JP6432828B2 - Sheet processing apparatus and image forming system - Google Patents

Description

  The present invention relates to a sheet processing apparatus and an image forming system.

  2. Description of the Related Art As a sheet processing apparatus used in an image forming system, an apparatus that performs a folding process on a sheet after an image is formed by the image forming apparatus is known.

  The sheet folding apparatus described in Patent Document 1 is provided with a pair of folding rollers that are rotated by receiving a driving force from a drive motor. Is folded. Further, downstream of the pair of folding rollers in the sheet conveying direction, the driving force from the driving motor is received to reciprocate in the sheet width direction, which is a direction orthogonal to the sheet bundle conveying direction, to press the folded portion of the sheet. An additional folding roller pair for additional folding is provided.

  In the sheet processing apparatus described in Patent Document 1, the additional folding roller pair is increased based on the current value flowing through the drive circuit of the drive motor that drives the additional folding roller pair when the additional folding roller pair rides on the widthwise end of the folding section. Control is performed to optimize the number of reciprocating movements of the folding roller pair.

  However, it is difficult to grasp the folded state other than the end portion in the width direction of the fold portion only by the information on the current value of the drive circuit when the additional folding roller pair rides on the end portion in the width direction of the fold portion. . For this reason, even if folding other than the end in the width direction of the folded portion is insufficient, the additional folding with respect to the folded portion by the additional folding roller pair is terminated.

In order to solve the above-described problems, the present invention includes a sheet folding unit that folds a sheet, a folding driving unit that drives the sheet folding unit, and a folding portion of the sheet folded by the sheet folding unit. In a sheet processing apparatus including a pressing unit that presses, a sheet folding operation based on a detection result of a folding driving state information detecting unit that detects information related to a driving state of the folding driving unit and a detection result of the folding driving state information detecting unit Based on the determination result of the folding state determination means, the folding state determination means for determining the folding state of the folding portion, grasping the change timing when the driving load of the folding driving means changes from increase to decrease The pressing means includes pressing operation frequency determining means for determining the number of pressing operations for pressing the folding portion.

  As described above, according to the present invention, there is an excellent effect that optimal additional folding according to the folding state of the folded portion of the sheet can be performed.

6 is a flowchart illustrating an example of a control flow for determining from a stage where a sheet has been conveyed to a folding portion forming unit. 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 an image forming system according to an embodiment. The external appearance perspective view of a press means. The figure which shows an example of the basic composition in a press means. The figure which shows an example of the basic operation | movement in a press means. The block diagram which shows the control part of a sheet | seat post-processing apparatus. The graph which shows the electric current waveform regarding folding operation | movement of a folding motor. The figure which showed the timing which acquires the detection result in folding operation. The figure which showed the behavior which the position where the electric current value which flows through a folding motor becomes the maximum electric current value moved ahead by the elapsed time with respect to the result at the time of a standard folding operation | movement. The figure which showed the behavior which the position where the electric current value which flows through a folding motor becomes the maximum electric current value moved later in elapsed time with respect to the result at the time of a standard folding operation | movement. 9 is a flowchart showing another example of a control flow for determining from the stage where a sheet has been conveyed to the folding part forming unit. The figure which showed the timing which acquires the detection result in folding operation. The figure which showed the case where the position where the electric current value which flows through a folding motor becomes the maximum electric current value is late with respect to the result at the time of a standard folding operation, and shows little delay with respect to FIG. 9 is a flowchart showing another example of a control flow for determining from the stage where a sheet has been conveyed to the folding part forming unit. 9 is a flowchart showing another example of a control flow for determining from the stage where a sheet has been conveyed to the folding part forming unit. The figure which showed the timing which acquires the detection result in folding operation. The figure which showed the case where the position where the electric current value which flows through a folding motor becomes the maximum electric current value is very early with respect to the result at the time of a standard folding operation. The figure which showed the folding position at the time of each folding operation | movement by a 1st folding part formation means and a 2nd folding part formation means. The figure which showed the folding position at the time of each folding operation | movement by a 1st folding part formation means and a 2nd folding part formation means. The flowchart which showed an example of the control flow determined from the step by which the folding part ((1) + (2)) shown in FIG. 26 was conveyed to the nip part of the 2nd folding part formation means. The figure which showed the timing which acquires the detection result in folding operation. The block diagram which shows the control part of a folding processing apparatus. The figure which showed the timing which acquires the detection result in folding operation.

  Hereinafter, an embodiment in which a folding processing apparatus which is a sheet processing 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 1 according to the present embodiment. The folding processing apparatus 1 is one of sheet post-processing apparatuses that performs sheet post-processing on sheets such as paper 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 apparatuses 90Y, 90M, 90C, and 90K are configured. Further, the tandem image forming unit 60 is configured by arranging the four image forming devices 90Y, 90M, 90C, and 90K side by side.

  A belt cleaning device 74 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 to emit the laser writing light L toward the photosensitive drum 7. Irradiate. 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 in the paper bank 43, a feeding roller 42 that feeds out the sheet P from the feeding cassette 44, a separation roller 45 that separates the sheet P and feeds it to the feeding path 46, and feeding A conveyance roller 47 that conveys the sheet P is provided in the 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 a start switch (not shown) 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 drive the first travel body 33 and the second travel. Travel through the body 34. 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. Further, 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 90M, 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, or the third support roller 73 is rotationally driven by a drive motor (not shown), and the other two support rollers are driven to rotate. The intermediate transfer belt 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 sheet P 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.

  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 74 to prepare for the image formation by the tandem image forming unit 60 again.

  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 (right side in the figure) 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 facing member. The driving roller 11b is driven to rotate by a driving force of an inlet motor 11m that is a DC motor. To do. 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 rotation roller 13 disposed in contact with the first folding roller 12, and a first forward / reverse rotation 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 rotation 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.

  Furthermore, in the present embodiment, a second folding roller 15 that is 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 with a nip between the first folding roller 12 and the first forward / reverse rotation roller 13 into 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, and the driving roller 16b is driven to rotate by a driving force of a forward / reverse motor 16m as a driving source. To do.

  The first forward / reverse rotation roller 13 can be driven to rotate in a forward / reverse manner by a driving force of a folding motor 13m, which is a DC motor, as a drive source. The first folding roller 12, the pressing roller 14, and the second folding roller 15 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 drive roller 16b constituting the second forward / reverse roller pair 16 can be rotationally driven so as to be forward / reversely driven by the drive force of the forward / reverse motor 16m as a drive source. 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 17 as a sheet end detection unit that detects the end 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 entrance side). ing. When the leading edge of the sheet P conveyed from the image forming apparatus 2 reaches the detection area, the inlet sensor 17 outputs a leading edge detection signal indicating that fact to the control unit. As such an inlet sensor 17, a well-known sensor can be widely used.

  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 18 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 18 outputs a leading edge detection signal indicating that fact to the control unit. As such a sheet detection sensor 18, a well-known sensor can be widely used as in the case of the inlet sensor 17 described above.

  In this embodiment, a sheet detection sensor 19 that detects the leading edge of the sheet P is provided on the downstream side in the sheet conveyance direction of the second forward / reverse roller pair 16 (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 19 outputs a leading edge detection signal indicating that fact to the control unit. As such a sheet detection sensor 19, a well-known sensor can be widely used like the entrance sensor 17 and the sheet detection sensor 18 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 fold forming means 20a. It is configured. In the present embodiment, the first forward / reverse rotation roller 13 and the second folding roller 15 constitute the second folding portion forming means 20b.

  As the second sheet conveying unit, a configuration of an adhesive roller or a suction belt may be employed instead of the configuration of such a roller pair. In this 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 separate 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. FIG. 5A to FIG. 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.

  FIG. 6A to FIG. 6H are explanatory diagrams for explaining a general operation when the folding device 1 performs the Z-folding process. First, the entrance sensor 17 detects the leading edge of the sheet P that is conveyed with a conveying force applied from a discharge roller (not shown) on the image forming apparatus 2 side. Accordingly, the control unit that has received the tip detection signal output from the inlet sensor 17 controls the inlet motor 11m to start 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 18 after passing through the nip. The control unit that has received the leading edge detection signal from the sheet detection sensor 18 that has detected this performs the following control. That is, when the leading edge of the sheet P protrudes from the nip position between the first forward / reverse rotation roller 13 and the pressing roller 14 by a predetermined protrusion amount Δ1 (FIG. 6C), the folding motor 13m is controlled. The rotation of the first forward / reverse rotation 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 protrusion amount Δ1 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 Δ1 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 18 and the rotation amount of the pressing roller 14.

  Thereafter, the folding motor 13m is controlled to start the reverse rotation of the first forward / reverse rotation roller 13 in the direction in which the sheet P is returned to the entrance side of the through conveyance path W1, and the rotation of the entrance roller pair 11 is started. As a result, the sheet portion between the entrance roller pair 11 and the first forward / reverse roller 13 is bent (FIG. 6D). Then, when the bent portion (folded portion) enters the nip between the first folding roller 12 and the first forward / reverse roller 13, 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 folding 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 19 after passing through the nip. The control unit that has received the leading edge detection signal from the sheet detection sensor 19 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 rotation roller pair 16 by a predetermined protrusion amount Δ2 (FIG. 6 (f)), the first folding motor 13m is controlled to control the first folding motor 13m. The rotation of the forward / reverse roller 13 is stopped. At the same time, the rotation of the second forward / reverse roller pair 16 and the entrance roller pair 11 is stopped. The protrusion amount Δ2 at this time is also determined as appropriate depending on the length of the sheet P in the sheet conveyance direction and the content (folding method, etc.) of the folding process. The protrusion amount Δ2 of the first folded 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 19 and the rotation amount of the second forward / reverse rotation roller pair 16.

  Thereafter, the forward / reverse rotation motor 16m is controlled to start the reverse rotation of the second forward / reverse rotation roller pair 16 in the direction in which the sheet P is directed toward the exit side of the branch conveyance path W2, and the reverse rotation of the first forward / reverse rotation roller 13 is started. And the rotation of the inlet roller pair 11 is resumed. Thereby, 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). Then, when the bent portion (folded portion) enters the nip between the first forward / reverse rotation roller 13 and the second folding roller 15, 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 folding 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.

  FIG. 7A to FIG. 7H are explanatory views for explaining a general operation when the folding processing device 1 performs the inner trifold processing. FIG. 8A to FIG. 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 both the inner trifold process and the outer trifold process is the same as that of the Z-fold process described above, but the protrusion amounts Δ1 and Δ2 are 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 tri-folding process, and the outer tri-folding process.

  FIG. 9 is a schematic configuration diagram of the sheet post-processing apparatus 3 provided in the image forming system according to 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 (not shown). This drive source is controlled by a control unit (not shown), and thereby the rotational driving and stopping of the inlet roller pair 303 by the drive 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 a discharge tray (not shown). Further, the discharge roller pair 305 is driven by a controllable drive source (not shown). 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.

  Next, a basic configuration and pressing operation of a pressing unit that is provided in the folding processing apparatus 1 and performs additional folding by pressing a folded portion of the sheet P will be described.

  FIG. 10 is an external perspective view of the pressing roller 81 constituting the pressing unit 80. FIG. 11 is a diagram illustrating an example of a basic configuration of the pressing unit 80. The pressing unit 80 includes a pressing roller 81, a conveyance guide plate 82, and a compression spring 83. The pressing roller 81 includes a shaft 81a, a sleeve 81b, and a pressing protrusion 81c. A compression spring 83 that is an elastic member is provided on the surface of the conveyance guide plate 82 opposite to the pressing roller 81. Then, when the pressing convex portion 81 c of the pressing roller 81 comes into contact with the conveyance guide plate 82 via the sheet P, the conveyance guide plate 82 is pushed upward, whereby the compression spring 83 is contracted and deformed, and the conveyance guide plate 82. An urging force is generated that urges the pressure roller 81 toward the pressing roller 81. Accordingly, the folded portion of the sheet P sandwiched between the pressing convex portion 81 c of the pressing roller 81 and the conveyance guide plate 82 is pressed and further folded by the pressing convex portion 81 c of the pressing roller 81 and the conveying guide plate 82. The

  The pressing convex portion 81c extends in the axial direction spirally on the peripheral surface of the sleeve 81b, and the entire width direction of the sheet P is sequentially shifted in the axial direction of the pressing roller by rotating the pressing roller 81 about the shaft 81a. Can be pressed. In this embodiment, the elastic member provided to urge the conveyance guide plate 82 toward the pressing roller 81 is a compression spring. However, another elastic member such as a plate spring may be used.

  FIG. 12 is a diagram illustrating an example of a basic operation in the pressing unit 80. A pressing unit 80 is provided on the downstream side of the folding processing apparatus 1 in the sheet conveyance direction to press and fold the folded portion of the sheet P. The sheet P folded by the first fold forming unit 20a and the second fold forming unit 20b of the fold processing apparatus 1 is moved by the first forward / reverse rotation roller 13 and the second folding roller 15 along the conveyance guide plate 82. Then, it is conveyed toward the pressing means 80 (FIG. 12A). When the first folding portion of the sheet P is conveyed to the vicinity of the pressing means 80, the conveyance of the sheet P by the first forward / reverse rotation roller 13 and the second folding roller 15 is stopped, and the pressing roller 81 starts to rotate (see FIG. 12 (b)). As a result, the vicinity of the first folding portion of the sheet P is sequentially pressed by the pressing means 80 in the direction of the pressing roller (FIG. 12C).

  After pressing the entire width direction of the first folding portion of the sheet P, the sheet P is conveyed again by the first forward / reverse rotation roller 13 and the second folding roller 15 (FIG. 12D). When the second folding portion of the sheet P is conveyed to the vicinity of the pressing means 80, the sheet P by the first forward / reverse rotation roller 13 and the second folding roller 15 stops, and the vicinity of the second folding portion of the sheet P is pressed. The means 80 sequentially presses in the direction of the pressure roller group (FIG. 12E). After pressing the entire width direction of the second folding portion of the sheet P, the sheet P is conveyed again by the first forward / reverse rotation roller 13 and the second folding roller 15 (FIG. 12F). The above series of operations is the basic operation of the additional folding operation of the folded portion of the sheet P by the pressing unit 80 in the present embodiment.

  FIG. 13 is a block diagram showing the control unit 95 of the folding processing apparatus 1. A folding drive unit 21 for operating the folding motor 13m by supplying power from a power source, a folding control unit 22 for controlling the folding driving unit 21 to instruct the operation of the folding motor 13m, and the like are provided. Further, an additional folding drive unit 85 for operating the additional folding motor 84 by supplying power from a power source, an additional folding control means 86 for controlling the additional folding drive unit 85 and instructing the operation of the additional folding motor 84, etc. It has.

  The folding motor 13m is monitored, and a current value flowing through the folding motor 13m, which is information relating to the driving state of the folding motor 13m, is detected by the folding motor detection means 23. Then, the detected result is compared with a target value or the like by the folding motor detection / comparison means 24 to grasp a change with time of the driving state during the sheet folding operation and determine the folding state of the folding portion. Based on the determination result, the number of additional folds is determined by the additional fold number determining means 87, and the additional fold driving unit 85 is controlled by the additional fold control means 86 in accordance with the determined number of additional folds. Make it work.

  Next, an example in which a method of detecting the current value flowing through the folding motor 13m is adopted as the folding motor detection means 23 will be described. FIG. 14 is a graph showing a current waveform related to the folding operation of the folding motor 13m. From this current waveform, it can be seen that the current flowing through the folding motor 13m during the folding operation section flows from increasing to decreasing. The change from an increase in current flowing through the folding motor 13m to a decrease may occur earlier or later depending on the behavior of the sheet P, and this characteristic can be used to detect and compare and determine the number of additional folds. To do.

  FIG. 1 is a flowchart illustrating an example of a control flow that is determined from the stage in which the sheet P is conveyed to a fold forming unit such as the first fold forming unit 20a and the second fold forming unit 20b. FIG. 15 illustrates the timing for acquiring the detection result during the folding operation, and Y1 in the drawing indicates the detection result in which the current flowing through the folding motor 13m at the elapsed time T1 at the standard folding operation becomes the maximum current value. It is the value which showed. FIGS. 16 and 17 show the behavior in which the position where the current flowing through the folding motor 13m becomes the maximum current value moves back and forth over time with respect to the result of the standard folding operation. Change the control of additional folding.

  As shown in FIG. 1, when the folding operation in the folding part forming unit is started (S1), detection of the current value flowing through the folding motor 13m by the folding motor detection unit 23 is started (S2). The folding motor 13m is monitored at any time until the time T1 elapses from the start of the folding operation (S3), and when T1 has elapsed (YES in S3), the current value flowing through the folding motor 13m by the folding motor detection means 23 at that time Is detected as the current value X1 (S4). Then, the current value X1, which is the detection result of the current value at the elapsed time T1, is compared with the preset design value Y1 (S5). If Y1 ≦ X1 (NO in S5), an additional folding process is executed with control that does not change the number of additional foldings (S11).

  On the other hand, if Y1> X1 (YES in S5), the folding motor 13m is monitored from time to time until the time T2 elapses from the start of the folding operation (S6). When the time T2 elapses (YES in S6), the detection result of the current value flowing through the folding motor 13m by the folding motor detection means 23 at that time is determined as the current value X2 (S7). Then, the current value X2 that is the detection result of the current value at the elapsed time T2 is compared with the current value X1 that is the detection result of the current value at the elapsed time T1 (S8). As shown in FIG. 17, if X2> X1 (YES in S8), it is determined that the folding accuracy by the folding means is insufficient, and the control is changed to the control in which the number of additional folding is increased by 1 (S9), and the additional folding is performed. Execute the process. Thereby, it is possible to increase the number of additional folds and increase the folding accuracy (reduce the height). On the other hand, as shown in FIG. 16, if X2 ≦ X1 (NO in S8), it is determined that the folding accuracy of the folding means is sufficient, and the control is changed to the control in which the number of additional foldings is reduced by 1 (S10), The additional folding process is executed. Thereby, productivity can be improved by reducing the number of additional foldings.

  As described above, by executing the control flow as shown in FIG. 1, it is possible to set the optimum additional folding control according to the folded state of each sheet (folded state of the folded portion). it can.

  FIG. 18 is a flowchart illustrating another example of a control flow that is determined from the stage where the sheet P has been conveyed to the folding portion forming unit. FIG. 19 illustrates the timing for acquiring the detection result during the folding operation, and Y1 and Y2 in the drawing indicate the detection result of the current value flowing through the folding motor 13m at the elapsed time T1 and T2 during the standard folding operation. It is the indicated value. FIG. 20 shows a case where the position where the current value flowing through the folding motor 13m becomes the maximum current value is delayed with respect to the result of the standard folding operation, and shows that there is little delay with respect to FIG. ing.

  As shown in FIG. 18, when the folding operation in the folding part forming unit is started (S1), detection of the current value flowing through the folding motor 13m by the folding motor detection unit 23 is started (S2). Monitoring is performed at any time until the time T1 elapses from the start of the folding operation (S3), and when T1 elapses (YES in S3), the detection result of the current value flowing through the folding motor 13m by the folding motor detection means 23 at that time is determined as the current value X1. (S4). Then, the current value X1, which is the detection result of the current value at the elapsed time T1, is compared with the preset design value Y1 (S5). If Y1 ≦ X1 (NO in S5), an additional folding process is executed with control that does not change the number of additional foldings (S13). On the other hand, if Y1> X1 (YES in S5), the folding motor 13m is monitored from time to time until the time T2 elapses from the start of the folding operation (S6). When the time T2 has elapsed (YES in S6), the detection result of the current value flowing through the folding motor 13m by the folding motor detection means 23 at that time is determined as the current value X2 (S7). Then, the current value X2 that is the detection result of the current value at the elapsed time T2 is compared with the preset design value Y2 (S8). If X2 ≦ Y2 (NO in S8), it is determined that the folding accuracy of the folding means is sufficient, the control is changed to the control in which the number of additional foldings is reduced by 1 (S12), and the additional folding process is executed. Thereby, productivity can be improved by reducing the number of additional foldings.

  On the other hand, if X2> Y2 (YES in S8), the current value X2 that is the detection result of the current value at the elapsed time T2 is compared with the current value X1 that is the detection result of the current value at the elapsed time T1. (S9). If X2> X1 (YES in S9), it is determined that the folding accuracy by the folding means is insufficient, the control is changed to the control in which the number of additional foldings is increased by 1 (S10), and the additional folding process is executed. Thereby, it is possible to increase the number of additional folds and increase the folding accuracy (reduce the height). As shown in FIG. 20, if X2 ≦ X1 (NO in S9), it is determined that the folding means is relatively good even when the folding accuracy is insufficient, and the rotational speed of the additional folding motor 84 is lowered to reduce the operating speed. Slow down (S11). Thereby, folding accuracy can be improved (height can be reduced) in a shorter time than increasing the number of additional foldings.

  As described above, by executing the control flow as shown in FIG. 18, it is possible to set the optimum additional folding control according to the folded state of each sheet.

  FIG. 21 is a flowchart showing another example of the control flow for determining from the stage where the sheet P has been conveyed to the folding portion forming means. As shown in FIG. 21, when the folding operation in the folding part forming unit is started (S1), detection of the current value flowing through the folding motor 13m by the folding motor detection unit 23 is started (S2). Monitoring is performed at any time until the time T1 elapses from the start of the folding operation (S3), and when T1 elapses (YES in S3), the detection result of the current value flowing through the folding motor 13m by the folding motor detection means 23 at that time is determined as the current value X1. (S4). Then, monitoring is performed at any time until the time T2 elapses from the start of the folding operation (S5), and when the time T2 elapses (YES in S5), the detection result of the current value flowing through the folding motor 13m by the folding motor detection means 23 at that time is the current value. X2 is confirmed (S6).

  Then, the current value X1 that is the detection result of the current value at the elapsed time T1 is compared with the preset design value Y1 (S7). If Y1 ≦ X1 (NO in S7), the current value X2 that is the detection result of the current value at the elapsed time T2 is compared with the preset design value Y1 (S13). If Y1> X2 (YES in S13), an additional folding process is executed with control that does not change the number of additional foldings (S14). If Y1 ≦ X2 (NO in S13), it is determined that the sheet P cannot be secured (non-standard), and the additional folding control is stopped (the number of additional foldings is changed to 0) (S15). ). Thereby, deterioration and breakage of the additional folding mechanism can be suppressed.

  On the other hand, if Y1> X1 (YES in S7), the current value X2 that is the detection result of the current value at the elapsed time T2 is compared with the preset design value Y2 (S8). If X2 ≦ Y2 (NO in S8), it is determined that the folding accuracy of the folding means is sufficient, the control is changed to a control in which the number of additional foldings is reduced by 1 (S12), and the additional folding process is executed. Thereby, productivity can be improved by reducing the number of additional foldings.

  If X2> Y2 (YES in S8), the current value X2 that is the detection result of the current value at the elapsed time T2 is compared with the current value X1 that is the detection result of the current value at the elapsed time T1 (S9). ). If X2> X1 (YES in S9), it is determined that the folding accuracy by the folding means is insufficient, the control is changed to the control in which the number of additional foldings is increased by 1 (S10), and the additional folding process is executed. Thereby, it is possible to increase the number of additional folds and increase the folding accuracy (reduce the height). If X2 ≦ X1 (NO in S9), it is determined that the folding means is relatively good even when the folding accuracy is insufficient, and the rotational speed of the additional folding motor 84 is lowered to reduce the operation speed (S11). Thereby, folding accuracy can be improved (height can be reduced) in a shorter time than increasing the number of additional foldings.

  As described above, by executing the control flow as shown in FIG. 21, optimum additional folding control can be set according to the folded state of each sheet.

  FIG. 22 is a flowchart showing another example of the control flow for determining from the stage where the sheet P has been conveyed to the folding portion forming means. FIG. 23 illustrates the timing at which the detection result during the folding operation is acquired. Y1, Y2, and Y3 in the drawing are current values that flow through the folding motor 13m at the elapsed times T1, T2, and T3 during the standard folding operation. This is a value indicating the detection result. FIG. 24 shows a case where the position where the current value flowing through the folding motor 13m becomes the maximum current value is very early with respect to the result of the standard folding operation.

  As shown in FIG. 22, when the folding operation is started by the folding portion forming means (S1), detection of the current value flowing through the folding motor 13m by the folding motor detecting means 23 is started (S2). The folding motor 13m is monitored from time to time until the time T3 elapses from the start of the folding operation (S3). When T3 time has elapsed (YES in S3), the detection result of the current value flowing through the folding motor 13m by the folding motor detection means 23 at that time is determined as the current value X3 (S4). Then, the current value X3, which is the detection result of the current value at the elapsed time T3, is compared with the preset design value Y1 (S5). As shown in FIG. 24, if Y1 ≦ X3 (NO in S5), it is determined that the sheet P (non-standard) cannot be folded, and folding control is stopped (S17). Thereby, deterioration and breakage of the folding mechanism and the additional folding mechanism can be suppressed.

  On the other hand, if Y1> X3 (YES in S5), the folding motor 13m is monitored from time to time until the time T1 elapses from the start of the folding operation (S6). When T1 has elapsed (YES in S6), the detection result of the current value flowing through the folding motor 13m by the folding motor detection means 23 at that time is determined as the current value X1 (S7). Then, the current value X1, which is the detection result of the current value at the elapsed time T1, is compared with a preset design value Y1 (S8). If Y1 ≦ X1 (NO in S8), the additional folding process is executed with control that does not change the number of additional foldings (S16).

  If Y1> X1 (YES in S8), the folding motor 13m is monitored from time to time until the time T2 elapses from the start of the folding operation (S9). When the time T2 has elapsed (YES in S9), the detection result of the current value flowing through the folding motor 13m by the folding motor detection means 23 at that time is determined as the current value X2 (S10). Then, the current value X2, which is the detection result of the current value at the elapsed time T2, is compared with the preset design value Y2 (S11). If X2 ≦ Y2 (NO in S11), it is determined that the folding accuracy of the folding means is sufficient, the control is changed to a control in which the number of additional foldings is reduced by 1 (S15), and the additional folding process is executed. Thereby, productivity can be improved by reducing the number of additional foldings.

  On the other hand, if X2> Y2 (YES in S11), the current value X2 that is the detection result of the current value at the elapsed time T2 is compared with the current value X1 that is the detection result of the current value at the elapsed time T1. (S12). If X2> X1 (YES in S12), it is determined that the folding accuracy by the folding means is insufficient, the control is changed to the control in which the number of additional foldings is increased by 1 (S13), and the additional folding process is executed. Thereby, it is possible to increase the number of additional folds and increase the folding accuracy (reduce the height). If X2 ≦ X1 (NO in S13), it is judged that the folding means is relatively good even when the folding accuracy is insufficient, and the rotational speed of the additional folding motor 84 is lowered to reduce the operating speed (S14). Thereby, folding accuracy can be improved (height can be reduced) in a shorter time than increasing the number of additional foldings.

  As described above, by executing the control flow as shown in FIG. 22, it is possible to set the optimum additional folding control according to the folded state of each sheet.

  FIG. 25 shows a first folding portion forming means 20a composed of the first folding roller 12 and the first forward / reverse rotation roller 13, and a second folding portion composed of the first forward / reverse rotation roller 13 and the second folding roller 15. The folding position at the time of each folding operation by the part forming means 20b is shown.

  At the time of each folding operation by the first fold forming means 20a and the second fold forming means 20b, processing is performed according to the control flow shown in FIG. 22, and the control of folding and additional folding is determined. Thus, the control of the folding and the additional folding is determined, so that the two folding portions (the first folding portion (1) and the first folding portion) of the sheet P by the first folding portion forming means 20a and the second folding portion forming means 20b are determined. An optimal additional folding according to the folded state can be performed on the two-folded portion (2).

  FIG. 26 shows a second fold portion 20a composed of a first fold roller 12 and a first forward / reverse roller 13, and a second fold portion composed of a first fold roller 13 and a second fold roller 15. The folding position at the time of each folding operation by the part forming means 20b is shown.

  At the time of each folding operation of the first fold forming means 20a and the second fold forming means 20b, processing is performed according to the control flow shown in FIG. 22 and the control of folding and additional folding is determined. However, the second folding operation of the folding part ((1) + (2)) shown in FIG. 26 is performed according to the control flow shown in FIG. 27, and the control of folding and additional folding is determined. To do.

  In FIG. 27, the folding portion ((1) + (2)) shown in FIG. 26 is conveyed to the nip portion between the first forward / reverse rotation roller 13 and the second folding roller 15 constituting the second folding portion forming means 20b. It is the flowchart which showed an example of the control flow determined from the step which came. FIG. 28 illustrates the timing for acquiring the detection result during the folding operation. In FIG. 28, “Z1” is a current value that flows through the folding motor 13m at the start of operation, and “Z2” is a value that indicates a detection result that is the maximum current value that flows through the folding motor 13m at the time of the standard second folding. It is.

  As shown in FIG. 27, when the folding operation in the second fold forming means 20b is started (S1), detection of the current value flowing through the folding motor 13m by the folding motor detecting means 23 is started (S2). Then, the detection result of the current value flowing through the folding motor 13m by the folding motor detection means 23 immediately after the start of detection is determined as the current value Z1 (S3). Thereafter, monitoring is performed from time to time until t1 time elapses from the start of the folding operation (S4), and when t1 time elapses (YES in S4), the detection result of the current value flowing through the folding motor 13m by the folding motor detection means 23 at that time is the current value. It is determined as Z2 (S5). Then, the current value Z2 which is the detection result of the current value at the elapsed time t1 is compared with the current value Z1 of the detection result of the current value flowing through the folding motor 13m by the folding motor detection means 23 immediately after the start of detection (S6). .

  If Z2> Z1 (YES in S6), it is determined that the folding accuracy has been improved by the second folding portion forming means 20b with respect to the control determined by the first folding portion forming means 20a, and the rotation of the additional folding motor 84 is determined. Increase the number to increase the folding speed. Thus, productivity can be improved by increasing the additional folding speed (S7). On the other hand, if Z2 ≦ Z1 (NO in S6), it is determined that the folding accuracy is not improved with respect to the control determined by the first folding portion forming means 20a, and the additional folding process is executed without changing the additional folding control. To do.

  As described above, by executing the control flow as shown in FIG. 27, the optimum additional folding control can be set in accordance with the folded state of each sheet.

  FIG. 29 is a block diagram showing the control unit 95 of the folding processing apparatus 1. A folding drive unit 21 for operating the folding motor 13m, a folding control means 22 for controlling the folding driving unit 21 and instructing the operation of the folding motor 13m, and the like are provided. Further, an additional folding drive unit 85 for operating the additional folding motor 84, an additional folding control means 86 for instructing the operation of the additional folding motor 84 by controlling the additional folding drive unit 85, and the like are provided. Furthermore, an inlet driving unit 25 for operating the inlet motor 11m by supplying power from a power source, an inlet control unit 26 for controlling the inlet driving unit 25 to instruct the operation of the inlet motor 11m, and the like are provided.

  The inlet motor detection means 27 that monitors the inlet motor 11m and detects the state of the inlet motor 11m detects the result of comparison with the initial assumed value by the inlet motor detection comparison means 28 as degradation of the folding processing apparatus 1. Infer. Then, based on the estimation result, the folding motor detection / comparison means 24 reflects the target value which is a threshold used when judging the folding state of the folding portion, and determines the target value.

  On the other hand, the folding motor 13m is monitored, and the current value flowing through the folding motor 13m, which is information relating to the driving state of the folding motor 13m, is detected by the folding motor detection means 23. Then, the detected result is compared with a target value or the like by the folding motor detection / comparison means 24 to grasp a change with time of the driving state during the sheet folding operation and determine the folding state of the folding portion. Based on the determination result, the number of additional folds is determined by the additional fold number determining means 87, and the additional fold driving unit 85 is controlled by the additional fold control means 86 in accordance with the determined number of additional folds. Make it work.

  Note that the control flow for determining the additional folding control executed from the stage when the sheet P is conveyed to the folding part forming means is in accordance with the flowcharts shown in FIG. 1, FIG. 18, FIG. 21, FIG. Done.

  FIG. 30 (a) illustrates the timing for acquiring the detection result during the folding operation, and Y1 in the diagram is the current value at which the current value flowing through the folding motor 13m at the elapsed time T1 during the standard folding operation is the maximum. Is a value indicating the detection result. FIG. 30B illustrates the timing for acquiring the detection result during the folding operation after the deterioration of the folding processing apparatus 1. In FIG. 30 (b), Y1 in FIG. 30 (a) is Yd1, and the detection result of the current value flowing through the folding motor 13m at the elapsed time T1, T2 is obtained from the current values X1, X2 in FIG. 30 (a). The current values Xd1 and Xd2 are replaced. It should be noted that such replacement of the current value before and after deterioration of the folding processing apparatus 1 is preferably performed before the sheet P reaches the first folded portion forming unit 20a.

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)
Sheet folding means such as first fold forming means 20a and second fold forming means 20b for folding the sheet, folding drive means such as a folding motor 13m for driving the sheet folding means, and the sheet folding means In a sheet processing apparatus such as the folding processing apparatus 1 provided with a pressing means such as the pressing means 80 for pressing the folded portion of the sheet folded by the folding motor detecting means 23 for detecting information on the driving state of the folding driving means. Based on the detection result of the folding driving state information detecting unit such as the folding driving state information detecting unit, the change in the driving state with time during the sheet folding operation is grasped, and the folding state of the sheet by the sheet folding unit is determined. A folding state detecting means such as a folding motor detection comparing means 24 and a determination result of the folding state judging means. There has a pressing operation times determining means such times judging means 87 folding determines the number of pressing operations for pressing the folded portion.
In (Aspect A), the number of pressing operations corresponding to the folding state of the folding portion of the sheet is determined by grasping the temporal change of the driving state during the sheet folding operation and determining the sheet folding state by the sheet folding means. Then, the folded portion of the sheet is pressed by the pressing means. Thereby, the frequency | count of pressing operation of the said folding part by a press means can be optimized with respect to the folding state of the said folding part. Therefore, optimal additional folding according to the folding state of the folded portion of the sheet can be performed.
(Aspect B)
In (Aspect A), the pressing means includes a rotating member such as a pressing roller 81 that is rotatably provided, and an opposing member such as a conveyance guide plate 82 that is disposed to face the rotating member. A control unit 95 that presses the sheet while sandwiching the sheet between the rotating member and the opposing member, and determines the number of rotations of the rotating member based on the determination result of the folding state determination unit, etc. It has a rotational speed determination means. According to this, as described in the above embodiment, it is possible to suppress the sheet from being excessively pressed and to reduce the damage to the sheet.
(Aspect C)
In (Aspect A) or (Aspect B), there is a pressing operation presence / absence determining means such as a control unit 95 that determines the presence or absence of the pressing operation of the folding part by the pressing means based on the determination result of the folding state determination means. . According to this, as described in the above embodiment, it is possible to reduce damage to the sheet processing apparatus and the sheet when a nonstandard sheet is conveyed.
(Aspect D)
In (Aspect A) or (Aspect B), based on the detection result of the folding driving state information detection means when the sheet is started to be folded by the sheet folding means, whether or not the folding portion is pressed by the pressing means is determined. It has a pressing operation presence / absence determining means such as a control unit 95 for determining. According to this, as described in the above embodiment, it is possible to reduce damage to the sheet processing apparatus and the sheet when a nonstandard sheet is conveyed.
(Aspect E)
In (Aspect A), (Aspect B), (Aspect C), or (Aspect D), the folding state determination unit determines the folded state of the sheet at least twice, and the pressing operation number determination unit determines the pressing force. Determine the number of actions. According to this, as described in the above embodiment, damage to the sheet can be reduced.
(Aspect F)
In (Aspect A), (Aspect B), (Aspect C), (Aspect D) or (Aspect E), after the sheet folding operation by the sheet folding means, based on the detection result of the folding drive state information detection means, The folding state determination unit determines the folding state of the sheet, and the pressing operation number determination unit determines the number of pressing operations. According to this, as described in the above embodiment, the folding state after the folding operation by the folding unit can be determined, and the number of pressing operations to the sheet by the pressing unit can be optimized.
(Aspect G)
In (Aspect A), (Aspect B), (Aspect C), (Aspect D), (Aspect E) or (Aspect F), conveying means such as an inlet roller pair 11 that conveys a sheet to the sheet folding means; A conveyance drive unit such as an inlet motor 11m for driving the conveyance unit; and a conveyance drive state information detection unit such as an inlet motor detection unit 27 for detecting information on a drive state of the conveyance drive unit. Based on the detection result of the drive state information detection means, the threshold value used when the folding state determination means determines the folding state of the folded portion is determined. According to this, it is possible to determine the deterioration of the sheet processing apparatus before the folding operation by the sheet folding means, and to optimize the number of pressing operations to the sheet by the pressing means.
(Aspect H)
In (Aspect A), (Aspect B), (Aspect C), (Aspect D), (Aspect E), (Aspect F), or (Aspect G), power supply such as a power source for supplying power to the folding drive means And the information on the driving state is a current value flowing through the folding driving unit, and a plurality of current values detected at different timings during the sheet folding operation by the folding driving state information detecting unit are compared. Then, the folding state determination unit determines the folding state of the sheet, and the pressing operation frequency determination unit determines the number of pressing operations. According to this, as described in the above embodiment, the folding state can be determined from the current value flowing through the folding driving unit, and the number of pressing operations to the sheet by the pressing unit can be optimized.
(Aspect I)
An image forming apparatus including an image forming apparatus such as an image forming apparatus 2 that forms an image on a sheet, and a sheet processing apparatus such as a folding processing apparatus 1 that performs predetermined processing on a sheet on which an image is formed by the image forming apparatus. In the system, the sheet processing apparatus is described in (Aspect A), (Aspect B), (Aspect C), (Aspect D), (Aspect E), (Aspect F), (Aspect G) or (Aspect H). The sheet processing apparatus was used. According to this, as described in the above embodiment, it is possible to perform optimum additional folding according to the folding state of the folded portion of the sheet on which the 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 Folding 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 Forward / reverse motor 16s Pressure spring 17 Entrance sensor 18 Sheet detection sensor 19 Sheet detection sensor 20a First fold formation means 20b Second fold formation means 21 Fold drive section 22 Fold control means 23 Fold mode Detection means 24 Folding motor detection comparison means 25 Entrance drive unit 26 Entrance control means 27 Entrance motor detection means 28 Entrance motor detection comparison means 30 Document table 32 Contact glass 33 First traveling body 34 Second traveling body 35 Imaging lens 36 Reading sensor 42 Feed roller 43 Paper bank 44 Feed cassette 45 Separation roller 46 Feed path 47 Transport roller 48 Feed path 49 Registration roller 50 Feed roller 51 Manual feed tray 52 Separating roller 53 Manual feed 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 71 First support roller 72 Second support roller 73 Three support rollers 74 Belt cleaning device 80 Pressing means 81 Pressing roller 81a Shaft 81b Sleeve 81c Pressing convex part 82 Conveying guide plate 83 Compression spring 84 Additional folding motor 85 Additional folding driving part 86 Additional folding control means 87 Additional folding number determination means 90 Image device 95 Control unit 100 Printer unit 200 Feed unit 300 Scanner unit 302 Inlet sensor 303 Inlet roller pair 304 Branch claw 305 Discharge roller pair 310 Binding tool 340 Conveying path 341 Dividing path 400 Document conveying unit

JP 2013-14430 A

Claims (9)

Sheet folding means for folding the sheet;
Folding driving means for driving the sheet folding means;
In a sheet processing apparatus comprising a pressing unit that presses a folded portion of a sheet folded by the sheet folding unit,
Folding drive state information detecting means for detecting information related to the drive state of the folding drive means;
Based on the detection result of the folding driving state information detecting means, the folding state is such that the change timing when the driving load of the folding driving means changes from rising to decreasing during the sheet folding operation is determined, and the folding state of the folding part is determined. Judgment means,
A sheet processing apparatus comprising: a pressing operation number determining unit that determines the number of pressing operations by which the pressing unit presses the folded portion based on a determination result of the folding state determining unit. The sheet processing apparatus according to claim 1,
The pressing means includes a rotating member that is rotatably provided and a facing member that is disposed to face the rotating member, and the sheet is sandwiched between the rotating member and the facing member. Press the
A sheet processing apparatus comprising: a rotation speed determination unit that determines a rotation speed of the rotating member based on a determination result of the folding state determination unit. In the sheet processing apparatus according to claim 1 or 2,
A pressing operation presence / absence determining unit that determines whether or not the pressing unit presses the folding portion based on whether or not the driving loads at different points in time during the sheet folding operation exceed a threshold value. A sheet processing apparatus. In the sheet processing apparatus according to claim 1 or 2,
A sheet processing apparatus, comprising: a pressing operation presence / absence determining unit that determines whether or not the pressing unit presses the folding portion based on the driving load when the sheet is started to be folded by the sheet folding unit. In the sheet processing apparatus according to claim 1, 2, 3, or 4,
The sheet processing apparatus according to claim 1, wherein the folding state determination unit determines the folding state of the sheet at least twice and determines the number of pressing operations by the pressing operation number determination unit. In the sheet processing apparatus according to claim 1, 2, 3, 4 or 5,
After the sheet folding operation by the sheet folding unit, the folding state determination unit determines the folding state of the sheet based on the detection result of the folding driving state information detection unit, and the number of pressing operations by the pressing operation number determination unit. A sheet processing apparatus characterized by determining In the sheet processing apparatus according to claim 1, 2, 3, 4, 5 or 6,
Conveying means for conveying the sheet to the sheet folding means;
Transport driving means for driving the transport means;
A conveyance drive state information detection unit that detects information related to the drive state of the conveyance drive unit;
The folding state determining means grasps the change timing depending on whether the driving load at a given point in time exceeds the threshold, that determining the threshold value based on a detection result of the conveyance drive state information detecting means A sheet processing apparatus. In the sheet processing apparatus according to claim 1, 2, 3, 4, 5, 6 or 7,
Power supply means for supplying power to the folding drive means;
The information on the driving state is a current value flowing through the folding driving means,
Comparing the plurality of current value detected at different times during the sheet folding operation by the folding driving state information detecting means to grasp the changing timing, determines the number of times of the pressing action by the prior SL pressing operation number determination means A sheet processing apparatus. An image forming apparatus for forming an image on a sheet;
An image forming system comprising: a sheet processing apparatus that performs a predetermined process on a sheet on which an image is formed by the image forming apparatus.
9. An image forming system using the sheet processing apparatus according to claim 1, 2, 3, 4, 5, 6, 7, or 8 as the sheet processing apparatus.

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