JP2017171505A - Sheet folding device, image formation apparatus, image formation system and sheet folding method - Google Patents

Sheet folding device, image formation apparatus, image formation system and sheet folding method Download PDF

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Publication number
JP2017171505A
JP2017171505A JP2017110537A JP2017110537A JP2017171505A JP 2017171505 A JP2017171505 A JP 2017171505A JP 2017110537 A JP2017110537 A JP 2017110537A JP 2017110537 A JP2017110537 A JP 2017110537A JP 2017171505 A JP2017171505 A JP 2017171505A
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Japan
Prior art keywords
sheet
folding
conveying
roller
conveyance
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Pending
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JP2017110537A
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Japanese (ja)
Inventor
山本 和也
Kazuya Yamamoto
和也 山本
永迫 秀也
Hideya Nagasako
秀也 永迫
朋裕 古橋
Tomohiro Furuhashi
朋裕 古橋
道貴 鈴木
Michitaka Suzuki
道貴 鈴木
亨育 中田
Kyosuke Nakada
亨育 中田
晶 國枝
Akira Kunieda
晶 國枝
賢裕 渡邉
Kenhiro Watanabe
賢裕 渡邉
裕史 鈴木
Yasushi Suzuki
裕史 鈴木
貴一郎 後藤
Kiichiro Goto
貴一郎 後藤
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株式会社リコー
Ricoh Co Ltd
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Priority to JP2017110537A priority Critical patent/JP2017171505A/en
Publication of JP2017171505A publication Critical patent/JP2017171505A/en
Pending legal-status Critical Current

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Abstract

PROBLEM TO BE SOLVED: To provide a sheet folding device, image formation apparatus and image formation system which can perform excellent folding processing by resolving unintended deflection and twisting of the sheet.SOLUTION: In a sheet folding device 1 including: first sheet conveyance means 11 which holds a portion of a sheet to apply the conveyance force to the sheet; pieces of second sheet conveyance means 13, 14 which are arranged on the downstream side in the sheet conveyance direction with respect to the first sheet conveyance means and hold a portion of the sheet to apply the conveyance force to the sheet; and pieces of fold formation means 12, 13 which form a fold on the sheet by holding the folded portion formed on the sheet portion between the first sheet conveyance means and the second sheet conveyance means by causing the first sheet conveyance means to hold a portion of the sheet and causing the second sheet conveyance means to apply the conveyance force of returning the sheet to the upstream side in the sheet conveyance direction to the sheet, the conveyance force of the first sheet conveyance means is smaller than the conveyance force of the second sheet conveyance means.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a sheet folding apparatus that performs folding processing on a sheet, and an image forming apparatus and an image forming system including the sheet folding apparatus.

  2. Description of the Related Art Conventionally, as a sheet folding device, a folding portion (bending) formed on a sheet of paper or the like is sandwiched between folds of a pair of folding rollers that are a pair of roller members and conveyed to perform a folding process. It has been known.

  In the sheet folding apparatus described in Patent Document 1, an upstream roller pair and a downstream roller pair that are disposed along the sheet conveyance direction, hold a part of the sheet, and apply conveyance force to the sheet are provided. Yes. Further, a folding roller pair is provided that forms a folded portion on the sheet by sandwiching a folded portion formed by bending the sheet between the upstream roller pair and the downstream roller pair. The upstream roller pair and the downstream roller pair hold a part of the sheet, and the downstream roller pair imparts a conveying force to the upstream side in the sheet conveying direction to the upstream roller pair and the downstream roller pair. A folded portion is formed in the sheet portion between the pair of side rollers. The folded portion formed in this manner is guided and sandwiched between a pair of folding rollers, whereby a folded portion is formed on the sheet, and the sheet is subjected to folding processing.

  If the sheet is skewed during sheet conveyance in the sheet folding apparatus, proper processing cannot be performed when the sheet is folded. For this reason, conventionally, a configuration has been adopted in which sheet skew (skew) is corrected on the upstream side in the sheet conveying direction of the processing location (sheet processing unit). As a configuration for skew correction, for example, the leading edge of the sheet is abutted against a pair of conveying rollers, and thereby the leading edge of the sheet is approximately parallel to the sheet surface and substantially parallel to the direction orthogonal to the sheet conveying direction. After such correction, a configuration in which the leading end of the sheet enters the nip of the pair of conveying rollers is generally used.

  Even after the skew correction is performed on the upstream side in the sheet conveyance direction of the sheet processing unit, the sheet may be skewed again by being conveyed by the conveyance roller pair on the upstream side in the sheet conveyance direction of the sheet processing unit. However, since skew correction is performed immediately upstream in the sheet conveyance direction of the sheet processing unit, the skew generated in the sheet portion passing through the sheet processing unit is not large, and seriously adversely affects processing in the sheet processing unit. Is less likely to bring However, when the sheet processing unit processes a sheet held by both of the two conveying roller pairs arranged on the upstream side and the downstream side in the sheet conveying direction of the sheet processing unit, a serious problem is caused. It turns out that there is a risk of bringing.

  Specifically, when a slight skew occurs when the sheet is conveyed to the upstream roller pair disposed on the upstream side in the sheet conveying direction of the sheet processing unit, the leading edge of the sheet with the slight skew is conveyed to the sheet of the sheet processing unit. It is fed to the downstream roller pair on the downstream side in the direction. At this time, when skew correction is performed on the downstream roller pair as in the case of the upstream roller pair, the sheet leading edge side portion held by the downstream roller pair is not skewed.

  On the other hand, the sheet rear end portion held by the upstream roller pair is kept in a skewed state. As a result, unintended bending or twisting occurs in the sheet portion existing between the upstream roller pair and the downstream roller pair. When a process is performed on a sheet in which such unintended bending or twisting occurs, the problem is often caused more seriously than when a process is performed on a sheet having a skew. For example, when performing a process of forming a folded portion on a sheet portion existing between the upstream roller pair and the downstream roller pair, the formation position of the folded portion is greatly deviated from the target position or folded. This causes the harmful effect of wrinkles on the sheet.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a sheet folding apparatus that can eliminate unintended bending and twisting of a sheet and perform a satisfactory folding process, and the sheet folding apparatus. An image forming apparatus and an image forming system are provided.

  In order to achieve the above object, the invention of claim 1 includes a first sheet conveying unit that holds a part of a sheet and applies a conveying force to the sheet, and a sheet conveying direction downstream of the first sheet conveying unit. A second sheet conveying unit disposed on a side for holding a part of the sheet and applying a conveying force to the sheet; and holding the part of the sheet by the first sheet conveying unit, and the second sheet Holding the folded portion formed in the sheet portion between the first sheet conveying means and the second sheet conveying means by applying a conveying force to the sheet that is returned to the upstream side in the sheet conveying direction by the conveying means. And a folding unit forming means for forming a folded part on the sheet. The conveying force of the first sheet conveying unit is smaller than the conveying force of the second sheet conveying unit. It is characterized in.

  In the present invention, by reducing the conveying force of the first sheet conveying unit to be smaller than the conveying force of the second sheet conveying unit, the force for feeding the sheet in the sheet conveying direction is greater than that of the first sheet conveying unit. Is bigger. As a result, the sheet portion between the first sheet conveying unit and the second sheet conveying unit is pulled by the second sheet conveying unit, and the sheet portion between the first sheet conveying unit and the second sheet conveying unit is extended. And the bending of the sheet can be eliminated. Further, even after the bending of the sheet is eliminated, the sheet can be prevented from being twisted by pulling the sheet by the second sheet conveying unit and feeding the sheet portion held by the first sheet conveying unit while slipping. . Therefore, the folded portion can be formed on the sheet by the folding portion forming means in a state where unintentional bending or twisting of the sheet portion between the first sheet conveying means and the second sheet conveying means has been eliminated. It is possible to suppress a large deviation from the target position and the occurrence of wrinkles on the folded sheet.

  As described above, according to the present invention, there is an excellent effect that unintended bending and twisting of the sheet can be eliminated and a satisfactory folding process can be performed.

FIG. 12 is an explanatory diagram illustrating an example of a mechanism for generating sheet twist and an operation for eliminating the twist / deflection of the sheet when the folding processing apparatus is viewed from an arrow A in FIG. 11. 1 is an explanatory diagram illustrating an example of an image forming system including a folding processing device according to an embodiment. 1 is a schematic configuration diagram of an image forming apparatus provided in an image forming system according to an embodiment. 1 is a schematic configuration diagram of a folding processing device provided in an image forming system according to an embodiment. (A)-(c) is explanatory drawing which respectively shows an example of the folding part formed by the folding process by a folding processing apparatus. (A)-(h) is explanatory drawing for demonstrating the general operation | movement at the time of performing Z folding process by a folding processing apparatus. (A)-(h) is explanatory drawing for demonstrating the general operation | movement at the time of an inner trifold process by a folding processing apparatus. (A)-(h) is explanatory drawing for demonstrating the general operation | movement at the time of an outer trifold process by a folding processing apparatus. 1 is a schematic configuration diagram of a sheet post-processing apparatus provided in the image forming system of the present embodiment. FIG. 6 is an explanatory diagram illustrating another example of an image forming system including a folding processing device according to an embodiment. Explanatory drawing which shows an example of the mechanism of generation | occurrence | production of the twist of a sheet | seat, and the operation | movement of the twist of a sheet | seat and elimination of a bending. The operation | movement flowchart of the twist of a sheet | seat and bending elimination. The figure which shows the structure of the principal part of the folding processing apparatus which has arrange | positioned the bending amount detection sensor. The schematic diagram at the time of seeing the folding processing apparatus which has arrange | positioned the skew amount detection sensor from apparatus information.

  Hereinafter, an embodiment in which a folding processing apparatus which is a sheet conveying apparatus according to the present invention is applied to an image forming system will be described.

  FIG. 2 is an explanatory diagram illustrating an example of an image forming system including the folding processing device according to the present embodiment.

  The folding processing apparatus 1 according to this example is one of sheet post-processing apparatuses that performs sheet post-processing on a sheet such as a sheet discharged from the image forming apparatus 2. In the image forming system of this example, a sheet post-processing for performing post-processing on a sheet on which a folding portion is formed by the folding processing device 1 or on a sheet on which no folding portion is formed by the folding processing device 1 A device 3 is provided. Examples of the sheet post-processing device 3 include a punch punching device that punches holes in a sheet, a sheet binding device that binds a sheet bundle by a stapler, and a sorting discharge device that sorts and discharges image-formed sheets to a plurality of discharge trays. Etc.

  FIG. 3 is a schematic configuration diagram of the image forming apparatus 2 provided in the image forming system according to the embodiment. The image forming apparatus 2 includes a printer unit 100 that is a main body of the apparatus, a feeding unit 200 that is a feeding table, a scanner unit 300 that is mounted on the printer unit 100, and an automatic document feeder (ADF) that is mounted on the scanner unit 300. ). The image forming apparatus 2 also includes a control unit that controls the operation of each device.

  The printer unit 100 includes an intermediate transfer belt 10 as an intermediate transfer member at the center thereof. The intermediate transfer belt 10 is wound around the first support roller 71, the second support roller 72, and the third support roller 73, and can move on the surface in the clockwise direction in the drawing. Then, a latent image carrier that carries one color toner image of yellow (Y), magenta (M), cyan (C), and black (K) on the surface so as to face the intermediate transfer belt 10. The four photosensitive drums 7Y, 7M, 7C, and 7K are provided.

  Around the photosensitive drums 7Y, 7M, 7C, and 7K, charging devices 4Y, 4M, 4C, and 4K that are charging means for uniformly charging the surfaces of the photosensitive drums 7Y, 7M, 7C, and 7K, and toner images Developing devices 5Y, 5M, 5C, and 5K, which are developing means for forming the. Further, the cleaning devices 6Y, 6M, 6C, and 6K for removing the toner remaining on the surface of the photosensitive drums 7Y, 7M, 7C, and 7K after the primary transfer, and the lubricant for applying a lubricant to the surface of the photosensitive drum. Coating devices 8Y, M, C, and K are also provided.

  The toner image forming unit includes the photosensitive drums 7Y, 7M, 7C, 7K, developing devices 5Y, M, C, and K, charging devices 4Y, M, C, and K, and cleaning devices 6Y, M, C, and K. The image forming devices 19Y, 19M, 19C, and 19K are configured. Further, the tandem image forming unit 60 is configured by arranging the four image forming devices 19Y, 19M, 19C, and 19K side by side.

  A belt cleaning device 17 that removes residual toner remaining on the intermediate transfer belt 10 after the toner image is transferred onto the sheet P as a recording medium so as to face the third support roller 73 with the intermediate transfer belt 10 interposed therebetween. It has. The printer unit 100 includes an exposure device 61 above the tandem image forming unit 60.

  Primary transfer rollers 9Y, 9M, 9C, and 9K are provided at positions on the inner side of the intermediate transfer belt 10 that face the photosensitive drums 7Y, 7M, 7C, and 7K with the intermediate transfer belt 10 therebetween. The primary transfer rollers 9Y, 9M, 9C, and 9K are provided so as to be pressed against the photosensitive drums 7Y, 7M, 7C, and 7K with the intermediate transfer belt 10 interposed therebetween to form a primary transfer portion.

  On the other hand, a secondary transfer device 69 is provided on the opposite side of the intermediate transfer belt 10 from the tandem image forming unit 60. The secondary transfer device 69 is configured such that a secondary transfer belt 64 is stretched between a secondary transfer roller 62 and a secondary transfer belt stretching roller 63. In the secondary transfer device 69, the secondary transfer belt 64 is pressed against the third support roller 73 via the intermediate transfer belt 10 at a position supported by the secondary transfer roller 62. A secondary transfer nip portion as a secondary transfer portion is formed between the secondary transfer belt 64 and the intermediate transfer belt 10.

  A fixing device 65 for fixing the transfer image on the sheet P is provided on the left side of the secondary transfer device 69 in the drawing. The fixing device 65 is configured by pressing a pressure roller 67 against a fixing belt 66 that is an endless belt. Further, the above-described secondary transfer device is also provided with a sheet conveyance function for conveying the sheet P that has received the transfer of the toner image at the secondary transfer nip portion to the fixing device 65. Note that a transfer roller or a non-contact charging charger may be disposed as the secondary transfer device. In such a case, it is difficult to provide this sheet conveying function together.

  Under the secondary transfer device and the fixing device 65, a sheet reversing device 68 for reversing the sheet P in order to record images on both sides of the sheet P is provided in parallel with the tandem image forming unit 60 described above. As a result, after the image is fixed on one side of the sheet P, the path of the sheet P is switched to the sheet reversing device side by the switching claw, and the sheet P is reversed and conveyed to the secondary transfer nip portion again to transfer the toner image. Thereafter, it can be discharged to the folding processing apparatus 1.

  The scanner unit 300 reads the image information of the document placed on the contact glass 32 by the reading sensor 36 and sends the read image information to the control unit.

  Based on the image information received from the scanner unit 300, the control unit controls the laser, LED, and the like disposed in the exposure device 61 of the printer unit 100, and irradiates the laser writing light L toward the photosensitive drum 7. Let By this irradiation, an electrostatic latent image is formed on the surface of the photosensitive drum 7, and this latent image is developed into a toner image through a predetermined development process.

  The feeding unit 200 includes a multi-stage feeding cassette 44 provided in the paper bank 43, a feeding roller 42 that feeds the sheet P from the feeding cassette 44, a separation roller 45 that separates the fed sheet P and feeds it to the feeding path 46. A conveyance roller 47 that conveys the sheet P is provided in the feeding path 48.

  In the image forming apparatus 2 of the present embodiment, manual feeding is possible in addition to the feeding unit 200, and the manual feed tray 51 for manual feeding and the sheet P on the manual tray 51 are directed toward the manual feeding path 53. A separation roller 52 for separating the sheets one by one is also provided on the side of the apparatus.

  The registration roller 49 discharges only one sheet P placed on the feeding cassette 44 or the manual feed tray 51, and is positioned between the intermediate transfer belt 10 as an intermediate transfer member and the secondary transfer device. Send to the next transfer nip.

  In the image forming apparatus 2 of the present embodiment, when copying a color image, a document is set on the document table 30 of the document transport unit 400. Alternatively, the original conveying unit 400 is opened, an original is set on the contact glass 32 of the scanner unit 300, and the original conveying unit 400 is closed to hold the original.

  When the start switch is pressed, when the document is set on the document transport unit 400, the document is transported onto the contact glass 32, and then the scanner unit 300 is driven to move the first traveling body 33 and the second traveling body 34. Run. On the other hand, when the document is set on the contact glass 32, the scanner unit 300 is immediately driven to travel the first traveling body 33 and the second traveling body 34. Then, the first traveling body 33 emits light from the light source and further reflects the reflected light from the document surface toward the second traveling body 34 and reflects by the mirror of the second traveling body 34 and passes through the imaging lens 35. The image information of the original is read by putting in the reading sensor 36.

  The surfaces of the photosensitive drums 7Y, 7M, 7C, and 7K are uniformly charged by the charging devices 4Y, 4M, 4C, and 4K, and the image information read by the scanner unit 300 is color-separated. In addition, laser writing is performed on the photosensitive drums 7Y, 7M, 7C, and 7K. Thereby, an electrostatic latent image is formed on the surface of the photosensitive drums 7Y, 7M, 7C, and 7K.

  As an example, description will be made by performing image formation of Y (yellow). The electrostatic latent image formed on the surface of the photoconductor drum 7C is developed by the developing device 5Y in accordance with the Y toner to form a single color toner image. Similarly, a monochrome toner image is formed on the photosensitive drum 7 in the same manner in each of the image forming devices 19M, C, and K in the order of M (magenta), C (cyan), and K (black). In this manner, a toner image is formed on each photosensitive drum 7 and one of the four feeding rollers is operated to feed the sheet P having a size corresponding to the image information.

  At the same time, one of the first support roller 71, the second support roller 72, and the third support roller 73 is driven to rotate by the drive motor, and the other two support rollers are driven to rotate. 10 is rotated and conveyed. Then, along with the conveyance of the intermediate transfer belt 10, monochromatic toner images on the photosensitive drums 7 Y, M, C, and K are sequentially transferred to form a composite color image on the intermediate transfer belt 10.

  On the other hand, in the feeding unit 200, one of the feeding rollers 42 is selectively rotated, the sheet P is fed out from one of the feeding cassettes 44, separated one by one by the separation roller 45, and put into the feeding path 46, and the conveying roller The sheet P is brought into contact with the registration roller 49 and stopped.

  Alternatively, the feeding roller 50 is rotated to feed out the sheets on the manual feed tray 51, separated one by one by the separation roller 52, put into the manual feed path 53, and abutted against the registration roller 49 and stopped.

  When using the sheet P on the manual feed tray 51, the feeding roller 50 is rotated to feed out the sheet P on the manual feed tray 51, separated one by one by the separation roller 52, and put into the manual feed path 53. Similarly, it abuts against the registration roller 49 and stops.

  Then, the registration roller 49 is rotated in time with the composite color image on the intermediate transfer belt 10, and the sheet P is fed into the secondary transfer nip portion where the intermediate transfer belt 10 and the secondary transfer roller 62 are in contact with each other. . Then, the composite color image is secondarily transferred from the intermediate transfer belt 10 onto the sheet P due to the influence of the transfer electric field and contact pressure formed at the secondary transfer nip, and the color image is transferred onto the sheet P. Record.

  The sheet P after receiving the color image transfer at the secondary transfer nip is sent to the fixing device 65 by the secondary transfer belt 64 of the secondary transfer device 69, and the pressure roller 67 and the fixing belt are fixed by the fixing device 65. The color image is fixed by applying pressure and heat. Thereafter, the paper is discharged to the folding processing device 1 by the discharge roller 56.

  Further, after fixing the color image, the sheet P on which images are formed on both sides is switched by the switching claw 55 and conveyed to the sheet reversing device 68 where it is reversed and guided again to the secondary transfer nip portion. After the image is also recorded, the image is discharged to the folding processing apparatus 1 by the discharge roller 56.

  On the other hand, the residual toner remaining on the surface of the intermediate transfer belt 10 after the color image is transferred to the sheet P at the secondary transfer nip portion is removed by the belt cleaning device 17, so that the tandem image forming unit 60 can form an image again. Prepare.

  FIG. 4 is a schematic configuration diagram of the folding processing apparatus 1 provided in the image forming system according to the embodiment.

  The folding processing apparatus 1 of the present embodiment includes a through conveyance path W1 for conveying the sheet P to the subsequent sheet post-processing apparatus 3 without folding the sheet P discharged from the image forming apparatus 2. Further, a branch conveyance path W2 is provided which is branched from the through conveyance path W1 and folds the sheet P discharged from the image forming apparatus 2 and conveys the sheet P to the subsequent sheet post-processing apparatus 3. Yes.

  On the inlet side (the right side in the drawing) of the through conveyance path W1 that receives the sheet P discharged from the image forming apparatus 2, an inlet roller pair 11 as a first sheet conveyance unit is disposed. The inlet roller pair 11 includes a pressing roller 11a that is a rotating member and a driving roller 11b that is a counter member. The driving roller 11b is rotationally driven by a driving force of an inlet motor 11m that is a driving source.

  Further, on the exit side (the left side in the figure) of the through conveyance path W 1, a first folding roller 12, a first forward / reverse roller 13 disposed in contact with the first folding roller 12, and a first forward / reverse roller 13 A pressing roller 14 disposed in contact therewith is provided. By passing through the nip between the first folding roller 12 and the first forward / reverse roller 13, the sheet P can move from the through conveyance path W1 to the branch conveyance path W2. Further, by passing through the nip between the first forward / reverse rotation roller 13 and the pressing roller 14, the sheet P can be conveyed to the subsequent sheet post-processing apparatus 3 via the through conveyance path W1.

  Further, in the present embodiment, a second folding roller 15 disposed in contact with the first forward / reverse rotation roller 13 is provided on the exit side of the branch conveyance path W2. In addition, the branch conveyance path W2 has a second fold roller 15 on the opposite side of the second fold roller 15 across the nip between the first folding roller 12 and the first forward / reverse rotation roller 13 through which the sheet P from the through conveyance path W1 enters. Two forward / reverse roller pairs 16 are provided. The second forward / reverse roller pair 16 includes a pressing roller 16a as a rotating member and a driving roller 16b as an opposing member. The driving roller 16b is driven by a driving force of a second forward / reverse motor 16m as a driving source. Rotation drive.

  The first forward / reverse roller 13 can be driven to rotate in a forward / reverse manner by the driving force of the first forward / reverse motor 13m capable of forward / reverse rotation. The first folding roller 12, the pressing roller 14, and the second folding roller 15 that are disposed in contact with the first forward / reverse roller 13 are all driven rollers that are driven to rotate as the first forward / reverse roller 13 rotates. It is.

  Further, the driving roller 16b constituting the second forward / reverse roller pair 16 can be rotationally driven so as to be able to rotate forward and backward by the driving force of the second forward / reverse rotation motor 16m capable of forward / reverse rotation. The pressing roller 16a constituting the second forward / reverse roller pair 16 is a driven roller that is driven to rotate as the driving roller 16b rotates.

  In the present embodiment, the roller shafts of all the driven rollers are urged by pressure springs 11s, 12s, 14s, 15s, and 16s as urging means. Is to be formed.

  Further, in the present embodiment, an inlet sensor 21 as a sheet edge detection unit that detects the edge of the sheet P is provided on the upstream side in the sheet conveyance direction of the inlet roller pair 11 (through conveyance path W1 inlet side). ing. When the leading edge of the sheet P conveyed from the image forming apparatus 2 reaches the detection area, the inlet sensor 21 outputs a leading edge detection signal indicating that fact to the control unit. As such an inlet sensor 21, a known sensor can be widely used.

  Further, in the present embodiment, the leading edge of the sheet P is disposed on the downstream side in the sheet conveyance direction (the exit side of the through conveyance path W1) of the second sheet conveyance unit including the first forward / reverse rotation roller 13 and the pressing roller 14. A sheet detection sensor 22 is provided as a sheet leading edge detection means for detecting the above. When the leading edge of the sheet P conveyed through the through conveyance path W1 reaches the detection area, the sheet detection sensor 22 outputs a leading edge detection signal indicating that fact to the control unit. As such a sheet detection sensor 22, a well-known sensor can be widely used as in the case of the inlet sensor 21 described above.

  In the present embodiment, a sheet detection sensor 23 that detects the leading edge of the sheet P is provided on the downstream side of the second forward / reverse roller pair 16 in the sheet conveyance direction (on the opposite side to the exit side of the branch conveyance path W2). ing. When the leading edge of the sheet P sent from the through conveyance path W1 to the branch conveyance path W2 reaches the detection area, the sheet detection sensor 23 outputs a leading edge detection signal indicating that fact to the control unit. As such a sheet detection sensor 23, a well-known sensor can be widely used like the entrance sensor 21 and the sheet detection sensor 22 described above.

  In the present embodiment, the first forward / reverse rotation roller 13 and the pressing roller 14 constitute a second sheet conveying means, and the first folding roller 12 and the first forward / reverse rotation roller 13 constitute a first folding portion forming means. Has been. In the present embodiment, the first forward / reverse rotation roller 13 and the second folding roller 15 constitute a second folding portion forming means.

  As the second sheet conveying unit, a configuration of an adhesive roller or a suction belt may be adopted instead of the configuration of such a roller pair. In the present embodiment, the first forward / reverse rotation roller 13 constituting the second sheet conveying unit and the first forward / reverse rotation roller 13 and the second folding roller 15 constituting the folding part forming unit are common rollers. However, the second sheet conveying means and the folded portion forming means may be configured separately and independently using different rollers.

  Next, the flow and operation of folding processing for forming a folding portion on the sheet P by the folding processing apparatus 1 will be described.

  FIGS. 5A to 5C are explanatory views respectively showing examples of folding portions formed by folding processing by the folding processing apparatus 1 of the present embodiment.

  The folding processing apparatus 1 according to the present embodiment can perform a Z-folding process in which two outward folding portions are formed on the sheet P to form a Z-fold as shown in FIG. Further, the folding processing apparatus 1 according to the present embodiment forms an inner trifold by forming two inwardly folded portions of the sheet P into approximately three equal parts and folding the sheet P into an inner trifold as shown in FIG. Processing can be performed. Further, the folding processing apparatus 1 according to the present embodiment forms an outer tri-fold by forming two outer folding portions with respect to the sheet P approximately in three equal parts and forming an outer tri-fold as shown in FIG. Processing can be performed.

  FIGS. 6A to 6H are explanatory diagrams for explaining a general operation when the folding processing device 1 performs the Z-folding process.

  First, the inlet sensor 21 detects the leading edge of the sheet P that is conveyed with a conveying force applied from the discharge roller on the image forming apparatus 2 side. As a result, the control unit that has received the tip detection signal output from the inlet sensor 21 controls the inlet motor 11m to start the rotation of the inlet roller pair 11 (FIGS. 6A and 6B). . After that, when the leading edge of the sheet P enters the nip of the entrance roller pair 11, the transport force is applied from the entrance roller pair 11 and the sheet P is transported through the through-conveying path W1 toward the exit side.

  The leading edge of the sheet P conveyed through the through conveyance path W1 enters the nip between the first forward / reverse rotation roller 13 and the pressing roller 14, and is detected by the sheet detection sensor 22 after passing through the nip. The control unit that has received the leading edge detection signal from the sheet detection sensor 22 that has detected this performs the following control. That is, when the leading edge of the sheet P protrudes by a predetermined protrusion amount from the nip position between the first forward / reverse rotation roller 13 and the pressing roller 14 (FIG. 6C), the first forward / reverse rotation motor 13m is controlled. Then, the rotation of the first forward / reverse roller 13 is stopped. At the same time, the inlet motor 11m is controlled to stop the rotation of the driving roller 11b of the inlet roller pair 11.

  The amount of protrusion at this time is appropriately determined depending on the length of the sheet P in the sheet conveyance direction and the content of the folding process (folding method, etc.). The protrusion amount of the leading edge of the sheet P can be grasped from, for example, the reception timing of the leading edge detection signal output from the sheet detection sensor 22 and the rotation amount of the pressing roller 14.

  Thereafter, the first forward / reverse rotation motor 13m is controlled to start the reverse rotation of the first forward / reverse rotation roller 13 in the direction to return the sheet P to the entrance side of the through conveyance path W1, and to start the rotation of the entrance roller pair 11. . As a result, the sheet portion between the entrance roller pair 11 and the first forward / reverse roller 13 is bent (FIG. 6D). Then, the bent portion (folded portion) enters the nip between the first folding roller 12 and the first forward / reverse roller 13, whereby a first folded portion is formed at the folded portion. The first folding portion that has passed through the nip between the first folding roller 12 and the first forward / reverse roller 13 enters the branch conveyance path W2 (FIG. 6E), and passes through the branch conveyance path W2 in the second forward / reverse direction. It is conveyed toward the roller pair 16.

  Then, the first folded portion of the sheet P enters the nip of the second forward / reverse rotation roller pair 16, and is detected by the sheet detection sensor 23 after passing through the nip. The control unit that has received the leading edge detection signal from the sheet detection sensor 23 that has detected this performs the following control. That is, when the first folding portion of the sheet P protrudes from the nip position of the second forward / reverse roller pair 16 by a predetermined protrusion amount (FIG. 6 (f)), the first forward / reverse motor 13m is controlled. The rotation of the first forward / reverse roller 13 is stopped. At the same time, the rotation of the second forward / reverse roller pair 16 and the inlet roller pair 11 is stopped. The amount of protrusion at this time is also appropriately determined depending on the length of the sheet P in the sheet conveyance direction and the content (folding method, etc.) of folding processing. The amount of protrusion of the first folding portion of the sheet P can be grasped from, for example, the reception timing of the leading edge detection signal output from the sheet detection sensor 23 and the rotation amount of the second forward / reverse rotation roller pair 16.

  Thereafter, the second forward / reverse rotation motor 16m is controlled to control the second forward / reverse rotation motor 16m, and the reverse rotation of the second forward / reverse rotation roller pair 16 is started in the direction in which the sheet P is directed toward the exit side of the branch conveyance path W2. At the same time, the reverse rotation of the first forward / reverse rotation roller 13 and the rotation of the inlet roller pair 11 are resumed. As a result, a bend is formed in the sheet portion between the first forward / reverse rotation roller 13 and the second forward / reverse rotation roller pair 16 (FIG. 6G). The bent portion (folded portion) enters the nip between the first forward / reverse rotation roller 13 and the second folding roller 15, whereby a second folded portion is formed at the folded portion.

  The second folding portion that has passed through the nip between the first forward / reverse rotation roller 13 and the second folding roller 15 is conveyed toward the exit side of the branch conveyance path W2 (FIG. 6 (h)). Then, the sheet P on which the two folded portions are formed in this way is conveyed to the subsequent sheet post-processing apparatus 3 under the conveyance force from the first forward / reverse rotation roller 13.

  FIGS. 7A to 7H are explanatory diagrams for explaining a general operation when the folding processing device 1 performs the inner tri-folding process.

  FIGS. 8A to 8H are explanatory diagrams for explaining a general operation when the folding processing device 1 performs the outer trifold process.

  The flow of operation of the inner tri-fold process and the outer tri-fold process is the same as that of the Z-fold process described above, but the protrusion amount is different. Therefore, the timing for starting the reverse rotation of the first forward / reverse rotation roller 13 and the second forward / reverse rotation roller pair 16 differs between the Z-folding process, the inner trifolding process, and the outer trifolding process.

  FIG. 9 is a schematic configuration diagram of the sheet post-processing apparatus 3 provided in the image forming system of the present embodiment.

  The sheet post-processing apparatus 3 includes an inlet sensor 302, an inlet roller pair 303, a branch claw 304, a discharge roller pair 305, a binding tool 310, a conveyance path 340, a branch path 341, and the like.

  The entrance sensor 302 detects the front end, the rear end, and the presence / absence of the sheet P carried from the folding processing apparatus 1 to the sheet post-processing apparatus 3.

  The entrance roller pair 303 is located at the entrance of the sheet post-processing apparatus 3 and has a function of carrying the sheet P into the sheet post-processing apparatus 3. By using the roller nip of the entrance roller pair 303, it is possible to correct the abutting skew of the sheet P. The inlet roller pair 303 is driven by a controllable drive source. This driving source is controlled by the control unit, and thereby, the rotational driving and stopping of the inlet roller pair 303 by the driving source and the conveyance amount of the sheet P by the inlet roller pair 303 are controlled. The control unit may be provided in the image forming apparatus 2.

  The conveyance path 340 is a normal path for conveying and discharging the received sheet P. The branch path 341 is a conveyance path that is provided to overlap and align the sheets P and is carried in from the rear end side by the switchback of the sheets P.

  The branch claw 304 is a claw member that is rotatably provided to switch the conveyance path in order to guide the rear end of the sheet P from the conveyance path 340 to the branch path 341. Further, the branching claw 304 is configured to be able to press the sheet P against the conveyance surface of the branching path 341, and the sheet P can be fixed by this pressing.

  The binding tool 310 is a tool for binding the sheet bundle aligned in the branch path 341 without using a metal needle. In the present embodiment, the binding tool 310 that deforms the sheet P and entangles the fibers by sandwiching the sheet bundle with a pair of tooth molds having irregularities on the surface is used. In addition, the sheet bundle is subjected to U-shaped cutting and bending, and at the same time, a slit is opened in the vicinity of the bending source so that the cut and bent leading end portion cannot be unwound through the slit without using a metal needle. A binding tool that binds the bundle may be used. Note that the binding means for binding the sheet bundle is not limited to the binding tool of the present embodiment, and may have a function of binding like a widely known binding tool.

  The discharge roller pair 305 is located at the exit of the sheet post-processing device 3 and has a function of discharging the sheet bundle bound by the binding tool 310 to the discharge tray. The discharge roller pair 305 is driven by a controllable drive source. The driving source is controlled by the control unit, and thereby the rotational driving and stopping of the discharge roller pair 305 by the drive source and the conveyance amount of the sheet P by the discharge roller pair 305 are controlled.

  FIG. 10 is an explanatory diagram illustrating another example of the image forming system including the folding processing device according to the present embodiment.

  The folding processing apparatus 1 according to this example forms a folded portion on the sheet P inside the image forming apparatus 2. In the image forming system of this example as well, a sheet that performs post-processing on the sheet P on which the folding portion is formed by the folding processing device 1 or on the sheet P on which the folding portion is not formed by the folding processing device 1. A post-processing device 3 is provided.

  FIG. 10 is a schematic configuration diagram of the image forming apparatus 2 in which the folding processing device 1 is disposed in the cylinder. In FIG. 1, the image forming apparatus 2 includes an image forming apparatus main body 101, a folding processing apparatus 1, and an image reading apparatus 500.

  The image forming apparatus main body 101 is an indirect transfer type tandem color image forming apparatus. In the figure, an image forming unit 110 in which four color image forming stations 111Y, 111C, 111M, and 111K are arranged at a substantially central portion. An optical writing device 18 is provided adjacent to the lower side of the image forming unit 110. A feeding unit 120 is provided below the optical writing device 18. Further, a feeding conveyance path (vertical conveyance path) 130 for conveying the sheet P fed from the feeding unit 120 to the secondary transfer unit 140 and the fixing device 150 is provided. Further, the discharge conveyance path 160 for conveying the sheet P on which the image is fixed by the fixing device 150 to the folding processing device 1 side, or both sides for reversing the sheet P on which the image is formed on one side and forming an image on the other side. A conveyance path 170 is provided.

  The image forming unit 110 includes photosensitive drums 20Y, C, M, and K for the respective colors of the image forming stations 111Y, 111C, 111M, and 111K. Along the outer periphery of the photosensitive drum 20Y, C, M, K, charging devices 80Y, C, M, K, developing devices 70Y, C, M, K, cleaning units 40Y, C, M, K, and static elimination Unit is arranged. In addition, the intermediate transfer belt 112 for intermediate transfer of images formed on the photosensitive drums 20Y, C, M, and K by primary transfer rollers 74Y, 74C, 74M, and K, and the respective colors on the photosensitive drums 20Y, 20C, 20M, and 20K. And an optical writing device 18 for writing an image every time.

  The optical writing device 18 is disposed below the image forming station 111, and the intermediate transfer belt 112 is disposed above the image forming station 111. Above the image forming unit 110, toner storage containers 116Y, 116C, 116M, and 116K that store toner for replenishing the developing devices 70Y, 70C, 70M, and 70K are disposed so as to be replaceable.

  The intermediate transfer belt 112 is rotatably supported by a plurality of support rollers. The support roller 114, which is one of the plurality of support rollers, faces the secondary transfer roller 115 through the intermediate transfer belt 112 in the secondary transfer unit 140, and the image on the intermediate transfer belt 112 is secondary to the sheet P. Can be transcribed.

  The image forming process of the indirect transfer tandem color image forming apparatus is well known and is not directly related to the gist of the present invention, and thus detailed description thereof is omitted.

  The feeding unit 120 includes a feeding tray 121, a pickup roller 122, and a feeding / conveying roller 123, and sends the sheet P picked up from the feeding tray 121 upward along the feeding / conveying path 130.

  The fed sheet P has the image transferred by the secondary transfer unit 140 and is sent to the fixing device 150. The fixing device 150 includes a fixing roller 150a and a pressure roller 150b. In the process where the sheet P passes through the nip between the both, heating and pressing are performed, and the toner is fixed to the sheet P.

  A discharge conveyance path 160 and a double-side conveyance path 170 are provided downstream of the fixing device 150, both of which are branched in two directions by a branching claw 161 and conveyed to the folding processing apparatus 1 side. The transport path is selected depending on the case of transport.

  A branch conveyance roller 162 is provided in the immediate vicinity of the branch claw 161 on the upstream side in the sheet conveyance direction, and applies a conveyance force to the sheet P.

  The folding processing apparatus 1 is arranged inside the image forming apparatus main body 101, performs a folding process on the image-formed sheet P conveyed from the image forming apparatus main body 101, and discharges it to the sheet post-processing apparatus 3 shown in FIG. Is.

  The image reading device 500 is a known device that optically scans a document set on a contact glass 501 and reads an image on a document surface. Since the configuration and function of the image reading apparatus 500 itself are known and are not directly related to the gist of the present invention, detailed description thereof is omitted.

  The image forming apparatus main body 101 configured as described above generates image data used for writing based on document data read from the image reading apparatus 500 or print data transferred from an external PC or the like. Then, based on the image data, optical writing is performed from the optical writing device 18 to each of the photosensitive drums 20Y, 20C, 20M, and 20K. The images formed for the respective colors at the respective image forming stations 111Y, 111C, 111M, and 111K are sequentially transferred to the intermediate transfer belt 112, and a color image in which four color images are superimposed on the intermediate transfer belt 112 is formed. The

  On the other hand, the sheet P is fed from the feeding tray 121 according to the image formation. The sheet P is temporarily stopped at the position of the registration roller immediately before the secondary transfer unit 140, sent out in time with the leading edge of the image on the intermediate transfer belt 112, secondarily transferred by the secondary transfer unit 140, and the fixing device 150. It is sent to.

  The sheet P on which the image is fixed by the fixing device 150 is conveyed to the discharge conveyance path 160 side by the switching operation of the branching claw 161 in the case of single-sided printing or after double-sided printing of double-sided printing. Is conveyed to the double-sided conveyance path 170 side.

  The sheet P conveyed to the double-sided conveyance path 170 is reversed and then sent again to the secondary transfer unit 140 to form an image on the other side, and then returned to the discharge conveyance path 160 side.

  The sheet P transported to the discharge transport path 160 side is transported to the folding processing device 1 and is subjected to folding processing by the folding processing device 1 or discharged to the sheet post-processing device 3 without processing.

  Note that the sheet post-processing apparatus 3 shown in FIG. 9 is used as the sheet post-processing apparatus 3 included in the image forming system, and the description thereof is omitted.

  Next, the characteristic part of the folding processing apparatus 1 which concerns on this embodiment is demonstrated.

  FIG. 11 is an explanatory diagram illustrating an example of a mechanism of twisting of the sheet P and an operation of eliminating twisting / deflection of the sheet P. FIG. 1 is an explanatory diagram showing an example of the mechanism of twisting of the sheet P and the operation of eliminating twisting / deflection of the sheet P when the folding processing apparatus 1 is viewed from the direction A of FIG. FIG. 12 shows an example of an operation flow for eliminating twisting and bending of the sheet P.

  In the operation flow shown in FIG. 12, first, the entrance sensor 21 detects the leading edge of the sheet (S1). When the front end of the sheet is detected by the inlet sensor 21 (YES in S1), the conveyance of the sheet by the inlet roller pair 11 is started, and as shown in FIGS. 1 (a) and 11 (a), the first forward / reverse rotation roller 13 and The sheet P is conveyed toward the nip to the pressing roller 14 (S2).

  Then, as shown in FIGS. 1B and 11B, the leading edge of the sheet P is abutted against the nip between the first forward / reverse rotation roller 13 and the pressing roller 14 to form a deflection. At this time, the skew of the sheet P is eliminated from the nip of the first forward / reverse rotation roller 13 and the pressing roller 14 to the downstream (S3). On the other hand, the sheet P is bent and twisted between the inlet roller pair 11, the pressing roller 14, and the first forward / reverse roller 13. If the folding operation is performed in this state, it leads to folding wrinkles and deterioration of folding accuracy.

  Thereafter, the conveying force of the inlet roller pair 11 is set to be smaller than the conveying force of the second sheet conveying means (the roller pair constituted by the first forward / reverse rotation roller 13 and the pressing roller 14). Here, as shown in FIGS. 1 (c) and 11 (c), the first sheet conveying means constituting the first sheet conveying means satisfies the relationship of the conveying speed of the second sheet conveying means> the conveying speed of the inlet roller pair. The forward / reverse roller 13 and the pressing roller 14 are rotated (S4). Then, the sheet P is conveyed so that the leading end of the sheet is positioned downstream of the nip between the first forward / reverse rotation roller 13 and the pressing roller 14.

  At this time, in a state where the conveyance speed of the second sheet conveyance unit is larger than the conveyance speed of the inlet roller pair 11, the sheet P is pulled by the second sheet conveyance unit, and the unintended bending of the sheet P formed by the skew correction is performed. Can be resolved.

  In order to make the conveying speed of the second sheet conveying means larger than the conveying speed of the inlet roller pair 11, the conveying speed of the inlet roller pair 11 (the rotational speed of the inlet motor 11m) is lowered. Alternatively, the first forward / reverse rotation motor 13m that rotates the first forward / reverse rotation roller 13 of the second sheet conveyance unit is driven so that the conveyance speed of the second sheet conveyance unit is larger than that of the entrance roller pair 11 (first positive / reverse rotation motor 13m). Increase the rotation speed of the reverse motor 13m).

  Note that the spring load of the pressure spring 11s for urging the pressing roller 11a of the inlet roller pair 11 and the pressure spring 14s for urging the pressing roller 14 satisfies the relationship of pressure spring 11s <pressure spring 14s. Keep it like that.

  In such a configuration, after the unintentional bending of the sheet P is eliminated in a state in which the conveyance force of the inlet roller pair 11 is smaller than the conveyance force of the second sheet conveyance unit, the sheet P is moved to the second sheet conveyance unit. The sheet P slips at the entrance roller pair 11.

  Alternatively, a torque limiter configured to cut off or connect the drive from the drive source to the drive system of the entrance roller pair 11 depending on whether or not the load torque of the entrance roller pair 11 exceeds a predetermined amount. Keep it. For example, a torque limiter is inserted into the roller shaft of the driving roller 11b of the inlet roller pair 11 or the driving roller 11b itself.

  In such a configuration, after the unintentional bending of the sheet P is eliminated in a state in which the conveyance force of the inlet roller pair 11 is smaller than the conveyance force of the second sheet conveyance unit, the sheet P is moved to the second sheet conveyance unit. Pull on. Then, the load torque in the counterclockwise direction in FIG. 11 applied to the driving roller 11b of the inlet roller pair 11 exceeds a predetermined amount, the torque limiter functions, and the driving is not transmitted from the inlet motor 11m to the driving roller 11b. The sheet P slips at the pair 11.

  Thus, by feeding the sheet P while slipping, the twist of the sheet P is eliminated as shown in FIGS. 1D and 11D.

  After the twisting and bending of the sheet P are eliminated (YES in S5), the conveying speed of the inlet roller pair 11 and the conveying speed of the second sheet conveying means are equalized (S6), and the sheet P is set at a predetermined position. Is stopped, and a series of twisting and bending elimination operations are terminated (S7). The subsequent sheet folding operation and the like are as described above.

  Regardless of whether or not skew correction is performed, unexpected deflection of the sheet P may occur when the sheet P is curled and hits a roller. In this case, if folding is performed in a state where unexpected bending has occurred in the sheet P, the sheet P is wrinkled, the formation position of the folded portion is greatly displaced, and the folding accuracy of the sheet P is deteriorated.

  On the other hand, in the folding processing apparatus 1 of the present embodiment, as described above, the sheet P is pulled by the second sheet conveying unit, and the sheet P is slipped by the entrance roller pair 11, thereby causing the sheet P to be curled. Unexpected bending of the sheet P can be eliminated.

  In the folding processing apparatus 1 according to the present embodiment, as described above, the sheet P is pulled by the second sheet conveying unit, and the sheet P is slipped by the inlet roller pair 11, thereby eliminating the bending and twisting of the sheet P. . However, if the sheet P is slipped too much, the sheet P and the image forming surface may be damaged. Therefore, it is desirable that the amount of slippage of the sheet P by the entrance roller pair 11 is the minimum necessary.

Here, the necessary conveyance amount, which is the conveyance amount of the sheet P required to pull the sheet P by the second sheet conveyance unit and cause the sheet P to slip by the inlet roller pair 11, is determined by the following factors.
(1) Deflection amount formed for control by skew correction.
(2) An unexpected amount of deflection outside the control that occurs when the sheet P is curled and hits the pressing roller 14 or the like.
(3) A twist amount of the sheet P generated by correcting the skew by the skew of the sheet P.

  Compared with (2) and (3), the required transport amount due to (1) is larger. Therefore, it is the sum of the conveyance amount of the sheet P necessary for eliminating the bending that occurs in (1) and the conveyance amount of the sheet P that eliminates (2) and (3) obtained by experiments or the like. The sheet P is always pulled by the second sheet conveying means by a specified amount. Thereby, it is possible to eliminate the twisting and bending of the sheet P without requiring an additional sensor or the like.

  However, (2) and (3) are amounts that vary depending on the thickness, type, curl, etc. of the sheet P. Therefore, the sheet P may be slipped more than necessary. Therefore, for example, a detection unit that detects the amount of bending and skew of the sheet P is provided. Then, the sheet P is pulled by the second sheet conveying means by the amount of the sheet conveyance amount calculated from the deflection amount and the skew amount of the sheet P by using, for example, a conversion formula obtained through an experiment, and the pair of inlet rollers 11 To slip the sheet P. As a result, the slip amount of the sheet P can always be made the minimum necessary.

  Examples of the bending detection means for detecting the bending amount of the sheet P include the following. For example, the amount of bending of the sheet P depends on the time difference at which the entrance sensor 21 and the sheet detection sensor 22 detect the sheet P, the distance from the entrance sensor 21 to the sheet detection sensor 22, and the conveyance speed of the sheet P of the entrance roller pair 11. Desired. Alternatively, as shown in FIG. 13, for example, a deflection amount detection sensor 24 that detects a deflection amount by a distance measuring sensor or the like is arranged at a point where the sheet P bends, and the deflection amount detection sensor of the sheet P at a certain point. The amount of deflection of the sheet P is determined by the distance from 24 to the sheet P. By detecting the amount of bending of the sheet P by such a method, the necessary conveyance amount due to (1) and (2) is obtained.

  On the other hand, as an example of skew detection means for detecting the skew amount of the sheet P, as shown in FIG. 14, two skew amounts using, for example, a reflective sensor in the sheet width direction orthogonal to the sheet P conveyance direction. Detection sensors 25a and 25b are provided. The skew amount of the sheet P can be detected based on the time difference between the skew amount detection sensor 25a and the skew amount detection sensor 25b detecting the sheet P and the distance between the skew amount detection sensor 25a and the skew amount detection sensor 25b. it can. By detecting the skew amount of the sheet P by such a method, the necessary conveyance amount due to (3) is obtained.

What has been described above is merely an example, and the present invention has a specific effect for each of the following modes.
(Aspect A)
A first sheet conveying unit such as an inlet roller pair 11 that holds a part of the sheet P or the like and applies a conveying force to the sheet, and is disposed downstream of the first sheet conveying unit in the sheet conveying direction, A second sheet conveying means such as a first forward / reverse rotation roller 13 and a pressing roller 14 that holds a part of the sheet and applies a conveying force to the sheet, and a part of the sheet is held by the first sheet conveying means. At the same time, a folding force formed on the sheet portion between the first sheet conveying means and the second sheet conveying means is obtained by applying a conveying force to the sheet that is returned to the upstream side in the sheet conveying direction by the second sheet conveying means. Sheet folding of the folding processing apparatus 1 or the like provided with folding part forming means such as a first folding roller 12 and a first forward / reverse rotation roller 13 that forms a folded part on the sheet by clamping. In the apparatus, the conveying force of said first sheet conveying means is smaller than the conveying force of said second sheet conveying means. According to this, as described in the above embodiment, unintended bending and twisting of the sheet can be eliminated, and a satisfactory folding process can be performed.
(Aspect B)
In (Aspect A), the driving system of the first sheet conveying means is connected to the driving system of the first sheet conveying means according to whether or not the load torque of the first sheet conveying means exceeds a predetermined amount. A torque limiter configured as described above was provided. According to this, as described in the above embodiment, the sheet is slipped by the first sheet conveying unit, and the twisting and the unexpected bending of the sheet that can occur in the sheet portion can be eliminated.
(Aspect C)
In (Aspect A) or (Aspect B), the sheet conveying speed of the second sheet conveying means is the first sheet conveying means while the sheet is held by the first sheet conveying means and the second sheet conveying means. Faster than the sheet transport speed. According to this, as described in the above embodiment, the sheet is pulled by the second sheet conveying unit, and the bending of the sheet formed by the skew correction can be eliminated.
(Aspect D)
In (Aspect C), the sheet conveyance speed of the second sheet conveyance means is higher than the sheet conveyance speed of the first sheet conveyance means, and after the sheet is conveyed by a specified amount, the sheet conveyance of the first sheet conveyance means Equal to speed. According to this, as described in the above embodiment, it is possible to prevent the sheet from slipping more than necessary.
(Aspect E)
(Aspect D) includes a deflection detection unit such as a deflection amount detection sensor 24 that detects the deflection of the sheet between the first sheet conveyance unit and the second sheet conveyance unit, and the specified amount is The sheet conveyance amount obtained by detecting the bending of the sheet by the bending detection means and adding a correction amount to the sheet conveyance amount required until the bending is eliminated. According to this, as described in the above embodiment, it is possible to more reliably eliminate the bending of the sheet.
(Aspect F)
(Aspect E) includes skew detection means such as skew amount detection sensors 25a and 25b for detecting a skew of the sheet between the first sheet conveyance means and the second sheet conveyance means, and the correction. The amount is a sheet conveyance amount calculated from the skew amount when the skew detection unit detects the skew amount of the sheet. According to this, as described in the above embodiment, it is possible to more reliably eliminate the twisting of the sheet.
(Aspect G)
An image forming apparatus 2 including an image forming unit such as an image forming unit 110 that forms an image on a sheet, and a sheet folding unit such as a folding processing apparatus 1 that is provided in the apparatus main body and performs a folding process on the sheet. In the image forming apparatus, the sheet folding device of (Aspect A), (Aspect B), (Aspect C), (Aspect D), (Aspect E) or (Aspect F) was used as the sheet folding means. According to this, as described in the above embodiment, a favorable folding process can be performed on a sheet on which an image is formed.
(Aspect H)
An image forming apparatus such as an image forming apparatus 2 that forms an image on a sheet, and a folding processing apparatus 1 that is provided separately from the image forming apparatus and that performs a folding process on a sheet on which an image is formed by the image forming apparatus. In an image forming system including a sheet folding device, the sheet folding device includes (Aspect A), (Aspect B), (Aspect C), (Aspect D), (Aspect E) or (Aspect F). A device was used. According to this, as described in the above embodiment, a favorable folding process can be performed on a sheet on which an image is formed.

DESCRIPTION OF SYMBOLS 1 Folding processing apparatus 2 Image forming apparatus 3 Sheet post-processing apparatus 4 Charging apparatus 5 Developing apparatus 6 Cleaning apparatus 7 Photosensitive drum 8 Lubricant coating apparatus 9 Primary transfer roller 10 Intermediate transfer belt 11 Inlet roller pair 11a Press roller 11b Drive roller 11m Inlet motor 11s Pressure spring 12 First folding roller 12s Pressure spring 13 First forward / reverse roller 13m First forward / reverse motor 14 Pressing roller 14s Pressure spring 15 Second folding roller 15s Pressure spring 16 Second forward / reverse roller Pair 16a Press roller 16b Drive roller 16m Second forward / reverse motor 16s Pressure spring 17 Belt cleaning device 18 Optical writing device 19 Image forming device 20 Photosensitive drum 21 Entrance sensor 22 Sheet detection sensor 23 Sheet detection sensor 24 Deflection Detection sensor 25a Skew amount detection sensor 25b Skew amount detection sensor 30 Document table 32 Contact glass 33 First traveling body 34 Second traveling body 35 Imaging lens 36 Reading sensor 40 Cleaning unit 42 Feeding roller 43 Paper bank 44 Feeding cassette 45 Separating roller 46 Feeding path 47 Conveying roller 48 Feeding path 49 Registration roller 50 Feeding roller 51 Manual feed tray 52 Separating roller 53 Feeding path 55 Switching claw 56 Discharge roller 60 Tandem image forming unit 61 Exposure device 62 Secondary transfer roller 63 Secondary transfer belt stretching roller 64 Secondary transfer belt 65 Fixing device 66 Fixing belt 67 Pressure roller 68 Sheet reversing device 69 Secondary transfer device 70 Developing device 71 First support roller 72 Second support roller 73 Third support roller 74 one Transfer roller 80 Charging device 100 Printer unit 101 Image forming apparatus main body 110 Image forming unit 111 Image forming station 112 Intermediate transfer belt 114 Support roller 115 Secondary transfer roller 116 Toner container 120 Feeding unit 121 Feeding tray 122 Pickup roller 123 Feeding Feeding / conveying roller 130 Feeding / conveying path 140 Secondary transfer unit 150 Fixing device 150a Fixing roller 150b Pressure roller 160 Discharge conveying path 161 Branching claw 162 Branching and conveying roller 170 Double-sided conveying path 200 Feeding unit 300 Scanner unit 302 Inlet sensor 303 Inlet Roller pair 304 Branch claw 305 Discharge roller pair 310 Binding tool 340 Transport path 341 Branch path 400 Document transport section 500 Image reading apparatus 501 Contact glass

JP 2007-277006 A

The present invention over preparative folding device, images forming device, an image forming system and a sheet folding method.

Even after skew correction in the sheet conveyance direction upstream side of the sheet processing unit, by being conveyed by the conveying roller pair of the sheet conveyance direction upstream side of the sheet processing unit, Ri when there again skew to the sheet occurs, The sheet processing unit is adversely affected.

To achieve the above object, the present invention includes a first conveyance roller pair for conveying a sheet over bets are placed in the sheet conveying direction downstream side of the first conveyance roller pair pinching the sheet the second conveyance roller pair for conveying the sheet, before Symbol second conveyance roller pair by sending the first transportable skip back the sheet to the sheet conveyance direction upstream side roller pair and the second conveyance roller pair and the sheet folding device and a fold roller pair fold the sheet by nipping the sheet between, one roller of said second pair of conveying rollers, one of said pair of folding rollers And the sheet conveyed from the first conveying roller pair abuts against the second conveying roller pair .

According to the present invention, an excellent effect that it is possible to perform good good folding process.

What was demonstrated above is an example, and there exists an effect peculiar for every following aspect.
(Aspect A)
A first sheet conveying unit such as an inlet roller pair 11 that holds a part of the sheet P or the like and applies a conveying force to the sheet, and is disposed downstream of the first sheet conveying unit in the sheet conveying direction; A second sheet conveying means such as a first forward / reverse rotation roller 13 and a pressing roller 14 that holds a part of the sheet and applies a conveying force to the sheet, and a part of the sheet is held by the first sheet conveying means. At the same time, a folding force formed on the sheet portion between the first sheet conveying means and the second sheet conveying means is provided by applying a conveying force to the sheet that is returned to the upstream side in the sheet conveying direction by the second sheet conveying means. Sheet folding of the folding processing apparatus 1 or the like provided with folding part forming means such as a first folding roller 12 and a first forward / reverse rotation roller 13 that forms a folded part on the sheet by clamping. In the apparatus, the conveying force of said first sheet conveying means is smaller than the conveying force of said second sheet conveying means. According to this, as described in the above embodiment, unintended bending and twisting of the sheet can be eliminated, and a satisfactory folding process can be performed.
(Aspect B)
In (Aspect A), the driving system of the first sheet conveying means is connected to the driving system of the first sheet conveying means according to whether or not the load torque of the first sheet conveying means exceeds a predetermined amount. A torque limiter configured as described above was provided. According to this, as described in the above-described embodiment, the sheet is slipped by the first sheet conveying unit, and the twist and the unexpected bending of the sheet that can occur in the sheet portion can be eliminated.
(Aspect C)
In (Aspect A) or (Aspect B), the sheet conveying speed of the second sheet conveying means is the first sheet conveying means while the sheet is held by the first sheet conveying means and the second sheet conveying means. Faster than the sheet transport speed. According to this, as described in the above embodiment, the sheet is pulled by the second sheet conveying unit, and the bending of the sheet formed by the skew correction can be eliminated.
(Aspect D)
In (Aspect C), the sheet conveyance speed of the second sheet conveyance means is higher than the sheet conveyance speed of the first sheet conveyance means, and after the sheet is conveyed by a specified amount, the sheet conveyance of the first sheet conveyance means Equal to speed. According to this, as described in the above embodiment, it is possible to prevent the sheet from slipping more than necessary.
(Aspect E)
(Aspect D) includes a deflection detection unit such as a deflection amount detection sensor 24 that detects the deflection of the sheet between the first sheet conveyance unit and the second sheet conveyance unit, and the specified amount is The sheet conveyance amount obtained by adding the correction amount to the sheet conveyance amount necessary until the deflection is eliminated by detecting the deflection of the sheet by the deflection detection means. According to this, as described in the above embodiment, it is possible to more reliably eliminate the bending of the sheet.
(Aspect F)
(Aspect E) includes skew detection means such as skew amount detection sensors 25a and 25b for detecting a skew of the sheet between the first sheet conveyance means and the second sheet conveyance means, and the correction. The amount is a sheet conveyance amount calculated by detecting the skew amount of the sheet by the skew detecting means and calculating the skew amount. According to this, as described in the above embodiment, it is possible to more reliably eliminate the twisting of the sheet.
(Aspect G)
An image forming apparatus 2 including an image forming unit such as an image forming unit 110 that forms an image on a sheet, and a sheet folding unit such as a folding processing apparatus 1 that is provided in the apparatus main body and performs a folding process on the sheet. In the image forming apparatus, the sheet folding apparatus of (Aspect A), (Aspect B), (Aspect C), (Aspect D), (Aspect E) or (Aspect F) is used as the sheet folding means. According to this, as described in the above embodiment, a favorable folding process can be performed on a sheet on which an image is formed.
(Aspect H)
An image forming apparatus such as an image forming apparatus 2 that forms an image on a sheet, and a folding processing apparatus 1 that is provided separately from the image forming apparatus and that performs a folding process on a sheet on which an image is formed by the image forming apparatus. In an image forming system including a sheet folding device, the sheet folding device is configured as (Aspect A), (Aspect B), (Aspect C), (Aspect D), (Aspect E) or (Aspect F). A device was used. According to this, as described in the above embodiment, a favorable folding process can be performed on a sheet on which an image is formed.

Claims (8)

  1. A first sheet conveying unit that holds a part of the sheet and applies a conveying force to the sheet;
    A second sheet conveying unit that is disposed downstream of the first sheet conveying unit in the sheet conveying direction, holds a part of the sheet, and applies a conveying force to the sheet;
    A part of the sheet is held by the first sheet conveying unit, and a conveying force is applied to the sheet by the second sheet conveying unit to return to the upstream side in the sheet conveying direction. In a sheet folding apparatus comprising: a folded portion forming means for forming a folded portion in the sheet by sandwiching a folded portion formed in the sheet portion between the second sheet conveying means,
    The sheet folding apparatus, wherein the conveyance force of the first sheet conveyance unit is smaller than the conveyance force of the second sheet conveyance unit.
  2. In the sheet folding apparatus according to claim 1,
    Torque configured to connect or disconnect the drive from the drive source to the drive system of the first sheet transport unit according to whether or not the load torque of the first sheet transport unit exceeds a predetermined amount A sheet folding apparatus comprising a limiter.
  3. In the sheet folding apparatus according to claim 1 or 2,
    The sheet conveying speed of the second sheet conveying means is higher than the sheet conveying speed of the first sheet conveying means in a state where the sheet is held by the first sheet conveying means and the second sheet conveying means. A sheet folding apparatus.
  4. In the sheet folding apparatus according to claim 3,
    The sheet conveying speed of the second sheet conveying means is equal to the sheet conveying speed of the first sheet conveying means after conveying a sheet by a specified amount in a state faster than the sheet conveying speed of the first sheet conveying means. A sheet folding apparatus.
  5. In the sheet folding apparatus according to claim 4,
    Having a deflection detecting means for detecting the bending of the sheet between the first sheet conveying means and the second sheet conveying means;
    The sheet folding apparatus according to claim 1, wherein the specified amount is a sheet conveyance amount obtained by detecting a deflection of the sheet by the deflection detection unit and adding a correction amount to a sheet conveyance amount necessary until the deflection is eliminated. .
  6. In the sheet folding apparatus according to claim 5,
    A skew detecting means for detecting a skew of the sheet between the first sheet conveying means and the second sheet conveying means;
    The sheet folding apparatus, wherein the correction amount is a sheet conveyance amount calculated by detecting the skew amount of the sheet by the skew detection unit and calculating the skew amount.
  7. Image forming means for forming an image on a sheet;
    In an image forming apparatus provided with a sheet folding unit that is provided in the apparatus main body and performs a folding process on a sheet,
    An image forming apparatus using the sheet folding apparatus according to claim 1 as the sheet folding means.
  8. An image forming apparatus for forming an image on a sheet;
    In an image forming system provided with a sheet folding device that is provided separately from the image forming device and performs a folding process on a sheet on which an image is formed by the image forming device,
    An image forming system using the sheet folding device according to claim 1, 2, 3, 4, 5 or 6 as the sheet folding device.
JP2017110537A 2017-06-05 2017-06-05 Sheet folding device, image formation apparatus, image formation system and sheet folding method Pending JP2017171505A (en)

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Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH01159666U (en) * 1988-04-25 1989-11-06
JP2005008337A (en) * 2003-06-18 2005-01-13 Ricoh Elemex Corp Paper folding device
JP2005231778A (en) * 2004-02-18 2005-09-02 Ricoh Elemex Corp Paper folding device
JP2011063373A (en) * 2009-09-16 2011-03-31 Fuji Xerox Co Ltd Sheet carrying device and image forming device

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH01159666U (en) * 1988-04-25 1989-11-06
JP2005008337A (en) * 2003-06-18 2005-01-13 Ricoh Elemex Corp Paper folding device
JP2005231778A (en) * 2004-02-18 2005-09-02 Ricoh Elemex Corp Paper folding device
JP2011063373A (en) * 2009-09-16 2011-03-31 Fuji Xerox Co Ltd Sheet carrying device and image forming device

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