JP7757630B2 - Folding device and image forming device - Google Patents

Description

The present invention relates to a folding processing device and an image forming device.

Patent Document 1 describes a creasing device that creases sheets one by one using a creasing device installed before the folding mechanism that performs the folding process. This creasing device includes a detection device that detects the position of the sheet, gripping devices that are located upstream and downstream of the creasing device in the sheet transport direction and grip the sheet, and a sag correction device that applies tension to the sheet between the gripping devices to correct any sag. The sag is corrected by the sag correction device before the creasing device creases the sheet.

Patent No. 5471211

The object of the present invention is to provide a folding processing device and image forming device that can improve the accuracy of the folding position of a recording medium compared to a configuration in which a pair of transport rolls located downstream in the transport direction relative to the folding section are always in a nipped state.

To achieve the above object, a first aspect of the folding processing device includes a folding unit that folds a recording medium at a middle portion in the transport direction of the recording medium, an upstream roll pair that is arranged upstream of the folding unit in the transport direction of the recording medium and transports the folded recording medium toward the folding unit, a downstream roll pair that is arranged downstream of the folding unit in the transport direction of the recording medium and transports the folded recording medium along the transport direction, and a transport roll pair that is arranged on the opposite side of the folding unit from the downstream roll pair and is switchable between a nip state and a nip elimination state, and the transport roll pair is placed in the nip elimination state when folding the recording medium at the folding unit.

The second aspect of the folding processing device is the folding processing device of the first aspect, in which the pair of transport rolls constitutes a transport path for transporting the recording medium to another processing section, and the pair of transport rolls are in a nip state when transporting the folded recording medium to the other processing section.

The folding processing device of the third aspect is the folding processing device of the second aspect, but with multiple folding sections, and the transport roll pair transports the recording medium folded at the final folding section to the other processing section.

The fourth aspect of the folding processing device is the folding processing device of the second aspect, but with multiple folding sections, and the transport roll pair transports the recording medium folded at the first and last folding sections to the other processing section.

The fifth aspect of the folding device is a folding device according to any one of the first to fourth aspects, in which a plurality of pairs of transport rolls are arranged along the transport direction, and a pair of transport rolls to be put into a nip-eliminating state is selected from the plurality of pairs of transport rolls according to the size of the recording medium and the folding state of the recording medium.

The sixth aspect of the image forming device includes a forming unit that forms an image on a recording medium, and the folding device described in any one of claims 1 to 5 that folds the recording medium on which the image has been formed by the forming unit in the folding unit.

The folding processing device of the first aspect improves the accuracy of the folding position of the recording medium compared to a configuration in which the pair of transport rolls located downstream in the transport direction from the folding section are always in a nipped state.

The folding device of the second aspect allows the folding device to be made smaller than a configuration that provides a dedicated space for escaping the recording medium when folding the recording medium.

The folding processing device of the third aspect can improve the accuracy of the final folding position of the recording medium compared to a configuration in which the pair of transport rolls located downstream in the transport direction from the folding section are always in a nipped state.

The fourth aspect of the folding processing device is configured so that the recording medium folded from the first and final folds is transported to another processing section by a common pair of transport rolls. This improves the accuracy of the initial folding position of the recording medium compared to a configuration in which the pair of transport rolls located downstream of the folding section in the transport direction are always in a nipped state.

The folding processing device of the fifth aspect reduces power consumption when folding a recording medium at the folding section compared to when all transport roll pairs located downstream of the folding section in the transport direction are in a nip-free state.

The sixth aspect of the image forming device improves the accuracy of the folding position of the recording medium compared to a configuration in which the pair of transport rolls located downstream in the transport direction from the folding section are always in a nipped state.

1 is a front cross-sectional view showing an example of an image forming apparatus including a folding device according to an embodiment of the present invention; FIG. 2 is a front cross-sectional view showing the main body side of the image forming apparatus of FIG. 1 . FIG. 2 is a front cross-sectional view showing the folding device side of FIG. 1 . FIG. 2 is an enlarged view showing a folding unit of the folding device according to the embodiment. 10 is an enlarged view showing a main part of the folding device according to the embodiment for explaining the operation of the first folding unit; FIG. This is an enlarged view showing the main parts to explain the action of a pair of transport rolls provided at the leading side of the recording medium when folding the recording medium at the second folding section as the folding section of the folding processing device of this embodiment. 10 is an enlarged view showing a main part for explaining the operation of a third folding unit as a folding unit of the folding device according to the embodiment; FIG. 10 is an enlarged view showing a main part of the folding processing device according to the embodiment in order to explain the operation of a conveying unit that conveys the folding processing device to the outside. FIG. 1A is a diagram showing an accordion-folded recording medium, and FIG. 1B is a diagram showing a gatefolded recording medium. (A) is a diagram showing a Z-fold of a recording medium, (B) is a diagram showing an inward three-fold of a recording medium, (C) is a diagram showing an outward three-fold of a recording medium, and (D) is a diagram showing a quarter-fold of a recording medium. 7 is an enlarged view corresponding to FIG. 6 showing a main part in an enlarged manner to explain the operation of a transport roll pair as a modified example. FIG.

Below, an example of an embodiment of the present invention will be described in detail with reference to the drawings.

First Embodiment
FIG. 1 shows an example of an image forming apparatus 10 equipped with a folding device 14 according to the first embodiment, and is a front cross-sectional view of the image forming apparatus 10 as seen from the front side.

As shown in FIG. 1, the image forming apparatus 10 according to this embodiment includes an image forming apparatus main body (forming unit) 12 that forms an image on a sheet material P serving as a recording medium, and a folding device 14 that creases the sheet material P (folds the sheet material P).

In this embodiment, the width direction (horizontal direction) of the device is defined as the X direction, the up-down direction (vertical direction) of the device is defined as the Y direction, and the depth direction (horizontal direction) of the device is defined as the Z direction. In this embodiment, the X direction, Y direction, and Z direction are perpendicular to each other.

Figure 2 shows an example of an image forming device main body 12, and is a front cross-sectional view of the image forming device main body 12 as seen from the front side.

As shown in FIG. 2, the image forming apparatus main body 12 according to this embodiment is equipped with a supply unit 16, a transport unit 18, an image forming unit 20, and an image reading unit 22, in this order. The supply unit 16 supplies sheet material P from the bottom to the top in the Y direction. The transport unit 18 transports the sheet material P supplied by the supply unit 16. The image forming unit 20 forms a toner image on the sheet material P transported by the transport unit 18. The image reading unit 22 reads the image of the original document G. The image reading unit 22 is an example of a reading unit. The image forming apparatus 10 also includes a fixing unit 24 that applies heat and pressure to the sheet material P on which the toner image has been formed, thereby fixing the toner image to the recording medium.

The supply unit 16 is provided with multiple storage members 26 that can be pulled out from the image forming apparatus main body 12 toward the front in the Z direction, and sheet materials P are stacked on each of these storage members 26. Furthermore, each storage member 26 is provided with a feed roll 30 that sends out the sheet materials P stacked on that storage member 26 to a transport path 28 that constitutes the transport unit 18. The transport unit 18 is provided with multiple transport roll pairs 32 that transport the sheet materials P along the transport path 28.

The image reading unit 22 is equipped with a platen glass 34 on which the original G is placed, and a reading unit 36 that reads the image of the original G placed on the platen glass 34. The reading unit 36 is equipped with a CCD (Charge Coupled Device) 36A, a lens 36B, and a lamp 36C. Light irradiated onto the original G from the lamp 36C is reflected and received by the CCD 36A via the lens 36B. In this way, the image of the original G is read and image data is obtained.

The image forming unit 20 is equipped with four image forming units 38Y, 38M, 38C, and 38K for yellow (Y), magenta (M), cyan (C), and black (K). In the following description, when there is no need to distinguish between Y, M, C, and K, the terms Y, M, C, and K may be omitted. The image forming unit 20 is also equipped with an exposure device 42 for each color that irradiates exposure light onto the image carrier 40 (only image carrier 40Y is shown) provided in the image forming unit 38 based on image data read by the reading unit 36.

The image forming units 38 for each color are detachably attached to the image forming apparatus main body 12. Each image forming unit 38 for each color is equipped with an image carrier 40 and a charging member 44 (only charging member 44Y is shown) that charges the surface of the image carrier 40. Furthermore, each image forming unit 38 for each color is equipped with a developing device 46 (only developing device 46Y is shown) that develops the electrostatic latent image formed by the exposure device 42 irradiating the charged image carrier 40 with exposure light, thereby visualizing it as a toner image.

The image forming unit 20 also includes an endless transfer belt 48 that rotates in the direction of arrow A in the figure, and primary transfer rolls 50 (only primary transfer roll 50Y is shown) that transfer toner images formed by the image forming units 38 of each color onto the transfer belt 48. The image forming unit 20 also includes a secondary transfer roll 52 that transfers the toner images transferred onto the transfer belt 48 onto the sheet material P.

In the image forming device 10 according to this embodiment, an image is formed as follows:

First, a voltage is applied to the charging member 44 of each color (only charging member 44Y is shown), which uniformly negatively charges the surface of the image carrier 40 of each color at a predetermined potential. Next, based on the image data read by the reading unit 36, the exposure device 42 irradiates the charged surface of the image carrier 40 of each color with exposure light to form an electrostatic latent image.

As a result, an electrostatic latent image corresponding to the image data is formed on the surface of the image carrier 40 for each color. The developing device 46 for each color then develops this electrostatic latent image, making it visible as a toner image. The toner image formed on the surface of the image carrier 40 for each color is then transferred to the transfer belt 48 by the primary transfer roll 50.

The sheet material P is then sent from the storage member 26 to the transport path 28 by the delivery roll 30, and is then sent to the transfer position T where the transfer belt 48 and the secondary transfer roll 52 come into contact. At the transfer position T, the sheet material P is transported between the transfer belt 48 and the secondary transfer roll 52, and the toner image on the surface of the transfer belt 48 is transferred to the sheet material P.

The toner image transferred to the sheet material P is fixed to the sheet material P by the fixing unit 24. The fixing unit 24 is located downstream of the secondary transfer roll 52 in the conveyance direction of the sheet material P, and includes a heating roll 54 that is driven to rotate by a torque transmitted from a stepping motor (not shown). A halogen heater 54A is located inside the heating roll 54.

The fixing unit 24 also includes a pressure roll 56 that presses the conveyed sheet material P against the heating roll 54 and is rotatably supported. The sheet material P with the transferred toner image is sandwiched between the heating roll 54 and the pressure roll 56 and conveyed, heating and pressurizing the sheet material P to fix the toner image to the sheet material P. The sheet material P with the fixed toner image is then discharged to the outside of the image forming apparatus main body 12 through the discharge port 57.

(folding device)
Next, the folding device 14 according to this embodiment will be described.

Figure 3 is a front cross-sectional view of the folding device 14. As shown in Figures 1 and 3, the folding device 14 has an entrance section 15 that connects to the discharge outlet 57 provided in the image forming device main body 12. The folding device 14 has a conveying section 60 that conveys the sheet material P discharged from the image forming device main body 12 through the entrance section 15, and a folding section 62 that performs a folding process on the sheet material P conveyed by the conveying section 60 (folds the sheet material P).

The conveying unit 60 includes multiple conveying roll pairs 66 that convey the sheet material P along a conveying path 59 along which the sheet material P is conveyed. Multiple sensors 67 are provided on the conveying path 59 to detect the leading and trailing edges of the sheet material P being conveyed. Detection of the sheet material P by the sensors 67 adjusts the drive timing of roll pairs, including a folding roll pair 74 (described below).

The conveying path 59 also includes a conveying path 61 (conveying path 63) for discharging the sheet material P to the outside of the folding device 14 without folding the sheet material P, and a conveying path 64 (conveying path 65) for folding the sheet material P.

Conveying path 63 is a path for transporting sheet material P discharged from image forming device main body 12 in the X direction (horizontal direction). Conveying path 65 is a path for folding sheet material P discharged from image forming device main body 12 and transporting the folded sheet material P. Conveying path 65 includes multiple conveying paths 65A, 65B, 65C, etc. corresponding to the folding specifications of sheet material P (described below).

Figures 4 to 8 are enlarged views of the folding section 62. As shown in Figure 4, the folding section 62 is provided on the conveying path 64, and includes a first folding section (initial folding section) 68, a second folding section (folding section) 70, and a third folding section (final folding section) 72.

As shown in FIG. 5, the first folding section 68 includes a pair of roll-shaped folding rolls 74 and a pushing member 76.

The folding roll pair 74 consists of folding roll 74A and folding roll 74B. Folding rolls 74A and 74B are arranged along the conveying direction of sheet material P, with their longitudinal direction intersecting (orthogonal, same below) the conveying direction of sheet material P, and apply a conveying force to sheet material P.

On the other hand, the pushing member 76 is positioned on the opposite side of the folding roll pair 74, with the conveying path 64 in between, and is arranged with its longitudinal direction intersecting the conveying direction of the sheet material P. Furthermore, the pushing member 76 has a sharp tip 76A, which enables it to push a portion of the sheet material P being conveyed (the position to be folded) between the folding rolls 74A and 74B.

A portion of the sheet material P is pushed between the folding rolls 74A and 74B via the pushing member 76, causing the sheet material P to be folded starting from that portion of the sheet material P, and as the sheet material P passes between the folding rolls 74A and 74B, a crease Q1 (see Figure 6) is formed in the sheet material P.

A conveying path 64A is provided between the folding rolls 74A and 74B in a direction intersecting the conveying path 64. The conveying path 64A branches off from the conveying path 64 and conveys the sheet material P along conveying path 65A, along which the sheet material P folded once by the pair of folding rolls 74 of the first folding unit 68 is conveyed.

An upstream roll pair 78 is provided upstream of the first folding section 68 in the conveying direction of the sheet material P. The upstream roll pair 78 is composed of an upstream roll 78A and an upstream roll 78B, and the upstream rolls 78A and 78B are arranged with their longitudinal direction intersecting the conveying direction of the sheet material P. The upstream roll 78A and the upstream roll 78B are arranged with the conveying path 64 between them, and the upstream roll 78A and the upstream roll 78B sandwich the sheet material P and apply a conveying force to the sheet material P.

As shown in FIG. 3, a guide 80 is provided downstream of the first folding unit 68 in the conveyance direction of the sheet material P, and the guide 80 is provided along the generally vertical direction of the folding device 14. Strictly speaking, the guide 80 is inclined downwards from the folding device 14 as it extends toward the image forming device main body 12.

In addition, an abutment portion 80A is provided at the tip of the guide 80. The abutment portion 80A is formed in a direction intersecting the conveying direction of the sheet material P and stands upright relative to the conveying surface 80B of the guide 80. Therefore, when the sheet material P is conveyed into the guide 80, the sheet material P abuts against the abutment portion 80A of the guide 80, restricting its movement.

The guide 80 is extendable and retractable along the conveying direction of the sheet material P. For example, the guide 80 includes a sliding member that slides relative to the main body along the conveying direction of the sheet material P. The sliding member has a stopper 80A at its tip, and the position of the stopper 80A can be adjusted depending on the folding position and size of the sheet material P.

On the other hand, as shown in FIG. 6 , the conveying path 64A along which the sheet material P folded once by the folding roll pair 74 of the first folding section 68 is conveyed is equipped with a conveying roll pair 66. Here, one conveying roll pair 66 is provided, but multiple conveying roll pairs 66 may be provided. The conveying roll pair 66 is composed of a conveying roll 66A and a conveying roll 66B, and in the conveying path 64A, the conveying roll 66A can be moved toward and away from the conveying roll 66B. In other words, the conveying roll pair 66 that constitutes the conveying path 64A can be switched between a nip state in which the sheet material P is nipped, and a nip release state in which the nipped state is released.

The mechanism for moving the transport roll 66A toward and away from the transport roll 66B uses well-known technology, such as a cam in contact with a bearing that rotatably supports the transport roll 66A, and rotating the cam moves the transport roll 66A toward and away from the transport roll 66B.

Furthermore, the conveying path 64A is connected downstream in the conveying direction of the sheet material P to a conveying path 73, which is made up of multiple conveying roll pairs 71 shown in Figure 3 and conveys the sheet material P to discharge ports 75 and 77, which will be described later. Therefore, when the sheet material P is folded only once, for example, in half, the sheet material P is conveyed to the outside of the folding device 14 (to another processing unit) by the conveying path 64A and the conveying path 73.

In this embodiment, as shown in FIG. 3, the folding device 14 is provided with two discharge openings 75, 77. The discharge opening 75 is provided in the transport path 65 and is formed on the top surface 14A of the folding device 14. On the other hand, the discharge opening 77 is provided in the transport paths 63, 65 and is formed on the right side surface 14B of the folding device 14 in the figure. Discharge trays 79, 81 are provided at the discharge openings 75, 77, respectively, and the folded sheet material P is discharged onto the discharge trays 79, 81, respectively.

In this embodiment, as shown in FIG. 1, the image forming device 10 is composed of an image forming device main body 12 that forms an image on the sheet material P, and a folding device 14 that folds the sheet material P. However, a post-processing device that performs bookbinding, such as binding, may also be provided as another processing device. In this case, the discharge outlet 77 discharges the sheet material P to the post-processing device. In other words, in a configuration without a binding device, the discharge process to the discharge unit may be considered another processing device. Furthermore, if a selvedge alignment device such as a tamper is provided in the discharge unit, the selvedge alignment device may also be considered another processing device.

In this embodiment, as shown in FIG. 3, the sheet material P transported via the transport path 65 (65A, 65B, 65C) is discharged from the discharge outlet 75 or discharge outlet 77 by the transport path 73 provided downstream in the transport direction of the sheet material P relative to the transport path 64 (64A, 64B, 64C).

The transport path 73 includes a transport path 73A where the transport paths 64 (64A, 64B, 64C) that make up the transport route 65 converge. This transport path 73A has a branching section 83 downstream in the transport direction of the sheet material P. The transport path 73A also has a transport path 73A1 that connects the branching section 83 to the discharge outlet 75, and a transport path 73A2 that connects the branching section 83 to the discharge outlet 77. The transport path 73A is branched by the branching section 83 into transport path 73A1 or transport path 73A2.

As mentioned above, the transport path 73 is composed of multiple transport roll pairs 71. Note that, although three transport roll pairs 71 are provided here, the number of transport roll pairs 71 is not limited to three. Also, as shown in FIG. 4, the transport roll pair 71 is composed of transport roll 71A and transport roll 71B, and in the transport path 73A, the transport roll 71A can be moved toward and away from the transport roll 71B by a mechanism similar to that of the transport roll pair 66 that constitutes the transport path 64A. Therefore, the transport roll pair 71 can be switched between a so-called nip state and a nip-release state with respect to the sheet material P.

As shown in FIG. 6, the second folding section 70, like the first folding section 68, is configured to include a pair of roll-shaped folding rolls 82 and a pushing member 84.

The folding roll pair 82 consists of folding roll 82A and folding roll 82B. The folding rolls 82A and 82B are arranged along the conveying direction of the sheet material P, with their longitudinal direction intersecting the conveying direction of the sheet material P, and apply a conveying force to the sheet material P.

On the other hand, the pushing member 84 is positioned on the opposite side of the folding roll pair 82, with the conveying path 64A in between, and is arranged with its longitudinal direction intersecting the conveying direction of the sheet material P. The pushing member 84 has a sharp tip 76A that allows it to move toward and away from the conveying path 64A, and to push another portion of the conveyed sheet material P (the position to be folded) between the folding rolls 82A and 82B.

By pushing a portion of the sheet material P between the folding rolls 82A and 82B via the pushing member 84, the sheet material P that has been folded once is folded again starting from another portion of the sheet material P, and as it passes between the folding rolls 82A and 82B, a crease is formed in the sheet material P.

Between the folding rolls 82A and 82B, a conveying path 64B is provided in a direction intersecting the conveying path 64A. The conveying path 64B branches off from the conveying path 64A and conveys the sheet material P along conveying path 65B, along which the sheet material P folded twice by the folding roll pair 74 of the first folding unit 68 and the folding roll pair 82 of the second folding unit 70 is conveyed.

As shown in FIG. 3, conveying path 64B is connected to conveying path 73, which is connected to conveying path 64A, downstream in the conveying direction of sheet material P. Therefore, when sheet material P is folded only twice, for example, in a Z-fold or a third fold, the sheet material P is conveyed to the outside of the folding device 14 via conveying path 64B and conveying path 73.

On the other hand, as shown in FIG. 6, a pair of folding rolls 74 of the first folding unit 68 is provided upstream of the second folding unit 70 in the conveying direction of the sheet material P. In the second folding unit 70, the pair of folding rolls 74 of the first folding unit 68 also serves as the upstream roll pair, with folding rolls 74A and 74B positioned with the conveying path 64A between them, sandwiching the sheet material P between them and applying a conveying force to the sheet material P.

Furthermore, a downstream roll pair 86 is provided downstream of the second folding unit 70 in the conveying direction of the sheet material P. The downstream roll pair 86 is composed of a downstream roll 86A and a downstream roll 86B. The downstream rolls 86A and 86B are provided with their longitudinal direction intersecting the conveying direction of the sheet material P, and the downstream roll 86A and the downstream roll 86B are arranged with the conveying path 64A between them, and the downstream roll 86A and the downstream roll 86B sandwich the sheet material P and apply a conveying force to the sheet material P.

Like the first folding section 68 and the second folding section 70, the third folding section 72 is configured to include a pair of roll-shaped folding rolls 88 and a pushing member 90.

The folding roll pair 88 consists of folding roll 88A and folding roll 88B. The folding rolls 88A and 88B are arranged along the conveying direction of the sheet material P, with their longitudinal direction intersecting the conveying direction of the sheet material P, and apply a conveying force to the sheet material P.

On the other hand, the pushing member 90 is positioned on the opposite side of the folding roll pair 88, with the conveying path 64B in between, and is arranged with its longitudinal direction intersecting the conveying direction of the sheet material P. The pushing member 90 has a sharp tip 90A that can be moved toward and away from the conveying path 64B, allowing it to push another portion of the conveyed sheet material P (the position to be folded) between the folding rolls 88A and 88B.

By pushing a portion of the sheet material P between the folding rolls 88A and 88B via the pushing member 90, the sheet material P that has been folded twice is further folded from another portion of the sheet material P as the starting point, and as shown in Figure 7, a crease is formed in the sheet material P when it passes between the folding rolls 88A and 88B.

Between the folding rolls 88A and 88B, a conveying path 64C is provided in a direction intersecting the conveying path 64B. The conveying path 64C branches off from the conveying path 64B and conveys the sheet material P along conveying path 65C, along which the sheet material P folded three times by the folding roll pair 74 of the first folding unit 68, the folding roll pair 82 of the second folding unit 70, and the folding roll pair 88 of the third folding unit 72 is conveyed.

As shown in FIG. 8, conveying path 64C is connected to conveying path 73, which is connected to conveying paths 64A and 64B, downstream in the conveying direction of sheet material P. In other words, conveying path 73 is a conveying path where conveying paths 64A, 64B, and 64C converge. When sheet material P is folded three times, such as in an accordion fold or gatefold, the sheet material P is conveyed to the outside of the folding device 14 by conveying paths 64C and 73.

Meanwhile, the folding roll pair 82 of the second folding unit 70 is provided upstream of the third folding unit 72 in the conveying direction of the sheet material P. In the third folding unit 72, the folding roll pair 82 of the second folding unit 70 also serves as the upstream roll pair, with the folding roll 82A and the folding roll 82B positioned with the conveying path 64B between them, sandwiching the sheet material P between them and applying a conveying force to the sheet material P.

Furthermore, a downstream roll pair 92 is provided downstream of the third folding unit 72 in the conveying direction of the sheet material P. The downstream roll pair 92 is composed of a downstream roll 92A and a downstream roll 92B. The downstream rolls 92A and 92B are provided with their longitudinal direction intersecting the conveying direction of the sheet material P, and the downstream roll 92A and the downstream roll 92B are arranged with the conveying path 64B between them, and the downstream roll 92A and the downstream roll 92B sandwich the sheet material P and apply a conveying force to the sheet material P.

In this embodiment, the folding roll pair 74 of the first folding section 68 shown in Figure 4 also serves as the upstream roll pair of the second folding section 70, and the folding roll pair 82 of the second folding section 70 also serves as the upstream roll pair of the third folding section 72. However, it goes without saying that dedicated upstream roll pairs may also be provided for the second folding section 70 and the third folding section 72.

(Action of the folding device)
The operation of the folding device 14 according to the first embodiment will be described.

As shown in Figure 3, in an image forming device 10 equipped with the folding device 14 according to this embodiment, if the user selects not to perform folding, a transport path 63 is selected within the folding device 14, and the sheet material P on which an image has been formed and discharged from the image forming device main body 12 is discharged outside the folding device 14.

On the other hand, if the user selects to perform folding processing, the transport path 65 is selected within the folding processing device 14, and folding processing is performed on the sheet material P discharged from the image forming device main body 12.

For example, as shown in Figure 9(B), the case where the sheet material P is folded gate-fold (three times) will be described with reference to Figures 3 and 5 to 8.

As shown in FIG. 3, the sheet material P transported by the transport path 64 that constitutes the transport path 65 is guided toward a guide 80 located downstream of the first folding section 68 in the transport direction of the sheet material P, and the leading edge of the sheet material P abuts against the abutment section 80A of the guide 80. This aligns the leading edges of the sheet material P.

In this state, as shown in FIG. 5, the sheet material P undergoes a first folding process (the sheet material P is folded) in the first folding section 68. In the first folding section 68, the pushing member 76 approaches the conveying path 64, and the tip 76A of the pushing member 76 pushes the sheet material P between the folding rolls 74A and 74B.

At this time, folding roll 74A of folding roll pair 74 is driven, and the driving of folding roll 74A applies a conveying force to sheet material P, causing sheet material P to pass between folding roll 74A and folding roll 74B in a folded state starting from a part of sheet material P (the folding position). As a result, fold line Q1 (see Figure 6) is made in sheet material P, and sheet material P is conveyed to conveyance path 64A with fold line Q1 at the front.

Next, as shown in Figure 6, the sheet material P with crease Q1 is folded a second time in the second folding section 70. In the second folding section 70, a folding roll pair 74 is provided as an upstream roll pair on the upstream side of the sheet material P in the conveying direction through the second folding section 70, and a downstream roll pair 86 is provided on the downstream side of the sheet material P in the conveying direction through the second folding section 70.

The sheet material P is then sandwiched between the folding roll pair 74 and the downstream roll pair 86. Meanwhile, the leading edge of the sheet material P (fold Q1) is transported toward the transport path 73A.

In this embodiment, in conveying path 64A, conveying roll 66A can be moved toward and away from conveying roll 66B, and in conveying path 73A, conveying roll 71A can be moved toward and away from conveying roll 71B. Therefore, in this embodiment, when the second folding process is performed in second folding section 70, as shown by the solid lines in Figure 6, conveying roll 66A moves away from conveying roll 66B, and conveying roll 71A moves away from conveying roll 71B (the so-called nip-released state).

Then, with the sheet material P sandwiched between the folding roll pair 74 as the upstream roll pair and the downstream roll pair 86, the pushing member 84 approaches the conveying path 64A, and the tip 84A of the pushing member 84 is pushed between the folding roll 82A and the folding roll 82B via the sheet material P.

Meanwhile, the sheet material P is pushed between the folding rolls 82A and 82B by the tip 84A of the pushing member 84, and a conveying force is applied to the sheet material P by driving the folding roll pair 82.

The sheet material P passes between folding rolls 82A and 82B in a folded state starting from another part of the sheet material P (the folding position). As a result, in addition to fold line Q1, fold line Q2 is formed on the sheet material P, and the sheet material P is transported to transport path 64B with fold line Q2 at the leading edge.

Furthermore, the sheet material P with creases Q1 and Q2 is folded a third time in the third folding section 72. In the third folding section 72, a folding roll pair 82 is provided as an upstream roll pair on the upstream side of the conveying direction of the third folding section 72, and a downstream roll pair 92 is provided on the downstream side of the conveying direction of the third folding section 72.

The sheet material P is then sandwiched between the folding roll pair 82 as the upstream roll pair and the downstream roll pair 92. In this state, the pushing member 90 approaches the conveying path 64B, and the tip 90A of the pushing member 90 is pushed between the folding roll 88A and the folding roll 88B via the sheet material P.

Meanwhile, the sheet material P with creases Q1 and Q2 is pushed between the folding rolls 88A and 88B by the tip 90A of the pushing member 90, and a conveying force is applied to the sheet material P by driving the pair of folding rolls 88.

The sheet material P passes between folding rolls 88A and 88B in a folded state, starting from another portion (Q3) of the sheet material P. As a result, as shown in FIG. 7, in addition to folds Q1 and Q2, an additional fold Q3 is made in the sheet material P, and the sheet material P is transported to transport path 64C with fold Q3 at the leading edge. In this way, the sheet material P is folded in a gate-fold pattern (see FIG. 9(B)).

Then, as shown in Figure 8, the gate-folded sheet material P is transported from transport path 64C to transport path 73 and transported to the outside of the folding device 14 (see Figure 3). At this time, in transport path 73A, as shown by the solid line, transport roll 71A is able to come into contact with transport roll 71B, and the sheet material P is nipped and transported by the transport roll pair 71.

In this embodiment, three folding sections 62 (first folding section 68, second folding section 70, and third folding section 72) are provided to fold the sheet material P. This allows the sheet material P to be folded three times, increasing the number of folding patterns compared to when there are two or fewer folding sections.

Here, examples of folding patterns include, for example, when the sheet member P is folded twice, the Z-fold shown in FIG. 10(A), the inner three-fold shown in FIG. 10(B), the outer three-fold shown in FIG. 10(C), and the quarter-fold shown in FIG. 10(D). On the other hand, when the sheet member P is folded three times, examples include the gate fold shown in FIG. 9(B) and the accordion fold shown in FIG. 9(A). In other words, in this embodiment, it is possible to perform gate folds, accordion folds, etc. on the sheet member P, which were not possible when there were two or fewer folds.

Generally, in a configuration for transporting sheet material that has been folded multiple times, for example, the dimensions of a sheet material P that has been folded only once in half are longer than the roll pitch, so it is sandwiched between multiple pairs of transport rolls 71 and subjected to a transport force. This can cause the sheet material P to become twisted or bent, potentially reducing the accuracy of the folding position of the sheet material P.

For this reason, in this embodiment, as shown in Figures 6 and 8, the transport roll pair 71 that makes up the transport path 73 is configured so that the transport roll 71A can be moved toward and away from the transport roll 71B, making it possible to switch between a nipped state and a nipped-off state with respect to the sheet material P.

As a result, as shown in FIG. 6, when the second folding process is performed in the second folding section 70, the transport roll 71A moves away from the transport roll 71B, resulting in a nip-free state. Therefore, in this embodiment, the accuracy of the folding position of the sheet material P is improved compared to a configuration in which the transport roll pair 71 is always in a nipped state.

On the other hand, as shown in Figure 8, when the folded sheet material P is transported outside the folding processing device 14 (see Figure 3), including to other processing units such as a post-processing device that performs binding and other bookbinding, in the transport path 73A, the transport roll 71A is able to come into contact with the transport roll 71B, and the sheet material P is transported in a nipped state by the transport roll pair 71.

In other words, in this embodiment, the transport path 73A, which is used as a space for allowing sheet material P to escape when folding the sheet material P, also serves as a discharge path for transporting the sheet material P to the outside of the folding device 14. As a result, in this embodiment, the folding device 14 can be made more compact than in a configuration that provides a dedicated space for allowing sheet material P to escape when folding the sheet material P.

Furthermore, in this embodiment, as shown in FIG. 6, all (here, three) transport roll pairs 71 that make up the transport path 73A are in a nip-disengaged state. However, since the position of the leading edge of the sheet material P changes depending on the folding style or size of the sheet material P, the number of transport roll pairs 71 that are in a nip-disengaged state can be changed depending on the folding style or size of the sheet material P.

For example, as a modified example, as shown in FIG. 11, when the size of the sheet material P is small, the amount of penetration of the sheet material P into the transport path 73A is shorter than in the case shown in FIG. 6. Therefore, in this case, in the transport roll pair 71 (one in this case) on the downstream roll pair 86 side, the transport roll 71A is in contact with and separates from the transport roll 71B (nip-disengaged state), and in the transport roll pair 71 (two in this case) at the branching section 83, the transport roll 71A can come into contact with the transport roll 71B (nip state).

In other words, when folding the sheet material P in the second folding unit 70, only the necessary transport roll pairs are placed in the nip-free state in the transport paths 64A, 73A used to release the sheet material P. As a result, in this embodiment, power consumption is reduced compared to when all transport roll pairs 71 are placed in the nip-free state when folding the sheet material P in the second folding unit 70.

The above describes one embodiment of the present invention, but the present invention is not limited to this embodiment, and various modifications and substitutions can be made to the above-described embodiment without departing from the spirit of the present invention. For example, conveying path 64B is not necessarily required, and the folding device may be provided with only two folding sections. Furthermore, image formation is not necessarily required, and the folding device may be used as a dedicated folding device.

10 Image forming device 12 Image forming device main body (forming section)
14 Folding device 62 Folding section 65C Conveying path 68 First folding section (upstream folding section, first folding section)
70 Second fold (fold)
71 conveying roll pair 72 third folding section (folding section, final folding section)
74 folding roll pair (upstream roll pair)
78: upstream roll pair 80: conveying section 82: folding roll pair (upstream roll pair)
86 Downstream roll pair 92 Downstream roll pair P Sheet member (recording medium)

Claims (6)

a folding unit that folds the recording medium at a middle portion in the conveying direction of the recording medium;
an upstream roll pair disposed upstream of the folding portion in a conveying direction of the recording medium, and configured to convey the folded recording medium toward the folding portion;
a downstream roll pair disposed downstream of the folding portion in a conveying direction of the recording medium, the downstream roll pair conveying the folded recording medium along the conveying direction;
a conveyance roll pair that is arranged on the opposite side of the folding portion with respect to the downstream roll pair, and that is located at a position where the recording medium reaches when the folding portion folds the recording medium, and that is switchable between a nip state and a nip release state;
Equipped with
The folding unit includes a pair of folding rolls and a pushing member,
A folding processing device that brings the pair of conveying rolls into a nip-disengaged state when the part of the recording medium is pushed between the pair of folding rolls by the pushing member in the folding section. The pair of transport rolls constitutes a transport path for transporting the recording medium to another processing section,
2. The folding processing device according to claim 1, wherein the pair of transport rolls are in a nip state when the folded recording medium is transported to the other processing section. The folding processing device described in claim 2 has multiple folding sections, and the transport roll pair transports the recording medium folded at the final folding section to the other processing section. The folding processing device described in claim 2 has multiple folding sections, and the transport roll pair transports the recording medium folded at the first folding section and the last folding section to the other processing section. The transport roll pairs are arranged in a plurality of directions along the transport direction,
A folding device according to any one of claims 1 to 4, wherein a pair of transport rolls to be put into a nip-eliminating state is selected from among the plurality of transport roll pairs depending on the size of the recording medium and the folding manner of the recording medium. a forming unit for forming an image on a recording medium;
6. An image forming apparatus comprising the folding device according to claim 1, wherein the folding section folds a recording medium on which an image has been formed in the forming section.