JP2016102009A - Sheet processing device and image formation apparatus having the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a device which can suppress damage to an end of a sheet as much as possible when pressing the fold of a folded sheet by moving a pressing member and can reduce the movement load.SOLUTION: A sheet processing device includes a pair of pressing rollers 75, 76 for pressing from the fold thickness direction of a folded sheet bundle BS that is folded and a pressing roller unit supporting the pressing rollers and moving along the sheet fold direction. The pressing rollers press the fold in any of first regions R1 in pressure-contact with each other and second regions R2 adjacent with the conveyance direction upstream side of the first regions and facing each other with a gap.SELECTED DRAWING: Figure 13

Description

  The present invention is an apparatus that folds sheets that are sequentially transported from an image forming apparatus such as a copying machine and a printer, and that folds the sheets together. More specifically, the folded sheet bundle is pressed and discharged. The present invention relates to a sheet processing apparatus that prevents a sheet end portion from being damaged or a sheet from being displaced due to movement when processing is performed so that a folded sheet does not spread.

2. Description of the Related Art Generally, a processing apparatus that aligns sheets conveyed from an image forming apparatus and folds them into a staple or booklet is widely known. Some of these processing apparatuses are saddle-stitched with a staple or an adhesive in the middle of a sheet and folded into a booklet shape. In such an apparatus, a sheet bundle of about 2, 3 to 30 sheets is folded in two, but the folded crease portion is opened after discharging, and the alignment of the folded sheet bundle is good. There was no accumulation amount.
For this reason, the process of pressing the sheet bundle from the front and back again against the folds of the bi-folded sheet once folded is widely known.

  For example, as shown in FIG. 21, Patent Document 1 discloses that the sheet is pressed by rollers from above and below the fold along the fold direction of the folded sheet bundle BS. A pair of the pressing rollers 361a and 361b are provided, and are moved along the fold direction F by a holder 362 that supports the pressing rollers 361a and 361b, thereby preventing the sheet from spreading after being discharged.

Further, as shown in FIG. 22, in Patent Document 2, a pair of pressing rollers is provided at two locations in the moving direction on a holder 462 that moves in the fold direction of the sheet bundle, and the pressing rollers are long pressing in the sheet conveying direction. A roller 461 and a short pressing roller 463 are provided. This device changes the position of the sheet crease forward and backward when the number of folded sheets is small and large. When the number of sheets is small, only the long roller presses the sheet crease, and when the number of sheets is large, long press The fold is pressed twice by both the roller 461 and the short pressing roller 463. As a result, when the number of sheets is large, the crease is reinforced by pressing at two places.

As another embodiment, one of the two rows of pressing rollers arranged in the crease direction can be moved away from the opposing roller so that when the number is large, the rollers are pressed by two rows, and when the number is small, 1 A configuration in which a pair of rollers presses is also disclosed.

  Further, as shown in FIGS. 23 (a) and 23 (b), Patent Document 3 discloses a pair of pressing rollers 561a and 562a for pressing a fold of a two-fold sheet bundle from the sheet thickness direction, and the pair of pressing rollers as a sheet width. A processing apparatus with a holder 560 that reciprocates in the direction is shown. This apparatus is further configured to move the pair of pressing rollers to a position where they are separated from each other and a position where they are pressed against each other. When the sheet is additionally folded, the pair of pressing rollers is moved as shown in FIG. The sheet moves inward from the end of the sheet in a separated state. After moving to the inside of the sheet, the pressing roller is pressed to press one side of the sheet. Then, after exiting one end, the pressure is released and separated, and when moving to the other side again, the end of the sheet is passed in a separated state. Thereafter, a processing device for pressing the other side from the inside is shown. In other words, pressing of the folds of the sheet bundle starts from the inner side in the sheet width direction and passes through the sheet end.

Japanese Patent No. 4514217 JP 2012-201462 A JP 2014-76903 A

  As described above, when pressing is performed on a fold of a folded sheet bundle carried out from an image forming apparatus or the like, there are the following problems.

  First, in Patent Document 1, the pair of pressing rollers 361a and 361b that are in pressure contact with each other is moved from the outside of the sheet bundle end portion into the sheet bundle width while being in pressure contact state. The sheet bundle is likely to be torn or pressed against the sheet, and the sheet bundle is tilted by the collision. Therefore, a large holding mechanism is required for holding the sheet bundle. In particular, since the supporting fulcrum of the pair of pressing rollers 361a and 361b is positioned on the downstream side in the moving direction of the holder 362, when the rollers collide with the end 371 of the sheet bundle, the rollers are forced in the closing direction. Worked, and the impact on the edge of the sheet was increasing.

Further, the one shown in Patent Document 2 also changes the position of the sheet bundle according to the number of folded sheet bundles BS, and if it is small, only the long pressing roller 461 presses the crease, and if it is large, the long pressing roller 461 is long. In other words, the pressure is pressed by two rows of short pressing rollers 463. However, even in this case, the pressing rollers 461 and 463 in each row are in pressure contact with each other. In particular, when there are a large number of sheets, the pressing rollers 461 and 463 collide with the end of the sheet, and the sheet The sheet bundle is easily broken and pressed, and the sheet bundle is tilted by the collision.

On the other hand, in Patent Document 3, a pair of pressing rollers are separated from each other at a standby position outside the sheet width, and in this separated state, these rollers are placed on the inner side where there is a fold in the sheet bundle. The sheet is pressed by pressing. When the sheet passes through the end portion in the width direction of the sheet, the sheet passes away, so that the end portion can be prevented from being damaged or pressed. However, regardless of the number of sheets, the pressing roller is separated even when it is small or large, so that a separation mechanism is required and the structure becomes complicated. Further, since the sheet is reciprocated after passing through the end regardless of the number of sheets, the pressing process takes time.

The present invention has been made in view of the above problems, and when performing a pressing process on a crease of a folded sheet, a region that is pressed against a pair of pressing members in a pressed state is set. To press. As a result, when the number of folded sheets is small, the pressing is performed in the press-contacted region, and when the number is large, the pressing is performed in the separated region. Therefore, even when the sheet end is thick, the impact due to the collision with the pressing roller can be reduced. Further, when the number of sheets is small, it is performed in the pressed area, so that the fold of the sheet is surely pressed.
That is, the present invention has an object to provide a sheet processing apparatus and an image forming apparatus including the sheet processing apparatus that can suppress damage to the end portion of the sheet as much as possible and reduce a moving load when the pressing member is moved and pressed. Yes.

  In order to solve the above problems, a sheet processing apparatus according to the present invention includes a pair of pressing members that press from a fold thickness direction of a folded sheet, and a moving member that supports the pressing member and moves along the sheet fold direction. And the pressing member presses the crease in any one of a first area that is in pressure contact with each other and a second area that is adjacent to the upstream side of the first area in the conveying direction and that faces each other with a gap therebetween. It is.

According to this, since the pressing member has the first region pressed against each other and the second region facing each other with a space between them, if the pressing member is pressed in the second region, It is possible to reduce the moving load.

In addition, the sheet processing apparatus of the present invention includes a conveying member that conveys a folded sheet, a pressing member that presses the sheet from the fold thickness direction of the folded sheet conveyed by the conveying member, and the pressing member that serves as a sheet crease. A moving member that moves along the direction, and a control unit that controls the moving member and the conveying member;
The pressing member is composed of a first region that is in pressure contact with each other and a second region that is adjacent to the upstream side in the transport direction of the first region and that faces each other with a gap therebetween.
When the number of folded sheets to be conveyed is equal to or less than the predetermined number, the conveying member moves to the first area, and when exceeding the predetermined number, the conveying member moves to the second area and controls to press the sheet crease. It is also a sheet processing apparatus.

  According to this, when the number of sheets is equal to or less than the predetermined number of sheets, the pressing members press the sheets in an area where they are pressed against each other, so that even a small number of sheets can be pressed firmly, and when the number of sheets exceeds the predetermined number, Therefore, it is possible to reduce the impact generated when getting over the sheet edge, and to reduce the deformation and damage of the sheet edge.

Furthermore, a sheet processing apparatus according to the present invention includes a conveying roller that conveys a folded sheet, a pair of pressing rollers that press a fold of the folded sheet from the thickness direction, and a sheet fold that supports the pressing roller. A moving unit that moves along the direction, and a control unit that controls sheet conveyance of the conveying roller and movement of the moving unit, and the moving unit narrows the distance between the pressing rollers stepwise along the moving direction. A plurality of rows are supported, and the last region of the plurality of rows of sheet pressing rollers is located on the upstream side in the sheet conveying direction adjacent to the large diameter roller and is spaced from each other with a gap therebetween. A second region composed of opposed small-diameter rollers,
The control unit moves the sheet fold to the first area when the number of fold sheets conveyed is equal to or less than the predetermined number, and moves to the second area to press the sheet fold when the number exceeds the predetermined number. It is also a processing device.

According to this, when the number of sheets is equal to or less than the predetermined number of sheets, the pressing members press the sheets in an area where they are pressed against each other, so that even a small number of sheets can be pressed firmly, and when the number of sheets exceeds the predetermined number, Therefore, it is possible to reduce the impact generated when getting over the sheet edge, and to reduce the deformation and damage of the sheet edge. Further, since there are a plurality of rows of pressing members whose intervals are narrowed in stages on the upstream side of the pressing members, the folds of the folded sheets are sequentially directed inward in stages. Accordingly, the sheet bundle is less likely to open after the folding is completed in the closing direction, and more sheets can be accumulated with better alignment.

The image forming apparatus field of the present invention includes an image forming means for forming an image on a sheet, and a sheet processing apparatus for performing a predetermined sheet processing on the sheet from the image forming means. An image forming apparatus comprising any one of the sheet processing apparatuses.

According to this, the image forming apparatus provided with the sheet processing apparatus having the above-described effects can be provided.

Since the present invention has the above-described solution, the present invention includes a sheet processing apparatus and a sheet processing apparatus capable of suppressing damage due to collision of the end with the sheet as much as possible when the pressing member is moved to press the crease. An image forming apparatus can be provided.
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It is explanatory drawing which showed the whole structure which combined the image forming apparatus concerning this invention, and the sheet processing apparatus which equipped the stage folding unit internally. 1 is an overall explanatory view of a sheet processing apparatus equipped with a stage folding unit according to the present invention. FIG. 10 is an explanatory diagram of folding processing of a folding roller in the sheet processing apparatus. It is the perspective view seen from the bundle discharge roller side of the stage folding unit of FIG. It is the perspective view seen from the folding roller side of the stage folding unit of FIG. It is explanatory drawing which showed the inside of the stage folding unit of FIG. It is a front view from the folding roller side of the stage folding unit of FIG. FIG. 8 is a front view of the presser roller unit shown in FIGS. 4 to 7 in an initial position. FIG. 8 is a front view showing a state where the presser roller unit shown in FIGS. 4 to 7 is moved in the middle in the width direction. FIG. 8 is a front view of the end state in the width direction of the presser roller unit shown in FIGS. 4 to 7. FIG. 11A is an explanatory diagram of a sheet folded booklet that is step-folded according to FIGS. 7 to 9 to form a plurality of fold lines, and FIG. 11A shows a state in which the sheet is pressed by a first upper presser roller and a first lower presser roller. It is. FIG. 11B is a diagram illustrating a state where the second upper presser roller and the second lower presser roller are pressed. FIG. 11C is a diagram illustrating a state in which the final third upper presser roller and the third lower presser roller are pressed. is there. It is a figure which shows the booklet which performed the stage folding of FIG. The conceptual diagram explaining the relationship between the press roller of the last stage of a stage folding unit, and the folded sheet | seat. FIGS. 14A and 14B are diagrams illustrating a plurality of rows of pressing rollers in the stage folding unit. FIG. 14A is a diagram for explaining a number of stages or more than a predetermined number of stages, and FIG. 14B is a state before folding in FIG. FIG. FIG. 14C is a diagram for explaining the step-folding of a small number of sheets less than a predetermined number, and FIG. 14D is a plan view before folding in FIG. 14C. It is a flowchart figure which performs a step folding to many sheets more than the predetermined number of sheets of FIG. 14, and a small number of sheets less than a predetermined number. It is a flowchart figure following FIG. FIG. 3 is an explanatory diagram of a control configuration of the sheet processing apparatus of FIG. 2. It is explanatory drawing of the stage folding unit of the modification 1. It is a whole explanatory view of Modification 2. It is sectional drawing of the stage folding unit of the modification 2. It is explanatory drawing of the cited reference 1. FIG. It is explanatory drawing of the cited reference 2. FIG. It is explanatory drawing of the cited reference 3. FIG.

The present invention will be described in detail below based on the illustrated embodiment. FIG. 1 shows an overall configuration including an image forming apparatus according to the present invention, FIG. 2 is an explanatory diagram of the overall configuration of the sheet processing apparatus, and FIG. 3 is a diagram for explaining a folded state of a sheet bundle in the sheet processing apparatus. Further, FIG. 4 is a perspective view seen from the discharge side of the stage folding unit that performs stepwise folding on the sheet bundle built in the sheet processing apparatus, and FIG. 5 is a perspective view seen from the folding roller side of the stage folding unit. is there.
Therefore, the image forming system shown in FIG. 1 includes an image forming apparatus A and a sheet processing apparatus B, and a stage folding unit 50 is incorporated in the sheet processing apparatus B.

[Configuration of Image Forming Apparatus]
The image forming apparatus A shown in FIG. 1 sends a sheet from the paper feeding unit 1 to the image forming unit 2, prints the sheet on the image forming unit 2, and then carries the sheet out from the main body discharge port 3. The sheet feeding unit 1 stores sheets of a plurality of sizes in sheet feeding cassettes 1 a and 1 b, and separates designated sheets one by one and feeds them to the image forming unit 2. The image forming unit 2 includes, for example, an electrostatic drum 4, a print head (laser light emitting device) 5 and a developing device 6 arranged around the electrostatic drum 4, a transfer charger 7, and a fixing device 8. An electrostatic latent image is formed by the light emitting device 5, toner is adhered to the developing device 6, an image is transferred onto the sheet by the transfer charger 7, and heat fixing is performed by the fixing device 8. The sheets on which images are formed in this way are sequentially carried out from the main body discharge port 3. 9 is a circulation path, and the sheet printed on the front side from the fixing device 8 is turned upside down through the main body switchback path 10 and then fed again to the image forming unit 2 to print on the back side of the sheet. This is the path for duplex printing. The sheet printed on both sides in this way is turned upside down by the main body switchback path 10 and then carried out from the main body discharge port 3.

  11 is an image reading apparatus, which scans an original sheet set on a platen 12 with a scan unit 13 and electrically reads it with a photoelectric conversion element 14 through a reflection mirror and a condenser lens. This image data is digitally processed by the image processing unit, for example, and then transferred to the data storage unit 17 to send an image signal to the laser emitter 5. 15 is a document feeder, which is a feeder device that feeds a document sheet stored in the document stacker 16 to the platen 12.

  The image forming apparatus A configured as described above is provided with a control unit (controller), and image forming conditions such as sheet size designation, color / monochrome printing designation, number of copies designation, single-sided / double-sided printing designation, enlargement / reduction from the controller panel 18 Printout conditions such as print designation are set. On the other hand, image data read by the scan unit 13 or image data transferred from an external network is stored in the data storage unit 17 in the image forming apparatus A, and the image data is transferred from the data storage unit to the buffer memory. Data signals are sequentially transferred from the buffer memory 19 to the laser emitter 5.

  From the controller panel 18, sheet processing conditions are also input and designated simultaneously with image forming conditions. For example, (1) “print-out mode”, (2) “staple binding mode”, (3) “saddle binding bundle folding mode”, and (4) “step folding mode” are designated as the sheet processing conditions. The image forming apparatus A forms an image on the sheet according to the image forming condition and the post-processing condition.

[Configuration of sheet processing apparatus]
The sheet processing apparatus B connected to the above-described image forming apparatus A is set so as to receive a sheet on which an image is formed from the main body discharge port 3 of the image forming apparatus A and perform the following sheet processing.
First, (1) a sheet on which an image has been formed is stored in the first paper discharge tray 21 (the aforementioned “print-out mode”). (2) Sheets from the main body discharge port 3 are aligned in a bundle and are stored in the first discharge tray 21 after being bound by the end face binding stapler 33 (the above-described “staple binding mode”). (3) The sheets from the main body discharge port 3 are aligned in a bundle shape by the stacker unit 35 which is the second processing tray, and the middle of the sheet bundle is bound by the saddle stitching stapler 40 and then folded into a booklet shape. (2) The paper is stored in the paper discharge tray 22 (the aforementioned “saddle stitch bundle folding mode”). (4) The sheet loop is folded in stages at the folds of the sheet bundle that has been saddle-stitched and folded into a booklet, and is stored in the second discharge tray 22 (the above-described “stage folding mode”). Etc. can be specified.

  Incidentally, as shown in FIG. 2, the sheet processing apparatus B includes the first discharge tray 21 and the second discharge tray 22 in the casing 20, and a sheet carry-in path P <b> 1 having a carry-in port 23 connected to the main body discharge port 3 is provided. It has been. The sheet carry-in path P <b> 1 is configured by a substantially horizontal straight path in the casing 20. A first switchback conveyance path SP1 and a second switchback conveyance path SP2 that branch from the sheet carry-in path P1 and transfer the sheet in the reverse direction are arranged. The first switchback conveying path SP1 is branched from the sheet downstream path and the second switchback conveying path SP2 is branched from the sheet carry-in path P1 on the upstream side, and the both conveying paths are spaced apart from each other.

  In such a path configuration, the carry-in roller 24 and the paper discharge roller 25 are arranged in the sheet carry-in path P1. The paper discharge roller 25 can be rotated forward and backward. Further, a path switching piece (not shown) for guiding the sheet to the second switchback transport path SP2 is disposed in the sheet carry-in path P1, and is connected to an operating means such as a solenoid. Further, in the sheet carry-in path P 1, stamp means for performing a stamping process on a sheet from the carry-in entrance 23, or a single-sheet punching unit 28 for punching sheets one by one is provided on the downstream side of the carry-in roller 24.

[Configuration of the first switchback transport path SP1]
As shown in FIG. 2, the first switchback conveyance path SP1 disposed on the downstream side (rear end portion of the apparatus) of the sheet carry-in path P1 is configured as follows. A discharge roller 25 is provided at the exit end of the sheet carry-in path P1, and a processing tray 29 is provided for stacking and supporting the sheets of the discharge roller 25. Above the processing tray 29, a forward / reverse roller 30 is disposed so as to be movable up and down between a position in contact with the sheet on the tray and a separated standby position. When the forward / reverse roller 30 is connected and a sheet enters the processing tray 29, the sheet rotates in the clockwise direction in the figure, and after the trailing edge of the sheet is discharged from the discharge roller 25 and enters the tray, the sheet rotates counterclockwise. Controlled to rotate. Accordingly, the first switchback transport path SP1 is formed on the processing tray 29.

  A first paper discharge tray 21 is disposed on the downstream side of the first switchback conveyance path SP1, and the first paper discharge tray 21 is guided to the first switchback conveyance path SP1 and the second switchback conveyance path SP2. It is comprised so that the front-end | tip of a sheet | seat may be supported.

  At the rear end of the processing tray 29 in the paper discharge direction, an end face binding staple device 33 is disposed. The stapling device 33 staples at one or a plurality of positions on the trailing edge of the sheet bundle stacked on the processing tray 29. The bound sheet bundle is discharged from the first discharge tray 21.

  The first switchback conveyance path SP1 configured as described above aligns the sheets from the paper discharge roller 25 on the processing tray 29 in the “staple binding mode” of (2), and binds the sheet bundle to the end face. The stapling device 33 staples one or more rear end edges. Further, in the “print-out mode” of (1), the sheet fed along the processing tray 29 is rotated by the forward / reverse rotation roller 30 in the clockwise direction shown in FIG. It is carried out to the first paper discharge tray 21.

[Configuration of second switchback transport path]
The configuration of the second switchback conveyance path SP2 branched from the sheet carry-in path P1 will be described. The second switchback conveyance path SP2 is a conveyance path that guides the sheet that is reversely switched from the normal rotation to the switchback conveyance in a state where the sheet is nipped by the paper discharge roller 25 as shown in FIG. As shown in FIG. 2, this conveyance path is arranged substantially vertically in the casing 20, and a conveyance roller 36 is arranged at the path entrance, and an outlet conveyance roller 37 is arranged at the path exit. Further, a stacker unit 35 constituting a second processing tray for aligning and temporarily collecting sheets fed from the transport path is provided on the downstream side of the second switchback transport path SP2. The illustrated stacker unit 35 is constituted by a conveyance guide for transferring a sheet. A saddle stitch stapler 40 and a folding roller 45 are arranged in the stacker portion 35. Hereinafter, these configurations will be sequentially described.

[Stacker configuration]
First, the stacker unit 35 is formed by a guide member that guides conveyance of a sheet, and is configured to stack and store sheets on the guide. The illustrated stacker unit 35 is connected to the second switchback transport path SP <b> 2 and is disposed substantially vertically in the center of the casing 20. As a result, the apparatus is made compact and compact. The stacker portion 35 is formed in a length shape that accommodates the maximum size sheet therein, and in particular, the illustrated stacker is curved so as to protrude toward the side where the saddle stitching stapler 40 and the folding rollers 45 (45a, 45b) described later are disposed. Or it is comprised in the bent shape.

  On the rear end side in the transport direction of the stacker unit 35, a switchback entry path 35a that overlaps the exit end of the second switchback transport path SP2 is connected. This is done by overlapping the leading edge of the loaded (following) sheet sent from the exit conveying roller 37 of the second switchback conveying path SP2 and the trailing edge of the stacked (preceding) sheet supported by the stacker unit 35. This is to secure the page order of the sheets to be processed. Further, the stacker unit 35 is provided with a leading end regulating member (hereinafter referred to as a stopper 38) as a stopper unit for regulating the leading end of the sheet in the carrying-in direction on the downstream side of the guide, and the stopper 38 moves along the stacker unit 35. It is supported by a guide rail or the like, and is configured to move to a position where the sheet is carried into the stacker unit 35 by a shift means (not shown), a position where the sheet is bound in the middle of the stacking direction, and a position where the folding roller 45 folds. Further, an alignment member 39 for aligning sheets is provided in the middle of the transport direction of the stacker unit 35, and alignment is performed by pressing the side edge every time a sheet is loaded.

[Description of saddle stitching stapler]
Next, the saddle stitching stapler 40 positioned above the stacker unit 35 includes a driver unit 41 that drives the staple needle into the sheet bundle and a clincher unit 42 that bends the leg portions of the staple needle that are driven in a direction facing each other. Each unit is configured to be opposed to each other with the stacker portion 35 interposed therebetween, and binds the sheet at a binding position shown in the figure X, which is usually a half of the sheet length. In addition, this saddle stitch stapler may use a metal needle as a staple needle for binding a sheet bundle, and may be bound by putting a paper-made needle made of paper or a crimp or cut not using the needle into the sheet.

[Description of folding roller]
Next, the configuration of the folding roller 45 will be described. As shown in FIG. 2, a folding roller 45 that folds the sheet bundle and a folding blade 46 that inserts the sheet bundle at the nip position of the folding roller 45 are disposed at the folding position Y arranged on the downstream side of the saddle stitching stapler 40 described above. Is provided. Referring also to FIG. 3, the folding roller 45 is composed of an upper pressure roller 45a and a lower pressure roller 45b that are in pressure contact with each other. The upper pressure roller 45a and the lower pressure roller 45b are formed to be slightly longer than the maximum sheet width. . The folding rollers 45 are urged toward each other by a compression spring (not shown). The pair of folding rollers 45 are formed of a material having a relatively large friction coefficient such as a rubber roller.

A folding blade 46 that intrudes toward the pressing position of the folding roller 45 is disposed so as to advance and retreat. The folding blade 46 moves so as to push the binding position into the folding roller 45 after the sheet bundle is saddle-stitched by the saddle stitching stapler 40, and the folding roller 45 is pressed and rotated in conjunction with this operation. Fold the binding sheet into two. In the middle of this, the folding blade 46 returns to the original position to prepare for the next sheet bundle. The moving position of the folding blade is shown in FIG. 2 as the folding position Y, and this position coincides with the position X where the sheets are bound by the binding needle.

Here, a folding process procedure of stacked or bundled sheet bundles will be described with reference to FIG. The sheet is locked by the stopper 38 to form a bundle, and the stopper 38 is raised and the saddle stitching stapler 40 performs a binding process at a middle position in the sheet conveyance direction. After the binding process, this time the bound sheet bundle is lowered and the stopper 38 is stopped so that the sheet binding position becomes the folding position. This state is shown in FIG. This position is stopped so as to coincide with the pressure contact positions of the upper pressure contact roller 45a and the lower pressure contact roller 45b of the folding roller 45. Thereafter, the upper pressure roller 45a and the lower pressure roller are rotated in the same direction by a drive motor (not shown), and the folding blade 46 moves so as to be pushed into the pressure position. This state is shown in FIG.

Next, as shown in FIG. 3C, the upper pressing roller 45a and the lower pressing roller continue to rotate in the same direction, and the folding blade 46 temporarily stops before the pressing position. This time, the folding blade 46 moves and retracts in the original return direction. Thereafter, when the upper pressure roller 45a and the lower pressure roller 45b continue to rotate in the same direction, the folded sheet bundle BS is folded in a fixed loop BL as shown in FIG. The sheet bundle includes a folding loop tip BL1 that becomes a fold projected by the folding blade 46, an upper loop BL2 that swells upward around this, a lower loop BL3 that swells downward, and a loop that presses the sheet so as to maintain the loop. A base end BL4 is formed, and temporarily stops in this state.

By the way, the reason why the loop is generated at the fold is that the sheet bundle itself exerts a force to open outward at the fold position. Therefore, as the number of folded sheet bundles BS increases, the force to open and spread the sheet becomes stronger. If the sheets are discharged as they are, the sheet bundle will be opened. Is going.
The folding roller 45 measures the distance between the shafts of the upper pressure contact roller 45a and the lower pressure contact roller 45b that are pressed against each other in a state in which the sheets are not folded and a state in which the folded sheet bundle BS is folded. It may also be used to detect the thickness. This point will be described later with reference to FIG.

[Description of stage folding unit]
From here, the stage folding unit 50 which becomes a part of the sheet processing apparatus according to the present invention for preventing the folded folded sheet bundle BS from being opened will be described. FIG. 4 is a perspective view of this unit as seen from the discharge side. FIG. 5 is a perspective view seen from the folding roller 45 side. Further, the pressing roller unit 56 will be described with reference to FIG. 6 which is a perspective view from the folding roller 45 side and FIG. 7 which is a front view. Thereafter, the operation will be described with reference to FIGS.

  As shown in FIG. 2, the stage folding unit 50 is disposed so as to cross the folding sheet conveyance path BP on the downstream side of the folding roller 45 described above. More specifically, in the stage folding unit 50, the folding roller 45 folds the folded sheet bundle BS and presses the folded sheet bundle with the pressing rollers 70 serving as pressing rollers having different intervals to perform the folding process. The stage folding unit 50 faces the fold of the folded sheet bundle BS having a crease in the sheet width direction and a fixed loop.

2 detects the discharge from the sheet bundle detection sensor (SEN3) 129 and the bundle discharge roller 49 that detect the back and front edge of the folded sheet that is folded and conveyed by the folding roller 45 before and after the stage folding unit 50 in FIG. A bundle discharge sensor (SEN4) 131 is disposed.
2 is installed between the folding roller 45 and a bundle discharging roller 49 as a discharging member for discharging outside the apparatus. However, if the folding unit 50 crosses the folded sheet conveying path BP, the step folding unit 50 shown in FIG. It can also be installed downstream of the discharge roller 49.

As shown in FIG. 4, the stage folding unit 50 includes a right side plate 53 disposed on one side of the device, a left side plate 54 facing the right side plate 53, and a connection angle 55 that connects them to the upper side of the frame. It is composed. A presser roller unit 56 is disposed between the right side plate 53 and the left side plate 54 as a moving unit that reciprocates between the side plates. The reciprocating movement between the side plates of the presser roller unit 56 is slid by the upper guide rail 57 and the lower guide rail 58 positioned between the right side plate 53 and the left side plate 54. That is, the upper slide block 60 attached above the presser roller unit 56 slides on the upper guide rail 57 and the lower slide block 61 attached below the presser roller unit 56 slides on the lower guide rail 58. It is supported by.

  A moving belt 65 is stretched between the right side plate 53 and the left side plate 54 of the apparatus above the presser roller unit 56. In this moving belt, a right pulley 63 for winding the moving belt 65 is positioned on the right side plate 53 side shown in FIG. 4, and a left pulley 64 for winding the moving belt 65 is positioned on the left side plate 54 side. One end of the moving belt 65 is fixed to the upper end of the presser roller unit 56 by a belt fixing portion 65b. Accordingly, when the moving belt 65 is moved and the belt fixing portion 65b is moved from the back side (right side) of the apparatus to the front side (left side), the presser roller unit 56 also moves along the upper guide rail 57 and the lower guide rail 58 in FIG. The device moves from the back side (right side) to the near side (left side). When the moving belt 65 is moved in the reverse direction, the belt fixing portion 65b is also moved in the reverse direction, and the presser roller unit 56 is also moved in the reverse direction.

By the way, the left pulley 64 around which the moving belt 65 is wound is attached to a motor gear unit 68 provided on the left side plate 54 of a unit drive motor 69 capable of forward and reverse rotation. The rotational drive of the unit drive motor 69 is connected to the left pulley 64 of the moving belt 65 via a transmission gear 66 provided from the motor output gear 67 to the motor gear unit 68.
Therefore, by selecting the driving rotation direction of the unit drive motor 69, the presser roller unit 56 is also selectively moved from the back side (right side) to the near side (left side), and conversely from the near side (left side) to the far side (right side). Can move. In the vicinity of the upper end of the presser roller unit 56 on the right side plate 53 side, a unit flag 107 indicating that it is at the home position located near the right side plate 53 is provided. When the unit flag 107 is detected by the home position sensor 108, the presser roller unit 56 is located at the home position.

When the presser roller unit 56 moves from the home position to the left side in the figure, the position is discriminated by a pulse generator (not shown) built in the unit drive motor 69 and is located at the folding position near the left side plate 54. Is determined. At this turn-back position, the unit drive motor 69 is reversely rotated, and this time, the press roller unit 56 is controlled to move toward the home position. Therefore, the presser roller unit 56 is a moving member that is moved by the moving belt 65 or the like.

[Description of presser roller unit]
Next, the pressing roller unit 56 that moves to the left and right in the drawing will be described. FIG. 5 is a view from the folding roller 45 side, but the presser roller unit 56 includes a unit base plate 62a constituting the back side of the unit, a front upper base plate 62b and a front lower base plate 62c which are divided vertically. The side is surrounded by a preceding unit side plate 95 and a succeeding unit side plate 96, and the upper and lower sides thereof are surrounded by a unit top plate 59a and a unit bottom plate 59b. The leading unit side plate 95 is provided with a leading side plate opening 97 that is relatively large, and the trailing unit side plate is provided with a trailing side plate opening 98 that is set narrower than the leading side plate opening. These openings are provided so that the presser roller unit 56 moves while sandwiching the sheet crease.

  As shown in FIG. 6, the presser roller unit 56 is provided with a plurality of rows of roller pairs in this embodiment from the preceding unit side plate 95 side to the following unit side plate. It has been. These rollers have different distances between a pair of rollers for each row. That is, the first lower presser roller 72 is disposed at a position spaced apart from the first upper presser roller 71 at a substantially equal position with the sheet crease position at the center in the first row of rollers. Each of the rollers has a first upper presser roller shaft 78a and a first lower presser roller shaft 78b, and these shafts are supported by a first upper presser roller bracket 86a and a first lower presser roller bracket 86b. The first upper presser roller bracket 86a is supported by the unit top plate 59a so that it can be raised and lowered, and the first lower presser roller bracket 86b is supported by the unit bottom plate 59b so that it can be raised and lowered.

Further, a first upper presser roller pressing spring 91a for biasing both in the separating direction is interposed between the first upper presser roller bracket 86a and the unit top plate 59a, and the first lower presser roller bracket 86b and the unit bottom plate are interposed. A similar first lower presser roller pressing spring 91b is also interposed between 59b and 59b. As a result, the first upper presser roller 71 and the first lower presser roller 72 are constantly applied with a biasing force. On the other hand, the unit base plate 62a and the front upper base plate 62b for supporting the first upper presser roller shaft 78a are provided with first upper presser roller shaft long holes 82a, respectively.

Accordingly, the urging force of the first upper presser roller pressing spring 91a is restricted by the first upper presser roller shaft long hole 82a, and the downward movement of the first upper presser roller 71 is also restricted. Further, the urging force of the first lower presser roller pressing spring 91b is also restricted by the first lower presser roller shaft elongated hole 82b, and the upward movement of the first lower presser roller 72 is also restricted. Thereby, as well shown in FIG. 7, the distance L1 between the first upper pressing roller 71 and the first lower pressing roller 72 is always kept constant. In this embodiment, L1 is set to about 14 millimeters. Further, the first upper presser roller pressing spring 91a and the first lower presser roller pressing spring 91b are set so that a load of approximately 4.0 kilograms is applied in a state where both rollers are in contact with each other.

In addition, the roller pair in the second row has the same configuration as the roller in the first row as can be seen from FIGS.
That is, the second row presser roller 73 is arranged at a position spaced apart from the second upper presser roller 73 by a predetermined distance from the second upper presser roller 73. Each of the rollers has a second upper presser roller shaft 79a and a second lower presser roller shaft 79b, and these shafts are supported by a second upper presser roller bracket 87a and a second lower presser roller bracket 87b. The second upper presser roller bracket 87a is supported by the unit top plate 59a so that it can be raised and lowered, and the second lower presser roller bracket 87b is supported by the unit bottom plate 59b so that it can be raised and lowered.

Further, a second upper presser roller pressing spring 92a for biasing both in the separating direction is interposed between the second upper presser roller bracket 87a and the unit top plate 59a, and the second lower presser roller bracket 87b and the unit bottom plate are interposed. A second lower pressing roller pressing spring 92b is also interposed between the second pressing roller 92b and 59b.
As a result, the second upper presser roller 73 and the second lower presser roller 74 are constantly biased in the direction of approaching. On the other hand, the unit base plate 62a that supports the second upper presser roller shaft 79a and the front upper base plate 62b are provided with second upper presser roller shaft long holes 83a, respectively. Accordingly, the urging force of the second upper presser roller pressing spring 92a is restricted by the second upper presser roller shaft elongated hole 83a, and the downward movement of the second upper presser roller 73 is also restricted.

Further, the urging force of the second lower pressing roller pressing spring 92b is also restricted by the second lower pressing roller shaft elongated hole 83b, and the upward movement of the second lower pressing roller 74 is also restricted. Thereby, as well shown in FIG. 7, the distance L2 between the rollers of the second upper presser roller 73 and the second lower presser roller 74 is always kept constant. In this embodiment, L2 is set to about 7 millimeters. Further, the second upper presser roller pressing spring 92a and the second lower presser roller pressing spring 92b are set so that a load of approximately 4.0 kilograms is applied when both rollers are in contact with each other.

Further, as can be seen from FIGS. 6 and 7, the roller pair in the third row has the same configuration as the rollers in the first row and the second row. Is different. That is, the first upper presser roller 71 and the first lower presser roller 72 in the first row have predetermined intervals L1 (approximately 14 mm in this embodiment) as shown in FIG. 7, and the second upper presser roller 73 in the second row. Similarly, the second lower presser roller 74 is spaced by a predetermined distance L2 (approximately 7 millimeters in this embodiment). The first upper presser roller shaft elongated hole 82a, the first lower presser roller shaft elongated hole 82b, the second upper presser roller shaft elongated hole 83a, and the second lower presser roller shaft elongated hole 83b serve as a spacing regulating member. Because. Accordingly, the positions of the rollers are regulated so as not to be narrower than a predetermined value.

However, the third upper presser roller 75 and the third lower presser roller 76 in the third row are elastically biased so that they can always be pressed against each other. In this case, the third upper presser roller shaft elongated hole 84a and the third lower presser roller shaft elongated hole 84b are set so that the roller interval L3 = 0. The third upper presser roller pressing spring 93a and the third lower presser roller pressing spring 93b are set so that a load of approximately 4.0 kilograms is applied at the roller contact position. Thus, the folds of the folded sheet bundle BS are subjected to stepwise folding while a load exceeding 4 kilograms is applied to both sides.

  Further, the third upper presser roller 75 and the third lower presser roller 76 in the third row are described in FIGS. 6 and 6 surrounded by a circular two-dot broken line. The second region R2 of the upper presser roller small-diameter portion 75b and the lower presser roller small-diameter portion 76b opposed to each other with a slight gap between the diameter portion 75a and the first region R1 (hereinafter referred to as region R1) of the lower presser roller large-diameter portion 76a. (Hereinafter referred to as region R2) is set adjacent to the upstream side from the upstream side in the sheet bundle conveyance direction. This stepped roller is integrally formed and rotated as shown in the figure. The reason why this stepped roller is used is to weaken the impact of the end of the sheet bundle and the pressing roller. This will be described later with reference to FIG.

As described above, the first upper presser roller 71, the second upper presser roller 73, and the third upper presser roller 75 as the pressing member 70 of the sheet bundle of the present invention are provided at positions facing each other (opposite positions). The first lower presser roller 72, the second lower presser roller 74, and the third lower presser roller 76 are supported in a plurality of rows by the presser roller unit 56 that is unitized as a moving member (multiple rows / three rows in this embodiment). Supported) and movable. These rollers are rotatable in the moving direction. The movement then moves in the direction of the crease in order from the first presser roller 71 which is the first row having a large interval between the first presser roller 71 and the second lower presser roller 72 opposite to the first presser roller 71. In the second upper presser roller 73 and the second lower presser roller 74, the distance between the rollers becomes narrower.

Then, in the large diameter region (R1) of the third upper presser roller 75 and the third lower presser roller 76 in the third row (last) which is the final row in the moving direction, the sheet fold is moved from both sides by a spring force of 4 kilograms. Pressing while pressing. In other words, in this embodiment, the three roller rows arranged and supported in one unit are gradually reduced in intervals, and moved stepwise along the sheet fold line while pressing from both sides of the folded sheet bundle BS. Fold. Further, it is folded in stages by pressing from both sides of the crease with the approximate center between the rollers as the pressing position.

[Explanation of stage folding unit operation]
From here, FIGS. 8 to 12 will be used to explain the carrying-in of the pressing roller unit 56 in the step-folding unit 50 into the folded sheet bundle BS and the step-by-step pressing operation. FIG. 8 shows a state where the presser roller unit 56 is positioned at the home position and is waiting for the folded sheet bundle BS to be carried. FIG. 9 shows a state where the presser roller unit 56 moves to the middle in the width direction of the folded sheet bundle BS and performs stepwise stepwise folding by three rows of rollers. FIG. 10 shows a state in which the stepwise step folding by the three rows of rollers is completed and the presser roller unit is located at the folding position. Hereinafter, each state will be described. Here, the basic operation of the step folding will be described, and the upper presser facing the region R1 of the upper presser roller large diameter portion 75a and the lower presser roller large diameter portion 76a with a slight gap therebetween. The region R2 of the roller small-diameter portion 75b and the lower presser roller small-diameter portion 76b will be described in FIG. 13 and later, and the description here will be omitted, and the step-folding operation will be described without touching the region R2.

First, FIG. 8 shows a state in which the presser roller unit 56 is positioned at the home position and is waiting for the carry-in of the folded sheet bundle BS. This figure is seen from the bundle discharge roller 49 side, and the unit base plate 62a is omitted for convenience of explanation.
In FIG. 8, the unit flag 107 of the press roller unit 56 having three rows of press rollers is detected by the home position sensor 108 attached to the right side plate 53, and the press roller unit 56 is located at the home position. At this position, when the above-described “stage folding mode” is set, the folding roller 45 performs the folding process and waits for the folded sheet bundle BS conveyed in the folded sheet conveyance path BP to be carried in.

  By the way, the press roller unit 56 positioned at the home position has an interval narrowed in order from the moving direction, and a press roller 70 is provided in pressure contact in the final row. As already described, in the present embodiment, the first upper presser roller 71 and the first lower presser roller 72 in the first row are arranged with an interval of approximately 14 millimeters. Further, the second upper presser roller 73 and the second lower presser roller 74 in the second row have an interval of approximately 7 mm. Further, the third upper presser roller 75 and the third lower presser roller 76 in the third row are in pressure contact with each other in the region R1. Furthermore, the centers of the separation and press-contact of these rollers are arranged so as to substantially coincide with the folded sheet loop tip (fold) BL1, which is the center of the folded sheet bundle BS.

  When the folding loop of the folded sheet bundle BS reaches a predetermined size (in this embodiment, the vertical direction of the loop is 22 millimeters, for example), the folding roller 45 is stopped and the presser roller unit 56 is moved to the left side in FIG. The unit is moved by driving the unit drive motor 69. When this movement starts, the first upper presser roller 71 and the first lower presser roller 72 in the first row pass over the right side (one end) in the figure of the folded sheet bundle, and slightly above the folded sheet leading end loop BL1. Move to the left with a crease in the position. As described above, the size of the loop in this embodiment is about 22 millimeters, and the distance between the first upper presser roller 71 and the first lower presser roller 72 is about 14 millimeters. The overlap is about 4 millimeters, which gives the first fold line 100 shown in FIG. Moreover, since the space | interval of the 1st upper pressing roller 71 and the 1st lower pressing roller 72 is open, these rollers get over without damaging the edge part of folded sheet bundle BS so much. The presser roller 70 including the first upper presser roller 71 and the first lower presser roller 72 is pivotally supported in the same direction as the sheet conveying direction and is rotatably supported on this shaft. This rotation also facilitates overcoming the folded sheet bundle end.

When the presser roller unit 56 continues to move, the loop pressed at the distance between the first upper presser roller 71 and the first lower presser roller 72 is further increased between the second upper presser roller 73 and the second lower presser roller 74. The second fold is made by pressing the loop of the folded sheet bundle BS at a slightly narrowed interval. In this embodiment, the distance between the second upper presser roller 73 and the second lower presser roller 74 is set to approximately 7 millimeters, which is higher than the distance between the first upper presser roller 71 and the first lower presser roller 72. Are overlapped by about 3.5 millimeters, and this gives a second fold line 101 shown in FIG.
Subsequently, the fold BL1 is gradually folded by the third upper presser roller 75 and the third lower presser roller 76 which are the third row rollers. In other words, the third upper presser roller 75 and the third lower presser roller 76 are in a substantially pressure contact state (region R1 of the large-diameter roller portion) with the interval between them being zero. While being pressed by the third upper presser roller pressing spring 93a and the third lower presser roller pressing spring 93b, it is gradually folded, and this gives the final fold line 102 shown in FIG.

  FIG. 9 shows a state in which the folded sheet bundle BS is pressed stepwise within one unit with the above contents and the presser roller unit 56 is positioned at the approximate center of the folded sheet bundle BS in the sheet width direction. From this state, the presser roller unit 56 further moves toward the left side of the drawing while giving a fold line to the sheet stepwise by the presser roller 70 whose distance from the crease thickness direction of the sheet becomes narrower. By this movement, the third upper presser roller 75 and the third lower presser roller 76 in the third row pass through the right side (one end) (sheet end) of the folded sheet bundle in the figure to perform stepwise folding. After the passage, the presser roller unit 56 reaches the folding position on the left side plate 54 side shown in the figure. This state is shown in FIG. When the turn-back position is reached, the drive of the unit drive motor 69 is stopped. Thereafter, the folded sheet bundle BS that has undergone stepwise folding (completion of pressing by the pressing roller 70) is discharged by rotation of the folding roller 45 and the bundle discharge roller 49 in the discharge direction. When the completion of discharging the folded folded sheet bundle BS is detected by the bundle discharge sensor (SEN4) 131 shown in FIG. 2, the press roller unit 56 is returned from the return position to the home position, and at the position shown in FIG. Ready to carry in the folded sheet bundle BS.

  In the above description, the folded sheet BS folded in stages in FIG. 10 is once discharged and then the presser roller unit 56 is returned to the home position. However, the presser roller unit 56 is again discharged without discharging the folded sheet bundle BS. 10 is moved from the left side to the right side in FIG. 10 and returned to the home position while the folds of the folded sheet bundle BS are again pressed by the third upper presser roller 75 and the third lower presser roller 76, It is also possible to make the stage folding more reliable.

As described above, in this embodiment, the folded sheet bundle BS is folded in three stages by the press roller unit 56. The folded sheet bundle BS discharged by performing this folding operation will be described with reference to FIGS.
As described above, the first upper presser roller 71 and the first lower presser roller 72 as the sheet bundle pressing members of the present invention are used in the fold thickness direction of the folded sheet bundle BS (the folded sheet bundle BS is conveyed in the fold line). (The vertical direction intersecting with), a portion where the crease is made by the folding roller 45 and the loop is generated is moved in the crease direction to make a plurality of creases. As already described, the interval between the first upper presser roller 71 and the first lower presser roller 72 in the first stage is slightly narrower than the folding loop (in this embodiment, it is substantially the same as the loop height of 22 mm). 14 mm), and moves along the crease made by the fold roller 45 to make the first crease. This is the first fold line 100 indicated by the solid line arrow in FIG. 11A. In FIG. 12, the first fold line 100 appears as a thin line in the folded sheet bundle BS. This is because the portion pressed by the first upper presser roller 71 and the first lower presser roller 72 receives a concentrated load in the looped portion as shown in FIG. This is because the first fold line 100 appears due to the movement of the upper presser roller 71 and the first lower presser roller 72 in the width direction.

Next, in the second stage, the distance between the second upper presser roller 73 and the second lower presser roller 74 as a sheet bundle pressing member is slightly narrower than the loop formed by pressing in the first stage (in this embodiment, And is moved along the crease formed by the folding roller 45 to make a second stage crease. This is the second fold line 101 indicated by the solid line arrow located behind the first fold line 100 shown in FIG. 11B, and in FIG. 12, the second fold line is a thin line in the folded sheet bundle BS. Appears as 101. Also in this case, the portion pressed by the second upper presser roller 73 and the second lower presser roller 74 is buckled into the sheet bundle due to the concentrated load in the looped portion as shown in FIG. This is because the first fold line 101 appears due to the movement of the upper presser roller 73 and the second lower presser roller 74 in the width direction.

As the final stage, the third upper presser roller 75 and the third lower presser roller 76 as the sheet bundle pressing members are pressed by the elastic force of the third upper presser roller pressing spring 93a and the third lower presser roller pressing spring 93b. ing. In the last row, the third upper presser roller 75 and the third lower presser roller 76 are not spaced apart from each other as in the first stage and the second stage. (The regulation interval in this embodiment is 0 millimeter in the region R1). Therefore, the pressing at the last row moves in the crease direction while pressing the position of the pressed thickness of the folded sheet bundle BS with the third upper pressing roller 75 and the third lower pressing roller 76. The folds of the press rollers 70 in the final row are the final fold line 102 indicated by the solid line arrow in FIG. 11 in the folded sheet bundle BS, and in FIG. 12, a relatively dark line appears in the folded sheet bundle BS as the final fold line 102. Yes. Note that an end fold 103 is formed at the end in the width direction of the folded sheet bundle BS when the folding roller 45 and the pressing roller 70 are pressed onto the sheet. The portion pressed by the third upper presser roller 75 and the third lower presser roller 76 in the substantially press-contact state appears as a final fold line 102 in which the fold is strengthened.

  As described above, the press rollers 70 are buckled at different intervals so that folds are formed, whereby the first fold line 100 that is the first stage thin line and the first fold line that is the second stage thin line. The folding direction of the folded sheet bundle BS (conveyance passing through the fold line) at each line position of the second folding line 101 and the final folding line 102, which is a relatively dark line generated according to the thickness of the folded sheet bundle BS on the final row. When the folding direction toward the (direction line) side is directed, it is possible to prevent the folded sheet bundle BS from being opened even after being discharged, and to reduce the alignment and stackability.

[Explanation of the last row of stepped rollers]
Here, a configuration in which the third upper presser roller 75 located in the last row of the presser roller unit 56 and the third lower presser roller 76 facing the third presser roller unit 56 which have been touched in FIGS. 6 and 7 is a stepped roller will be described. To do.
This is because the end portion in the width direction of the folded sheet bundle BS is an end portion having a relatively large number of sheets when the third upper presser roller 75 and the third lower presser roller 76 opposed to the end of the folded sheet bundle BS ride on the sheet. If there is, the third upper presser roller 75 and the third lower presser roller 76 opposite to the third upper presser roller 75 come into contact with the end portion to be in a collision state, and the end portion is damaged or damaged. Alternatively, when the impact of this collision is large, the position of the folded sheet bundle BS held by the folding roller 45 may be displaced.

Therefore, in this embodiment, as shown in FIGS. 6, 7, and 13, the third upper pressing roller 75 in the last row is connected to the upper pressing roller large diameter portion 75 a and the upstream side in the sheet conveying direction. The third lower pressing roller 76 includes a lower pressing roller large diameter portion 76a and a lower pressing roller small diameter portion 76b. As shown in FIG. 6 and the two-dot broken line in FIG. 6, these are a region R1 where the upper presser roller large diameter portion 75a and the lower presser roller large diameter portion 76a that are in pressure contact with each other, and a slight gap between them. A region R2 of the upper presser roller small-diameter portion 75b and the lower presser roller small-diameter portion 76b facing each other is set. The upper presser roller 75 and the lower presser roller 76 are integrally formed as stepped rollers.

Therefore, as shown in FIG. 7, since the region R1 of the upper presser roller large diameter portion 75a and the lower presser roller large diameter portion 76a is in pressure contact with each other, L3 is 0, and the upper presser roller small diameter portion 75b and The region R2 of the lower presser roller small-diameter portion 76b is set to L4, which is set to about 2 millimeters in this embodiment. Although this L4 depends on the number and thickness of sheets to be handled, it may be in the range of about 2 to 4 millimeters. This is a relatively large number of sheets. In this embodiment, when the number of sheets exceeds 15 sheets (30 sheets folded over about 3 mm), the upper presser roller small diameter part 75b and the lower presser roller small diameter part are folded. In this embodiment, when the number of sheets is small so that it is located in the region R2 of 76b, and the number of sheets is 15 or less, the upper presser roller large diameter portion 75a and the lower presser roller large diameter portion 76a that are in pressure contact with each other. The crease is positioned in the region R1. By doing in this way, a thick edge part with many sheets can be easily ridden, and the damage given to a sheet edge part can be decreased.

[Folded sheet area setting]
Next, as shown in FIG. 13, the front end (back) of the folded portion of the folded sheet BS is positioned in the region R1 of the upper presser roller large-diameter portion 75a and the lower presser roller large-diameter portion 76a, or the upper presser roller. The configuration of whether or not the small diameter portion 75b and the lower presser roller small diameter portion 76b are located in the region R2 where there is an opposing gap will be described.
As described with reference to FIG. 3, the sheet bundle that is saddle-stitched in the substantially center of the sheet bundle conveyance direction is pushed between the upper pressure roller 45 a and the lower pressure roller 45 b by the folding blade 46. The folded folded sheet bundle BS is conveyed toward the presser roller 70 by the rotation of the upper press roller 45a and the lower press roller 45b. The leading edge (back) of the conveyed folded sheet bundle is detected by a sheet bundle detection sensor (SEN 3) 129 between the folding roller 45 and the pressing roller 70. When detected by the sensor SEN3, an encoder 127 that counts the encoder 127 that is attached to the drive shaft of the folding motor 126 that rotationally drives the upper pressure contact roller 45a and rotates integrally therewith is counted. When the number of folded sheet bundles is a small number (15 or less in this embodiment), the folding motor 126 is stopped when the sheet folds (back) within the range of the region R1. On the other hand, when the number of folded sheet bundles is many (in this embodiment, more than 15), the folding motor 126 is stopped when the count reaches the range of the region R2. In this way, the folding roller 45 is also used as a conveying member, and rotates in conjunction with the bundle discharging roller during discharging.

By the way, the number information of the folded sheet bundle is obtained by counting the number of documents of the document feeder 15 mounted on the image forming apparatus A and receiving this number information by the sheet folding control section 122 via the image forming apparatus control section 110. To set. Alternatively, the number of sheets discharged from the main body discharge port 3 within a predetermined interval is counted in the image forming apparatus A and transmitted to the sheet processing apparatus, or counted by the S1 sensor at the carry-in port 23 of the sheet processing apparatus B. You can also set it. Further, as shown in FIG. 13, the shaft 45bx of the lower pressure contact roller 45b may be measured by the laser displacement meter 130 and the thickness information may be recognized as the number information and set as a large number or a small number.

Next, with reference to FIG. 14, description will be given of the step-folding of the folded sheet stopped in the region R <b> 1 corresponding to the small number of sheets and the region R <b> 2 corresponding to the large number of sheets by the pressing roller unit 56.
First, FIGS. 14A and 14B show the case where a large number of folded sheet bundles are used. As shown in FIG. 14B, the folded sheet bundle BS stops in a region R2 where there is a gap between the upper presser roller small diameter portion 75b and the lower presser roller small diameter portion 76b. Although the folded sheet bundle BS stopped at this position has been described with reference to FIGS. 8 to 10, as shown in FIG. 14B, the presser roller unit 56 for supporting the three presser rollers 70 having different intervals is provided. Move in the direction of the arrow in the figure and fold it in stages. At this time, the third upper presser roller 75 and the third lower presser roller 76 at the final stage have a gap between the upper presser roller small-diameter portion 75b and the lower presser roller small-diameter portion 76b facing each other (2 mm in this embodiment). The end of a large number of folded sheets BS, which has a certain area R2, can be overcome with little resistance and little impact. Further, since the bundle is thicker than the gap L4 (see FIG. 7), it can be reliably folded.

On the other hand, FIGS. 14C and 14D show a case where the number of folded sheet bundles is small. As shown in FIG. 14D, the folded sheet bundle BS stops in a region R1 where there is no gap between the upper presser roller large diameter portion 75a and the lower presser roller large diameter portion 76a. Although the folded sheet bundle BS stopped at this position has been described with reference to FIGS. 8 to 10, as shown in FIG. 14D, the press roller unit 56 for supporting the press rollers 70 in three rows having different intervals is provided. Move in the direction of the arrow in the figure and fold it in stages. At this time, the third upper presser roller 75 and the third lower presser roller 76 at the final stage are in a region R1 where the upper presser roller large diameter portion 75a and the lower presser roller large diameter portion 76a are in pressure contact with each other. Because it is a small number, it can get over the end without much resistance and less impact. Further, the crease can be ensured by the inter-roller L3 (see FIG. 7) with no pressure contact.

Next, steps (S) for executing a large number exceeding the predetermined number shown in FIG. 14 and a small number equal to or less than the predetermined number will be described with reference to the flowcharts of FIGS.
First, “step folding mode” is designated from the control panel as the sheet processing condition. By this designation, the designated number of sheet bundles are created, and the saddle stitching stapler 40 performs saddle stitching for each bundle. Next, the sheet bundle is folded in half by a folding roller 45 and a folding blade, and is conveyed through the folded sheet conveyance path BP to reach the stage folding unit 50. In this process, the number of folded sheets is 15 as shown in FIG. It is determined whether the number is less than 15 (30 in two folds) or more than 15 (S201). In this case, a large number and a small number may be distinguished depending on the thickness.

[For decimal]
When the number of folded sheet bundles is 15 or less, the drive rotation range of the folding motor 126 that rotates the folding roller 45 is within the clearance between the upper presser roller large diameter portion 75a and the lower presser roller large diameter portion 76a shown in FIGS. It sets so that it may stop to area | region R1 which press-contacted without. After the setting, the counter counts whether the fold (back) of the folded sheet bundle BS is located in the region R1 of the large diameter roller portion (S203). If it is located in the region R1, the driving rotation of the folding motor 126 is stopped and the edge side of the folded sheet bundle BS is held (S204).

This time, the forward drive of the unit drive motor 69 that moves the presser roller unit 56 in the sheet width direction is started (S205). When the unit drive motor 69 is driven in the forward direction, the unit flag 107 shown in FIG. 5 separates (turns off) the home position sensor 108. From this separation, a counter is counted, and this counts the width of the folded sheet bundle. The presser roller unit 56 is moved until it crosses (S206). When the movement amount for the width is counted, the driving of the unit drive motor 69 is stopped as the pressing is completed (S207). By the unidirectional movement of the presser roller unit 56 in the width direction, the folds of the folded sheet bundle BS are pressed. This is done by folding the folds of the folded sheet BS step by step by the action of FIG. 11 already described. At this time, the third upper presser roller 75 and the third lower presser roller 76 at the final stage are pressed in a region R1 where the upper presser roller large diameter portion 75a and the lower presser roller large diameter portion 76a are in pressure contact with each other. As a result, the folds of the small number of folded sheet bundles BS are surely pressed.

  Due to the stop of the unit drive motor 69, the presser roller unit 56 is positioned on the side opposite to the home position as the movement is completed. After the pressing is completed, the driving of the bundle discharging motor for driving the folding motor 69 and the bundle discharging roller 49 as the discharging member is started (S208). By the rotation of these motors, a small number of folded sheet bundles BS subjected to stepwise folding are discharged to the second paper discharge tray 22. This discharge completion is detected by a bundle discharge sensor (SEN4) 131 in the vicinity of the bundle discharge roller 49. The detection of the discharge is confirmed by the bundle discharge sensor (SEN4) 131 being changed from “ON” to “OFF” (S209). By this detection, the driving of the bundle discharging motor that drives the folding motor 69 and the bundle discharging roller 49 is stopped (S210).

  When the folded sheet bundle BS is discharged to the second discharge tray 22, this time, the reverse drive of the unit drive motor 69 is started (S211). By this reverse driving, the presser roller unit 56 located on the opposite side of the home position moves toward the home position. As shown in FIG. 4, the unit flag 107 attached to the presser roller unit 56 is detected by the home position sensor 108 (S212). As a result of this detection, assuming that the presser roller unit 56 has returned to the home position, the drive of the unit drive motor 69 is stopped (S213). In this process, the presence or absence of the next folded sheet bundle BS is confirmed (S214). If there is a subsequent folded sheet bundle BS, the process returns to the initial stage (circle 1 in FIG. 15), and the processing from S201 is performed.

  In the above operation flow, when the folded sheet bundle BS is discharged to the second paper discharge tray 22 (S210), the unit drive motor 69 starts to rotate in reverse (S211), and the press roller unit 56 is moved. Return to the home position (S213). However, when processing a very small folded sheet bundle of 2 to 3 sheets, the next folded sheet bundle is discharged without discharging the previous folded sheet bundle and returning the presser roller unit 56 to the home position. After the fold (back) is positioned in the region R1, the crease may be pressed by the pressing roller unit 56 and returned while being creased. As described above, the processing speed (productivity) is further improved by discharging the previous folded sheet bundle BS and carrying it into the region R1 of the next folded sheet bundle BS every time the pressing roller unit 56 is operated in one direction. .

[In the case of many sheets]
Next, a process when there are a large number of folded sheet bundles will be described. Returning to FIG. 15, when the folded sheet bundle exceeds 15 sheets (S201), the driving rotation range of the folding motor 126 that rotates the folding roller 45 is opposed to each other with a slight gap shown in FIGS. A setting is made to stop in the region R2 between the upper presser roller small-diameter portion 75b and the lower presser roller small-diameter portion 76b, and the folding motor 126 is driven (S221). After this setting, the counter counts whether the fold (back) of the folded sheet bundle BS is located in the region R2 of the small diameter roller portion (S222). When positioned in the region R2, the driving rotation of the folding motor 126 is stopped, and the small edge side of the folded sheet bundle BS is held (S223).

Subsequent steps are set in the same manner as the above-described decimal steps (from S223 to S226), and the description thereof will be omitted. However, differences will be described.
The first point is the region R2 between the upper presser roller small diameter portion 75b and the lower presser roller small diameter portion 76b facing each other with a slight gap in the third upper presser roller 75 and the third lower presser roller 76 in the final stage. The folds (backs) of a large number of folded sheet bundles BS are stopped. For this reason, many comparatively thick creases are overcome in the region R2 having a gap. As a result, it is possible to get over with less resistance and less impact, and the deviation of the folded sheet bundle can be prevented.

The second point is that the discharge timing of the folded sheet bundle BS to the second paper discharge tray after the stage folding process is different. That is, in the case of a small number of sheets, after performing the step folding by the presser roller unit 56, the folded sheet bundle BS is discharged to the second discharge tray by being positioned at a position opposite to the home position. In some cases, the presser roller unit 56 is returned to the home position without being discharged, and then the folded sheet bundle BS is discharged. This point will be described with reference to FIGS. 15 and 16 again.

When the stage folding in one direction is completed by the movement of the presser roller unit 56, the unit drive motor is stopped once (SS226). Here, without discharging the folded sheet bundle BS, the unit drive motor 69 is rotated at a lower speed and slower than the moving speed when the number of sheets is small (S227). By this reverse drive, the presser roller unit 56 located on the opposite side of the home position moves at a low speed toward the home position. As shown in FIG. 4, the unit flag 107 attached to the presser roller unit 56 is detected by the home position sensor 108 (S228). As a result of this detection, assuming that the presser roller unit 56 has returned to the home position, the drive of the unit drive motor 69 is stopped (S229).

Therefore, even by the returning operation of the presser roller unit 56, the fold of the folded sheet bundle BS is pressed by the upper presser roller small-diameter portion 75b and the lower presser roller small-diameter portion 76b, and it is ensured by pressing the fold again. Can be folded. In the case of a large number of sheets, even if the folded sheet bundle is ejected upon completion of the reciprocating motion of the presser roller unit 56, it is assumed that the processing time is long since the number of sheets is large, so there is no particular problem. Instead, the crease is pressed again by reciprocating and returning the moving speed at a lower speed than in the case of processing a small number of sheets, thereby further ensuring the folding.
On the other hand, in the case of a small number of sheets, the upper presser roller large-diameter portion 75a and the lower presser roller large-diameter portion 76a that are in pressure contact are pressed so that it is easy to make a crease without performing the pressing again, and the smaller the number of sheets, the faster Therefore, it is discharged after fold in one direction.

  The presser roller unit 56 is located at the home position by stopping the driving of the unit drive motor 69. Thereafter, driving of the bundle discharging motor for driving the folding motor 69 and the bundle discharging roller 49 is started (S230). A small number of folded sheet bundles BS subjected to stepwise folding by the rotation of these motors are discharged to the second discharge tray 22. This completion of discharge is detected by the bundle discharge sensor (SEN4) 131 in the vicinity of the bundle discharge roller 49 (S231), and the driving of the bundle discharge motor for driving the folding motor 69 and the bundle discharge roller 49 is stopped (S232).

  When the second sheet discharge tray 22 of the folded sheet bundle BS is discharged, the driving of the bundle discharge motor that drives the folding motor 69 and the bundle discharge roller 49 is terminated (S232). Is confirmed (S233). If there is a subsequent folded sheet bundle BS, the process returns to the initial stage (circle 1 in FIG. 15), and the processing from S201 is performed.

  As described above, in the above-described operation, in the case of a small number of sheets with a small bundle thickness, the folded sheet bundle BS is discharged by moving the presser roller unit 56 in one direction (outward path), and in the case of a large number of sheets with a large bundle thickness, reciprocation is performed. (Return trip) Discharged by movement. In addition, the unit drive motor 69 is driven and rotated at a low speed in the return path. Thereby, a fold can be reliably given also to the thick folded sheet bundle BS.

[Description of control configuration]
The control configuration of the sheet processing apparatus B including the above-described stage folding unit 50 and the image forming apparatus A including the sheet processing apparatus will be described with reference to the block diagram of FIG. An image forming apparatus control unit 110 including an image forming unit inputs a desired process from an input unit 111 provided on the control panel 18. This input is controlled by the sheet processing apparatus control unit 115 of the sheet processing apparatus B by mode setting means.

As described above, the mode of the sheet processing apparatus B of the present embodiment has the following mode.
That is, (1) “print-out mode” in which a sheet on which an image has been formed is stored in the first paper discharge tray 21. (2) “Staple binding mode” in which the sheets from the main body discharge port 3 are aligned in a bundle and are stored in the first discharge tray 21 after being bound by the end face binding stapler 33. (3) From the main body discharge port 3. The sheets are aligned in a bundle by the stacker unit 35, which is the second processing tray, the middle of the sheet bundle is bound by the saddle stitch stapler 40, folded into a booklet, and stored in the second sheet discharge tray 22. "Bundling and binding bundle folding mode". (4) A “step folding mode” in which a fold loop of a sheet bundle that has been saddle-stitched and folded into a booklet is stepwise folded and stored in the second paper discharge tray 22. These modes can be specified.

  The sheet processing apparatus B includes a sheet processing apparatus control unit 115 that can be operated in the designated mode, a ROM that stores an operation program, and a RAM that stores control data. The sheet processing apparatus control unit 115 includes a sheet conveyance control unit 116 that controls sheet conveyance in the apparatus, and a single sheet punching control unit 117 that performs a pressing process on each sheet by the single sheet punching unit 28. A processing tray control unit 118 that performs sheet stacking control on the processing tray 29 and an end surface binding control unit 119 that binds the end surface side of the sheets stacked as a sheet bundle on the processing tray 29 and discharges them after binding.

When performing saddle stitching or folding in the vicinity of half of the sheet conveyance direction of the sheet bundle, the stacker unit control unit 120 that stacks the sheet bundle on the sheet stacker unit 35 is controlled. The stacker unit control unit 120 generates a sheet bundle by aligning with a stopper 38 and an alignment member 39 that regulate the leading edge of the sheet that is carried into the stacker unit 35 one by one. Further, the saddle stitching control unit that controls the saddle stitching stapler so as to drive the staples and the like in the middle of the sheet bundle and the saddle stitched sheet bundle are pushed into the folding roller 45 by the folding blade 46 so as to perform the middle folding. The sheet folding control unit 122 is provided. The sheet folding control unit 122 is connected to a sheet bundle detection sensor (SEN3) 129 and an encoder sensor 128, and controls a folding motor 126 that drives the folding roller 45 based on output signals thereof.

The folded sheet bundle BS is connected to a unit driving motor 69 that moves the presser roller unit 56 in accordance with the “stage folding mode” described so far, and includes a folded sheet stage folding control unit 123 that controls the unit. This sheet folding sheet stage folding control unit 123 is also connected to a home position sensor 108 for confirming that the stage folding unit is at the home position.
Then, the folded sheet bundle BS that has undergone the stepwise folding is controlled by the half-folded sheet discharge control unit 124 that is connected to the bundle discharge roller drive motor that drives the bundle discharge roller 49, and is discharged and accumulated on the second discharge tray. . The middle folded sheet discharge control unit is connected to the bundle discharge sensor (SEN4) and confirms the discharge operation of the folded sheet bundle BS.
The folding sheet stage folding control particularly related to the present invention has been described in the explanation of each mechanism, each operation state explanation diagram from FIG. 8 to FIG. 10 and the flowchart diagrams in FIG. 15 and FIG. However, the step folding unit 50 is controlled so as to execute the step folding method based on the contents.

Next, modified examples in which the present invention can be implemented will be described. The members having the same functions and operations as those of the embodiments described so far are denoted by the same reference numerals and the description thereof is omitted, but the structure of the pressing roller unit 56 in the stage folding unit 50 is different.
[Modification 1]
First, Modification 1 will be described with reference to FIG. In the embodiments so far, as shown well in FIG. 6, the folds of the folded sheet bundle BS are pressed from the thickness direction by the three rows of pressing rollers 70 having different intervals. The presser roller 70 is configured to support the presser roller unit 56 by supporting three rows in one frame. However, in the first modification, as shown in FIG. 56b and 56c are respectively supported (the other symbols are different for each unit, a, b and c are attached). Although not particularly illustrated, these units are connected to a drive motor that moves the units independently, and each unit is individually moved so as to be pressed stepwise from the fold thickness direction of the folded sheet bundle. The third upper presser roller 75 and the third lower presser roller 76 at the final stage also have the upper presser roller large diameter portion 75a and the lower presser roller large diameter portion 76a in the region R1 and the upper presser roller, as in the previous embodiments. It has area | region R2 with the clearance gap which the small diameter part 75b and the lower pressing roller small diameter part 76b opposed.
Accordingly, also in the first modification, since the folds of a large number of folded sheet bundles are pressed at the position of the region R2, the roller can easily ride over the relatively thick end portion, and damage to the end portion of the sheet is reduced. it can.

[Modification 2]
Next, Modification 2 will be described with reference to FIGS. 19 and 20. In the embodiment and the first modification described above, three rows of the press rollers 70 having different intervals are provided, but in this second modification, the press roller pair 170 is set in three stages, and three times in the sheet width direction ( It moves one reciprocating half) and presses the crease of the folded sheet bundle.
FIG. 18 is a view from the bundle discharge roller 49 side. The upper restriction pin 182 of the upper presser roller support block 173 that supports the presser roller pair 170 is spaced by the cam member 180 between the lower restriction pin 183 of the lower presser roller support block 174. It is set. As shown in the sectional view of FIG. 19, the upper presser roller support block 173 is formed by a presser roller pressing spring 90 of the upper spring holder 175, and the lower presser roller support block 174 is pressed by a presser roller pressing spring 90 of the lower spring holder 176. , And are biased in a direction in which they are pressed against each other. The cam member 180 regulates against this urging force. The cam member 180 is moved by a cam drive motor 184, and the interval between the press roller pair 170 can be set in three stages.

  Therefore, the folds of the folded sheet bundle are first pressed at a relatively wide interval, and the folds are pressed at a narrow interval at the next stage in the next backward movement. In the final pressing, a small number of relatively thin folded sheet bundles BS are pressed in a pressure contact state between the upper presser large diameter roller 151 and the lower presser large diameter roller 152 (region R1). A large number of relatively thick folded sheet bundles BS are pressed with a gap between the upper presser small-diameter roller 153 and the lower presser small-diameter roller 154 each having a smaller α diameter than the large-diameter roller (region R2). Even if comprised in this way, a roller can run over a comparatively thick edge part easily, and the damage given to a sheet | seat edge part can be decreased.

A Image forming apparatus B Sheet processing apparatus X Adhesive application position Y Fold position BS Fold sheet bundle BL Fold sheet bundle loop BL1 Fold sheet bundle loop tip (fold)
R1 Large diameter area R2 Small diameter area 35 Stacker section 40 Saddle stitching stapler 45 Folding roller 49 Bundle discharge roller 50 Stage folding unit 53 Right side plate 54 Left side plate 55 Connection angle 56 Pressing roller unit (moving member)
57 Upper guide rail 58 Lower guide rail 60 Upper slide block 61 Lower slide block 62 Step folding base plate 63 Right pulley 64 Left pulley 65 Moving belt 66 Transmission gear 67 Motor output gear 68 Motor gear unit 69 Drive motor 70 Pressing roller (pressing member )
71 First upper pressing roller 72 First lower pressing roller 73 Second upper pressing roller 74 Second lower pressing roller 75 Third upper pressing roller 75a Upper pressing roller large diameter portion 75b Upper pressing roller small diameter portion 76 Third lower pressing roller 76a Lower presser roller large diameter portion 76b Lower presser roller small diameter portion 77 Presser roller shaft 78a First upper presser roller shaft 78b First lower presser roller shaft 79a Second upper presser roller shaft 79b Second lower presser roller shaft 80a Third upper presser roller Shaft 80b Third lower presser roller shaft 81 Roller shaft long hole 82a First upper presser roller shaft long hole 82b First lower presser roller shaft long hole 83a Second upper presser roller shaft long hole 83b Second lower presser roller shaft long hole 84a Third upper presser roller shaft elongated hole 84b Third lower presser roller shaft elongated hole 85 Presser roller bracket 86a First upper presser roller bracket 86b First lower presser roller bracket 7a Second upper pressing roller bracket 87b Second lower pressing roller bracket 88a Third upper pressing roller bracket 88b Third lower pressing roller bracket 90 Pressing roller pressing spring 91a First upper pressing roller pressing spring 91b First lower pressing roller pressing spring 92a Second upper presser roller pressing spring 92b Second lower presser roller pressing spring 93a Third upper presser roller pressing spring 93b Third lower presser roller pressing spring 95 Predecessor unit side plate 96 Subsequent unit side plate 97 Preceding side plate opening 98 Subsequent side plate opening 100 First fold line 101 Second fold line 102 Final fold line 103 End fold line 107 Unit flag 108 Home position sensor 122 Sheet folding control section (control section)
123 Folded sheet stage folding control unit (control unit)
124 Folded sheet discharge control unit (control unit)
151 Upper presser large diameter roller 152 Lower presser large diameter roller 153 Upper presser small diameter roller 154 Lower presser small diameter roller 170 Presser roller pair

Claims (11)

A pair of pressing members for pressing from the fold thickness direction of the folded folded sheet;
A moving member that supports the pressing member and moves along the sheet crease direction,
The sheet processing is characterized in that the pressing member presses a crease in any one of a first area that is in pressure contact with each other and a second area that is adjacent to the upstream side of the first area in the conveyance direction and that faces each other with a gap therebetween. apparatus. 3. The pressing member according to claim 2, wherein the first area is integrally formed with a large-diameter roller and the second area is integrally formed with a small-diameter roller, and is supported by a common shaft in the sheet conveying direction. Sheet processing device. A conveying member for conveying the folded sheet;
A pressing member that presses the sheet from the fold thickness direction of the folded sheet conveyed by the conveying member;
A moving member that moves the pressing member along the sheet crease direction;
A control unit for controlling the moving member and the conveying member;
The pressing member is composed of a first region that is in pressure contact with each other and a second region that is adjacent to the upstream side in the transport direction of the first region and that faces each other with a gap therebetween.
When the number of folded sheets to be conveyed is equal to or less than the predetermined number, the conveying member moves to the first area, and when exceeding the predetermined number, the conveying member moves to the second area and controls to press the sheet crease. A sheet processing apparatus. 4. The sheet according to claim 3, wherein the pressing member is integrally molded with a large-diameter roller in the first area and a small-diameter roller in the second area, and is rotatably supported by being pivotally supported in the sheet conveying direction. Processing equipment. 5. The sheet processing apparatus according to claim 4, wherein the conveying member is used both as a conveying roller for conveying the sheet and a folding roller for bending the sheet. A transport roller for transporting the folded sheet,
A pair of pressing rollers for pressing the folds of the folded sheet from the thickness direction;
A moving unit that supports the pressing roller and moves along the sheet crease direction; and a control unit that controls sheet conveyance of the conveying roller and movement of the moving unit.
The moving unit supports the plurality of rows of pressing rollers in a stepwise manner along the moving direction, and a first region including a large-diameter roller in which the pressing rollers in the final stage of the plurality of rows are in pressure contact with each other. Consists of a second region consisting of small-diameter rollers that are adjacent to the large-diameter roller and located upstream in the sheet conveying direction and face each other with a gap between them,
The controller moves the sheet fold to the first area when the number of fold sheets conveyed is equal to or less than the predetermined number, and moves to the second area to press the sheet fold when the number exceeds the predetermined number. A sheet processing apparatus. 5. The pair of pressing rollers arranged in a plurality of rows along the moving direction in the unit are disposed at substantially equal facing positions with the sheet crease position as the center for each pair. Sheet processing device. The first area is formed by integrally forming a large-diameter roller in pressure contact with each other and a small-diameter roller as a second area upstream of the sheet conveying direction, and the large-diameter roller and the small-diameter roller are supported on a common shaft. The sheet processing apparatus according to claim 7, wherein the sheet processing apparatus is rotatably provided. The sheet processing apparatus according to claim 7, wherein the pressing roller is provided with at least three rows of pressing rollers having different intervals. 10. The sheet processing apparatus according to claim 9, wherein among the pressing rollers arranged in a plurality of rows, at least the sheet pressing rollers in the last row in the moving direction are elastically urged to each other. Image forming means for forming an image on a sheet;
A sheet processing apparatus that performs a predetermined sheet processing on the sheet from the image forming unit, and the sheet processing apparatus includes the sheet processing apparatus according to any one of claims 1 to 10. An image forming apparatus.

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