JP2023000427A - Sheet folding device, image forming device and image forming system - Google Patents

Abstract

To provide a sheet folding device, an image forming device, and an image forming system that can fold properly the sheet at a target position.SOLUTION: A sheet folding device 1 of the invention is equipped with: first sheet transport means comprising a first transport roller 21 and a dual-use transport roller 22; second sheet transport means comprising a second transport roller pair 23; and folding means comprising a third transport roller 24 and a dual-use transport roller 22. The sheet folding device 1 is also provided with a pre-fold section 10 as a fold line forming means for applying a fold line to the sheet upstream in the sheet transport direction from the first sheet transport means.SELECTED DRAWING: Figure 3

Description

The present invention relates to a sheet folding device, an image forming device, and an image forming system.

Patent Document 1 describes a sheet folding device having the following configuration. That is, the sheet folding device includes first sheet conveying means for holding a part of the sheet and applying a conveying force to the sheet, and holding a part of the sheet conveyed from the first sheet conveying means and conveying it to the sheet. A second sheet conveying means for applying force and a folding means for folding the sheet are provided. The first sheet conveying means and the second sheet conveying means hold a part of the sheet and the second sheet conveying means imparts a conveying force to the sheet to return the sheet to the upstream side in the sheet conveying direction. creates a flexure in the portion of the sheet during The sheet folding device folds the sheet by pinching the bent portion of the sheet with folding means.

However, there is a possibility that the sheet may not be folded at the intended position of the sheet.

In order to solve the above-described problems, the present invention provides a first sheet conveying means that holds a part of a sheet and applies a conveying force to the sheet, and a sheet conveying means that conveys the sheet conveyed from the first sheet conveying means. a second sheet conveying means for holding a part of the sheet and applying a conveying force to the sheet; and a folding means for folding the sheet. By applying a conveying force to the sheet to return the sheet in a direction opposite to the conveying direction of the sheet conveyed from the first sheet conveying means to the second sheet conveying means by the second sheet conveying means, the first sheet In a sheet folding device in which a portion of the sheet between the conveying means and the second sheet conveying means is bent, and the bent portion of the sheet is sandwiched by the folding means to fold the sheet, the first sheet conveying The sheet folding device is characterized by comprising crease forming means arranged on the upstream side in the sheet conveying direction of the sheet folding means for forming creases in the sheet.

According to the present invention, the sheet can be folded at the desired position.

2 is a diagram showing the system configuration of an image forming system according to the present embodiment; FIG. FIG. 6 is a diagram showing another example of the system configuration of the image forming system; 1 is a schematic configuration diagram of a sheet folding device; FIG. FIG. 4 is an operation flow diagram of folding processing of the sheet folding device. FIG. 10 is a view showing how the leading edge of the sheet is guided by the guide member toward the second conveying nip; FIG. 10 is a diagram showing a state in which a sheet is conveyed downstream of a second conveying nip; FIG. 10 is a diagram showing a state in which the fold of the sheet abuts against the guide member; FIG. 10 is a view showing how the fold line of the sheet is detected by the third sheet detection sensor; FIG. 4 is a diagram showing how a folded sheet is conveyed; FIG. 5 is an explanatory diagram of a sheet conveying speed in the first conveying nip;

FIG. 1 is a diagram showing the system configuration of an image forming system 4 according to this embodiment. In this embodiment, a sheet folding device 1 and a post-processing device 2 are provided in this order after the image forming device 3 .

The image forming apparatus 3 forms an image on a sheet based on input image data or read image data. For example, copiers, printers, facsimiles, or digital multi-function peripherals having at least two of these functions correspond to this. The image forming apparatus 3 employs a known system such as an electrophotographic system or a droplet ejection system, and any image forming system may be used.

Examples of the post-processing device 2 include a punching device that punches holes in sheets, a sheet binding device that binds a bundle of sheets using a stapler or the like, a sorting and discharging device that sorts and discharges image-formed sheets to a plurality of discharge trays, and the like. mentioned.

FIG. 2 is a diagram showing another example of the system configuration of the image forming system 4. As shown in FIG.
Image forming system 4 shown in FIG. ing.

FIG. 3 is a schematic configuration diagram of the sheet folding device 1 provided in the image forming system according to the embodiment.

The sheet folding device 1 of the present embodiment includes a pre-folding section 10 as a folding line forming means for forming a folding line in a sheet, and a folding processing section 20 for performing folding processing on the sheet. The sheet folding device 1 has a first transport path W1 for receiving sheets and transporting the sheets to the folding processing unit 20, and a second transport path W2 for folding the sheets transported from the first transport path W1. , and a third conveying path W3 for discharging the folded sheet. A pre-folding portion 10 and a sheet retention portion 41 are arranged in the first conveying path W1.

The pre-folding unit 10 is composed of a convex roller 10a having a convex portion 101a and a cradle 10b having a concave portion 101b. Since the leading edge of the sheet may be caught on the convex portion 101a of the convex roller 10a, the convex portion 101a is positioned at the retracted position shown in FIG. 3 until the leading edge of the sheet passes through. After the leading edge of the sheet passes through the pre-folding section 10, the convex roller 10a is rotated counterclockwise in the drawing by 90 degrees to move the convex section 101a from the retracted position to the crease forming position facing the sheet.

When the intended folding position of the sheet comes directly below the convex portion 101a, the conveying of the sheet is temporarily stopped, and the convex roller 10a is raised to press the convex portion 101a against the sheet to form a fold in the sheet. After the crease is formed on the sheet, the convex roller 10a is lowered to separate the convex roller 10a from the sheet, and then the conveyance of the sheet is resumed. Instead of the convex roller 10a, a fold forming member, which is a plate-shaped member, may be used to form the fold on the sheet.

The folding section 20 has a first conveying roller 21 , a dual-purpose conveying roller 22 , a second conveying roller pair 23 as second conveying means, and a third conveying roller 24 . The first conveying roller 21 is in contact with the combined conveying roller 22 so that the first conveying nip N1 is formed at the exit of the first conveying path W1. The third conveying roller 24 is in contact with the combined conveying roller 22 so as to form a third conveying nip N3 at the exit of the second conveying path W2. A second conveying roller pair 23 composed of a pair of conveying rollers 23a and 23b is arranged on the second conveying path W2. In this embodiment, the first transport roller 21 and the combined transport roller 22 constitute the first transport means, and the third transport roller 24 and the combined transport roller 22 constitute the folding means.

The second conveying nip N2 that imparts conveying force to the sheet of the second conveying roller pair 23 is arranged to be positioned below the third conveying nip N3 formed by the third conveying roller 24 and the combined conveying roller 22. It is Also, the first transport nip N1 formed by the first transport roller 21 and the combined transport roller 22 is arranged above the second transport nip N2 and the third transport nip N3. The sheet that has entered the first conveying nip N1 is conveyed between the second conveying nip N2 and the third conveying nip N3.

A guide member 40 serving as a sheet guide member is arranged between the second conveying nip N2 and the third conveying nip N3. The guide member 40 is vertically inclined so that the second conveying nip N2 side is positioned downward.

A first sheet detection sensor 31 serving as sheet detection means for detecting a sheet is provided on the downstream side of the second conveying roller pair 23 in the sheet conveying direction (the side opposite to the exit side of the second conveying path W2). Between the second conveying nip N2 and the third conveying nip N3 of the second conveying path W2, a second sheet detecting sensor 32 as guide contact sheet detecting means and a third sheet detecting means as perpendicular position sheet detecting means are provided. A sheet detection sensor 33 is arranged. A fourth sheet detection sensor 34 is provided on the entrance side of the third transport path W3 (near the third transport nip N3).

The third sheet detection sensor 33 is arranged at the starting point (the intersection of the perpendicular line S and the guide member 40) of a perpendicular line S (broken line in the figure) passing through the first conveying nip N1 among the perpendicular lines of the guide surface of the guide member 40. there is

Here, a general operation of the sheet folding processing by the folding processing section 20 will be described.
The leading edge of the sheet P conveyed along the first conveying path W1 enters the first conveying nip N1 formed by the first conveying roller 21 and the dual-purpose conveying roller 22, and passes through the first conveying roller 21 and the dual-purpose conveying roller. 22 to the second transport path W2. The leading edge of the sheet conveyed to the second conveying path W2 contacts the guide member 40 arranged between the second conveying nip N2 and the third conveying nip N3 of the second conveying path W2. Since the guide member 40 is inclined so that the second conveying nip N2 side is positioned downward, the leading edge of the sheet in contact with the guide member 40 is guided by the guide member 40 to the second conveying nip N2.

Then, the leading edge of the sheet enters the second conveying nip N2 of the second conveying roller pair 23 and is detected by the first sheet detection sensor 31 after passing through this nip. When a specified time has passed since the first sheet detection sensor 31 detected the sheet P and the sheet P protrudes from the second conveying nip N2 by a predetermined protrusion amount, the rotation of the second conveying roller pair 23 is reversed. The prescribed time is appropriately determined according to the length of the sheet in the sheet conveying direction and the content of the folding process (folding method, etc.).

By reversing the rotation of the second conveying roller pair 23, the sheet portion between the first conveying nip N1 and the second conveying nip N2 is flexed. 22 into the third conveying nip N3. As a result, the flexed portion is sandwiched between the third conveying roller 24 and the dual-purpose conveying roller 22, and the flexed portion becomes a folded portion, thereby folding the sheet.

In the sheet folding device, the rotation of the second conveying roller pair 23 is reversed to bend the sheet portion between the first conveying nip N1 and the second conveying nip N2, and the bent portion is pinched to fold the sheet. , had the following problem. That is, the way the sheet portion bends between the first conveying nip N1 and the second conveying nip N2 may differ depending on the type of sheet, such as the stiffness of the sheet. Since the bending of the sheet portion between the first conveying nip N1 and the second conveying nip N2 is different, the portion different from the target position first enters the third conveying nip N3 and is different from the target position. The problem is that the sheet is folded at the position.

On the other hand, the present sheet folding device 1 is provided with a pre-folding section 10 to form a fold line at a target position. As a result, when the rotation of the second conveying roller pair 23 is reversed to bend the sheet portion between the first conveying nip N1 and the second conveying nip N2, the fold portion of the sheet whose stiffness is weakened is bent. The sheet bends as a fulcrum. Then, with this crease portion leading, the sheet enters the third conveying nip N3, is nipped between the third conveying roller 24 and the combined conveying roller 22, and is folded at the crease portion. As a result, the sheet can be folded satisfactorily at the target position.

Further, for example, the sheet conveying speed V2a at the second conveying nip N2 and the sheet conveying speed V1a at the first conveying nip N1 may differ from the target speed, and when the second conveying roller pair 23 is reversely rotated, the The deflection amount of the sheet portion between the first conveying nip N1 and the second conveying nip N2 may differ. As a result, there is a possibility that a position different from the position of the crease may enter the third conveying nip N3 as the leading position.

Further, depending on the type of sheet, the leading edge of the sheet may pass through the first conveying nip straight in the vertical direction, or may pass through the first conveying nip N along the outer peripheral surface of the first conveying roller 21 and pass through the second conveying nip side. It may hit the guide member 40 . As a result, the way in which the leading edge of the sheet is guided by the guide member 40 and the sheet bends until it reaches the second conveying nip may differ depending on the sheet type. As a result, the bending amount of the sheet portion between the first conveying nip N1 and the second conveying nip N2 when the second conveying roller pair 23 is reversely rotated differs depending on the type of the sheet, and the position of the fold differs. may enter the third conveying nip N3 first.

For this reason, the sheet folding apparatus 1 is provided with the second sheet detection sensor 32 and the third sheet detection sensor 33, and based on the detection results of these sheet detection sensors 32 and 33, sheet conveyance is controlled. As a result, it is possible to more reliably enter the third conveying nip N3 with the folded portion at the front, and fold the sheet at the desired position with high accuracy. The sheet folding operation of the sheet folding apparatus 1 will be described below with reference to the drawings.

FIG. 4 is an operation flow diagram of folding processing of the sheet folding device 1, and FIGS. 5 to 9 are explanatory diagrams of folding processing operations of the sheet folding device 1. FIG.
First, the first conveying roller 21 and the dual-use conveying roller 22 are rotated forward as shown by the arrows in FIG. Transport (S1). Further, the second conveying roller pair 23 is rotated forward as indicated by the arrow in FIG. 5 (S2).

As shown in FIG. 5, the leading edge of the sheet conveyed to the second conveying path W2 contacts the guide member 40 and is guided to the second conveying nip N2. Then, the leading edge of the sheet enters the second conveying nip N2 of the second conveying roller pair 23, and as shown in FIG. 22 and the first conveying means.

Depending on the type of sheet, the position where the leading edge of the sheet conveyed to the second conveying path W2 abuts against the guide member 40 may be closer to the third conveying nip than the position where the second sheet detection sensor 32 is arranged. 32 may detect the sheet. However, since the first sheet detection sensor 31 does not detect the sheet, the device determines that the fold line F does not contact the guide member 40 at this time.

The sheet conveying speed V2a at the second conveying nip N2 can be made faster than the sheet conveying speed V1a at the first conveying nip N1. When the sheet conveying speed V2a at the second conveying nip N2 is set higher than the sheet conveying speed V1a at the first conveying nip N1, the sheet is conveyed between the second conveying nip N2 and the first conveying nip N1. , the sheet portion between the first conveying nip N1 and the second conveying nip N2 gradually decreases in deflection amount and separates from the guide member 40 (see FIG. 6). In this manner, the sheet portion between the first conveying nip N1 and the second conveying nip N2 is conveyed so as to reduce the amount of deflection of the sheet portion. It is possible to more reliably prevent the detection sensor 32 from detecting the sheet.

Next, when the first sheet detection sensor 31 detects the leading edge of the sheet and a specified time elapses (YES in S3), the rotation of the second conveying roller pair 23 is temporarily stopped (S4). The specified time is determined based on the length from the leading edge of the sheet to the folding position (folding position). By temporarily stopping the rotation of the second conveying roller pair 23, the sheet portion between the first conveying nip N1 and the second conveying nip N2 bends around the folding line F as a fulcrum, and as shown in FIG. , the fold line F of the sheet comes into contact with the guide member 40 . When the fold line F of the sheet contacts the guide member 40, the second sheet detection sensor 32 detects the sheet while the first sheet detection sensor 31 is detecting the sheet. At this time, the device determines that the fold line F of the sheet abuts against the guide member 40 .

In addition, since the sheet conveying speed V2a at the second conveying nip N2 and the sheet conveying speed V1a at the first conveying nip N1 are different from the target speed, the fold line F of the sheet is located at the third conveying nip N3 rather than the target position. side of the guide member 40 in some cases. In this case, the second sheet detection sensor 32 detects the second conveying nip side (leading end side of the sheet) from the fold line F. However, the sheet portion between the first conveying nip N1 and the second conveying nip N2 bends around the folding line F and contacts the guide member 40 . Therefore, the timing at which the fold line F contacts the guide member 40 and the timing at which the second conveying nip side (the leading end side of the sheet) of the fold line F contacts the guide member 40 are substantially the same timing. Therefore, even if the fold line F of the sheet abuts against the guide member 40 at the third conveying nip N3 side of the target position, when the fold line F abuts against the guide member 40, the second sheet detection sensor 32 detects the sheet. is detected, and it can be detected that the fold line F abuts on the guide member 40 .

Next, when the second sheet detection sensor 32 detects that the folding line F of the sheet abuts against the guide member 40 (YES in S5), the first conveying roller 21 and the combined conveying roller 22 are moved in the direction indicated by the arrow in FIG. As shown, reverse rotation is performed (S6). Also, the second conveying roller pair 23 is reversely rotated (S7).

At this time, the sheet conveying speed V1b at the first conveying nip N1 and the sheet conveying speed at the second conveying nip N2 are adjusted so that the deflection of the sheet portion between the first conveying nip N1 and the second conveying nip N2 does not change. V2b is set. As a result, as indicated by the dashed line in FIG. 7, the folding line F of the sheet maintains contact with the guide member 40 and moves toward the third conveying nip N3.

When the first conveying roller 21 and the dual-purpose conveying roller 22 are rotated in reverse, the trailing edge of the sheet may be inside the image forming apparatus and the sheet may be conveyed toward the sheet folding device 1 . In this case, the sheet conveying direction at the first conveying nip N1 is opposite to the sheet conveying direction at the trailing edge side of the sheet in the image forming apparatus. Therefore, the sheet folding device 1 is provided with a sheet retention portion 41 upstream of the pre-folding portion 10 in the sheet conveying direction (see FIG. 3). Therefore, when the first conveying roller 21 and the combined conveying roller 22 are reversely rotated, and the sheet conveying direction of the first conveying nip N1 and the sheet conveying direction of the sheet rear end side in the image forming apparatus are opposite to each other, , the sheet is retained in the sheet retention portion 41 . As a result, even if the sheet conveying direction of the first conveying nip N1 and the sheet conveying direction of the trailing edge side of the sheet in the image forming apparatus are opposite to each other, the sheet jam does not occur in the first conveying path W1 and the jam does not occur. I'm trying not to wake up.

The fold line F of the sheet maintains contact with the guide member 40 and moves toward the third conveying nip N3. Then, when the third sheet detection sensor 33 detects the sheet (YES in S8), as shown in FIG. 8, the first conveying roller 21 and the combined conveying roller 22 are rotated forward (S9).

The distance from the position where the third sheet detection sensor 33 detects the sheet to the first conveying nip N1 is the shortest, and the distance from the guide surface of the guide member on the side of the third conveying nip N3 to the first conveying nip N1 is the shortest. is gradually lengthened. Therefore, when the third sheet detection sensor 33 detects the sheet, the sheet is sent to the second conveying path W2 by the first conveying nip N1, thereby maintaining the fold line F in contact with the guide member 40. It can be transported to the third transport nip N3.

By forwardly rotating the first conveying roller 21 and the combined conveying roller 22 , the sheet is conveyed to the third conveying nip formed by the combined conveying roller 22 and the third conveying roller 24 with the folding line F leading. Then, the sheet enters the third conveying nip N3 with the crease F at the front, is nipped by the third conveying roller 24 and the combined conveying roller 22, and is folded at the crease F to reach the target position. can be folded (see Figure 9).

In this manner, the sheet folding apparatus 1 can fold the sheet satisfactorily at the position where the crease is made by the pre-folding section 10 by performing the folding processing operation described above. As a result, the sheet can be folded at the target position with higher accuracy.

Here, sheet conveying speeds (V1b, V1c) at the first conveying nip N1 from when the second conveying roller pair 23 reversely rotates until the folding line F enters the third conveying nip N3 will be described.

FIG. 10 is an explanatory diagram of the sheet conveying speeds V1b and V1c at the first conveying nip N1.
As shown in FIG. 10, the center position of the third conveying nip N3 is A, the center position of the first conveying nip is B, and the sheet detection position D of the second sheet detection sensor 32 is assumed. Also, the position of the tangential line of the first conveying roller 21 passing through the sheet detection position D of the second sheet detection sensor 32 is set to C, and the sheet detection position E of the third sheet detection sensor 33 is set. The sheet conveying speed V1b (see FIG. 7) at the first conveying nip until the second conveying roller pair 23 reversely rotates and the folding line F reaches the sheet detection position E of the third sheet detecting sensor 33 is obtained by the following equation: (1).
V1b=(BC+CD-BE)/(DE/V2b) (Formula 1)

By reversely conveying the sheet at the first conveying nip N1 until it reaches the sheet detection position E of the third sheet detection sensor 33 at a conveying speed that satisfies the above formula 1, the fold line F of the sheet comes into contact with the guide member 40. The sheet can be conveyed while maintaining the state.

Also, the sheet conveying speed V1c (see FIG. 8) at the first conveying nip N1 after the third sheet detection sensor 33 detects the sheet can be obtained by the following equation 2. The "RBA" below is the circumferential length from the central position B of the first conveying nip of the dual-use conveying roller 22 to the central position A of the third conveying nip.
V1c=(RBA−BE)/(EA/V2b) (Formula 2)

By setting the sheet conveying speed V1c at the first conveying nip N1 after the third sheet detection sensor 33 detects the sheet to be the conveying speed that satisfies the above formula (2), the sheet is wrapped around the combined conveying roller 22. It can be made to enter the third conveying nip N3.

What has been described above is only an example, and each of the following aspects has a unique effect.
(Aspect 1)
A first sheet conveying means (in this embodiment, constituted by a first conveying roller 21 and a combined conveying roller 22) that holds a part of the sheet and applies a conveying force to the sheet; A second sheet conveying means such as a second conveying roller pair 23 that holds a part of the conveyed sheet and imparts a conveying force to the sheet, and a folding means that folds the sheet (in this embodiment, the combined conveying roller 22 and the third sheet). A sheet conveyed from the first sheet conveying means to the second sheet conveying means by the second sheet conveying means while holding a part of the sheet by the first sheet conveying means. By applying a conveying force to the sheet to return the sheet in a direction opposite to the conveying direction of the sheet, bending is formed between the first sheet conveying means and the second sheet conveying means, and the bent portion of the sheet is formed by the folding means. A sheet folding device 1 for folding a sheet by sandwiching a sheet is provided with a crease forming means such as a pre-folding section 10 arranged upstream in the sheet conveying direction from the first sheet conveying means to crease the sheet.
Between the first sheet conveying means and the second sheet conveying means when the first sheet conveying means holds a part of the sheet and the second sheet conveying means gives the conveying force to the sheet to return it to the upstream side in the sheet conveying direction There were variations in the way the sheet part bent, and it was sometimes folded at a position different from the intended position.
On the other hand, in mode 1, as described in the embodiment, the sheet is partially held by the first sheet conveying means, and conveying force is applied to the sheet to return it to the upstream side in the sheet conveying direction by the second sheet conveying means. At this time, the sheet portion between the first sheet conveying means and the second sheet conveying means can be flexed so as to be bent at the crease formed by the crease forming means. As a result, when the bent portion of the sheet is pinched by the folding means, the sheet can be folded at the crease formed by the crease forming means. Therefore, it is possible to favorably fold the sheet at the target position.

(Aspect 2)
In aspect 1, the position where the conveying force is applied to the sheet such as the second conveying nip N2 of the second sheet conveying means such as the second conveying roller pair 23 is the folding means such as the third conveying nip N3. The second sheet conveying means is positioned below the position where the flexible portion of the sheet is sandwiched by the dual-purpose conveying roller 22 and the third conveying roller 24, and the first sheet such as the first conveying nip N1 is arranged. The position of applying the conveying force to the sheet of the conveying means (constituted by the first conveying roller 21 and the combined conveying roller 22 in the present embodiment) is the position of applying the conveying force to the sheet of the second sheet conveying means and the folding formation. The means is positioned above a position where the bent portion of the sheet is sandwiched, the first conveying means is configured to convey the sheet between the second sheet conveying means and the folding means, and the second sheet conveying means and A sheet guide member such as a guide member 40 disposed between the folding means and inclined so that the second sheet conveying means side is positioned downward.
According to this, the sheet conveyed by the first sheet conveying means between the second sheet conveying means and the folding means contacts the sheet guide member, and is conveyed to the second sheet conveying means by the inclination of the sheet guide member. can do.

(Aspect 3)
In Aspect 2, the pre-folding portion is arranged between the second sheet conveying means such as the second conveying roller pair 23 and the folding means (in the present embodiment, the combined conveying roller 22 and the third conveying roller 24). Guide contact such as the second sheet detection sensor 32 for detecting the sheet contacting the sheet guide member such as the guide member 40 when the fold of the sheet made by the fold forming means such as 10 comes into contact with the sheet guide member such as the guide member 40 A sheet detection means is provided.
According to this, as described in the embodiment, the sheet conveyance of the first sheet conveying means and the second sheet conveying means is controlled based on the detection result of the guide contact sheet detecting means, so that the fold line F is formed into the sheet. The fold line F can be conveyed to the folding means while being in contact with the guide member.

(Aspect 4)
In mode 3, when the guide contact sheet detecting means such as the second sheet detecting sensor 32 detects the sheet, the first sheet conveying means (in this embodiment, constituted by the first conveying roller 21 and the combined conveying roller 22) and A second sheet conveying means such as a second conveying roller pair 23 conveys the folding line F to folding means (in this embodiment, composed of a combined conveying roller 22 and a third conveying roller 24).
According to this, as described in the embodiment, at the stage where the crease F formed on the sheet comes into contact with a sheet guide member such as the guide member 40, the first sheet conveying means and the second conveying means can convey the fold line F to the folding means.

(Aspect 5)
In mode 4, the second sheet is conveyed from the first sheet conveying means (in this embodiment, constituted by the first conveying roller 21 and the dual-purpose conveying roller 22) rather than the second sheet conveying means such as the second conveying roller pair 23. A state in which a first sheet detection means such as a first sheet detection sensor 31 for detecting a sheet is provided downstream of the sheet conveying direction conveyed to the means, and the first sheet detection means detects the sheet. Then, when the guide contact sheet detection means such as the second sheet detection sensor 32 detects the sheet, the first sheet conveying means and the second sheet conveying means reach the crease folding means (in this embodiment, the combined conveying roller 22 and the third conveying roller 24).
According to this, as described in the embodiment, when the leading edge of the sheet conveyed by the first sheet conveying means contacts the sheet guide member such as the guide member 40, the second sheet detection sensor 32 or the like is activated. The guide contact sheet detection means may detect the sheet. In such a case, the sheet conveying by the first sheet conveying means and the second sheet conveying means is not switched to the sheet conveying for conveying the fold to the folding means. Therefore, when the fold of the sheet comes into contact with the sheet guide member, the sheet transport by the first sheet transport means and the second sheet transport means can be switched to the sheet transport in which the fold is transported to the folding means. .

(Aspect 6)
In any one of modes 3 to 5, from the first sheet conveying means (constituted by the first conveying roller 21 and the combined conveying roller 22 in this embodiment) rather than the second sheet conveying means such as the second conveying roller pair 23 A first sheet detecting means such as a first sheet detecting sensor 31 arranged downstream in the conveying direction of the sheet conveyed to the second sheet conveying means for detecting the sheet is provided, and the first sheet conveying means detects the second sheet from the first sheet conveying means. When the first sheet detecting means detects the sheet conveyed to the conveying means and a specified time elapses, the second sheet conveying means holds the sheet so that the sheet does not move downstream of the second sheet conveying means. and when the guide contact sheet detection means detects the sheet, the first sheet conveying means applies a conveying force to the sheet to return the sheet in the direction opposite to the direction in which the sheet is conveyed between the second sheet conveying means and the folding means. At the same time, the second sheet conveying means applies a conveying force to the sheet to return the sheet in a direction opposite to the conveying direction of the sheet conveyed from the first sheet conveying means to the second sheet conveying means.
According to this, as described in the embodiment, the fold line F formed on the sheet is brought into contact with a sheet guide member such as the guide member 40, and the state in which the fold line F is in contact with the sheet guide member is maintained. The fold F can be conveyed to the folding means.

(Aspect 7)
In aspect 6, between the guide contact sheet detecting means such as the second sheet detecting sensor 32 and the folding means (in this embodiment, the third conveying roller 24 and the combined conveying roller 22), and the width of the sheet When viewed from the direction, a sheet guide member such as the guide member 40 passes through the position of the first sheet conveying means (in this embodiment, constituted by the first conveying roller 21 and the dual-purpose conveying roller 22) that imparts conveying force to the sheet. A perpendicular position sheet detection means such as a third sheet detection sensor 33 for detecting a sheet is provided at the starting point of the perpendicular to the guide surface of the guide surface.
According to this, by controlling the sheet conveyance of the first sheet conveying means based on the detection result of the sheet detected by the perpendicular position sheet detecting means, the state where the fold line F abuts on the sheet guide member is maintained. , the fold line F can be conveyed to the folding means.

(Aspect 8)
In mode 7, when the perpendicular position sheet detecting means such as the third sheet detecting sensor 33 detects the sheet, the first sheet conveying means (in this embodiment, constituted by the first conveying roller 21 and the combined conveying roller 22) , the conveying force applied to the sheet is returned in the opposite direction to the second sheet conveying means such as the second conveying roller pair 23 and the folding means (in this embodiment, the third conveying roller 24 and the combined conveying roller 22 ) to convey the sheet.
According to this, as described in the embodiment, the fold line F can be conveyed to the folding means while maintaining the state in which the fold line F is in contact with the sheet guide member.

(Aspect 9)
In any one of Aspects 6 to 8, the sheet retention portion 41 that retains the sheet is provided on the upstream side in the sheet transport direction of the first sheet transport means (in this embodiment, configured by the first transport roller 21 and the combined transport roller 22). Prepare.
According to this, as described in the embodiment, when the first sheet conveying means applies a conveying force to the sheet to return the sheet to the upstream side in the sheet conveying direction, the sheet folding device is arranged on the upstream side in the sheet conveying direction. If the sheet conveying direction is opposite to the sheet conveying direction on the trailing end side of an apparatus such as an image forming apparatus, the sheet stays in the sheet staying portion 41 . Accordingly, when the first sheet conveying means applies a conveying force to the sheet to return the sheet to the upstream side in the sheet conveying direction, it is possible to suppress the occurrence of sheet jams on the upstream side in the conveying direction from the first sheet conveying means.

(Mode 10)
In an image forming apparatus comprising an image forming means for forming an image on a sheet and a sheet folding device 1 provided in the apparatus main body for folding the sheet, the sheet folding device 1 is any one of aspects 1 to 9. A sheet folding device was used.
According to this, as described in the embodiment, it is possible to favorably fold at the target position.

(Aspect 11)
An image forming apparatus comprising an image forming apparatus 3 for forming an image on a sheet and a sheet folding apparatus 1 provided separately from the image forming apparatus 3 for folding a sheet on which an image is formed by the image forming apparatus 3. In System 4, the sheet folding device according to any one of Modes 1 to 9 was used as the sheet folding device.
According to this, as described in the embodiment, it is possible to favorably fold at the target position.

Reference Signs List 1: sheet folding device 2: post-processing device 3: image forming device 4: image forming system 10: pre-folding unit 10a: convex roller 10b: receiving table 20: folding processing unit 21: first conveying roller 22: dual-use conveying roller 23 : Second conveying roller pair 24 : Third conveying roller 25 : First conveying roller pair 26 : Third conveying roller pair 31 : First sheet detection sensor 32 : Second sheet detection sensor 33 : Third sheet detection sensor 34 : Third Fourth sheet detection sensor 40 : guide member 41 : sheet retention portion F : folding line N1 : first conveying nip N2 : second conveying nip N3 : third conveying nip P : sheet S : perpendicular line W1 : first conveying path W2 : second Transport path W3: Third transport path

Japanese Patent No. 6197441

Claims (11)

a first sheet conveying means for holding a part of the sheet and applying a conveying force to the sheet;
a second sheet conveying means for holding a part of the sheet conveyed from the first sheet conveying means and applying a conveying force to the sheet;
folding means for folding the sheet,
A part of the sheet is held by the first sheet conveying means, and the conveying direction of the sheet conveyed from the first sheet conveying means to the second sheet conveying means by the second sheet conveying means is opposite to the conveying direction. A deflection is formed in the portion of the sheet between the first sheet conveying means and the second sheet conveying means by applying a conveying force to the sheet to return the sheet in a direction such that the folding means causes the sheet to In a sheet folding device that folds the sheet by pinching the flexing portion of
A sheet folding device, comprising: a crease forming unit arranged upstream of the first sheet conveying unit in the sheet conveying direction and forming a crease in the sheet. The sheet folding device according to claim 1,
The second sheet conveying means is arranged such that a position of the second sheet conveying means that applies a conveying force to the sheet is positioned below a position of the folding means that clamps the bent portion of the sheet,
The position of the first sheet conveying means that applies the conveying force to the sheet is higher than the position of the second sheet conveying means that applies the conveying force to the sheet and the position of the folding means that pinches the bent portion of the sheet. positioned above, said first sheet conveying means configured to convey said sheet between said second sheet conveying means and said folding means;
A sheet folding device, comprising: a sheet guide member arranged between the second sheet conveying means and the folding means and inclined so that the second sheet conveying means side is positioned downward. In the sheet folding device according to claim 2,
The sheet that is disposed between the second sheet conveying means and the folding means and is in contact with the sheet guide member when the crease of the sheet formed by the crease forming means abuts against the sheet guide member. A sheet folding device, comprising guide contact sheet detection means for detecting a. The sheet folding device according to claim 3,
A sheet folding apparatus, wherein when the guide contact sheet detecting means detects the sheet, the fold is conveyed to the folding means by the first sheet conveying means and the second sheet conveying means. The sheet folding device according to claim 3 or 4,
a first sheet detecting means arranged downstream of the second sheet conveying means in a conveying direction of the sheet conveyed from the first sheet conveying means to the second sheet conveying means for detecting the sheet; prepared,
In a state where the first sheet detection means detects the sheet, when the guide contact sheet detection means detects the sheet, the fold is formed by the first sheet conveying means and the second sheet conveying means. A sheet folding device that conveys a sheet to the folding means. The sheet folding device according to any one of claims 3 to 5,
a first sheet detecting means arranged downstream of the second sheet conveying means in a conveying direction of the sheet conveyed from the first sheet conveying means to the second sheet conveying means for detecting the sheet; prepared,
When the first sheet detecting means detects the sheet conveyed from the first sheet conveying means to the second sheet conveying means and a specified time elapses, the second sheet conveying means moves to the second sheet conveying means. holding the sheet so as not to move the sheet to the downstream side of
When the guide contact sheet detecting means detects the sheet, the first sheet conveying means returns a conveying force in a direction opposite to the direction in which the sheet is conveyed between the second sheet conveying means and the folding means. to the sheet, and the second sheet conveying means returns the sheet in a direction opposite to the conveying direction of the sheet conveyed from the first sheet conveying means to the second sheet conveying means to the sheet. The sheet folding device according to claim 6,
When viewed from the width direction of the sheet and between the guide contact sheet detecting means and the folding means, the sheet guide member passes through a position of the first sheet conveying means that imparts a conveying force to the sheet. A sheet folding apparatus, comprising perpendicular position sheet detecting means arranged at a starting point of a perpendicular line of a guide surface and detecting the sheet. The sheet folding device according to claim 7,
When the perpendicular position sheet detecting means detects the sheet, the first sheet conveying means converts the conveying force applied to the sheet from the conveying force returning in the opposite direction to the second sheet conveying means and the folding means. A sheet folding device characterized by switching to a conveying force that conveys the sheet between and. The sheet folding device according to any one of claims 6 to 8,
A sheet folding device, comprising: a sheet retention portion that retains the sheet upstream of the first sheet transport means in the sheet transport direction. an image forming means for forming an image on a sheet;
An image forming apparatus comprising a sheet folding device that is provided in an apparatus main body and performs folding processing on the sheet,
An image forming apparatus using the sheet folding device according to any one of claims 1 to 9 as the sheet folding device. an image forming apparatus that forms an image on a sheet;
An image forming system comprising a sheet folding device that is provided separately from the image forming device and folds a sheet on which an image has been formed by the image forming device,
An image forming system using the sheet folding device according to any one of claims 1 to 9 as the sheet folding device.

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