JP6119301B2 - Sheet processing apparatus and image forming system - Google Patents

Description

  The present invention relates to a sheet processing apparatus and an image forming system, and more particularly to a binding processing mechanism for a sheet after image formation.

Sheets printed out by an image forming apparatus such as a copying machine, a printer, or a printing machine, in addition to being discharged from the image forming apparatus, are partly bundled with a stapler in a state where a predetermined number of sheets are collected. Post-processing may be performed.
As an apparatus for this purpose, a sheet processing apparatus connected to the sheet discharge unit of the image forming apparatus is used.

Staples are generally used for the binding process, but in recent years, an apparatus that does not use metal products such as staples has been desired from the viewpoint of resource saving, ecology, and recyclability.
As one of the devices described above, the paper sheets are formed by engaging a plurality of minute tooth molds in the paper group using a tooth mold member capable of sandwiching and pressing the group of paper sheets stacked together to perform uneven deep drawing. A binding device that performs the binding process is proposed (for example, Patent Document 1).

By the way, when performing uneven | corrugated deep drawing with a crimping tooth, a sheet | seat is dragged when a crimping tooth meshes.
For this reason, the resistance at the time of overcoming a crimping tooth becomes large, and if the fiber strength in the paper is exceeded, there is a risk of tearing or breaking.
Accordingly, in order to reduce the load on the paper, a configuration is provided in which a gap is provided between the tooth surfaces facing each other between a plurality of crimping teeth arranged in succession, and used as a buffer portion when a tensile force generated during crimping acts on the fibers. Has been proposed (for example, Patent Document 2).

However, in the configuration used in the conventional binding process, the uneven tooth shape of the crimping tooth is transferred to the sheet as it is, and therefore the bulging along the transferred uneven shape occurs at the outermost part of the binding process. Occurs.
The “twist” forms a bulge or a stepped portion or even a saddle shape protruding from the paper surface at both ends of the binding processing portion of the sheet bundle, which deteriorates the appearance. In addition, the presence of such a deformed portion may cause jamming during conveyance of the sheet bundle and may affect the loading amount during loading.

  Although Patent Document 2 discloses that the pulling force that acts on the paper during crimping does not exceed the fiber strength in the paper, there is a countermeasure against “warping” that occurs on both sides of the binding processing portion. No consideration is given.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a sheet processing apparatus and an image having a configuration capable of preventing a conveyance abnormality and a reduction in a stacking amount by preventing occurrence of “twisting” on both sides of a binding processing portion when performing deep drawing with uneven crimping teeth. It is to provide a forming system.

  In order to achieve this object, the present invention provides a sheet processing apparatus that performs a binding process by pressurizing and deforming a part of a sheet bundle in which a plurality of sheets are stacked into an uneven shape, and deforms the uneven shape into the uneven shape. Therefore, a plurality of pressure-bonding teeth are arranged and can mesh with each other, and the pressure-bonding teeth have a tooth width corresponding to a direction perpendicular to the arrangement direction for at least one of the end portions in the arrangement direction. The sheet processing apparatus is characterized in that it is shorter than the tooth width of the crimp tooth at the center in the direction.

  According to the present invention, since the tooth width of the crimping tooth at the end in the arrangement direction is shorter than the crimping tooth at the center in the arrangement direction, it is possible to reduce the area receiving the deep drawing force in the paper. Thereby, the area | region where the bulge along the uneven | corrugated shape which arises at the time of meshing of crimping teeth can be decreased.

1 is a schematic diagram for explaining a configuration of an image forming system including an image forming apparatus using a sheet processing apparatus according to the present invention. It is a figure for demonstrating the structure of the control system used for the image forming system shown in FIG. It is a figure for demonstrating the procedure of the crimp binding which is an example of a binding process. It is a figure for demonstrating the structure of the crimping tooth used for the crimping binding shown in FIG. It is a figure which shows an example of the binding apparatus used for the sheet processing apparatus which concerns on embodiment of this invention. It is a figure which shows the structure of the crimping tooth which the sheet processing apparatus which concerns on embodiment of this invention presupposes. It is the figure which looked at the crimping tooth shown in FIG. 6 from the tooth surface. It is a figure for demonstrating the malfunction by the crimping tooth shown in FIG. It is a figure for demonstrating the 1st Example regarding the sheet processing apparatus which concerns on embodiment of this invention. It is a figure for demonstrating one of the effect | actions by 1st Example shown in FIG. It is a figure for demonstrating the 2nd Example regarding the sheet processing apparatus which concerns on embodiment of this invention. It is a figure for demonstrating one of the effect | actions by 2nd Example shown in FIG. It is a figure for demonstrating the 3rd Example regarding the sheet processing apparatus which concerns on embodiment of this invention. It is a figure for demonstrating one of the effect | actions by 3rd Example shown in FIG. It is a figure for demonstrating the 4th Example regarding the sheet processing apparatus which concerns on embodiment of this invention. It is a figure for demonstrating one of the effect | actions by 4th Example shown in FIG. It is a figure for demonstrating the 5th Example regarding the sheet processing apparatus which concerns on embodiment of this invention.

DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments for carrying out the present invention will be described with reference to embodiments shown in the drawings.
FIG. 1 is a schematic diagram for explaining an image forming system using a sheet processing apparatus according to an embodiment of the present invention.

In FIG. 1, an image forming system 1 includes a sheet processing apparatus 3 used for sheet processing continuously attached to and connected to a sheet discharge unit in an image forming apparatus 2 such as a copying machine, a printer, or a printing machine.
A sheet processing apparatus 3 used in the image forming system 1 is a post-processing apparatus that performs a folding process such as a binding process for binding a plurality of sheets together or a middle fold (hereinafter, the sheet processing apparatus is expressed as a sheet post-processing apparatus for convenience). Function).

In the image forming system 1, after the image forming apparatus 2 forms an image on the sheet 5, the sheet post-processing apparatus 3 receives the sheet 5 from the image forming apparatus 2 and performs various post-processing on the received sheet 5.
Examples of the various post processes include an end binding process and a half-fold process. The half-folding process includes a saddle stitching process.

In the present embodiment, in the edge binding process and the saddle stitching process, the sheet post-processing device 3 is attached to the image forming apparatus 2 and uses a sheet bundle 6 instead of a needle instead of a needle. To bind.
The sheet post-processing apparatus 3 that performs such various post-processing has a discharge mode, an end binding mode, and a middle folding mode as operation modes.

The image forming apparatus 2 has a known configuration, and an example is an electrophotographic color image forming apparatus.
In the image forming apparatus 2, for example, a control unit, an image forming unit, an optical writing unit, a paper feeding unit, a paper feeding conveyance path, an image reading unit, an intermediate transfer unit, a fixing unit, a paper discharge conveyance path, a double-side conveyance path, etc. Neither is shown), and an image is formed on both sides or one side of the paper 5.

In FIG. 1, a sheet post-processing apparatus 3 used as a sheet processing apparatus will be described.
The sheet post-processing device 3 includes a first transport path Pt1.
The first transport path Pt <b> 1 is used to receive the paper 5 discharged from the image forming apparatus 2 and discharge the paper 5 to the first paper discharge tray 10.
The first conveyance path Pt1 is branched in the middle and is connected to the second conveyance path Pt2 for performing the end binding processing or the like on the sheet bundle 6 and the second conveyance path Pt2 is saddle-stitched to the sheet bundle 6. It is divided into a third transport path Pt3 for performing the middle folding process.

Each of the transport paths Pt1 to Pt3 is formed by, for example, a guide member (not shown) that can move the paper.
In the first transport path Pt1, an entrance roller 11, transport rollers 12, 13, and a paper discharge roller 14 are arranged in order from the upstream portion to the downstream portion of the first transport path Pt1. In this case, the upstream side and the downstream side are targeted for the paper transport direction.
The entrance roller 11, the transport rollers 12 and 13, and the paper discharge roller 14 are rotationally driven by a motor and transport the paper 5 in the direction indicated by the arrow A. An inlet sensor 15 is disposed upstream of the inlet roller 11. The entrance sensor 15 detects that the sheet 5 has been carried into the sheet post-processing device 3.

A branching claw 17 is disposed downstream of the transport roller 12 in the transport direction of the paper 5.
The branch claw 17 can be rotated to switch its position. Thereby, the branching claw 17 selectively guides the paper 5 to either the downstream portion of the branching claw 17 or the second transport path Pt2 in the transport direction of the paper 5 in the first transport path Pt1. can do. For this reason, the branch claw 17 is driven by, for example, a motor or a solenoid.

  In the discharge mode, the paper 5 carried into the first transport path Pt1 from the image forming apparatus 2 is transported by the entrance roller 11, the transport rollers 12, 13 and the paper discharge roller 14, and is transferred to the first paper discharge tray 10. Discharged.

  On the other hand, in the end binding mode and the middle folding mode, the paper 5 carried into the first transport path Pt1 is transported by the entrance roller 11 and the transport roller 12, and the traveling direction is changed by the branching claw 17, so that the second Is transported to the transport path Pt2.

  The second transport path Pt2 includes transport rollers 20, 21, 22, a paper stacking tray 23, a first jogger fence 24, and an end binding portion (first binding portion) that is a characteristic portion of the present embodiment. 25) are arranged.

The transport rollers 20, 21 and 22 are driven by a motor to transport the paper 5. The first jogger fence 24 is driven by a motor.
In addition, branch claws 26 and 27 are arranged downstream of the paper stacking tray 23. The branch claws 26 and 27 are rotated to switch their positions, so that the sheet 5 is transferred to either the downstream portion of the branch claw 17 in the first transport path Pt1 or the third transport path Pt3. Selectively guide to. For this reason, the branch claws 26 and 27 are driven by, for example, a motor or a solenoid.

  In the edge binding mode, the sheets are sequentially stacked on the sheet stacking tray 23. Thereby, a sheet bundle 6 in which a plurality of sheets 5 are laminated is formed. At this time, the rear end of the paper 5 comes into contact with a first movable reference fence (not shown) provided on the paper stacking tray 23, the paper transport direction position is aligned, and the first jogger fence 24 has a width. The direction position is aligned.

  Here, the paper stacking tray 23, the first jogger fence 24, and the first movable reference fence constitute a first bundling unit 28 as a bundling unit that stacks a plurality of papers 5 to form a paper bundle 6. ing. The first bundling unit 28 also includes a motor that drives the first jogger fence 24 and a motor that drives the first movable reference fence.

As shown in FIG. 3, in the end binding portion 25 that is the first binding portion, a pair of concave and convex crimping teeth 101 and 102 are arranged with the sheet bundle 6 interposed therebetween.
In a state where the sheet bundle 6 is present, the sheet bundle 6 is bound by a crimping binding portion that applies a force to one crimping tooth in the direction of the other crimping tooth. Details of the binding method will be described later.

  The sheet bundle 6 with the edge bound is conveyed to the first conveyance path Pt1 by the first movable reference fence, and then conveyed by the conveyance roller 13 and the discharge roller 14 to the first discharge tray 10. Discharged. Here, the paper discharge roller 14 is an example of a paper discharge unit that discharges the sheet bundle 6 bound by the end binding unit 25.

  On the other hand, in the middle folding mode, the sheet 5 conveyed to the second conveyance path Pt2 is conveyed to the third conveyance path Pt3 by the conveyance rollers 20, 21, 22 and the first movable reference fence.

Conveying rollers 31 and 32 and a saddle stitch folding part 33 are arranged in the third conveying path Pt3.
The transport rollers 31 and 32 are driven by a motor to transport the paper 5. The saddle stitch folding part 33 includes a center folding part 34, a saddle stitching part (second binding part) 35, and a second bundling part 36. The saddle stitch folding portion 33 is used as an example of a binding forming portion.

The sheets 5 conveyed to the third conveyance path Pt3 are sequentially accumulated in the second bundling unit 36 by the conveyance rollers 31 and 32. Thereby, a sheet bundle 6 in which a plurality of sheets 5 are laminated is formed. That is, the second bundling unit 36 overlaps the plurality of sheets 5 conveyed by the conveyance unit 51 to form a sheet bundle 6. At this time, the front end of the paper 5 comes into contact with the second movable reference fence 37, the paper transport direction position is aligned, and the width direction position is aligned by a second jogger fence (not shown).
Then, the sheet bundle 6 is bound (saddle-stitched) by the saddle stitching section 35 in the vicinity of the center in the sheet transport direction. The saddle-stitched sheet bundle 6 is returned to the center folding position by the second movable reference fence 37. The second movable reference fence 37 is driven by a motor.

The sheet bundle 6 positioned at the center folding position is folded (center folded) by the center folding section 34 at the center in the sheet transport direction. In the middle folding section 34, the folding blade 38 facing the central portion in the sheet conveyance direction of the sheet bundle 6 located at the middle folding position moves from right to left in FIG. It pushes between a pair of press rollers 39 and 40, bending.
The folding blade 38 is driven by a motor (not shown). The folded sheet bundle 6 is pressed from above and below by the pair of pressing rollers 39 and 40.
The pair of pressing rollers 39 and 40 are driven by a motor (not shown), and the sheet bundle 6 bent in this manner is placed on the second discharge tray 42 by the pressing rollers 39 and 40 and the discharge roller 41. The paper is discharged. The paper discharge roller 41 is driven by a motor.

Here, the entrance roller 11, the transport rollers 12, 13, 20, 21, 22, 31, 32 and the paper discharge rollers 14, 41 shown in FIG. 1 together with the motors that drive them, as shown in FIG. The transport unit 51 is configured. Further, the branch claws 17, 26 and 27 shown in FIG. 1 constitute a path switching unit 52 as shown in FIG. 2 together with a motor or a solenoid for driving them.
In FIG. 1, reference numeral 49 indicates a punching device used when punching holes for binding holes.

The sheet post-processing apparatus 3 includes a control unit 61 shown in FIG.
As the control means 61, a computer having a CPU, a storage unit, a communication interface and the like is used.
The storage unit of the control unit 61 is configured by a ROM, a RAM, and the like, and stores a program executed by the CPU.
The control means 61 is connected to the inlet sensor 15, the processing section 16, the first bundling section 28, the saddle stitch folding section 33, the transport section 51, the path switching section 52, and the like.
The control means 61 (CPU) drives and controls each unit of the sheet post-processing apparatus 3 according to a program stored in the storage unit. The control unit 61 is connected to the control unit of the image forming apparatus so that data communication is possible.

Next, the binding process executed by the end binding unit 25 that is the first binding unit will be described.
FIG. 3 is a diagram for explaining a crimp binding method for an end binding portion.
In the figure, the crimping binding unit 25 is configured to form a plurality of concave and convex crimping teeth (lower concave and convex teeth 101 and upper concave and convex teeth 102) that are arranged and meshed with each other in order to deform the binding processing area of the paper into a concave and convex shape. The sheet bundle is disposed at a position facing the sheet bundle 6 (FIG. 3A).
Either one of the crimping teeth (or both) is moved and a force is applied (FIGS. 3B to 3C).
As the pressing force is increased, the paper is pressed and deformed into an uneven shape, the shape is transferred, and the binding is completed. (Fig. 3 (D))
In this crimping binding, it is possible to bind the sheets by fitting the unevenness or entanglement or fixation of the fibers between the sheets. The concavo-convex shape of the crimping teeth 101 and 102 has a slope portion having an arbitrary angle.
Also, the shape of the concavo-convex apex and valley is different, and when the crimping teeth 101 and 102 mesh with each other, as shown in FIG. 4, for example, the apex of the upper crimping tooth 102 and the valley of the lower crimping tooth 101 The parts do not touch. As a result, the sheet bundle 6 is pressure-bonded only by the inclined surface portion, and the binding can be performed efficiently.

Next, a configuration used for the above-described end binding will be described.
FIG. 5 shows an example of an operation mechanism used for the crimping binding portion 25.
As this mechanism, an upper concavo-convex tooth 102 (lower concavo-convex tooth 101) is arranged on an upper tooth arm 104 (lower tooth arm 103), and the lower tooth arm 103 rotates around an arm rotation center portion 103a.
In the rotation operation, the cam drive gear 106 is rotated by rotating the gear 105 by a drive source (not shown), and the cam contact surface of the lower tooth arm 103 is moved by a non-linear rotational movement of the cam 107 fixed thereto. Press down. As a result, the lower uneven tooth 101 moves upward and comes into contact with the upper uneven tooth 102.
Further, a return spring 108 for returning the upper and lower concave and convex teeth 101 and 102 to a separated state and a base 109 for supporting 101 to 108 are installed.

6 and 7 are diagrams illustrating the configuration of the pressure-bonding teeth that are the premise of the sheet processing apparatus according to the present embodiment.
In the figure, as described in FIGS. 3 and 4, a plurality of crimping teeth are arranged in the binding processing region, and each uneven tooth corresponds to a direction (vertical direction in the figure) perpendicular to the arrangement direction. The tooth width is the same.
When deep drawing is performed using the pressure-bonding teeth having the above-described configuration, as shown in FIG. 8, the paper bulges along the uneven shape of the uneven pressure-bonding teeth 101 and 102 on the outermost side of the binding processing region.
This swelling occurs on the paper surface protruding from the paper surface located at the engaging portion of the concave and convex crimping teeth, and becomes more prominent as the crimping force acting on the paper with the tooth surface engaging in the concave and convex shape, that is, the pressing force is larger.
The brazing force on the paper is also affected by the tooth width of the pressure-bonding teeth facing the paper. The larger the tooth width, the larger the brazing force and, as a result, the bulge tends to occur.

In this way, the raised portion generated on the outermost side of the binding processing region deforms the sheet surface reaching the sheet end portion side, causing a so-called distortion and causing a phenomenon called “swing”.
This “swaying” phenomenon becomes an obstacle when transporting a bundle of sheets, causing a transport failure due to being caught by a member in the transport path, and a decrease in the load amount in a stacking portion having a predetermined volume. .

Therefore, in the present embodiment, the above-described problems are solved by the configuration shown as an example shown in FIG.
9 and 10 are diagrams illustrating a first example of the sheet processing apparatus according to the present embodiment.
In the figure, the configuration relating to the tooth width is different from the configuration shown in FIG. 7 when used for the crimping teeth used in the sheet processing apparatus (for the sake of convenience, indicated by reference numerals 101A and 102A).
In other words, the pressure-bonding teeth 101A2 (102A2) located at least at the end in the arrangement direction are shorter than the tooth width of the pressure-bonding teeth 101A1 (102A1) located at the center in the arrangement direction (in the figure, reference numeral L1> L2). Relationship).

  In the above configuration, the tooth width at least at the end in the arrangement direction is shorter than the tooth width at the center in the arrangement direction, so that the crimping force to the paper generated when engaging the unevenness at the end in the arrangement direction is also weaker than the center in the arrangement direction. Become. Accordingly, since the acting force when the sheet is creased along the uneven shape of the pressure-bonding teeth is reduced at the end in the arrangement direction, the bulge at the end in the arrangement direction is suppressed as shown in FIG. In FIG. 10, the bulge indicated by the two-dot chain line corresponds to the bulge obtained by the configuration shown in FIG. 6, and the bulge indicated by the solid line means the bulge obtained by the configuration shown in FIG.

In the case where the tooth width of the crimping tooth is shortened in the entire binding processing area, it is possible to reduce the uneven brazing force acting on the paper in the entire binding processing area.
However, in this structure, since the area for crimping becomes small, the force which entangles fibers also becomes small and crimping | compression-bonding performance falls. In addition, if the tooth width of each crimping tooth is extremely shortened, the concentrated load on the sheet increases, and the sheet may be torn at the apex of the crimping tooth when the sheet is thin.
On the other hand, in the configuration of the first embodiment, it is possible to prevent “swing” of the paper without lowering the crimping performance only by setting the tooth width for the end portion of the binding processing area.

Next, a second example of the sheet processing apparatus according to the present embodiment will be described.
FIG. 11 is a view seen from the tooth surface of the pressure-bonded teeth for explaining the second embodiment.
In the figure, with respect to the above-described tooth widths, the tooth widths of the pressure-bonding teeth 101 and 102 are gradually shortened from the center in the arrangement direction toward the end portion (relationship indicated by reference sign L1> L2 ′> L3 in the figure).
That is, in the example of the crimping tooth shown in FIG. 9, the tooth width is shortened with respect to the crimping tooth at the center in the arrangement direction only for the arrangement direction end, but the example of the crimping tooth shown in FIG. 11. Then, the tooth width is successively shortened for the crimping teeth existing in the range from the center in the arrangement direction to the end.
In addition, instead of sequentially reducing the tooth width from the center to the end portion for the entire binding processing region, it is also possible to sequentially reduce the tooth width for a plurality of end side objects. .
In this configuration, the tooth width on the central side in the arrangement direction is set to a tooth width that can provide a brazing force necessary for the crimping binding, so that the crimping binding can be secured on the central side in the arrangement direction, and FIG. Similar to the configuration shown, the brazing force is weakened and swelling is suppressed.

In the above configuration, as shown in FIG. 12, the tooth width of each crimping tooth from the center in the arrangement direction of the crimping teeth to the end in the binding processing region is sequentially changed, so that the center in the arrangement direction reaches the end. Accordingly, the sheet brazing power is gradually weakened.
As a result, it is possible to secure a pressure-bonding force to the sheet in the binding processing area and to suppress swelling on the end side.

Next, a third example relating to the sheet processing apparatus according to the present embodiment will be described.
The third embodiment shown in FIG. 13 is different from the configuration in the embodiment shown in FIG. 11, that is, the configuration in which the tooth width is sequentially shortened from the center in the arrangement direction to the end, and the reference for shortening is different. It is
In other words, in the configuration shown in FIG. 11, the center in the tooth width direction common to all the pressure-bonded teeth as the reference for shortening the tooth width from the center to the end in the arrangement direction (position indicated by reference sign HP in FIG. 11). Is based on.
In this configuration, as shown in FIG. 12, the crimped binding position has a drum shape over the entire binding processing region.
When the sheet bundle is bound, a uniform turning force acts on a deeply drawn portion at the crimping binding position when turning the sheet. At this time, in the configuration shown in FIG. 11, the end portions in the width direction of the concavo-convex crimping portion are non-uniformly arranged with respect to the paper turning direction (the direction indicated as the turning direction in FIG. 14). The turning force is concentrated at each crimping part.
For this reason, if a turning force is exerted on each crimping portion beyond the bonding force due to the crimping, the binding force is reduced at the single crimping portion, and the paper may be peeled off.

The embodiment shown in FIG. 13 has the above-described configuration for preventing a reduction in the binding force of the crimping portion during turning.
That is, as shown in FIGS. 13 and 14, the tooth width reference position of each crimp tooth is made to coincide on the upstream side in the direction indicated by the turning direction in FIG. 14 (position indicated by symbol HP in FIG. 13).
Since the tooth width of the crimping tooth is sequentially shortened from the center in the arrangement direction to the end, as in the configuration shown in FIG. 11, securing of the crimping force to the paper in the binding processing region and the end side Swelling suppression is possible.

  On the other hand, in addition to the above-described action, the tooth width reference position is matched on the upstream side in the turning direction, so that the turning force acts equally on all the crimping parts. As a result, it is possible to disperse the turning force and prevent peeling at the crimping portion.

Next, a fourth example relating to the sheet processing apparatus according to the present embodiment will be described.
In the embodiment shown in FIGS. 15 and 16, for the configuration of the crimping tooth shown in FIG. 9, the one side and the other side in the arranging direction of the crimping tooth have different shorts with respect to the tooth width at the center in the arranging direction. It is set.

The reason for this configuration is as follows.
As shown in FIG. 9 to FIG. 14, the binding method for paper is applied in parallel to the width direction of the paper as shown in FIG. A binding position may be provided.
In such a case, the space occupied by the paper surface on the edge side of the binding process area is different between the edge part side in the paper width direction and the center side in the paper width direction in the crimping part. That is, since the edge of the paper is located in the vicinity on the edge side in the paper width direction, the space on the paper surface occupied between the edge of the binding processing region and the paper edge is small. On the other hand, on the central side in the paper width direction, the space on the paper surface occupied between the edge of the binding processing area and the central side in the paper width direction is large.

For this reason, when crimp binding is performed on both sides in the paper width direction, the swelling of the paper when deep drawing is different depending on the space occupied by the paper surface. In particular, since the space occupied by the paper surface is large at the end of the binding processing region located on the center side in the paper width direction, the amount of paper dragged during deep drawing increases and the swelling also increases.
When the degree of swelling differs in the paper width direction, the amount of occurrence of “flickering” differs. If the “twist” at the center in the width direction becomes larger than both sides in the paper width direction, there will be more opportunities to contact the transport section during transport. It becomes easy.

In the fourth embodiment, one side in the arrangement direction of the crimping teeth, and in the configuration shown in FIG. 16, the tooth width of the crimping tooth at the binding processing region end located at the center side in the sheet width direction is the end side in the sheet width direction. It is made shorter than the tooth | gear width | variety of the crimping | compression-bonding tooth | gear in the binding process area | region edge part located in this. That is, the tooth width at the center side in the paper width direction corresponding to the right side, which is one of the edge portions of the binding processing region in FIG. 16B, is larger than the tooth width at the edge side in the paper width direction corresponding to the left side. It is shortened. In FIGS. 16A and 16B, reference numerals L1, L2, and L3 indicate displays in which the relationship between the center of the binding processing region and the tooth width at each end is L1>L2> L3. .
In this case, the relationship between the tooth widths of the respective teeth in the binding processing region is such that the tooth width at the end of the binding processing region is shorter than the tooth width at the center of the binding processing region, as shown in FIG. Relationship is used.

  In the above configuration, the tooth width on the side where the “swing” is likely to occur greatly at the end of the binding processing region is shortened relative to the tooth width on the side where the “swing” is not so large. As a result, it is possible to suppress the occurrence of large “swing” in the paper width direction. As a result, it is possible to prevent a conveyance failure when a large amount of “warp” occurs while securing the binding force.

Next, a fifth example of the sheet processing apparatus according to the present embodiment will be described.
In the embodiment shown in FIG. 17, the height of the crimping tooth at the end in the arrangement direction is lower than the crimping tooth at the center in the arrangement direction in the binding processing region. In FIG. 17, the upper concave and convex teeth 102 are indicated by reference numerals H <b> 1 and H <b> 2, and the lower concave and convex teeth 101 are indicated by reference signs H <b> 1 ′ and H <b> 2, and the relationship between the heights is H1> H2 and H1 ′> H2 ′. It is said that. In addition, although not shown in figure, regarding the tooth | gear width, the end part side has a short relationship from either of the structure mentioned above, ie, the binding area | region center.

  In the above configuration, the swelling of the sheet is reduced by reducing the brazing force due to the reduction in the brazing force due to the reduction in the brazing force at the binding region end side due to the difference in the tooth width and the lower tooth height. Deformation can be made difficult to occur. In other words, since there is no tooth surface that deeply draws the paper surface at both ends of the binding processing portion of the sheet bundle and floats up following the irregular shape, the opportunity to lift the paper surface at the edge of the binding processing region can be eliminated. As a result, it is possible to suppress swelling at the end of the binding processing area.

  In the above embodiment, by a simple configuration in which the tooth width at the end in the arrangement direction of the crimping teeth for performing crimping binding of the paper by meshing the uneven teeth is shorter than the tooth width at the center in the arrangement direction, Swelling due to floating of the paper surface can be suppressed. As a result, it is possible to reliably prevent a conveyance failure and a decrease in the load when there is a bulge. In particular, since the swelling can be prevented only by determining the shape of the teeth, it is not necessary to use a special structure such as a pressurizing mechanism for eliminating the swelling.

DESCRIPTION OF SYMBOLS 1 Image forming system 2 Image forming apparatus 3 Paper post-processing apparatus 25 Edge binding part 101,102 Crimping tooth 101A1,102A1 Crimping tooth 101A2,102A2 of the arrangement direction center side Crimping tooth L1. L2. L3 tooth width

Japanese Patent Laid-Open No. 07-165365 International Publication No. 2009/110298

Claims (5)

A sheet processing apparatus that performs a binding process by pressurizing and deforming a part of a sheet bundle in which a plurality of sheets are stacked in an uneven shape,
A plurality of crimping teeth arranged to mesh with each other in order to deform into the irregular shape,
In the crimping tooth, a tooth width corresponding to a direction perpendicular to the arranging direction is made shorter than a tooth width of the crimping tooth in the center in the arranging direction, targeting at one of the end portions in the arranging direction. A sheet processing apparatus.   2. The sheet processing apparatus according to claim 1, wherein the crimping teeth are successively shortened in width from the center in the arrangement direction toward the end.   The sheet processing apparatus according to claim 1, wherein the crimping teeth are set to have different lengths with respect to the tooth width at the center in the arrangement direction on one side and the other side in the arrangement direction. .   The said crimping tooth has the height of the tooth | gear of the said arrangement | positioning direction edge part with respect to the thing of the said arrangement | sequence direction center, The one of Claim 1 thru | or 3 characterized by the above-mentioned. Sheet processing device.   An image forming system comprising the sheet processing apparatus according to claim 1 attached to an image forming apparatus.

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