JP6626688B2 - Sheet folding apparatus and image forming apparatus having the same - Google Patents

Description

  The present invention relates to a sheet folding apparatus for folding sheets discharged from an image forming apparatus such as a copying machine and various printers, and more particularly to a sheet folding apparatus capable of performing compact folding and an image forming apparatus including the same.

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

  For example, in Japanese Patent Application Laid-Open No. H11-163, there are three conveyance paths located between the image forming unit and the post-processing apparatus, which guide an image-formed sheet conveyed from the image forming unit, and three pressure-contacting members located on the conveyance path. A folding device in which a folding roller, a leading end stopper for regulating the leading end of the sheet, and a folding blade for pushing the regulated sheet between three folding rollers is arranged. The folding apparatus repeats switchback conveyance of a sheet in order, and sequentially passes three folding rollers to perform a folding process.

Also, in Japanese Patent Application Laid-Open No. H11-163873, the image-formed sheet discharged from the image forming unit is disposed before a post-processing device that performs sheet binding, and is once conveyed to a curved conveyance path. 1 shows a sheet folding apparatus that performs folding processing by pressing a folding member against three folding rollers that are in pressure contact with each other.

Japanese Patent No. 5218836 Japanese Patent No. 5559009

The sheet folding apparatus disclosed in Patent Documents 1 and 2 requires a relatively long conveyance path for holding the length of a sheet to be folded. In addition, any of the sheet folding apparatuses performs the folding process by repeating the operation of feeding the sheet in one direction and carrying the sheet into the three rollers while performing switchback conveyance.
By the way, since the folding device shown in Patent Document 2 is configured by a conveyance path curved above and below three rollers, it is relatively smaller than the folding device of Patent Document 1 configured by a straight conveyance path. However, a conveying path over the entire length of the curved sheet is required.
However, it basically has a transport path corresponding to the sheet transport length, and requires a shift during transport and a complicated transport path for folding the sheet while performing switchback transport of the sheet.
Particularly, in order to cope with the so-called internal type, in which a recent sheet processing apparatus is installed in a paper discharge space between a reading apparatus arranged above the image forming unit, a small size is achieved. Had not been.

  The present invention has been made based on the above problem, and does not require a conveyance path along the conveyance length of a sheet to be folded, and does not perform complicated conveyance of switchback conveyance of a sheet, and is relatively compact. An object of the present invention is to provide a sheet folding apparatus that can easily perform a folding process.

The present invention employs the following configurations in order to solve the above-mentioned problems.
A sheet folding device for folding a sheet, comprising: a holding member for holding a conveyed sheet in a substantially cylindrical shape; a folding roller provided at one end of the holding member for folding the sheet; And a shift member that presses the outer peripheral surface of the substantially cylindrical sheet held by the holding member and moves to the folding roller side.

  According to the present invention, a folding mechanism that holds a sheet in a substantially cylindrical shape, discharges the sheet while pressing the sheet in a substantially flat shape, without using a transport path along the sheet length or three folding rollers that are in pressure contact with each other. A relatively compact folding device can be provided.

FIG. 1 is an explanatory diagram showing an overall configuration in which a folding unit, which is a sheet folding device according to the present invention, and an image forming apparatus are combined. FIG. 1 is an explanatory diagram showing an overall configuration in which a folding unit according to the present invention, a tray unit having an extended lifting range, and an image forming apparatus are combined. FIG. 2 is an explanatory diagram showing a sheet processing apparatus including the folding unit shown in FIG. FIG. 4 is an exemplary perspective view showing a main part inside the folding unit in FIG. 3; 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. FIG. 7 is a perspective view of a shift unit before pressing the substantially cylindrical sheet of FIG. 6. FIG. 8 is an explanatory diagram illustrating a driving relationship between a shift unit and a folding roller illustrated in FIGS. 4 to 7. FIG. 8 is an explanatory cross-sectional view in which a substantially cylindrical sheet is pressed flat by the shift unit in FIG. 7. FIG. 10 is a perspective view of a shift unit that presses the substantially cylindrical sheet of FIG. 9 in a substantially flat shape. FIG. 11 is a perspective view showing a state in which the substantially flat sheet of FIG. 10 is discharged while being folded. 12A and 12B are state diagrams showing a sheet to be folded according to FIGS. 4 to 11, wherein FIG. 12A shows a state in which the sheet is held in a tubular shape, and FIG. FIG. 9 is a perspective view showing a state in which folded sheets discharged from a folding unit while being folded by a folding roller are stacked. Sectional explanatory drawing which comprises winding a sheet in a substantially cylindrical shape in a direction opposite to that of FIG. 5 to form a cylindrical sheet. FIG. 15 is an explanatory view of the mechanism of the guide gate of FIGS. 5 and 14. FIG. 16A is a diagram for explaining the relationship between the winding state in a substantially cylindrical shape and the front and back sides of the sheet. FIG. FIG. 16B is an explanatory view of a state in which the winding surface is turned clockwise as shown in FIG. 14A is a state diagram showing a sheet to be folded, FIG. 14A is a diagram illustrating a state where the sheet is held in a substantially cylindrical shape, and FIG. 14B is a diagram illustrating a state of the folded sheet after the folding process. FIG. 3 is an explanatory diagram of a control configuration in the overall configuration of FIGS. 1 and 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 an 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 the overall configuration of a combination of the sheet processing apparatus B and the image forming apparatus A, which have the folding unit 31 according to the present invention and extend the range in which the stacking tray 90 is moved up and down.

[Image Forming Apparatus A]
The image forming apparatus A shown in FIGS. 1 and 2 uses an electrophotographic method, and includes a sheet feeding unit including three-stage sheet feeding cassettes 1a, 1b, and 1c for storing 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, the apparatus is a so-called internal type apparatus that uses the above-described paper discharge space.

The image forming section 2 employs a tandem system 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 And an exposure device 5a that uses the 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 the 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 other color components as shown in FIGS.

The image on the intermediate transfer belt 9 is transferred to a sheet fed from the sheet feeding unit 1 by the secondary transfer roller 10, and the image is melted and fixed on the sheet by the fixing device 12 by pressing force and heat. The superposed 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 an image has been formed in this manner is directed to the main body discharge port 16 by the main body discharge roller 14. When images are formed on both sides of the sheet, the sheet once conveyed to the sheet processing apparatus B by the switching gate 15 is switched. Then, the sheet is conveyed to the circulation path 17 and sent to the image forming unit 2 again to form an image on the back side of the sheet.
The sheet on which the image is formed on one side 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 feeder 24, and the sent original is irradiated with the scan unit 22 to be sequentially read by a photoelectric conversion element (for example, a CCD) and shown. Not storing data in data storage. The image formation of the stored image on the sheet by the image forming unit is as described above.

[Sheet processing device B]
Next, a description will be given of the sheet processing apparatus B arranged in the paper discharge space above the image forming unit 2 and below the image reading apparatus 20 in FIGS. As a part of the sheet processing apparatus B, a folding unit 31 as a sheet folding apparatus for folding a sheet according to the present invention is provided.
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 unit, for example. A folding unit 31 for folding in three, a binding unit 32 for temporarily placing an image-formed sheet sequentially conveyed on a processing tray 76 and binding it as a bundle with a stapler 80, and a sheet bundle or binding bound by the binding unit 32 A tray unit 33 having an accumulation tray 90 for accumulating and raising sheets discharged without being stacked is arranged.
Note that the binding unit 32 having 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 and the folding unit can be placed. It is possible to omit it.

By the way, in FIG. 1, the tray unit 33 having the stacking tray 90 which moves up and down is such that the binding unit 32 is moved from the staple of the apparatus frame 29 of the image forming apparatus A to a position within L1a and the stacking tray 90 is moved to the lifting rack 100. On the other hand, it goes up and down. Therefore, since the sheet processing apparatus B is disposed in the paper discharge space, the entire image forming apparatus A becomes compact. For example, when only the binding unit 32 is placed in the paper discharge space, the stacking tray 90 which moves up and down also discharges the paper. It can be more compact by being located in space.

On the other hand, in the apparatus shown in FIG. 1 in this case, the moving range where 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. Generally, this L1t range is set to about 500 to 1000 sheets as the amount of sheets to be stacked, and when the number of sheets is increased beyond this range, the image forming apparatus A is stopped and the sheets placed on the stacking tray 90 are taken out. Alternatively, the sheet processing apparatus B which 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 capable of easily expanding the elevating range is added to the conventional elevating rack 100 (elevating rail 99) to increase the amount of sheets stacked on the stacking tray 90. B, the image forming apparatus, and FIG. The mechanism for extending the extension will be described later. However, by adding the extension rack 102 (extension rail 101), the amount of accumulated sheets can be increased from about 500 sheets to about 1000 sheets.

Here, in order to add the above-mentioned extension rack 102 and to cause the accumulation tray 90 to move down to this extension rack 102, first, the guide unit 30 having the length in the conveyance direction of L1y in FIG. Is replaced with a guide unit 30 having a length in the transport direction of L2y. Here, the length L2y 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.
In the following, a description will be given of a folding unit 31, a binding unit 32, a tray unit 33 attached thereto, and an elevating mechanism of the stacking tray 90 of the tray unit 33, which form part of the sheet processing apparatus B. The extension rails including this will be described.
Although the guide unit 30 is a unit for guiding the conveyance of a sheet for adjusting the length of the sheet processing apparatus B in the conveyance direction, the unit includes a punch unit for punching a sheet and a stamp unit for attaching a stamp. Alternatively, an embossing unit for providing unevenness to a sheet may be arranged alone 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 outline of the folding unit 31 will be described, and the details will be described later with reference to FIG.
FIG. 3 is an enlarged explanatory view of the folding unit 31, the binding unit 32, and the tray unit 33 attached to the folding unit 31, the binding unit 32, and the sheet processing apparatus B of FIG. The sheet processing apparatus B in FIG. 2 has the same configuration as that in FIG.
First, an entrance roller 45 and an exit roller 47 are disposed in the lower folding conveyance path 43 of the path extending from the main body discharge port 16 to the switchback path 35 and the conveyance path 37 of the guide unit 30. A switching flapper 49 is provided between the entrance roller 45 and the exit roller 47, and the switching flapper 49 performs folding processing in the tubular folding section 50 without transporting the sheet to the subsequent binding unit 32. I have.
A folding switchback path 41 communicating with the guide unit 30 shown in FIGS. 1 and 2 is provided in the upper stage.

The tubular folding unit 50 includes a carry-in roller 51 serving as a transport roller of the present invention for carrying in the sheet, and a first gate 53 that determines a winding direction of the sheet around the tubular folding unit. The two gates 55 can be selectively moved to the operating position. For example, the first gate 53 winds the tube forming portion 57 in a substantially cylindrical shape in a counterclockwise direction in the drawing. The cylindrical forming portion 57 is made of a deformable sheet member, and is wound around the sheet in a substantially cylindrical shape, for example, with three surfaces overlapping. When the sheet is shifted in the direction approaching each other by the shift members 60 and 61 located on both sides in a state of being wound on the cylindrical forming portion, the wound sheet also has a flat shape with a vertical 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 later with reference to FIG.
Here, the “substantially cylindrical shape” referred to in the present invention refers to a substantially cylindrical shape having a shape shown in FIG. 12A, FIG. 16 or FIG. a) and FIG. 12 (b) or FIG. 17 (a) and FIG. 17 (b), a substantially cylindrical ellipsoidal cross section which presses the substantially cylindrical sheet from both sides to narrow the lateral direction and extend in the vertical direction. A sheet having a smaller interval 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 description will be given of the binding unit 32 that binds the sheet conveyed from the folding unit 31 without performing the folding process in the folding unit 31 in FIG.
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 transport 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 side of the image forming unit 2, and places both sides of a thick sheet or a sheet unsuitable for binding processing above the tray unit 33 as necessary. The paper can be discharged to the escape tray 34 by the discharge roller 70. In the folding switchback path 41 and the binding switchback path 65, the upper cover of each unit may be used as a switchback path.

  A binding transport path 67 communicating with the folding transport path 43 of the folding unit 31 is provided below the binding switchback path 65. At the entrance side of the binding conveyance path 67, a binding carrying-in roller 72 and a carrying-out roller 74 for discharging a sheet to the processing tray 76 or the collecting tray 90 are provided. When the sheets discharged from the unloading rollers 74 are temporarily placed on the processing tray 76 to form a bundle, the sheets discharged by the bundle discharge rollers 86 which also function as a bundle are nipped counterclockwise ( The sheet is conveyed until the sheet comes into contact with the reference surface 79 by rotating the writing roller 78 which rotates counterclockwise in cooperation with the rotation. At the same time, a pair of alignment plates 84 located 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 sheets to be bound is reached. When the number of sheets to be bound has been reached, the stapler 80 is moved to a predetermined position on the moving table 82 to perform the binding process. The sheet bundle bound by the stapler 80 at the designated location is moved to the stacking tray 90 side of the reference surface 79 (not shown) and the lower bundle discharging roller 86b fixed to the discharging side of the processing tray 76 is moved up and down by the lifting bundle discharging roller 86a. The sheet bundle is discharged to the stacking tray 90 by pressing.

[Tray unit 33]
The sheet bundle or the next sheet discharged by the above-mentioned bundle discharge roller 86 is accumulated in a tray unit 33 having an accumulation tray 90 which moves up and down. The stacking tray 90 is configured so that a lifting pinion 98 of the stacking tray 90 engages with a lifting rack 100 which forms a part of a lifting rail 99 which is a moving rail described later, and moves up and down. The elevating pinion 98 is driven by an elevating motor 95 located at an elevating motor installation section 94 below the stacking tray 90 via a transmission gear 97 and the like.
As described above, the range of lifting and lowering of the stacking tray 90 shown in FIG. 3 is within the L1t range since the sheet processing apparatus B including the binding unit 32 is located within the L1a cylinder from the side of the apparatus frame 29. Has become. The extension range of the stacking tray 90 can be extended by providing the extension rail 101 shown in FIG. 2, and the stacking amount of sheets can be increased.
The extension rail 101 is fixed to the apparatus frame 29 of the image forming apparatus A and the extension rail attaching section 141 that is fixed to the sheet processing apparatus B. However, this attachment may be performed only to the sheet processing apparatus B.

Hereafter, the folding unit 31 as a sheet folding device constituting a part of the sheet processing apparatus B will be described in detail. FIG. 4 is a perspective view of a tubular folding section (folding processing section) 50 of the folding unit 31, and FIG. 5 is a sectional explanatory view of the folding unit 31.
[Tube-shaped folding part (folding processing part) 50]
As shown in FIGS. 4 and 5, the cylindrical folding section (folding processing section) 50 conveys the folding conveyance path 43 from an entrance roller 45 through a folding entrance 104 communicating with the folding conveyance path 43 of the guide unit. An exit roller 47 is located on the exit side of the folding conveyance path 43 so as to feed the sheet 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 section 50, which is a tubular folding section that forms a tubular shape without sending the sheet to the binding unit 32, the switching flapper 49 moved by a solenoid (not shown) is moved to the position shown in FIG. I do. Thus, the sheet conveyed by the entrance roller 45 is guided to the folding introduction path 108 and is carried into the cylindrical forming section 57. FIG. 4 shows that the cylindrical forming portion 57 constituting the cylindrical folding portion 50 is located below the entrance roller 45 and the exit roller 47 of the folding unit 31, and the sheet conveyed by the carry-in roller 51 near the center thereof is approximately shown. FIG. 3 is a perspective view showing the formation into a cylindrical shape.

[Cylindrical forming part 57]
The tubular forming portion 57 is formed in a substantially cylindrical tubular state as shown in FIG. 12A or 17A for forming and holding a sheet in a tubular shape. In FIG. 5, a first gate 53 on the left side of FIG. 5 is located as a guide gate between the carry-in roller 51 and the cylindrical forming portion 57, whereby the sheet is moved in a counterclockwise direction (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 to be described later with an interval provided therebetween. The guides 60 and 61 are formed by inner guides 57b each having a part 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.
Although only the outer guide is shown in FIG. 4 for convenience, only the outer guide may be used depending on the sheet. In short, the sheet conveyed by the carry-in roller 51 is formed in a substantially cylindrical shape. Any material and shape that can be deformed by the addition of any material may be used.

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

These shift plates deform the substantially cylindrical shape into a substantially flat shape having an elliptical cross section in close proximity to a shift plate release position SO for receiving a substantially cylindrical sheet in the tubular forming portion 57 as shown in FIG. It is configured to approach and separate from the pressing position SC.
In this configuration, as shown in FIG. 4, one end of the frame of the folding unit 31 is supported by the left link shaft 110J at the front and rear two places, and the other end is supported by the left shift plate 114 by the left shift plate support shaft 114J. The left and right link portions 110 approach and separate from each other. The right shift plate 116 is also supported by a right link shaft 112J, and the other end is moved by a right link portion 112 that supports the right shift plate 116 with a right shift plate support shaft 116J.
With this link mechanism, the left shift plate 114 of the left shift unit 60 and the right shift plate 116 of the right shift unit 61 move toward 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 formed of an L-shaped member, and a substantially cylindrical sheet is formed to be substantially flat. There is a rear end pushing member (a left rear end pushing section 118 and a right rear end pushing section 120) which engages with and pushes out the rear end edge in the discharge direction.
On the discharge side pressed by the shift members (the left shift unit 60 and the right shift unit 61), folding rollers (left folding roller 132 and right folding roller 136) which can be separated from and separated from each other sandwich the folded sheet outlet 145. This is located on the near side. The left folding roller 132 and the right folding roller 136 press each other to make 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, since the left folding roller 132 and the right folding roller 136 have an overlap of approximately 1/3 when they are substantially cylindrical, they are slightly longer than 1/3 of the sheet length. Is set. This is more compact than a conventional folding apparatus that is set longer than the entire area in the sheet width direction.

The structures of the above-mentioned shift members (left shift unit 60, right shift unit 61) and folding rollers (left folding roller 132, right folding roller 136) and their driving mechanisms will be described with reference to FIGS.
FIG. 6 is an explanatory plan view of a 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 right shift unit 61 in FIG. Is a drive explanatory diagram including a left folding roller 132 and a right folding roller 136.

[Rear end extrusion of shift member]
In FIG. 6, the shift members (the left shift portion 60 and the right shift portion 61) are each formed of an L-shaped member as described above, and the substantially cylindrical sheet is formed into a substantially flat shape. It has a rear end pushing member (a left rear end pushing section 118, a right rear end pushing section 120) that engages with and pushes out the rear end edge in the sheet discharging direction when moving to It is shown. FIG. 7 is a perspective view of only the shift members (the left shift unit 60 and the right shift unit 61).
As can be understood from these drawings, the left shift plate 114 of the left shift unit 60 and the right shift plate 116 of the right shift unit 61 are each a shift plate that is positioned so that the sheet is supported by the tubular forming unit 57 in a substantially cylindrical shape. It is also shown that it is located at a release position SO and a shift plate pressing / pressing position SC where the substantially cylindrical sheet is pressed from a direction intersecting the width direction to be substantially flat.

At the shift plate release position SO, the left rear end pushing section 118 and the right rear end pushing section 120 are positioned substantially linearly. When the sheet has completely entered the tubular forming portion 57 and becomes substantially tubular, the sheet is deformed and moves to the shift plate pressing position SC. In this position, the left rear end pushing portion 118 and the right rear The end pushing parts 120 are formed in a comb shape so as to overlap each other (see FIG. 7). This shape is adopted in order to prevent collision with each other at the shift plate pressing position SC, and to allow them to be sufficiently close to each other so as to be substantially flat.

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

[Folding rollers (left folding roller 132, right folding roller 136)]
As described above, the left folding roller 132 is arranged on the opposite side of the left rear end pushing section 118 near the folded sheet outlet 145, and the right folding roller 136 is arranged on the opposite side of the right rear end pushing section 120. I have. The left folding roller 132 and the right folding roller 136 also move between the folding roller separating position RR for receiving a substantially flat sheet separated from each other and the folding roller pressing position RA for pressing and folding together. Is configured. Therefore, after moving to a position where the sheet that is becoming substantially flat by the shift members (the left shift unit 60 and the right shift unit 61) is sandwiched between the left folding roller 132 and the right folding roller 136, the left folding roller 132 The right folding roller 136 is driven to rotate by pressing.

Here, a 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 has a rear roller 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. Thus, the carry-in roller 51 is driven by the transport drive motor 170 together with the inlet roller 45 and the outlet roller 47 shown in FIG.

[Structure 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 driving mechanism of the left shift plate 114 of the left shift unit 60 for convenience of illustration.
That is, the drive of the shift / separation motor 174 is transmitted to the transmission worm gear 182 via the transmission gear 181. The above-described sector gear 183 is rotated by the drive rotation of the transmission worm gear 182, and the left link 110 can be moved between the shift plate releasing position SO and the shift plate pressing position SC.
Drive 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 also moves synchronously with the same configuration.

[Structure and drive mechanism of folding roller]
Next, a description will be given of a mechanism for driving and rotating the folding rollers (the left folding roller 132 and the right folding roller 136), and the folding of a substantially flat sheet.
First, the separation and contact of the folding roller is performed by stretching the left folding roller shaft 133 of the left folding roller 132 and the right folding roller shaft of the right folding roller 136 on the upper pulleys 193 and 195 at positions facing each other in the vertical axial direction. The moving belt 191 and the lower supporting belt 192 stretched on the lower pulleys 194 and 196 are individually provided on the respective shaft support portions 197.
Therefore, when the folding roller separating / contacting motor 178 is driven, the left folding roller 132 and the right folding roller 136 can move in a direction in which one rotation causes the left folding roller 132 and the right folding roller 136 to be in pressure contact with each other, and can move in a direction separating from each other by the other rotation. The rotation arrows between the upper pulley 193 and the lower pulley 194 in FIG. 8 move in directions in which they are pressed against each other.

Further, the left folding roller 132 and the right folding roller 136 are attached to a shaft that drives the folding roller separation / contact motor 178, the upper pulley 193, and the lower pulley 194 so that a predetermined pressing force is obtained for the sheet folding. The intermediate gear 199 is provided between the transmission gear 198 and the gear 198.
The intermediate gear 199 is composed of two gears: an outer driving gear 199a to which the driving of the folding roller separation / contact motor 178 is directly transmitted, and a spring receiving gear 199e coaxial with the driving gear 199e and engaged with the transmission gear 198. . A spring 199c is disposed between the driving gear 199a and the spring receiving gear 199e and interposed in a spring receiving portion 199b cut out from the driving gear 199a. One end of the spring 199c is in contact with an inner wall of the driving 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, 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, and a pressing force for folding the sheet is generated.
Although the folding roller separation / contact motor 178 in FIG. 8 is shown on the discharge side, the apparatus is arranged 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 driving of the folding roller drive motor 176 rotationally drives a square shaft 185 extending in the same direction as the lower moving belt 192 via a transmission gear. The rotation of the angular shaft 185 causes the left sliding worm gear 187 and the right sliding worm gear 188 to rotate. Thus, 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 pressing position RA where they are pressed against each other and the separated roller separating position RR, the drive transmission is formed by the angular shaft 185, so that the square shaft 185 is used. Can be slid to transmit the drive.

[Pressing tubular sheet to flat shape]
The state where the sheet held in a substantially cylindrical shape in FIGS. 4 and 5 is pressed substantially flat by the seven shift members (left shift part 60, right shift part 61) will be described with reference to FIGS.
As shown in FIG. 9, the sheet formed in the substantially cylindrical shape by the tubular forming portion 57 is driven by the above-described proximity plate separation motor 174 of the shift plate, so that the left shift plate 114 and the right shift portion 61 of the left shift portion 60 are driven. The right shift plate 116 moves from the shift plate release position SO to the shift plate pressing position SC close 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 tubular forming portion 57 are made of a flexible sheet film material, so that they change to a substantially flat shape extending downward as shown in the figure. . As a result, the sheet is held from the substantially cylindrical shape to the substantially flat shape. During this change, the rear 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 tubular 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 section 60, right shift section 61) of FIG. This figure shows a state where the left link portion 110 and the right link portion 112 in FIG. 7 are moved to move the left shift plate 114 and the right shift plate 116 from the shift plate release position SO to the shift plate pressing position SC, and the sheet is substantially cylindrical. This shows a state where the shape has changed to a substantially flat shape. This shows the same state as the already described figure in which the left link unit 110 and the right link unit 112 in FIG. 6 have been moved from the broken line position to the solid line position.
The movement of the shift members (the left shift portion 60 and the right shift portion 61) deforms the substantially cylindrical sheet into a substantially flat shape, and also causes the folding rollers (the left folding roller 132 and the right folding roller 132) at the roller separation position RR to move. 136). After the substantially flat sheets are located on the left folding roller 132 and the right folding roller 136, they are moved to a roller pressing position RA by driving a 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 members (the left shift portion 60 and the right shift portion 61) deform the substantially cylindrical shape into a substantially flat shape and move between the left folding roller 132 and the right folding roller 136.
Further, the left rear end pushing section 118 and the right rear end pushing section 120 which engage with the sheet trailing edge in the substantially cylindrical discharge direction are formed in a comb shape so as to overlap each other, as shown in FIG. A right rear end pushing portion 120 formed integrally with the right shift plate 116 from the left shift plate 114 end side is shown.

Next, a state where the substantially flat sheet of FIG. 10 is discharged while being folded will be described with reference to FIG. As described above, the substantially flat sheet having a substantially flat shape located between the left folding roller 132 and the right folding roller 136 is turned into a folding roller separation motor by using the left folding roller 132 and the right folding roller 136 this time. 178 is driven to move to the roller pressing position SC in FIG. 10, and a pressing force for folding by the intermediate gear mechanism described with reference to FIG. 8 is applied. After that, the left folding roller 132 and the right folding roller 136 are driven to rotate the folding roller driving motor 176 to fold and discharge the substantially flat sheet. This state is indicated by a two-dot chain line left-hand folded sheet FP (L) in FIG.
By the pressing and rotating of the left folding roller 132 and the right folding roller 136, when the discharging process is performed while performing the folding process, the left link portion 110 and the right link portion 112 are returned. Then, the shift members (the left shift portion 60 and the right shift portion 61) move to the shift plate releasing position SO, return the tubular forming portion 57 to a substantially tubular shape, and prepare for carrying in the next sheet. 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 tubular folding section (folding processing section) 50 described above 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 above with reference to FIGS. 4, 5, and 7. In this figure, the sheet conveyed by the carry-in roller 51 is formed in a cylindrical shape. The sheet is conveyed while rotating at the portion 57 and is formed in a substantially cylindrical shape in which a part thereof is overlapped with each other. This sheet forms a left-hand folded sheet CP (L). When the folding process is performed in this superimposed state, it is a commonly known tri-fold.
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. A left-handed folded sheet FP (L) obtained by forming the substantially tubular left-handed cylindrical sheet CP (L) shown in FIG. 12A into a substantially flat shape and thereafter folding it is shown.

It should be noted that “substantially cylindrical shape” in the present invention refers to a substantially cylindrical shape having the shape shown in FIG. 12A, and “substantially flat” refers to FIGS. 12 (a) and 12 ( b) A sheet having a substantially elliptical cross-section, which is an intermediate shape from that of b), and pressing the substantially cylindrical sheet from both sides so as to have a narrower lateral direction and a smaller interval than the substantially cylindrical shape extending in the vertical direction. . The meaning of this intermediate shape is that the diameter of the sheet having a narrower cylindrical shape is made smaller than that of the substantially cylindrical shape and between the left folding roller 132 and the right folding roller 136 located at the roller separation position RR. It is enough to allow intrusion.

[Folded sheet storage tray]
Next, a state where 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 from the frame of the folding unit 31 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 covering the frame of the folding unit 31 and a release position shown in the drawing.
The folding unit cover 147 is provided with a frame attaching portion 147a to be attached to the frame of the folding unit 31 and a frame-side rotating shaft 147b for pivotally supporting the frame attaching portion 147a, as shown in the enlarged view of the two-dot chain line. I have. A release spring 147c that constantly urges the folding unit cover 147 in the release direction is bridged between the frame side stopper 147d of the folding unit 31 and the stopper pin 147f of the folding unit cover 147 on the rotation 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 facing the folded sheet outlet 145 serves as a folded sheet tray section 148 for storing the folded sheets discharged from the folded sheet outlet 145. Therefore, even if a discharge tray is not separately provided, as shown in FIG. 13, the sheet is dropped and stored in the folded sheet tray section 148 on the back surface side of the folding unit cover 147.

Further, a locking claw 147e that enters the locking hole 149 on the frame side is provided on the folding unit cover 147 on the opposite side of the frame mounting portion 147a. The locking claw 147e is locked when the folding unit 31 is not used by a lock mechanism that is moved by a solenoid (not shown) provided in the locking hole 149.
Therefore, when the folding control unit 211 (control unit) described later is configured to perform a folding process, the lock mechanism is operated to release the locking and the folding unit cover 147 is released, so that the folding unit 31 operates. It functions as a display and a fold sheet tray, increasing convenience.

Further, a folding unit cover sensor Sen3 for detecting a locking claw 147e of the folding unit cover 147 is provided in the above-mentioned locking hole 149. The splicing unit cover sensor Sen3 detects the locking claw 147e as a detection flag, and releases the locking mechanism when the operation of the folding unit 31 is instructed and the locking claw 147e is detected.
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 tubular folding unit shown in FIGS. By operating the switching flapper solenoid 172 so as to guide the sheet to the unit 50 to cause the switching flapper 49 to enter the folding / folding conveyance path 43, the folding process can be executed by opening 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 having the substantially cylindrical shape in the tubular folding portion 50 will be described with reference to FIGS. By this switching of the winding direction, it becomes easy to change which of the front and back of the sheet subjected to the folding process to be the front cover of the folded sheet, and it becomes more convenient.
FIG. 14 is an explanatory view of a cross section in which the substantially cylindrical sheet is formed by winding the sheet around the cylindrical forming portion 57 in the opposite direction to that in FIG. Here, for the sake of explanation, differences from FIG. 5 will be mainly described, and the description of other points will be omitted with reference to FIG.
In FIG. 5, the sheet conveyed by the carry-in roller 51 is guided by the first gate 53 to the tubular forming portion 57 as a guide gate. For this reason, the sheet is shown as a counterclockwise left-handed cylindrical sheet CP (L).

14 is wound around the cylindrical forming portion 57 by a second gate 55 provided at a position facing the first gate 53. As a result, the conveyed sheet becomes the right-handed cylindrical sheet CP (R) in the cylindrical forming portion 57 in the clockwise direction as shown in FIG.
The difference is that, as shown in FIG. 16, it is possible to select which of the front and back surfaces of the folded sheet is to be the front and back of the folded sheet. The image forming apparatus A shown in FIG. 1 or FIG. 2 discharges the 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. Thereby, the sheet from FIG. 16 and the sheet from the carry-in roller 51 are carried in the same front-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 (the cylindrical forming part 57), so that the cylindrical forming part This is based on the fact that the direction in which the sheet is wound around 57 is changed.

First, in FIG. 16A, the sheet is conveyed and guided to the tubular 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 in the case of a folded sheet, a left-hand folded sheet FP (L) is created as shown in FIG. This fold sheet is three-fold inside, and a fold 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, a clockwise right-handed tubular sheet CP (R) is created in reverse. According to this, the sheet is wound with the image forming surface outside, and in the case of a folded sheet, a right-hand folded sheet FP (R) is created as shown in FIG. This fold sheet is also three-fold inside, and the fold line FL similarly appears.

In this way, the front side of the folded sheet can be selected by selecting the first gate 53 or the second gate 55 as the guide gate that determines the winding direction of the tubular forming portion 57.
In the above description, the example in which the image forming apparatus A discharges with the image forming surface facing down has been described, but the image forming apparatus A can also be applied to a device that discharges with the image forming surface facing up. In short, if the winding direction around the cylindrical forming portion 57 is selected, the front and back can be switched.

[Switching mechanism of guide gate (first gate 53, second gate 55)]
Here, the switching mechanism of the guide gate for switching the winding direction of the tubular folding section 50 around the tubular forming section 57 described above 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 tubular forming portion 57 (not shown), and Is going to retreat.

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

A support plate rack 166 is integrally attached to the gate support plate 157 below, and the support plate rack 166 meshes with a drive motor pinion 164 via a 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 that can be driven forward and backward, and moves the gate support plate 157 by one rotation so that the first gate 53 enters.
Further, the gate support plate 157 can be moved in the opposite direction by the other rotation of the gate switching motor 160 to retract the first gate 53 and allow the second gate 55 to enter. Two movement guide holes provided in the gate support plate 157 engage with pins (not shown) protruding from the rear frame of the folding unit 31 to guide the movement of the gate support plate in the horizontal direction in the figure. It has become.
The reason why both the first gate 53 and the second gate 55 are supported in a cantilever manner as shown in the drawing is to prevent a failure in discharging the folded sheet. 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 are configured as the guide gate unit 150 to facilitate switching.

[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 above-described sheet folding apparatus 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 an image forming apparatus A, a sheet processing control unit 205 of a 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 forming control unit 200 includes a paper feed control unit 202 and an input unit 203. Then, a sheet processing mode such as “print mode”, “sheet folding mode (including folded sheet surface setting)”, and “sheet binding mode” to be described later is 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 according to the above-described designated sheet processing mode. The sheet processing control unit 205 includes a ROM 206 storing an operation program, and a RAM 207 storing control data. The sheet processing control unit 205 includes, for example, a sheet carry-in sensor Sen1 for detecting a sheet conveyed near the entrance roller 45 and a discharge of a folded sheet near the folded sheet exit 145 for the folding unit 31 according to the present invention. Sheet sensor Sen2 to be folded, a fold unit cover sensor Sen3 for detecting whether the fold unit cover 147 is released, a sheet level sensor for detecting a sheet level for detecting the amount of sheets stacked on the accumulation tray 90, and the like. Are input from the various sensor input units 208.

    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. Further, the sheet processing control unit 205 includes a folding control unit 211 that performs sheet folding processing in the folding unit 31 and a processing tray that controls an alignment plate 84 and the like when placed on the processing tray 76 for binding in the binding unit 32. The control unit 212 includes a control unit 212 and a stapler control unit 213 that controls the stapler 80 that performs a binding process on a sheet bundle placed on the processing tray 76.

  In particular, the folding control unit 211 (control unit) for controlling the folding unit 31 according to the present invention guides the guide to the tubular forming portion 57 of the tubular folding portion 50 by using the first gate 53 or the second gate 55 which is a guide gate. The gate switching motor 160 for selectively moving the gate support plate is determined in order to determine the winding direction. Further, the folding control unit 211 (control unit) guides the sheet from the folding conveyance path 43 to the folding introduction path 108 and the conveyance roller motor 170 for driving the entrance roller 45 and the exit roller 47 and the entrance roller 51, and guides the sheet to the entrance roller 51. The switching flapper solenoid 172 for moving the switching flapper 49 for selecting whether or not to perform the control is controlled. Further, the folding control section 211 (control section) shifts the shift members (the left shift section 60 and the right shift section 61) in order to deform the tubular forming section 57 of the tubular folding section 50 from a substantially cylindrical shape to a substantially flat shape. ) And a folding roller separation motor that separates or presses the folding rollers (the left folding roller 132 and the right folding roller 136) to further fold the substantially flat sheet. 178 and a folding roller drive motor 176 that drives and rotates the folding roller.

Although not shown in FIG. 18, the folding control unit 211 (control unit) controls the folding unit cover 147 described in FIG. 13 to release the folding unit cover 147 by operating a lock mechanism using a solenoid or the like. If this is the case, the folding unit 31 functions as a display indicating that the folding unit 31 is operating and as a folded sheet tray, thereby increasing convenience.
When the operation instruction of the folding unit 31 is instructed, if the unit cover sensor Sen3 detects the engaging claw 197e, the above-described lock mechanism can be released.

As control in another case, when the user releases the folding unit cover 147, the folding control unit 211 () determines that there has been an instruction to execute the folding process because the engagement claws 197e have been released by the unit cover sensor Sen3. If the control flapper is determined and the switching flapper solenoid 172 is operated so as to guide the sheet to the tubular folding part 50 shown in FIGS. As described above, the folding process can be executed by releasing the folding unit cover 147.
Further, the sheet processing control unit 205 includes an accumulation tray elevating control unit 214 that controls the elevating motor 95 based on a detection signal from a paper surface level sensor for elevating and lowering the accumulation tray 90.

[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"
The sheet on which the image is formed is received from the main body discharge port 16 of the image forming apparatus A, and the sheets are 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 transport path 37 of the guide unit 30 is transported to the cylindrical folding section of the folding unit 31 to perform simple sheet folding, and the folded sheet is discharged to the front side of the transport path 37 that intersects the sheet transport direction. .
In addition to this sheet folding mode setting, it is set which side of the image-formed sheet shown in FIG. 16 is to be the front side of the folded sheet. If there is no setting, the state shown in FIG.
(3) "Sheet binding mode"
After the sheet on which an image is formed from the main body discharge port 16 passes through the guide unit 30 and the folding unit 31, the sheet is temporarily placed on the processing tray 76 of the binding unit 32 to form a bundle, and after the bundle is bound by the stapler 80, The sheets are accumulated on the accumulation tray 90.

According to the embodiment of the present invention described above, the following effects can be obtained.
1. A sheet folding device (folding unit 31) for folding a sheet, comprising a holding member (tubular forming portion 57) for holding a conveyed sheet in a substantially cylindrical shape, and a sheet provided at one end of the holding member. Folding rollers (left folding roller 132, right folding roller 136) which can be separated from and separated from each other and press the outer peripheral surface of the substantially cylindrical sheet held by the holding member against the folding rollers, and And a shift member (left shift unit 60, right shift unit 61) that moves to the right.
According to this, a folding mechanism that discharges the sheet while holding the sheet in a substantially cylindrical shape while pressing the sheet in a substantially flat shape, performs the folding process without using a conveyance path along the sheet length or three folding rollers that are in pressure contact. And a relatively compact folding device can be provided.

2. The shift members (the left shift portion 60 and the right shift portion 61) are separated from each other at a first position (shift plate release position SO) where the sheet is held in a substantially cylindrical shape by the holding member (the cylindrical forming portion 57). And a second position (shift plate pressing position SC) reciprocally movable between the first position and the second position (shift plate pressing position SC) narrower than the first position pressing the substantially cylindrical sheet so as to be flat. It is a sheet folding device.
According to this, sheet folding can be performed with a simple configuration.

3. The reciprocating movement between the first position and the second position of the shift members (left shift unit 60, right shift unit 61) is performed by link members (left link unit 110, right link unit 112). 3. The sheet folding device according to the above item 2.
According to this, the reciprocating movement of the shift member can be easily and reliably performed.

4. The shift members (the left shift unit 60 and the right shift unit 61) are engaged with the sheet at the opposite ends of the folding rollers (the left folding roller 132 and the right folding roller 136) across the shift member. 4. The sheet folding apparatus according to the above item 3, comprising a trailing end pushing section (left trailing end pushing section 118, right trailing end pushing section 120) that moves to the folding roller side.
According to this, since the trailing end pushing section that engages with the sheet is provided in the shift section that moves the link, the sheet can be easily moved to the folding roller side.

5. The shift members (left shift portion 60, right shift portion 61) are a pressing portion (left shift plate 114, right shift plate 116) that presses from both sides of the substantially cylindrical sheet, and an edge on the opposite side to the folding roller. And a rear-end extruding portion (left rear-end extruding portion 118 and right rear-end extruding portion 120) which pushes out to the folding roller side is formed in an L-shape facing each other, and the L-shaped shift member is closely spaced. 4. The sheet folding device according to the above 3.
According to this, since the shift member is formed in an L-shape facing each other, the substantially cylindrical sheet can be easily pressed from both sides and moved to the folding roller side.

6. The sheet folding apparatus according to the item 5, wherein the holding member (tubular forming portion 57) is set to have a length in which a part of the sheets to be held overlap each other (length overlapping in the winding direction).
According to this, an inner tri-folded sheet can be created according to the degree of the overlap.

7. A sheet folding device (folding unit 31) for folding a sheet, in which a conveying roller (conveying roller 51) for conveying the sheet and a front end and a rear end of the sheet conveyed by the conveying roller are overlapped with each other. A holding member (cylindrical forming portion 57) made of a deformable flexible sheet that is held in a substantially cylindrical shape, and pressed against a sheet, which is located at a sheet end of the holding member and held in a substantially cylindrical shape by the holding member, Rollers (left folding roller 132, right folding roller 136) that rotate and can be separated from each other, and a substantially cylindrical sheet held by the holding member and a substantially flat sheet outer peripheral surface together with the holding member. And a shift member (left shift section 60, right shift section 61) that is pressed from both sides to deform and move to the folding roller side.
According to this, a folding mechanism that discharges the sheet while holding the sheet in a substantially cylindrical shape while pressing the sheet in a substantially flat shape, performs the folding process without using a conveyance path along the sheet length or three folding rollers that are in pressure contact. And a relatively compact folding device can be provided.

8. The shift members (the left shift portion 60 and the right shift portion 61) are flat L-shaped members facing each other, and link members (the left link portion 110, the left link portion 110, which operate the L-shaped members so as to approach and separate from each other). The sheet folding device according to the above 7, which is supported by the right link portion 112).
According to this, since the shift member is formed in an L-shape facing each other, the substantially cylindrical sheet can be easily pressed from both sides and moved to the folding roller side.

9. The link members (the left link portion 110 and the right link portion 112) are composed of a pair of sector gears 183 that are arranged so as to overlap with the holding member (the tubular forming portion 57), and a drive mechanism (a proximity / separation motor) for driving the pair of sector gears 183. 174, the transmission gear 181 and the transmission worm gear 182).
According to this, the shift member can be reliably moved.

10. The image forming unit 2 for forming an image on a sheet, a sheet folding device (folding unit 31) for folding a sheet from the image forming unit, and the sheet folding device is configured as described in any of 1 to 9 above. Is an image forming apparatus A including:
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) for reading 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;
11. The image forming apparatus according to the item 10, wherein the sheet folding device (folding unit 31) is arranged in the sheet discharge space.
According to this, it is possible to provide an image forming apparatus equipped with a sheet folding device which has the above-described effects 1 to 9, which is also applied to a so-called internal type.

  In the description of the effects of the above-described embodiment, for each part of the present embodiment, the members corresponding to the respective components in the claims are shown in parentheses or the reference numerals are used to indicate the relationship between the two. Clarified.

  Furthermore, the present invention is not limited to the above-described embodiment, 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. Although the embodiments described above show preferred examples, those skilled in the art can realize various alternatives, modifications, variations, or improvements from the contents disclosed in this specification. And 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 transport path 49 switching flapper 50 tubular folding section (folding processing section)
51 Loading roller (transport roller)
53 1st gate (guide gate)
54 2nd 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 unit)
99 Elevating rail 100 Elevating rack 101 Extension rail 102 Extension rack 104 Folding entrance 106 Folding exit 108 Folding path 110 Left link part 112 Right link part 114 Left shift plate (pressing part)
116 Right shift plate (pressing part)
118 left rear end pushing section 120 right rear end pushing section 132 left folding roller (discharge roller / folding roller)
136 Right folding roller (ejection roller / folding roller)
145 Folded sheet outlet 147 Folded unit cover 148 Folded sheet tray section 150 Guide gate unit 160 Gate switching motor 170 Conveyance drive motor 174 Proximity separation motor 176 Fold roller drive motor 178 Fold roller separation motor 181 Transmission gear 182 Transmission worm gear 183 Sector gear 199 Intermediate gear 210 Sheet transport control unit 211 Fold control unit (control unit)

Claims (11)

A sheet folding device for folding sheets,
A holding member for holding the conveyed sheet in a substantially cylindrical shape,
A folding roller provided at one end of the holding member and capable of folding and separating the sheet,
A sheet folding device comprising: a shift member that presses an outer peripheral surface of a substantially cylindrical sheet held by a holding member against the folding roller and that moves to the folding roller side.   The shift member is separated from a first position where the sheet is held in a substantially cylindrical shape by the holding member and a first position where the outer peripheral surface is pressed so that the substantially cylindrical sheet becomes substantially flat. The sheet folding device according to claim 1, wherein the sheet folding device is also capable of reciprocating to a second position having a narrow interval. 3. The sheet folding device according to claim 2, wherein the reciprocating movement of the shift member between the first position and the second position is performed by a link member.   4. The shift member according to claim 3, wherein the shift member includes a rear end pushing portion that engages with a sheet and moves toward the folding roller at an opposite end of the folding roller with the shift member interposed therebetween. The sheet folding apparatus according to the above. The shift member has a pressing portion that presses from both sides of the outer peripheral surface of the substantially cylindrical sheet, and a rear end pushing portion that engages with the sheet edge opposite to the folding roller and pushes the sheet toward the folding roller. 4. The sheet folding apparatus according to claim 3, wherein the shift member has an L-shape, and the L-shaped shift members are close to and away from each other.   6. The sheet folding apparatus according to claim 5, wherein the holding member is set to a length such that a part of the held sheets overlap with each other. A sheet folding device for folding sheets,
A conveying roller for conveying the sheet,
A holding member made of a deformable flexible sheet that holds the leading end and the trailing end of the sheet conveyed by the conveying roller to be overlapped with each other and held in a substantially cylindrical shape;
A folding roller that is located at a sheet end of the holding member, rotates while being pressed against a sheet held in a substantially cylindrical shape by the holding member, and that can be separated from each other;
A substantially cylindrical sheet held by the holding member is deformed by pressing the sheet from both sides of the outer peripheral surface of the sheet in a substantially flat shape together with the holding member, and the shift member moves to the folding roller side. Sheet folding device. The sheet folding apparatus according to claim 7, wherein the shift member is formed of a planar L-shaped member facing each other, and is supported by a link member that operates the L-shaped member so as to approach and separate from each other. .   9. The sheet folding apparatus according to claim 8, wherein the link member comprises a pair of sector gears arranged so as to overlap with the holding member, and a drive mechanism for driving the sector gears. An image forming unit that forms an image on a sheet,
A sheet folding device for folding a sheet from the image forming unit,
An image forming apparatus, comprising: the sheet folding device having the configuration according to claim 1. A reading unit that reads an image of a document above the image forming unit;
A sheet discharging space 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