JP2017081730A - Sheet folding device and image formation apparatus having the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a relatively-compact sheet folding device which can perform folding processing without using a conveyance path along a sheet length and three folding rollers to be in pressure-contact and can easily change the front and rear faces of a folded sheet.SOLUTION: A sheet folding device includes: a conveyance roller (carry-in roller 51) which conveys a sheet; a holding member (cylindrical shape formation part 57) onto which a sheet conveyed from the conveyance roller is wound and which holds the sheet in the substantially-cylindrical shape; shift members (left shift part 60, right shift part 61) which deform the substantially-cylindrical shape sheet held by the holding member into a substantially-flat shape; folding rollers (left folding roller, right folding roller) which are located on the end of the holding member for folding the sheet made into the substantially-flat shape by the shift members; and guide gates (first gate 53, second gate 55) which are provided between the conveyance roller and the holding member and switch the sheet winding direction to the holding member.SELECTED DRAWING: Figure 14

Description

  The present invention relates to a sheet folding apparatus that folds sheets discharged from image forming apparatuses such as copying machines and various printers, and more particularly to a sheet folding apparatus that can perform compact folding and an image forming apparatus including the same.

In general, a folding apparatus that performs a folding process at a predetermined position on a sheet conveyed from an image forming apparatus is widely known.
Incidentally, in recent years, there has also been provided an apparatus that is connected to an image forming apparatus and is disposed in front of a post-processing apparatus, for example, a binding apparatus, and performs sheet folding processing.

  For example, in Patent Document 1, there are three conveyance paths that are positioned between an image forming unit and a post-processing device and that guide an image-formed sheet conveyed from the image forming unit and are in pressure contact with each other. A folding device is shown in which a folding blade and a leading edge stopper for regulating the leading edge of the sheet and a folding blade for pushing the regulated sheet between three folding rollers are arranged. In this folding apparatus, a sheet folding apparatus is illustrated in which a sheet is sequentially switched back and conveyed, and three folding rollers are sequentially passed to perform folding processing.

Also, in Patent Document 2, an image-formed sheet discharged from the image forming unit is disposed in front of a post-processing apparatus that binds sheets, and is conveyed to a curved conveyance path. A sheet folding apparatus is shown in which a folding member presses against three folding rollers that are in pressure contact with each other to perform a folding process.

Japanese Patent No. 5218836 Japanese Patent No. 5595009

The sheet folding apparatus shown in Patent Document 1 and Patent Document 2 described above requires a relatively long conveyance path that holds the length of the sheet to be folded. Each of the sheet folding apparatuses repeatedly performs a folding process by repeatedly feeding the sheet in one direction and carrying it into three rollers while being switched back and conveyed.
By the way, since the folding apparatus shown in Patent Document 2 is configured by a conveyance path curved above and below three rollers, it is relatively smaller than the folding apparatus of Patent Document 1 configured by a linear conveyance path. However, a conveyance path is required over the entire length of the curved sheet.
However, basically, the sheet has a conveyance path corresponding to the sheet conveyance length, and the sheet is folded while being switched back, so that a deviation during conveyance and a complicated conveyance path are required.
In particular, as the apparatus for processing a sheet in recent years is arranged in this space so as to correspond to the so-called in-body type in which the apparatus for processing a sheet is installed in a paper discharge space between the reading apparatus arranged above the image forming unit, a small size is achieved. Was not.

  The present invention has been made based on the above problems, and does not require a conveyance path along the conveyance length of the sheet to be folded, and is relatively compact without performing complicated conveyance of the switchback conveyance of the sheet. It is another object of the present invention to provide a sheet folding apparatus that can easily perform folding processing.

The present invention adopts the following configuration in order to solve the above problems.
A sheet folding device that folds sheets, a conveyance roller that conveys the sheet, a holding member that winds and holds the sheet conveyed from the conveyance roller in a substantially cylindrical shape, and a substantially cylindrical shape that is held by the holding member A shift member that deforms the sheet into a substantially flat shape, a folding roller positioned at an end of the holding member that folds the sheet that has become substantially flat by the shift member, and the conveyance roller and the holding member, The sheet folding device includes a guide gate that switches a sheet winding direction around the holding member.

  According to the present invention, the folding mechanism that moves while pressing the sheet holding the sheet in a substantially flat shape without pressing the conveyance path along the sheet length or the three folding rollers that are pressed against each other. It is possible to provide a sheet folding apparatus that is relatively compact and that can easily change the front and back of a folded sheet.

FIG. 3 is an explanatory diagram showing an overall configuration in which a folding unit that is a sheet folding apparatus according to the present invention and an image forming apparatus are combined. FIG. 3 is an explanatory diagram showing the overall configuration of a combination of a folding unit according to the present invention, a tray unit with an extended elevation range, and an image forming apparatus. FIG. 2 is an explanatory view showing a sheet processing apparatus including the folding unit shown in FIG. The perspective view which shows the principal part inside the folding unit of FIG. Sectional explanatory drawing of the folding unit of FIG. 4 is an explanatory plan view of the folding mechanism of the folding unit of FIG. The perspective view of the shift part before pressing the substantially cylindrical sheet | seat of FIG. Explanatory drawing which shows the drive relationship of the shift part shown in FIGS. 4-7, and a folding roller. Cross-sectional explanatory drawing which pressed the substantially cylindrical sheet | seat in the flat shape in the shift part of FIG. The perspective view of the shift part which pressed the substantially cylindrical sheet | seat of FIG. 9 to substantially flat shape. The perspective view which shows the state discharged | emitted while folding the substantially flat sheet | seat of FIG. FIG. 12A is a state diagram showing a sheet to be folded according to FIGS. 4 to 11, FIG. 12A shows a state where the sheet is held in a cylindrical shape, and FIG. 12B is an explanatory view showing a state where the sheet is folded. The perspective view which shows the state which accumulate | stores the folded sheet discharged | emitted from a folding unit, being folded by a folding roller. Cross-sectional explanatory drawing which comprises the cylindrical sheet | seat by winding the winding direction of the sheet | seat by substantially cylindrical shape in the opposite direction to FIG. The mechanism explanatory drawing of the guide gate of FIG.5 and FIG.14. FIG. 16A is a diagram for explaining the relationship between the winding state in a substantially cylindrical shape and the front and back of the sheet, and FIG. FIG.16 (b) is explanatory drawing of the state which winds clockwise according to FIG. 14, and becomes the outer side. FIG. 14A is a state diagram illustrating a sheet to be folded, and FIG. 14A illustrates a state in which the sheet is held in a substantially cylindrical shape, and FIG. 14B illustrates a state of the folded sheet that has been folded. Explanatory drawing of the control structure in the whole structure of FIG.1 and FIG.2.

Hereinafter, a sheet processing apparatus B including a folding unit 31 as a sheet folding apparatus according to the present invention and an image forming apparatus A to which the sheet processing apparatus B is attached will be described with reference to the drawings.
FIG. 1 is an explanatory diagram showing the overall configuration of a sheet processing apparatus B and an image forming apparatus A including a folding unit 31 according to the present invention. FIG. 2 is an explanatory diagram showing an overall configuration in which the sheet processing apparatus B having the folding unit 31 according to the present invention and extending the raising / lowering range of the stacking tray 90 and the image forming apparatus A are combined.

[Image forming apparatus A]
An image forming apparatus A shown in FIGS. 1 and 2 uses an electrophotographic system, and includes a sheet feeding unit including three-stage sheet feeding cassettes 1a, 1b, and 1c that store sheets below the image forming unit 2. When the sheet processing apparatus B is not mounted, the image reading device 20 is disposed above the image forming unit 2 as a paper discharge space. Therefore, when the sheet processing apparatus B is arranged, it is a so-called in-body type apparatus that uses the paper discharge space.

The image forming unit 2 employs a tandem method using an intermediate transfer belt. That is, four color components (yellow 2Y, magenta 2M, cyan 2C, black 2BK) are used. For example, in yellow 2Y, a photosensitive drum 3a as an image carrier and a charging roller for charging the photosensitive drum 3a are used. And an exposure device 5a that uses an image signal read by the image reading device 20 as a latent image. Further, a developing device 6a that forms a latent image formed on the photosensitive drum 3a as a toner image, and a primary transfer roller 7a that primarily transfers an image on the photosensitive drum 3a formed by the developing device 6a to the intermediate transfer belt 9. It has. This configuration is primarily transferred to the intermediate transfer belt 9 for each color component. The color components remaining on the photosensitive drum 3a are collected by the photosensitive cleaner 8a and prepared for the next image formation. These are the same for the other color components as shown in FIGS.

By the way, the image on the intermediate transfer belt 9 is transferred to the sheet fed from the sheet feeding unit 1 by the secondary transfer roller 10, and this image is melted and fixed on the sheet by the fixing device 12 by the applied pressure and the amount of heat. The superimposed color components remaining on the intermediate transfer belt 9 are removed by the intermediate belt cleaner 11 and prepared for the next transfer.

The sheet on which the image is formed in this way is directed to the main body discharge port 16 by the main body discharge roller 14, but when an image is formed on both sides of the sheet, the sheet once transported to the sheet processing apparatus B side by the switching gate 15 is switched. Then, the sheet is conveyed to the circulation path 17 and again sent to the image forming unit 2 to form an image on the back side of the sheet.
Thus, the sheet on which an image is formed on one or both sides of the sheet is conveyed to the sheet processing apparatus B including the folding unit 31 through the main body discharge roller 14.

Note that an image reading device 20 is disposed above the paper discharge space above the image forming unit 2. Here, the original placed on the original stacker 25 is sent to the platen 21 by the original feeding device 24, and this sent original is sequentially read by a photoelectric conversion element (for example, CCD) by irradiating the scanning unit 22 and shown in the drawing. Accumulate images in no data store. The accumulated image is formed on the sheet by the image forming unit as described above.

[Sheet Processing Device B]
Next, the sheet processing apparatus B disposed in the paper discharge space above the image forming unit 2 in FIGS. 1 and 2 and below the image reading apparatus 20 will be described. As a part of the sheet processing apparatus B, there is provided a folding unit 31 as a sheet folding apparatus for folding a sheet according to the present invention.
The sheet processing apparatus B sends a sheet discharged from the main body discharge port 16 to a downstream apparatus or guides a sheet to be switched back to form an image on both sides, and a sheet, for example, A folding unit 31 that folds in three, a binding unit 32 that temporarily stores sequentially formed image-formed sheets on the processing tray 76 and binds them as a bundle with the stapler 80, and a sheet bundle and bindings bound by the binding unit 32 A tray unit 33 having an accumulation tray 90 for accumulating sheets that are discharged without being collected is disposed.
Note that the binding unit 32 including the guide unit 30, the folding unit 31, and the tray unit 33 constituting the sheet processing apparatus B can be selectively arranged. For example, only the binding unit 32 or the folding unit can be placed, It can be omitted.

By the way, in FIG. 1, the tray unit 33 having the stacking tray 90 that moves up and down has the stacking unit 32 placed in the lifting rack 100 at a position within L1a from the staple of the apparatus frame 29 of the image forming apparatus A. It is designed to move up and down. Accordingly, since the sheet processing apparatus B is disposed in the paper discharge space, the entire image forming apparatus A becomes compact. For example, the stacking tray 90 that moves up and down when only the binding unit 32 is placed in the paper discharge space is also discharged. It can be made more compact by being located in space.

On the other hand, in the apparatus shown in FIG. 1 in this case, the moving range in which the stacking tray 90 moves up and down is the range of the L1t range up to the upper surface of the apparatus frame 29. In general, the L1t range is set to a sheet accumulation amount of about 500 to 1000 sheets. When the sheet accumulation amount is larger than this, the image forming apparatus A is stopped and the sheet placed on the accumulation tray 90 is taken out. Alternatively, the sheet processing apparatus B that can be externally attached to a completely different apparatus frame 29 is replaced.

Therefore, the stacking tray 90 according to the present invention is a sheet processing apparatus in which the extension rack 102 that can easily extend the lifting range is added to the lifting rack 100 (elevating rail 99) so that the amount of sheets stacked on the stacking tray 90 is increased. B and the image forming apparatus are shown in FIG. Although the extending mechanism will be described later, by adding the extension rack 102 (extension rail 101), the accumulated amount of sheets can be increased by about 500 to 1000 sheets.

Here, in order to add the above-described extension rack 102 so that the stacking tray 90 moves downward to the extension rack 102, first, the guide unit 30 having a length in the conveying direction L1y in FIG. Is replaced with a guide unit 30 having a length in the transport direction of L2y. The length L2y here is such that the distance L1a between the side surface of the binding device and the side surface of the device frame 29 in FIG. 1 is eliminated, and the lifting rack 100 and the extension rail 101 are in communication with each other.
In the following, the folding unit 31, the binding unit 32, which is a part of the sheet processing apparatus B, the tray unit 33 attached to the binding unit 32, and the raising / lowering mechanism of the stacking tray 90 of the tray unit 33 will be described. The extension rail including it will be described.
The guide unit 30 is shown as a unit for guiding the conveyance of the sheet for adjusting the length in the conveyance direction of the sheet processing apparatus B. However, a punch unit for punching a sheet in the unit, and a stamp unit for attaching a stamp. Or you may arrange | position the embossing unit which attaches an unevenness | corrugation to a sheet | seat independently or in combination.

[Folding unit 31]
Here, the folding unit 31 which is a sheet folding apparatus according to the present invention will be described. Here, the folding unit 31 will be described in outline, and will be described in detail with reference to FIG.
3 is an enlarged explanatory view of a folding unit 31, a binding unit 32, and a tray unit 33 attached to the folding unit 31 and a part of the sheet processing apparatus B of FIG. The sheet processing apparatus B of FIG. 2 is the same as that of FIG. 3 except for the expansion of the moving range of the stacking tray 90.
First, out of the paths connecting from the main body discharge port 16 to the switchback path 35 and the conveyance path 37 of the guide unit 30, an inlet roller 45 and an outlet roller 47 are arranged in the lower folding conveyance path 43. A switching flapper 49 is provided between the entrance roller 45 and the exit roller 47, and the switching flapper 49 performs a folding process at the cylindrical folding unit 50 without conveying the sheet to the subsequent binding unit 32. Yes.
A folding switchback path 41 communicating with the guide unit 30 shown in FIGS. 1 and 2 is provided in the upper stage.

The cylindrical fold 50 includes a carry-in roller 51 that is a conveyance roller according to the present invention for carrying in the cylindrical fold 50, a first gate 53 that determines a winding direction of the sheet around the cylindrical fold, and a first gate 53. The two gates 55 are selectively moved to the operating position. For example, the first gate 53 is wound in a substantially cylindrical shape around the cylindrical forming portion 57 in the illustrated counterclockwise direction. The cylindrical forming portion 57 is made of a deformable sheet member, and the sheet is wound and kicked into a substantially cylindrical shape in a state where, for example, three surfaces overlap. And when it shifts in the direction which mutually approaches with the shift members 60 and 61 located in the both sides in the state wound around this cylindrical formation part, the wound sheet | seat will also become a flat shape of a cross-sectional elliptical cross section. In this state, a folded sheet is obtained by pulling out the sheet wound by a cylindrical roller (not shown). Details will be described with reference to FIG.
Here, the “substantially cylindrical shape” referred to in the present invention refers to the substantially cylindrical shape shown in FIG. 12A, FIG. 16 or FIG. 17A, which will be described later, and the “substantially flat shape” refers to FIG. 12a or 12b, or a substantially cylindrical ellipse in the middle between FIG. 17a and FIG. 17b, pressing the substantially cylindrical sheet from both sides to narrow the lateral direction and extend in the vertical direction. A sheet having a shape narrower than the shape will be referred to. The “outer peripheral surface” refers to a substantially cylindrical arc surface, and the outer peripheral edge refers to an edge in the sheet width direction that intersects the winding direction.

[Binding unit 32]
Next, a binding unit 32 that binds sheets conveyed from the folding unit 31 without performing the folding process in the folding unit 31 in FIG. 3 will be described.
The binding unit 32 is also provided with a binding switchback path 65 communicating with the folding switchback path 41 in the upper stage, and a conveying roller 69 on the entrance side and a discharge roller 70 on the exit side. The binding switchback path 65 functions as a path for switching back to form an image on the back surface of the image forming unit 2, and a thick sheet such as a thick sheet or a sheet not suitable for binding processing is positioned above the tray unit 33 as necessary. The paper can be discharged to the escape tray 34 by the discharge roller 70. The folding switchback path 41 and the binding switchback path 65 may use the top cover of each unit as a switchback path.

  A binding conveyance path 67 that communicates with the folding conveyance path 43 of the folding unit 31 is provided below the binding switchback path 65. A binding carry-in roller 72 and a carry-out roller 74 that discharges the sheet to the processing tray 76 or the stacking tray 90 are provided on the entrance side of the binding conveyance path 67. When the sheets discharged from the carry-out roller 74 are temporarily placed on the processing tray 76 to form a bundle, the sheets discharged by the bundle discharge roller 86 that also functions as a bundle discharge are nipped counterclockwise ( The sheet is conveyed until it abuts against the reference surface 79 by rotating the scraping roller 78 that rotates in the counterclockwise direction in cooperation with this. At the same time, a pair of alignment plates 84 positioned in the sheet width direction of the processing tray 76 are brought into contact with the sheet side edges to align the sheets.

This is repeated until the number of bindings is reached, and when the number of bindings is reached, the stapler 80 is moved to a predetermined position on the moving table 82 and the binding process is performed. The sheet bundle that has been bound by the stapler 80 at a designated location is moved by moving the reference surface 79 (not shown) to the stacking tray 90 side, and the lower bundle discharge roller 86b fixed to the discharge side of the processing tray 76 is moved up and down the bundle discharge roller 86a. The sheet bundle is discharged to the stacking tray 90 by pressure contact.

[Tray unit 33]
The sheet bundle discharged by the bundle discharge roller 86 or the next sheet is stacked by the tray unit 33 having the stacking tray 90 that moves up and down. The stacking tray 90 is moved up and down by engaging and rotating the lifting pinion 98 of the stacking tray 90 on a lifting rack 100 that forms part of a lifting rail 99 that is a moving rail described later. The lift pinion 98 is driven by a lift motor 95 located on a lift motor installation portion 94 below the stacking tray 90 via a transmission gear 97 and the like.
As described above, the stacking tray 90 shown in FIG. 3 is moved up and down because the sheet processing apparatus B including the binding unit 32 is located in the L1a cylinder from the side of the apparatus frame 29. It has become. Further, it is possible to extend the raising / lowering range of the stacking tray 90 by providing the extension rail 101 shown in FIG. 2, and the amount of sheets stacked can be increased.
The extension rail 101 is fixed by an extension rail attachment portion 141 that is fixed to the apparatus frame 29 of the image forming apparatus A and the sheet processing apparatus B. However, this attachment may be performed only on the sheet processing apparatus B.

From here on, the folding unit 31 as a sheet folding apparatus constituting a part of the sheet processing apparatus B will be described in detail. FIG. 4 is a perspective view of a cylindrical folding portion (folding processing portion) 50 of the folding unit 31, and FIG. 5 is a sectional explanatory view of the folding unit 31.
[Cylindrical folding part (folding part) 50]
As shown in FIGS. 4 and 5, the cylindrical folding unit (folding processing unit) 50 conveys the folding conveyance path 43 from the inlet roller 45 through the folding inlet 104 communicating with the folding conveyance path 43 of the guide unit. An exit roller 47 is positioned on the exit side of the folding conveyance path 43 so that the sheet is fed to the subsequent binding unit 32. The sheet to be carried in is detected by the sheet carry-in sensor Sen1.
When the sheet is conveyed to the folding processing unit 50 that is a cylindrical folding unit that forms a cylindrical shape without feeding the sheet to the binding unit 32, the switching flapper 49 that is moved by a solenoid (not shown) is moved to the position shown in FIG. To do. As a result, the sheet conveyed by the entrance roller 45 is guided to the folding introduction path 108 and carried into the cylindrical forming portion 57. In FIG. 4, the cylindrical forming portion 57 constituting the cylindrical folding portion 50 is positioned below the entrance roller 45 and the exit roller 47 of the folding unit 31, and the sheet carried by the carry-in roller 51 near the center is substantially omitted. A cylindrical shape is shown as a perspective view.

[Cylindrical forming portion 57]
The cylindrical forming portion 57 is in a substantially cylindrical cylindrical state as shown in FIG. 12A or FIG. 17A for forming and holding the sheet in a cylindrical shape. In FIG. 5, the first gate 53 on the left side of FIG. 5 is positioned as a guide gate between the carry-in roller 51 and the cylindrical forming portion 57, whereby the sheet is rotated counterclockwise (counterclockwise / CP (L )).
The cylindrical forming portion 57 includes an outer guide 57a made of a flexible sheet material (for example, a polyester film sheet) whose end is attached to the frame of the folding unit 31, and a shift member which will be described later with an interval therebetween. 60 and 61 are constituted by inner guides 57b partially attached to the rear end pushing members 118 and 119, respectively. The inner guide 57b is also made of the same material as the outer guide 57a, and is deformed when an external force is applied to the outer guide 57a and the inner guide 57b.
In FIG. 4, only the outer guide is shown for convenience. However, depending on the sheet, only this outer guide may be used. In short, the sheet conveyed by the carry-in roller 51 is formed in a substantially cylindrical shape, and this shape is the force. Any material and shape which can be deformed by adding

[Shift member (left shift part 60, right shift part 61)]
Next, a shift member (left shift) that deforms the sheet into a substantially flat shape by pressing the substantially cylindrical sheet in the tubular forming portion 57 in a direction intersecting the sheet width direction (a direction crossing the substantially tubular shape). The unit 60 and the right shift unit 61) will be described.
First, in the left shift portion 60, a left shift plate 114 made of a flat plate pressing member extends in the sheet width direction. In this shape, a right shift plate 116 made of a flat plate pressing member is also arranged in the right shift portion 61.

As shown in FIG. 5, these are shift plates that deform a substantially cylindrical shape into a substantially flat shape with an elliptical cross section close to a shift plate release position SO that receives a substantially cylindrical sheet in a cylindrical forming portion 57. It is configured so as to be close to and away from the pressing position SC position.
As shown well in FIG. 4, this configuration has one end pivotally supported by the left link shaft 110J on the frame of the folding unit 31 at two positions on the front and rear, and the other end supported by the left shift plate 114 on the left shift plate support shaft 114J. The left link portion 110 that moves is approached and separated. The right shift plate 116 is also supported by the right link shaft 112J, and the other end is moved by the right link portion 112 that supports the right shift plate 116 by the right shift plate support shaft 116J.
By this link mechanism, the left shift plate 114 of the left shift portion 60 and the right shift plate 116 of the right shift portion 61 are moved close to and away from the shift plate release position SO and the shift plate pressing position SC.

Each of the shift members (the left shift portion 60 and the right shift portion 61) is composed of an L-shaped member. The substantially cylindrical sheet has a substantially flat shape, and the sheet is moved when the sheet is moved in the discharge direction. It has a rear end pusher member (left rear end pusher 118, right rear end pusher 120) that engages and pushes the rear end edge in the discharge direction.
In addition, folding rollers (left folding roller 132, right folding roller 136) that can be separated from each other sandwich the folded sheet outlet 145 on the discharge side pushed by the shift members (left shift unit 60, right shift unit 61). It is arranged on this side. The left folding roller 132 and the right folding roller 136 are pressed against each other to form a substantially flat sheet into a folded sheet shown in FIGS. 12B and 17B. The left folding roller 132 and the right folding roller 136 also function as a discharge row for discharging the folded sheet from the folding unit 31.
In this embodiment, the left folding roller 132 and the right folding roller 136 overlap each other by about 1/3 when they are substantially cylindrical, and are slightly longer than 1/3 of the sheet length. Is set. This can be made more compact than a conventional folding device which is set longer than the entire sheet width direction.

The configuration of the shift member (left shift unit 60, right shift unit 61) and folding rollers (left folding roller 132, right folding roller 136) and the driving mechanism thereof will be described with reference to FIGS.
FIG. 6 is an explanatory plan view of the shift unit (left shift unit 60, right shift unit 61) of the folding unit 31, and FIG. 7 is a perspective view of the left shift unit 60 and the right shift unit 61 of FIG. FIG. 4 is a driving explanatory diagram including a left folding roller 132 and a right folding roller 136.

[Rear end push part of shift member]
In FIG. 6, as described above, the shift members (the left shift portion 60 and the right shift portion 61) are each composed of an L-shaped member, and the substantially cylindrical sheet is formed into a substantially flat shape, and this sheet is discharged in the discharge direction. It has a rear end pushing member (left rear end pushing portion 118, right rear end pushing portion 120) that engages and pushes the rear end edge of the sheet discharging direction when moving to a plan view. It is shown. FIG. 7 shows a perspective view of only the shift members (the left shift portion 60 and the right shift portion 61).
As can be understood from these figures, the left shift plate 114 of the left shift unit 60 and the right shift plate 116 of the right shift unit 61 are shift plates positioned so as to support the sheet in a substantially cylindrical shape by the cylindrical forming unit 57, respectively. It is also shown that it is located at the release position SO and the shift plate pressing and pressing position SC that presses the substantially cylindrical sheet from the direction crossing the width direction to make it substantially flat.

In the shift plate release position SO described above, the left rear end pusher 118 and the right rear end pusher 120 are positioned substantially in a straight line. When the sheet is completely intruded into the cylindrical forming portion 57 and becomes substantially cylindrical, it is deformed and moved to the shift plate pressing position SC. At this position, the left rear end pushing portion 118 and the right rear The end extruding parts 120 are formed in a comb shape so as to overlap each other (see FIG. 7). This shape is used so that they do not collide with each other at the shift plate pressing position SC, and in order to allow them to be sufficiently close to each other in order to have a substantially flat shape.

Further, when the shift members (the left shift portion 60 and the right shift portion 61) move from the shift plate releasing position SO to the shift plate pressing position SC, the left rear end pushing portion 118 and the right rear end pushing portion 120 are folded left. The roller 132 and the right folding roller 136 move to the folding sheet exit 145 side. This is because the left shift plate 114 is provided on the left link portion 110 that rotates about the left link shaft 110J in the frame described above, and the right shift plate 116 is provided on the right link portion 112 that rotates about the right link shaft 112J. Results from being pivotally mounted.
Therefore, when the shift member (left shift unit 60, right shift unit 61) moves from the shift plate release position SO to the shift plate pressing position SC, the folded sheet outlet 145 of the shift member (left shift unit 60, right shift unit 61). The side end also moves from the outlet separation position AO to the outlet proximity position AC. By this operation, the sheet supported in the substantially cylindrical shape by the cylindrical forming portion 57 is deformed into a substantially flat shape and is moved while being deformed into a substantially flat shape between the left folding roller 132 and the right folding roller 136. become.

[Folding rollers (left folding roller 132, right folding roller 136)]
As described above, the left folding roller 132 is disposed on the opposite side to the left rear end pushing portion 118 in the vicinity of the folded sheet outlet 145, and the right folding roller 136 is disposed on the opposite side to the right rear end pushing portion 120. Yes. The left folding roller 132 and the right folding roller 136 are also moved between positions of a folding roller separation position RR that receives a substantially flat sheet separated from each other and a folding roller pressure contact position RA that presses and folds the sheet. It is configured. Therefore, after the left folding roller 132 and the right folding roller 136 have moved to a position where the substantially flat sheet is sandwiched by the shift members (the left shift portion 60 and the right shift portion 61), the left folding roller 132 and The right folding roller 136 is driven to rotate while being pressed.

Here, the drive mechanism including the left shift unit 60, the right shift unit 61, the left folding roller 132, and the right folding roller 136 will be described with reference to FIG.
First, the carry-in roller 51 includes a rear frame (not shown) of the folding unit 31 and a left roller support arm 124 supported on the front side (folded sheet discharge side). A roller shaft 128 is supported. Accordingly, the carry-in roller 51 is driven by the conveyance drive motor 170 together with the entrance roller 45 and the exit roller 47 shown in FIG.

[Configuration of shift member and drive mechanism]
The shift members (the left shift unit 60 and the right shift unit 61) move by rotating a sector gear 183 integrally provided on the left link unit 110 that moves the left shift plate 114. FIG. 8 shows a drive mechanism for the left shift plate 114 of the left shift portion 60 for convenience of illustration.
That is, the drive of the shift plate proximity / separation motor 174 is transmitted to the transmission worm gear 182 via the transmission gear 181. The fan-shaped gear 183 is rotated by the driving rotation of the transmission worm gear 182, and the left link portion 110 can be moved between the shift plate releasing position SO and the shift plate pressing position SC.
Driving is transmitted at a lower position overlapping with the shift members (the left shift unit 60 and the right shift unit 61), and the right shift unit 61 is also moved synchronously in the same configuration.

[Folding roller configuration and drive mechanism]
Next, a mechanism for driving and rotating the folding roller (left folding roller 132, right folding roller 136) and folding the substantially flat sheet will be described.
First, the folding roller is separated from the upper pulley 193, 195 at a position where the left folding roller shaft 133 of the left folding roller 132 and the right folding roller shaft of the right folding roller 136 face each other in the vertical axis direction. The moving belt 191 and the lower moving belt 192 stretched around the lower pulleys 194 and 196 are individually provided on the shaft support portions 197.
Accordingly, when the folding roller separation motor 178 is driven, the left folding roller 132 and the right folding roller 136 can be moved in the direction of pressure contact with one rotation, and can be moved away from each other with the other rotation. In the rotation arrow between the upper pulley 193 and the lower pulley 194 in FIG.

Further, the left folding roller 132 and the right folding roller 136 are attached to shafts that drive the folding roller separating motor 178, the upper pulley 193, and the lower pulley 194 so as to obtain a predetermined pressure contact force for sheet alignment. The intermediate gear 199 shown in the enlarged view of the two-dot chain line is provided between the transmission gear 198 and the transmission gear 198.
The intermediate gear 199 includes two gears: an outer driving gear 199a to which the driving of the folding roller separating motor 178 is directly transmitted and a spring receiving gear 199e that is coaxial with the gear and engages with the transmission gear 198. . Between the drive side gear 199a and the spring receiving gear 199e, a spring 199c interposed in a spring receiving portion 199b cut out in the driving side gear 199a is disposed. One end of the spring 199c is in contact with the inner wall of the drive side gear 199a by a spring receiver 199b, and the other end is in contact with a spring receiving portion formed integrally with the spring receiving gear 199e.

With this configuration, when the left folding roller 132 and the right folding roller 136 are not in contact with each other, the spring 199c rotates without being compressed. When the left folding roller 132 and the right folding roller 136 come into contact with each other, the driving gear 199a compresses and drives the spring 199c. The compression of the spring 199c acts as a force for pressing the left folding roller 132 and the right folding roller 136 to generate a pressing force for folding the sheet.
Although the folding roller separation motor 178 in FIG. 8 is shown on the discharge side, the apparatus is disposed below the folding roller.

Next, a configuration in which the left folding roller 132 and the right folding roller 136 are rotationally driven in the discharge direction will be described with reference to FIG.
The left folding roller 132 and the right folding roller 136 are driven by a folding roller drive motor 176. The folding roller driving motor 176 drives the angular shaft 185 extending in the same direction as the lower moving belt 192 via a transmission gear. The rotation of the square shaft 185 rotates the left sliding worm gear 187 and the right sliding worm gear 188. Accordingly, the left sliding worm gear 187 drives the left folding roller gear 134 of the left folding roller 132, and the right sliding worm gear 188 drives the right folding roller gear 138 of the right folding roller 136.
In this case, even if the left folding roller 132 and the right folding roller 136 move between the roller pressure contact position RA where they are pressed against each other and the separated roller separation position RR, the drive transmission is formed by the angular shaft 185, so this angular shaft Can be transmitted by sliding.

[Pressing the cylindrical sheet into a flat shape]
From here, the state which pressed the sheet | seat hold | maintained in the substantially cylindrical shape in FIG.4 and FIG.5 by the 7 shift member (the left shift part 60, the right shift part 61) to substantially flat shape is demonstrated in FIG.9 and FIG.10.
As shown in FIG. 9, the left shift plate 114 and the right shift portion 61 of the left shift portion 60 are driven by driving the above-described shift plate proximity / separation motor 174 on the sheet formed in the substantially cylindrical shape by the cylindrical forming portion 57. The right shift plate 116 moves from the shift plate release position SO to the shift plate pressing position SC adjacent to each other. Due to the movement to the shift plate pressing position SC, the outer guide 57a and the inner guide 57b of the cylindrical forming portion 57 are flexible sheet film materials, so that the shape changes to a substantially flat shape extending downward as shown in the figure. . As a result, the sheet is also changed from a substantially cylindrical shape to a substantially flat shape. At the time of this change, the trailing end of the sheet held in a substantially cylindrical shape is regulated by the carry-in roller 51, so that the sheet changes to an elliptical shape extending downward and becomes substantially flat.
In this figure, the inner guide 57b of the cylindrical forming portion 57 is omitted, but the inner guide 57b is similarly deformed. Further, as described above, the inner guide 57b may be omitted.

FIG. 10 is a perspective view of the shift member (left shift portion 60, right shift portion 61) of FIG. This figure shows a state where the left link part 110 and the right link part 112 of FIG. 7 are moved and the left shift plate 114 and the right shift plate 116 are moved from the shift plate release position SO to the shift plate pressing position SC. The state which changed from the shape into the substantially flat shape is shown. This shows the same state as the figure in which the left link portion 110 and the right link portion 112 in FIG. 6 described above have moved from the broken line position to the solid line position.
Further, the movement of the shift members (the left shift unit 60 and the right shift unit 61) deforms the substantially cylindrical sheet into a substantially flat shape, and the folding rollers (left folding roller 132, right folding roller) at the roller separation position RR. 136). After the substantially flat sheets are positioned on the left folding roller 132 and the right folding roller 136, they are moved to the roller pressure contact position RA by driving the folding roller separation / contact motor. In this way, the sheet is conveyed by the carry-in roller 51 and is formed into a substantially cylindrical shape by the cylindrical forming portion 57. Next, the shift member (left shift unit 60, right shift unit 61) is deformed from a substantially cylindrical shape to a substantially flat shape and moves between the left folding roller 132 and the right folding roller 136.
Further, the left rear end pushing portion 118 and the right rear end pushing portion 120 which are engaged with the substantially rear end of the sheet in the discharge direction are formed in a comb shape so as to overlap each other, as shown in FIG. The right rear end pushing part 120 formed integrally with the right shift plate 116 from the left shift plate 114 end side is shown.

Next, a state in which the substantially flat sheet in FIG. 10 is discharged while being folded will be described with reference to FIG. As described above, a substantially flat sheet having a substantially flat shape located between the left folding roller 132 and the right folding roller 136 is used, and this time, the left folding roller 132 and the right folding roller 136 are connected to the folding roller separation motor. 178 is driven to move to the roller press-contact position SC in FIG. 10, and a press-contact force to be folded by the intermediate gear mechanism described in FIG. 8 is applied. Thereafter, the left folding roller 132 and the right folding roller 136 are driven to rotate the folding roller driving motor 176, and the substantially flat sheet is folded and discharged. In FIG. 11, this state is indicated by a two-dot chain left-hand folded sheet FP (L).
If the left folding roller 132 and the right folding roller 136 are pressed and rotated to discharge while performing the folding process, the left link unit 110 and the right link unit 112 are restored. Then, the shift members (the left shift portion 60 and the right shift portion 61) move to the shift plate release position SO, return the cylindrical forming portion 57 to a substantially cylindrical shape, and prepare for the next sheet carry-in. The sheet winding direction will be described later with reference to FIG.

[Substantially cylindrical sheet and folded sheet]
Here, the state of the folded sheet created by the cylindrical folding portion (folding processing portion) 50 described so far will be described with reference to FIG.
FIG. 12A shows a state in which the sheet is held in a substantially cylindrical shape as described in FIGS. 4, 5, and 7 until now. In this figure, the sheet conveyed by the carry-in roller 51 is formed in a cylindrical shape. It is formed in a substantially cylindrical shape that is conveyed while rotating at the portion 57 and partially overlapped with each other. This sheet is formed with a left-hand folded sheet CP (L). When the folding process is performed in this overlapped state, a generally known tri-fold is obtained.
FIG. 12B is an explanatory diagram showing a state in which the left folding roller 132 and the right folding roller 136 shown in FIG. FIG. 12 shows a left-hand folded sheet FP (L) in which the substantially cylindrical left-handed tubular sheet CP (L) shown in FIG.

In addition, although being repeated, the “substantially cylindrical shape” in the present invention refers to the substantially cylindrical shape shown in FIG. 12 (a), and the “substantially flat shape” refers to FIG. 12 (a) and FIG. The sheet having a substantially narrower interval than the substantially cylindrical shape in which the lateral direction is narrow and extends in the vertical direction by pressing the substantially cylindrical sheet from both sides with an elliptical section substantially in the middle of b). . The meaning of this intermediate shape is that the diameter of the substantially cylindrical shape is reduced between the left folding roller 132 and the right folding roller 136 and the folding roller located at the roller separation position RR. It is enough to allow intrusion.

[Folded sheet storage tray]
Next, a state in which the folded sheet discharged from the folding unit 31 while being folded by the left folding roller 132 and the right folding roller 136 will be described with reference to FIG. As shown in this figure, a folded sheet outlet 145 cut out in the frame of this unit is provided on the folded sheet discharge side of the folding unit 31. The folding sheet outlet 145 is provided with a folding unit cover 147 that moves to a position that covers the frame of the folding unit 31 and a release position that is illustrated.
As shown in the enlarged view of the two-dot chain line, the folding unit cover 147 is provided with a frame attachment portion 147a attached to the frame of the folding unit 31 and a frame-side rotation shaft 147b that rotatably supports the frame attachment portion 147a. Yes. A release spring 147c that always urges the folding unit cover 147 in the releasing direction is spanned between the frame side stopper 147d of the folding unit 31 and the stopper pin 147f of the folding unit cover 147 on the rotating shaft 147b. . This configuration is the same for the opposite image of the folding unit 31.
Further, the surface of the folding unit cover 147 that faces the folded sheet outlet 145 serves as a folded sheet tray portion 148 that stores the folded sheets discharged from the folded sheet outlet 145. Therefore, even if a separate discharge tray is not provided, the paper is dropped and stored in the folded sheet tray portion 148 on the back side of the folding unit cover 147 as shown in FIG.

Further, the folding unit cover 147 opposite to the frame attaching portion 147a is provided with a locking claw 147e that enters the locking hole 149 on the frame side. The locking claw 147e is locked when the folding unit 31 is not used by a locking mechanism that is moved by a solenoid (not shown) provided in the locking hole 149.
Therefore, if the folding control unit 211 (control unit) described later is folded, the folding unit 31 operates if the lock mechanism is operated to release the latch and release the folding unit cover 147. And functions as a folded sheet tray, increasing convenience.

The locking hole 149 is provided with a folding unit cover sensor Sen3 that detects the locking claw 147e of the folding unit cover 147. This spending unit cover sensor Sen3 detects the locking claw 147e as a detection flag, and when the locking claw 147e is detected when the operation of the folding unit 31 is instructed, the locking mechanism is released.
On the other hand, as another case, when the user releases the folding unit cover 147, the folding control unit 211 (control unit) determines that there is an instruction to execute the folding process, and the cylindrical folding shown in FIGS. If the switching flapper solenoid 172 is operated so as to guide the sheet to the section 50 to cause the switching flapper 49 to enter the folding conveyance path 43, the folding process may be executed by releasing the folding unit cover 147. it can.

[Cylinder-forming part 57 winding direction switching]
Next, switching of the winding direction of the tubular forming portion 57 of the sheet that is substantially tubular at the tubular folding portion 50 will be described with reference to FIGS. By switching the winding direction, it becomes more convenient to easily change which one of the front and back sides of the folded sheet is used as the cover sheet of the folded sheet.
FIG. 14 is an explanatory view of a cross section constituting a substantially cylindrical sheet by winding the sheet winding direction of the cylindrical forming portion 57 in the opposite direction to FIG. 5. Here, for the sake of explanation, differences from FIG. 5 are mainly described, and the explanation of the other points is omitted here with reference to FIG.
In FIG. 5, the sheet conveyed by the carry-in roller 51 is guided to the cylindrical forming portion 57 by the first gate 53 as a guide gate. For this reason, the sheet is shown as a counterclockwise left-handed cylindrical sheet CP (L).

On the other hand, the thing of FIG. 14 is wound around the cylindrical formation part 57 by the 2nd gate 55 provided in the position facing said 1st gate 53. As shown in FIG. As a result, the conveyed sheet becomes the right-handed cylindrical sheet CP (R) in the clockwise direction in the cylindrical forming portion 57 as shown in FIG.
As shown in FIG. 16, the difference is that it is possible to select whether the front and back surfaces of the formed image are the front or back side of the folded sheet. The image forming apparatus A shown in FIG. 1 or FIG. 2 discharges paper with the front side facing down, and delivers it to the sheet processing apparatus B including the subsequent folding unit 31 and binding unit 32. Accordingly, in FIG. 16 as well, the sheet from the carry-in roller 51 is carried in the same front and back order. In the present invention, this is guided by either the first gate 53 or the second gate 55 located between the carry-in roller 51 and the cylindrical folding part 50 (cylindrical forming part 57), thereby forming the cylindrical forming part. The fact that the sheet winding direction to 57 is changed is utilized.

First, in FIG. 16A, a sheet is conveyed and guided to the cylindrical forming portion 57 by the first gate 53 shown in FIG. According to this, a counterclockwise left-handed cylindrical sheet CP (L) is created. According to this, the sheet is wound with the image forming surface inside, and when it is a folded sheet, a left-hand folded sheet FP (L) is created as shown in FIG. This folded sheet is an inner tri-fold, and a folding line FL appears.
On the other hand, in FIG. 16B, the sheet is conveyed and guided to the cylindrical forming portion 57 by the second gate 55 shown in FIG. According to this, conversely, a clockwise clockwise cylindrical sheet CP (R) is created. According to this, the sheet is wound with the image forming surface facing outward, and when it is a folded sheet, a right-hand folded sheet FP (R) is created as shown in FIG. This folded sheet is also an inner tri-fold, and the fold line FL appears similarly.

In this manner, the front side of the folded sheet can be selected depending on whether the guide gate that determines the winding direction of the cylindrical forming portion 57 is the first gate 53 or the second gate 55.
In the above description, the example in which the image forming apparatus A discharges with the image forming surface down is shown. However, the image forming apparatus A can also be applied to an apparatus that discharges with the image forming surface up. In short, if the winding direction to the cylindrical forming portion 57 is selected, the front and back can be interchanged.

[Guide gate (first gate 53, second gate 55) switching mechanism]
Here, the guide gate switching mechanism for switching the winding direction of the cylindrical folding portion 50 to the cylindrical forming portion 57 described so far will be described with reference to FIG.
As shown in this figure, the first gate 53 and the second gate 55 are unitized and supported by the guide gate unit 150. As described so far, the first gate 53 and the second gate 55 are located between the carry-in roller 51 and the cylindrical forming portion 57 (not shown), and any one from the direction intersecting the carrying direction of the carry-in roller 51. Is going to move forward and backward.

This selective advance / retreat has the following configuration. First, the first gate 53 is supported on the first gate mounting portion 154 of the gate support plate 157 by a first gate support shaft 153 formed of a square shaft. First, the second gate 55 is supported on the second gate mounting portion 156 of the gate support plate 157 by a second gate support shaft 155 formed of a square shaft. Therefore, the first gate 53 and the second gate 55 are attached to the same gate support plate 157.

A support plate rack 166 is integrally attached to the lower side of the gate support plate 157, and the support plate rack 166 meshes with the drive motor pinion 164 via the drive shaft 162 of the gate switching motor 160. The gate switching motor 160 is a motor that is attached to the frame on the rear side of the folding unit 31 and can be driven forward and backward. The gate switching motor 160 moves the gate support plate 157 by one rotation and causes the first gate 53 to enter.
Further, the other rotation of the gate switching motor 160 can move the gate support plate 157 in the opposite direction to retract the first gate 53 and allow the second gate 55 to enter. The two movement guide holes provided in the gate support plate 157 engage with a pin protruding from the rear frame of the folding unit 31 (not shown), and move and guide the gate support plate in the horizontal direction in the drawing. It is like that.
The reason why the first gate 53 and the second gate 55 are both cantilevered as shown in the drawing is that they do not become an obstacle to discharging when the folded sheet is discharged. As described above, the first gate 53 and the second gate 55 are supported by the gate support plate 157 disposed on the rear side of the folding unit 31 and configured as the guide gate unit 150 so that the switching is easy.

[Description of control configuration]
A system control configuration of the image forming apparatus A including the sheet processing apparatus B including the folding unit 31 as the sheet folding apparatus described above will be described with reference to a block diagram of FIG. The image forming apparatus system shown in FIGS. 1 and 2 includes an image forming control unit 200 of the image forming apparatus A, a sheet processing control unit 205 of the sheet processing apparatus B including a guide unit 30, a folding unit 31, a binding unit 32, and a tray unit 33. (Control CPU). The image formation control unit 200 includes a paper feed control unit 202 and an input unit 203. Then, sheet processing modes such as “print mode”, “sheet folding mode (including folded sheet surface setting)”, and “sheet binding mode” to be described later are set from a control panel 204 provided in the input unit 203.

  The sheet processing control unit 205 is a control CPU that operates the sheet processing apparatus B in accordance with the specified sheet processing mode. The sheet processing control unit 205 includes a ROM 206 that stores an operation program and a RAM 207 that stores control data. Further, the sheet processing control unit 205 detects, for example, the sheet carry-in sensor Sen1 that detects the sheet conveyed near the entrance roller 45 and the discharge of the folded sheet near the folded sheet exit 145 for the folding unit 31 according to the present invention. A folded sheet carry-out sensor Sen2, a folding unit cover sensor Sen3 that detects whether or not the folding unit cover 147 is released, a sheet level sensor that detects a sheet level to detect the amount of sheets stacked on the stacking tray 90, and the like. The signals from the various sensor input units 208 are input.

    Next, the sheet processing control unit 205 includes a sheet conveyance control unit 210 that controls sheet conveyance of each of the guide unit 30, the folding unit 31, the binding unit 32, and the tray unit 33. The sheet processing control unit 205 also controls a folding control unit 211 that performs sheet folding processing by the folding unit 31, a processing tray that controls the alignment plate 84 that is placed on the processing tray 76 for binding by the binding unit 32, and the like. A control unit 212 and a stapler control unit 213 that controls the stapler 80 that performs the binding process on the sheet bundle placed on the processing tray 76 are provided.

  In particular, the folding control unit 211 (control unit) for controlling the folding unit 31 according to the present invention guides to the cylindrical forming unit 57 of the cylindrical folding unit 50 by either the first gate 53 or the second gate 55 which is a guide gate. The gate switching motor 160 that selectively moves the gate support plate is controlled in order to determine the winding direction depending on whether or not to do so. The folding control unit 211 (control unit) guides the sheet from the folding conveyance path 43 to the folding introduction path 108 by the conveyance drive motor 170 that drives the inlet roller 45, the outlet roller 47, and the conveyance roller 51, and to the conveyance roller 51. A switching flapper solenoid 172 that moves a switching flapper 49 that selects whether or not is controlled. Further, the folding control unit 211 (control unit) is configured to shift the cylindrical forming unit 57 of the cylindrical folding unit 50 so as to change from a substantially cylindrical shape to a substantially flat shape. ) And a folding roller separation / contact motor that separates or presses the folding rollers (left folding roller 132 and right folding roller 136) to further fold the substantially flat sheet. 178 and a folding roller driving motor 176 for driving and rotating the folding roller are controlled.

Although not shown in FIG. 18, the folding control unit 211 (control unit) controls the folding unit cover 147 described in FIG. 13 to operate the lock mechanism by a solenoid or the like to release the folding unit cover 147. If this is done, the function of the folding unit 31 operating and a folding sheet tray will increase, and convenience will increase.
Further, when the operation of the folding unit 31 is instructed, when the unit cover sensor Sen3 detects the engaging claw 197e, it is possible to release the lock mechanism.

In other cases, when the user releases the folding unit cover 147, the folding control unit 211 (if the folding cover unit 147e is instructed by the unit cover sensor Sen3 to release the engaging claw 197e. And the switching flapper solenoid 172 is operated so as to guide the sheet to the cylindrical folding portion 50 shown in FIGS. 3 and 5 so that the switching flapper 49 enters the folding conveyance path 43. As described above, the folding process can be performed by releasing the folding unit cover 147.
Further, the sheet processing control unit 205 includes a stacking tray lifting / lowering control unit 214 that controls the lifting motor 95 based on a detection signal from the paper level sensor.

[Sheet Processing Mode]
The sheet processing control unit 205 of the present embodiment configured as described above causes the sheet processing apparatus B to execute, for example, “print mode”, “sheet folding mode (including folded sheet surface setting)”, “sheet binding mode”, and the like. . Hereinafter, this processing mode will be described.
(1) “Printout mode”
An image-formed sheet is received from the main body discharge port 16 of the image forming apparatus A, and the sheet is stored one by one in the stacking tray 90 by the bundle discharge roller 86 via the binding carry-in roller 72 and the carry-out roller 74.
(2) “Sheet folding mode”
The sheet from the conveyance path 37 of the guide unit 30 is conveyed to the cylindrical folding portion of the folding unit 31, simple sheet folding is performed, and the folded sheet is discharged to the front side of the apparatus that intersects the sheet conveyance direction of the conveyance path 37. .
In addition to this sheet folding mode setting, it is set which side of the image-formed sheet shown in FIG. 16 is the front side of the folded sheet. When there is no setting, the state shown in FIG.
(3) “Sheet binding mode”
After the sheets formed with images from the main body discharge port 16 are temporarily placed on the processing tray 76 of the binding unit 32 via the guide unit 30 and the folding unit 31 to form a bundle and the bundle is bound by the stapler 80. Stack on the stacking tray 90.

According to the form for carrying out this invention demonstrated above, there exist the following effects.
1. Sheet folding device (folding unit 31) for folding sheets, a conveyance roller (carrying roller 51) that conveys a sheet, and a holding member that winds the sheet conveyed from the conveyance roller and holds it in a substantially cylindrical shape (Cylindrical forming portion 57), a shift member (left shift portion 60, right shift portion 61) that deforms the substantially cylindrical sheet held by the holding member into a substantially flat shape, and a substantially flat shape by the shift member. A folding roller (left folding roller 132, right folding roller 136) positioned at the end of the holding member that folds the formed sheet, and the conveyance roller and the holding member are provided between the holding roller and the sheet winding direction on the holding member Is a sheet folding device comprising a guide gate (first gate 53, second gate 55) for switching between.
According to this, folding processing is performed without using a conveying path along the sheet length or three folding rollers that are pressed against each other by a folding mechanism that moves while pressing the sheet that is held in a substantially cylindrical shape while pressing the sheet in a substantially flat shape. Therefore, it is possible to provide a sheet folding apparatus that is relatively compact and that can easily change the front and back of a folded sheet.

2. The guide gate (first gate 53, second gate 55) can select whether the sheet is wound around the holding member (cylindrical forming portion 57) clockwise or counterclockwise. The sheet folding apparatus according to 1 above.
According to this, the winding direction is changed by selecting the guide gate, whereby the front and back of the folded sheet can be easily changed.

3. The sheet folding device according to 2 above, wherein the guide gates (first gate 53, second gate 55) are a pair of guide gates that selectively enter and retreat between the transport roller and the holding member. .
According to this, any of the guide gates can easily enter and retreat between the transport roller and the holding member.

4. The pair of guide gates (first gate 53, second gate 55) is supported by a guide gate unit (guide gate unit 150) that can reciprocate in a direction intersecting the sheet conveyance direction by the conveyance rollers. The sheet folding apparatus according to 3 above.
According to this, since the guide gate is supported by the guide gate unit, switching can be performed quickly and accurately.

5. The guide gate unit 150 is the sheet folding apparatus according to 4 above, wherein the guide gate unit 150 is reciprocated by a gate switching motor 160 disposed on the rear side of the apparatus and supports the guide gate in a cantilever state.
According to this, the guide gate can be switched smoothly and cantilevered so that the folded sheet is not hindered.

6. A sheet folding device (folding unit 31) that folds a sheet, and can be deformed by winding and holding a conveyance roller (loading roller 51) for conveying the sheet and a sheet conveyed by the conveyance roller in a substantially cylindrical shape. A holding member (cylindrical forming portion 57) made of a flexible sheet, and a shift member (left shift portion 60) that presses the outer peripheral surface of the sheet held in a substantially cylindrical shape by the holding member to deform it into a substantially flat shape. A right shift portion 61), and folding rollers (left folding roller 132, right folding roller 136) provided at the end portion in the sheet width direction that can press and convey the sheet that is substantially flat by the shift member. A guide gate (a first gate 53, a second gate 55) that is interposed between the conveying roller and the holding member and switches a winding direction of the sheet to the holding member between a clockwise direction and a counterclockwise direction. ).
According to this, folding processing is performed without using a conveying path along the sheet length or three folding rollers that are pressed against each other by a folding mechanism that moves while pressing the sheet that is held in a substantially cylindrical shape while pressing the sheet in a substantially flat shape. Therefore, it is possible to provide a sheet folding apparatus that is relatively compact and that can easily change the front and back of a folded sheet.

7. The guide gate (first gate 53, second gate 55) includes a pair of guide gates, and is capable of reciprocating in a direction intersecting the sheet conveyance direction by the conveyance roller (loading roller 51). 7. The sheet folding apparatus according to 6, wherein the sheet folding device is selectively supported between the conveying roller and the holding member to change the winding direction of the sheet in the holding unit.
According to this, since the guide gate is supported by the guide gate unit, switching can be performed quickly and accurately, and the winding direction can be easily changed, thereby changing the front and back of the folding sheet.

8. The holding member (cylindrical forming portion 57) is the sheet folding device according to the above 7, which includes an outer guide 57a and an inner guide 57b so as to sandwich the sheet conveyed by the conveying roller.
According to this, the conveyed sheet | seat can be reliably made into a substantially cylindrical shape.

9. The holding member (cylindrical forming portion 57) is set to a winding length (substantially cylindrical length shorter than the sheet length) in which the sheets held in a substantially cylindrical shape overlap each other. 9. The sheet folding apparatus according to 8 above.
According to this, an inner trifold folded sheet can be created depending on the degree of overlap of the sheets.

10. Image forming unit 2 for forming an image on a sheet, sheet folding device (folding unit 31) for folding a sheet from the image forming unit, and the sheet folding device according to any one of 1 to 9 above Is an image forming apparatus A.
According to this, an image forming apparatus having the effects described in the above items can be provided.

11. A reading unit (image reading device 20) that reads an image of a document above the image forming unit 2 and a sheet discharge space between the reading unit and the image forming unit,
The image forming apparatus according to 10 above, wherein the sheet folding device (folding unit 31) is disposed in the sheet discharge space.
According to this, it is possible to provide an image forming apparatus equipped with a sheet folding apparatus that exhibits the effects 1 to 9 that are also applied to a so-called in-body type.

  In the description of the effects in the above-described embodiment, for each part of the present embodiment, the corresponding members of each component in the claims are indicated in parentheses, or a reference numeral is attached and the relationship between them is shown. Was clarified.

  Further, the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the present invention, and all technical matters included in the technical idea described in the claims are described in the present invention. The subject of the invention. The embodiments described so far show preferred examples, but those skilled in the art will realize various alternatives, modifications, variations, and improvements from the contents disclosed in this specification. These are included in the technical scope described in the appended claims.

A Image forming apparatus B Sheet processing apparatus 30 Guide unit 31 Folding unit (sheet folding apparatus)
32 Binding unit 33 Tray unit 41 Folding switchback path 43 Folding conveyance path 49 Switching flapper 50 Cylindrical folding part (folding processing part)
51 Loading roller (conveying roller)
53 1st Gate (Guide Gate)
54 Second Gate (Guide Gate)
57 Cylindrical forming part (holding member)
57a Outer guide 57b Inner guide 60 Left shift unit 61 Right shift unit 80 Stapler (binding processing unit)
99 Lift rail 100 Lift rack 101 Extension rail 102 Extension rack 104 Folding inlet 106 Folding outlet 108 Fold introduction path 110 Left link portion 112 Right link portion 114 Left shift plate (pressing portion)
116 Right shift plate (pressing part)
118 Left rear end pusher 120 Right rear end pusher 132 Left folding roller (discharge roller / folding roller)
136 Right Folding Roller (Discharge Roller / Folding Roller)
145 Folding sheet outlet 147 Folding unit cover 148 Folding sheet tray 150 Guide gate unit 160 Gate switching motor 170 Conveyance drive motor 174 Proximity separation motor 176 Folding roller driving motor 178 Folding roller separation motor 181 Transmission gear 182 Transmission worm gear 183 Fan gear 119 Intermediate gear 210 Sheet conveyance control unit 211 Folding control unit (control unit)

Claims (11)

A sheet folding device for folding sheets,
A transport roller for transporting the sheet;
A holding member that winds the sheet conveyed from the conveying roller and holds the sheet in a substantially cylindrical shape;
A shift member that deforms the substantially cylindrical sheet held by the holding member into a substantially flat shape;
A folding roller located at the end of the holding member that folds the sheet that is substantially flat by the shift member;
A sheet folding apparatus comprising a guide gate provided between the conveying roller and a holding member and for switching a sheet winding direction around the holding member.   2. The sheet folding apparatus according to claim 1, wherein the guide gate can select whether the sheet is wound around the holding member clockwise or counterclockwise.   The sheet folding apparatus according to claim 2, wherein the guide gate includes a pair of guide gates that selectively enter and retract between the conveyance roller and the holding member. The sheet folding apparatus according to claim 3, wherein the pair of guide gates are supported by a guide gate unit that can reciprocate in a direction intersecting a sheet conveyance direction by the conveyance rollers. 5. The sheet folding apparatus according to claim 4, wherein the guide gate unit reciprocates by a gate switching motor disposed on the rear side of the apparatus and supports the guide gate in a cantilever state. A sheet folding device for folding sheets,
A transport roller for transporting the sheet;
A holding member made of a deformable flexible sheet for holding the sheet conveyed by the conveying roller in a substantially cylindrical shape;
A shift member that presses the outer peripheral surface of the sheet held in a substantially cylindrical shape by the holding member and deforms it into a substantially flat shape;
A folding roller provided at an end portion of the sheet width direction capable of pressing and conveying the substantially flat sheet by the shift member;
A sheet folding apparatus comprising a guide gate interposed between the conveying roller and the holding member to switch a winding direction of the sheet around the holding member between a clockwise direction and a counterclockwise direction.   The guide gate is composed of a pair of guide gates, and is supported by a guide gate unit that can reciprocate in a direction crossing the sheet conveyance direction by the conveyance roller, and selectively enters and retracts between the conveyance roller and the holding member. The sheet folding apparatus according to claim 3, wherein the sheet winding direction in the holding portion is switched.   The sheet folding apparatus according to claim 7, wherein the holding member includes an outer guide and an inner guide so as to sandwich the sheet conveyed by the conveying roller. 9. The sheet folding apparatus according to claim 8, wherein the holding member is set to a winding length in which the sheets held in a substantially cylindrical shape are overlapped with each other. An image forming unit for forming an image on a sheet;
A sheet folding device for folding sheets from the image forming unit;
An image forming apparatus comprising the sheet folding device according to any one of claims 1 to 9. A reading unit that reads an image of a document above the image forming unit;
A sheet discharge space is provided between the reading unit and the image forming unit,
The image forming apparatus according to claim 10, wherein the sheet folding device is disposed in the sheet discharge space.

Images