide members 170a are arranged on either side of the center of the sheet width inside the smallest sheet width in the sheet width direction. The dashed lines in FIG. 33 indicate the folding rollers 22a and 22b, and the engagement piece 171 is provided at a position corresponding to the engagement portion 22d of the folding roller 22a. Also, the guide member 170a is arranged at a position corresponding to the two innermost thrust tips 23a of the six thrust tips 23a, 23a1, and 23a2.

The guide member 170a guides the sheet S not only when the sheet S is transported in the first transport direction and the second transport direction, but also when the folding blade 23 is protruding. As described above, FIG. 25 shows a state in which the folding position of the sheet S is positioned opposite the folding blade 23 when performing the folding process. In FIG. 25, the guide member 170a is positioned at the first guide position.

When the folding blade 23 is moved in the protruding direction in this state, the position of the sheet S is stabilized between the guide member 170a and the abutment portion 140a of the blade guide member 140, so that the sheet can be prevented from shifting its position during folding. As described above, the guide member 170a is made of flexible Mylar or the like, so when the sheet S abuts against it, the guide member 170a guides the sheet S in a state of being bent in the protruding direction.

When the pushing tip 23a1 of the folding blade 23 pushes the sheet S into the nip portion 22c of the folding roller pair 22 and the folding roller pair 22 is rotated a predetermined amount, the engagement piece 171 engages with the second roller surface 22a3 and the guide member 170a is positioned at the second guide position (see FIG. 28). This is because if the guide portion 170a continues to urge the sheet S in the return direction even after the folded end portion S2 of the sheet S is folded into the nip portion 22c, the conveying load of the sheet S by the folding roller pair 22 will become large. Therefore, when the folding position of the sheet S reaches the nip portion 22c of the folding roller pair 22 and the folding process by the folding roller pair 22 begins, it is desirable to move the guide portion 170a to the second guide position and guide the sheet S toward the nip portion 22c.

From the above, when the sheet S is transported in the first transport direction (sheet transport for receiving the sheet S in the sheet stacking tray 21), the guide member 170a of the deflection guide 170 is positioned at the first guide position to guide the sheet S from the guide space 180 to the storage space 183, and when the sheet S is transported in the second transport direction (sheet transport for transporting the sheet S received in the sheet stacking tray 21 to the binding processing unit 17a, or for bringing the second folding position of the sheet S into opposition to the folding blade 23 for performing the second folding process after the first folding process is completed), the guide member 170a is positioned at the second guide position to guide the sheet S from the storage space 183 to the guide space 180.

When performing the folding process, the guide member 170a is positioned at the first guide position to guide the sheet S so that the folding position does not shift until the folding blade 23 pushes the sheet S into the nip portion 22c of the pair of folding rollers 22, and after the folding position of the sheet S reaches the nip portion 22c, it is positioned at the second guide position to guide the sheet S to the nip portion 22c while reducing the transport load.

In this embodiment, the guide member 170a is moved between the first guide position and the second guide position by abutting the engagement piece 171 against the peripheral surface (engagement portion 22d) of the folding roller 22a of a different diameter, but it may be moved using a different drive source. Also, while the guide member 170a is shown to be disposed between the folding roller 22a and the guide surface 21a, it may be disposed between the folding roller 22b and the guide surface 21a, or may be disposed on both.

In addition, in this embodiment, the first guide position of the guide member 170a during sheet transport and the first guide position of the guide member 170a during folding processing are the same position, but they do not need to be exactly the same position and can be changed as appropriate. It goes without saying that the second position can also be changed as appropriate in the same way.

In addition, in all of the above-described embodiments, the sheet S is folded twice to fold in three, but if the above-described blade guide members 40 and 140 are provided, the sheet S can be appropriately guided during folding even in a single folding process (the first folding process for folding in three or the folding process for folding in two).

A ... image forming apparatus B ... sheet processing apparatus F ... folding processing apparatus L1 ... nip line L2 ... rotation axis line L3 ... rotation trajectory S ... sheet S1 ... sheet leading end S2 ... folding end 20 ... sheet transport path 21 ... sheet stacking tray 21a ... guide surface 22 ... folding roller pair 22a, 22b ... folding roller 22a1, 22b1 ... rotation shaft 22a2, 22b2 ... first roller surface 22a3, 22b3 ... second roller surface 22c ... nip portion 23 ... folding blade 23a ... thrust leading end 24 ... blade carrier 24a ... engagement portion 24b ... pressing protrusion 24c ... cam pin 25 ... cam member 25a ... rotation shaft 25b ... cam groove 26 ... regulating stopper 27 ... sheet lifting mechanism 27c ... transmission belt 28a, 28b Description of the Related Art Sheet side alignment member 30 Pressing guide member 30a Rotating portion 30b Guide portion 30c Pressing portion 31 Rotating shaft 32 Drive transmission member 33 Pressing guide motor 40 Blade guide member 40a Contact portion 40b Fitting hole portion 40c Arm portion 40d Engagement protrusion 40e Base portion 40e1 Locking portion 40e2 Abutment portion 40f Shaft portion 40f1 Protrusion 50 Long hole 51 Tension spring 52 Coil spring 60 Control portion 61 Folding roller motor 62 Discharge roller motor 63 Restriction stopper motor 64 Cam motor 124 Blade carrier 140 Blade guide member 170 Deflection guide

Claims (6)

A sheet processing device performs a first folding process on a sheet, and then performs a second folding process at a position different from the crease formed by the first folding process, so that one end of the sheet folded by the first folding process is located inside the folded sheet,
a conveying path having a guide surface that guides a sheet conveyed in a predetermined conveying direction;
a pair of rotating bodies that rotate while nipping the sheet conveyed to the conveying path at a nip portion to draw in the sheet and perform a folding process;
a pushing member that pushes the sheet into a nip portion between the pair of rotating bodies;
a push-out guide member having a guide portion that pushes out the one end of the sheet folded in the first folding process so as to approach the pair of rotating bodies when the push-out member pushes out the sheet into the nip portion during the second folding process;
a moving means for moving the protruding member and the protruding guide member in a protruding direction toward the nip portion and in a return direction opposite thereto;
An angle changing means for changing an angle of the guide portion in association with the movement of the protrusion guide member;
Equipped with
the protrusion guide member is configured to be rotatable about a rotation fulcrum provided at one end of the guide portion closer to the protrusion member,
The sheet processing apparatus, wherein the angle changing unit rotates the other end of the guide portion so as to approach a movement path of the rotation fulcrum when the protrusion guide member moves in the protruding direction. The sheet processing device according to claim 1, characterized in that an arm portion is extended from the other end of the guide portion, and the end of the arm portion is slidable approximately parallel to the conveying direction in conjunction with the movement of the protruding member. The sheet processing device according to claim 2, characterized in that when the surface of the guide portion is substantially flush with the guide surface of the transport path, the end of the arm portion is located on the return direction side of the guide surface. The sheet processing device according to any one of claims 1 to 3, characterized in that the angle change means adjusts the angle so that the surface of the guide portion of the protruding guide member is approximately parallel to the guide surface of the transport path when the protruding member is in the home position. A sheet processing device performs a first folding process on a sheet, and then performs a second folding process at a position different from the crease formed by the first folding process, so that one end of the sheet folded by the first folding process is located inside the folded sheet,
a conveying path having a guide surface that guides a sheet conveyed in a predetermined conveying direction;
a pair of rotating bodies that rotate while nipping the sheet conveyed to the conveying path at a nip portion to draw in the sheet and perform a folding process;
a pushing member that pushes the sheet into a nip portion between the pair of rotating bodies;
a push-out guide member having a guide portion that pushes out the one end of the sheet folded in the first folding process so as to approach the pair of rotating bodies when the push-out member pushes out the sheet into the nip portion during the second folding process;
a moving means for moving the protruding member and the protruding guide member in a protruding direction toward the nip portion and in a return direction opposite thereto;
An angle changing means for changing an angle of the guide portion in association with the movement of the protrusion guide member;
Equipped with
The angle change means changes the angle of the guide portion so that the portion of the guide portion farther from the protruding member is tilted toward the upstream side in the protruding direction when the protruding guide member moves in the protruding direction. an image forming apparatus for forming an image on a sheet;
a sheet processing device that performs folding processing on the sheet sent from the image forming device;
having
6. An image forming system, comprising: the sheet processing apparatus according to claim 1.

Images