JP6248436B2 - Paper processing apparatus, image forming system, and paper folding method - Google Patents

Description

  The present invention relates to a paper processing apparatus, an image forming system, and a paper folding method, and in particular, a sheet-like recording medium such as a paper, a transfer paper, a printing paper, and an OHP sheet (hereinafter referred to as “paper”). ), A sheet processing apparatus that performs predetermined processing, an image forming system including the sheet processing apparatus and an image forming apparatus such as a copying machine, a printer, a facsimile machine, and a digital multifunction peripheral, and a sheet folding executed by the sheet processing apparatus Regarding the method.

  In a folding processing apparatus that receives a sheet on which an image is formed and performs folding processing such as bi-folding, tri-folding, and Z-folding, a paper leading end abutting member that is generally operable in accordance with the paper size to adjust the folding position And a method of adjusting the folding position by abutting the front end of the paper against the paper front end abutting member.

  In order to make a crease, a mechanism for making a crease by pushing a sheet into a nip of a crease unit such as a roller that sandwiches the sheet by a pushing unit and pinching at the nip is generally widely used.

  In addition, a technique is also known in which a sheet is bent between two pairs of rollers and the sheet is folded by sandwiching the bent portion in another roller nip. As such a technique, for example, a technique described in JP 2007-277006 A (Patent Document 1) is known.

  This technique relates to a method of folding a medium with a folding device, wherein the folding device includes a rotatable folding cylinder and a first rotatable pinch that engages with the folding cylinder to form a first folding pinch. A press member, a second rotatable press member that engages with the folding cylinder to form a second folded pinch, and a medium feeding means; a) the medium is fed by the first pinch and the first pinch; Feeding toward the middle cylinder between the two pinches; b) directing the medium into the first pinch by rotating the cylinder in the first direction; and c) slackening the medium between the feeding means and the cylinder. And d) moving the slack into the second pinch by rotating the cylinder in a second direction opposite to the first direction.

  In the known technology, one pair of two pairs of cylinders (hereinafter referred to as rollers) is forward-conveyed and one pair on one side is reverse-conveyed to form a deflection between the two pairs of rollers. The bent portion is sandwiched between the roller nips and folded.

  By the way, in the method of adjusting the folding position by abutting the leading end of the sheet against the leading end abutting member as described above, or pressing the sheet into the nip of the crease unit and sandwiching the nip by the nip, the folding process is performed. Takes a certain amount of processing time. For this reason, when folding processing is performed on paper that is continuously sent at regular intervals, the paper may continue to be fed even during the folding processing. In addition, the next sheet may catch up during the folding process. In this way, if the sheet continues to be fed during the folding process, and the next sheet catches up during the folding process, a sheet jam occurs at the folding portion, and the processing becomes impossible.

  In order to prevent such a paper jam from occurring, normally, the paper transport speed is slowed down so that the next paper does not reach the folding portion at the end of the folding process, or until the folding process is completed. The method of taking a stand-by or waiting at a preset position is taken. However, if the conveyance speed of the next sheet is slowed down or the sheet is not conveyed until the folding process is completed, or if the sheet is kept waiting at a preset position, the production efficiency cannot be denied.

  On the other hand, in the technique described in Patent Document 1, it is intended to continuously fold sheets that are continuously fed, but the time required for the folding process is short, and the sheet is conveyed during the folding processing time. It is considered that there is no need to actively process the incoming paper.

  Therefore, the problem to be solved by the present invention is that paper that continues to be conveyed even during the folding process can be received, and even when the next sheet catches up, the folding process can be performed without hindering the conveyance of the sheet. The purpose is to accept paper.

In order to solve the above problems, according to one embodiment of the present invention, a first transport member that transports a preceding sheet transported from another apparatus upstream in the sheet transport direction and the first transport member are transported. The second transport member that receives the preceding paper and transports it to the subsequent stage, and reverses the second transport member while holding the preceding paper by the first transport member and the second transport member. A sheet conveying direction of the first conveying member with the third conveying member rotating in the direction and folding the preceding sheet and the subsequent sheet continuously conveyed from the other apparatus at a constant speed. The sheet processing apparatus includes a sheet conveyance permission unit that allows conveyance of the preceding sheet in parallel with the folding process on the upstream side .

According to one aspect of the present invention, it is possible to receive a sheet that is continuously conveyed even during the folding process, and even when the next sheet catches up, the folding process can be performed without hindering the conveyance of the sheet, and the next sheet can be received. It becomes possible. Note that problems, configurations, and effects other than those described above will be clarified by the following description of embodiments.

1 is a diagram illustrating a schematic configuration of an image forming apparatus and an image forming system according to an embodiment of the present invention. It is a figure which shows schematic structure of the folding apparatus in FIG. 1 is a block diagram illustrating a control configuration of an image forming system according to an embodiment of the present invention. It is operation | movement explanatory drawing which shows the basic operation | movement of the folding apparatus in embodiment of this invention, and shows the state immediately after a paper was carried in into a folding apparatus. FIG. 5 is an operation explanatory diagram showing a state immediately after the folding process is started from the state of FIG. 4. It is operation | movement explanatory drawing which shows the state which the folding process is advancing from the state of FIG. FIG. 7 is an operation explanatory diagram showing a state when the folding process is finished from the state of FIG. 6 and the paper is discharged. It is a flowchart which shows the basic operation | movement procedure of the folding apparatus in embodiment of this invention. 1 is a diagram illustrating a schematic configuration of a folding device according to Embodiment 1. FIG. FIG. 5 is an operation explanatory diagram illustrating basic operations of the folding device according to the first exemplary embodiment, and illustrates a state when a sheet is carried into the folding device and conveyed to the discharge tray side. It is operation | movement explanatory drawing which shows the state by which bending is absorbed in the arrangement | positioning location of a 1st elastic material from the state of FIG. It is operation | movement explanatory drawing when the folding process is performed in the state from which bending was absorbed in the arrangement | positioning location of a 1st elastic material from the state of FIG. 3 is a flowchart illustrating an operation procedure of the folding device according to the first embodiment. It is a flowchart which shows the process sequence of the subroutine of FIG.13, FIG18 and FIG.27. It is a figure which shows schematic structure of the folding apparatus which concerns on Example 2. FIG. FIG. 9 is an operation explanatory diagram of the folding device in Embodiment 2 and shows a state when a sheet is carried into the folding device and conveyed to the discharge tray side. It is operation | movement explanatory drawing when the folding process is performed in the state from which the bending was absorbed in the arrangement | positioning location of a 1st and 2nd elastic material from the state of FIG. 6 is a flowchart (part 1) illustrating an operation procedure of the folding device according to the second embodiment. 9 is a flowchart (part 2) illustrating an operation procedure of the folding device according to the second embodiment. It is a figure which shows schematic structure of the folding apparatus 6 which concerns on Example 3. FIG. FIG. 10 is an operation explanatory view showing the operation of the folding device in Embodiment 3 and shows a state when a sheet is carried into the folding device and conveyed to the discharge tray side. FIG. 21 is an operation explanatory diagram illustrating a state when the rear end of the sheet is conveyed from the state of FIG. 20 to the downstream side of the branching claw. FIG. 22 is an operation explanatory diagram illustrating a state when the rear end of the sheet is retracted from the state of FIG. 21 to the switchback path. FIG. 23 is an operation explanatory diagram showing a state when folding processing is started on the preceding sheet from the state of FIG. 22 and the next sheet is conveyed to a position beyond the first conveying member. FIG. 24 is an operation explanatory diagram illustrating a state in which the leading edge of the next sheet is superimposed on the trailing edge of the preceding sheet from the state illustrated in FIG. 23 and conveyed. FIG. 25 is an operation explanatory diagram showing a state in which the preceding sheet is conveyed at an increased speed after the folding process of the preceding sheet from the state of FIG. 24 and the next sheet is conveyed to the third conveying member side. FIG. 26 is an operation explanatory diagram illustrating a state in which the next sheet reaches the third conveying member position and is conveyed while the preceding sheet is discharged from the state illustrated in FIG. 25. 10 is a flowchart (part 1) illustrating an operation procedure of the folding device according to the third embodiment. 12 is a flowchart (part 2) illustrating an operation procedure of the folding device according to the third embodiment. 12 is a flowchart illustrating an operation procedure of the folding device according to the third embodiment. It is a figure which shows schematic structure of the folding apparatus which concerns on Example 4, and shows the state from which the 2nd conveyance member is not separated. It is a figure which shows schematic structure of the folding apparatus which concerns on Example 4, and shows the state which the 2nd conveyance member separated. FIG. 10 is an operation explanatory diagram of the folding device according to the fourth embodiment. A state when the next sheet catches up during the folding process of the preceding sheet and an overlapping portion occurs is shown. FIG. 31 is an operation explanatory diagram illustrating a state in which the preceding sheet is conveyed at an increased speed after the folding process of the preceding sheet from the state of FIG. 30 and the next sheet is conveyed to the third conveying member side.

  According to the present invention, when folding a sheet, the sheet is not hindered even if the sheet is continuously fed during the folding process, and the sheet is continuously fed at regular intervals. Even if the next sheet is folded during the folding process or catches up with the folded sheet, the folding process can be performed without reducing the productivity so that the conveyance of the sheet is not hindered. And

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the following description, equivalent parts are denoted by the same reference numerals, and duplicate descriptions are omitted as appropriate.

  FIG. 1 is a diagram illustrating a schematic configuration of an image forming apparatus and an image forming system according to an embodiment of the present invention. In FIG. 1A, the image forming apparatus PR basically includes an image forming unit 1, a paper feeding unit 2, a fixing unit 3, a paper discharge unit 4, and an image reading unit 5.

  The image forming unit 1 is provided in the main body of the image forming apparatus PR, and includes an image forming engine that forms a single-color or color image on a sheet. The paper feeding unit 2 is located below the image forming unit 1 and includes a paper feeding stage in which paper is stacked and stored in each stage. Images are picked up from each paper feeding stage and are displayed on the image forming unit 1 side. Paper is fed to the transfer section. After the image is transferred by the image forming unit 1, the sheet is heated and pressed by the fixing unit 3 to fix the image. The paper on which the image is fixed by the fixing unit 3 is discharged to the paper discharge unit 4 and stacked.

  The image reading unit 5 includes a document placement tray, a document transport device, a document discharge tray, and an optical reading device, and transports a document placed on the document placement tray by the document transport device and discharges it to the document discharge tray. While paper is being read, it is optically read by an optical reader. Then, the read signal is converted into an image signal for image formation and sent to the image forming unit 1 side. On the image forming unit 1 side, the transmitted image signal is processed by an image processing circuit, an image is formed as an output of the image forming engine, transferred to a sheet, and sent to the fixing unit 3 side.

  For example, an electrophotographic image forming apparatus is used as the image forming engine. The image forming operation on the paper by the image forming engine is known for both single color and full color, and is a commonly practiced technique, and thus the description thereof is omitted here. In addition to the electrophotographic method, the image forming engine method is not limited as long as it has a function of forming an image on a sheet by a known image forming method such as a droplet discharge method or a letterpress printing method.

  In FIG. 1B, the image forming system 100 includes the image forming apparatus PR shown in FIG. 1A and a sheet folding apparatus 6 as a sheet (post) processing apparatus. As can be seen from FIG. 1A, the paper discharge section 4 is provided in the main body of the image forming apparatus PR. Since the paper discharge unit 4 is provided in the main body of the image forming apparatus PR, it is also called an in-body paper discharge unit. In the present embodiment, a sheet folding device (hereinafter simply referred to as a folding device) 6 is mounted on the in-body sheet discharge unit 4 as shown in FIG.

  FIG. 2 is a diagram showing a schematic configuration of the folding device 6. The folding device 6 is provided with a first transport path W1 and a second transport path W2. The first transport path W1 is a transport path that extends in the horizontal direction in order to receive a sheet from the transport member R of the image forming apparatus PR and transport the sheet to the paper discharge tray T, and the second transport path W2 is the first transport path W1. This is a detour conveyance path that branches downward from a later-described third conveyance member R3 and merges on the upstream side in the conveyance direction of the fifth conveyance member R5. In the following description, the conveyance direction is omitted and simply referred to as upstream or downstream. Further, the transport direction refers to the direction of transport from the transport member R side toward the fifth transport member R5, and the reverse direction refers to the direction of transport from the fifth transport member R5 toward the third transport member R3.

  In the first transport path W1, a first transport member R1, a second transport member R2, a third transport member R3, and a fifth transport member R5 are provided in this order from the upstream side. Further, a fourth transport member R4 for performing folding processing on the paper is provided in contact with a transport member (transport roller) on the driving side of the third transport member R3. The second transport path W2 extends from the first transport path W1 to the downstream side of the nip between the fourth transport member R4 and the third transport member R3.

  The first to third transport members R1, R2, R3 and the fifth transport member R5 are each configured by a transport roller pair, and the fourth transport member R4 is configured by a transport roller. The transport rollers on the drive side of the first to third transport members R1, R2, R3 and the fifth transport member R5 are respectively connected to the first, second, third and fourth drive motors M1, M2, via timing belts. It is rotationally driven by M3 and M4. The first, second, third, and fourth drive motors M1, M2, M3, and M4 are constituted by, for example, pulse motors, and pulse control is possible. In the present embodiment, the drive rollers on the driving side of the first to third transport members R1, R2, R3 and the fifth transport member R5 are transport rollers positioned below the first transport path W1.

  In addition, first, second, and third sheet detection sensors SN1, SN2, and SN3 are provided from the upstream side to the downstream side of the first transport path W1. The first sheet detection sensor SN <b> 1 is an entrance sensor, and is disposed immediately downstream of the entrance of the folding device 6. The second sheet detection sensor SN2 is immediately after the downstream side of the third conveyance member R3, and the third sheet detection sensor SN3 is immediately before the upstream side of the fifth conveyance member R5, and the first conveyance path of the second conveyance path W2. This is a so-called paper discharge sensor arranged immediately after the junction with W1. Each of the sheet detection sensors SN1, SN2, and SN3 is configured by, for example, an optical sensor that optically detects the edge of the sheet.

  Further, in the first to fifth transport members R1 to R5, first, second, and second that pressurize the driven-side transport roller against the drive-side transport roller and apply a transport force to the sheet at the nip of each transport member. Third, fourth and fifth elastic members S1, S2, S3, S4 and S5 are provided.

  The first conveying member R1 and the second conveying member R2 convey the sheet sent from the conveying member R of the upstream image forming apparatus PR to the downstream side, and the third conveying member R3 has a function of adjusting the folding position. . The fourth transport member R4 is a transport member that performs the folding process, and the fifth transport member R5 transports the paper onto the discharge tray T regardless of whether or not the folding process is performed.

  FIG. 3 is a block diagram showing a control configuration of the image forming system in the present embodiment.

  In FIG. 3, the folding device 6 includes a control circuit on which a microcomputer having a CPU 6a, an I / O interface 6b, and the like is mounted. Signals from the CPU of the image forming apparatus PR, each switch of the operation panel PR1, and each sheet detection sensor (not shown) are input to the CPU 6a via the communication interface 6c.

  The CPU 6a executes predetermined control based on a signal input from the image forming apparatus PR side. Further, the CPU 6a drives and controls a solenoid and a motor via a driver and a motor driver, and acquires paper detection sensor information in the apparatus from the interface. Further, for example, the motor drive is controlled by the motor driver via the I / O interface 6b for the control target, and the paper detection sensor information is acquired from the paper detection sensors SN1, SN2, SN3, and the like.

  The control is executed based on the program defined by the program code while the CPU 6a reads the program code stored in the ROM (not shown), expands it in the RAM (not shown), and uses the RAM as a work area and a data buffer. Is done.

  In this embodiment, the folding mechanism shown in FIG. 3 can be used to perform two-fold, Z-fold, inner three-fold, and outer three-fold. Each of these folding operations and rotational drive control of rollers, which will be described later, are instructed and executed by the CPU 6a shown in FIG.

  Hereinafter, the operation of the folding process executed in the folding device 6 will be described.

  4 to 7 are operation explanatory views showing the basic operation of the folding device 6 in the present embodiment, and FIG. 8 is a flowchart showing the processing procedure at that time.

  When the leading edge P1 of the paper P sent from the upstream image forming apparatus PR by the conveying member R is detected by the first paper detection sensor SN1 (step 101: YES), the first to fourth drive motors M1, M2, M3 are detected. M4 (first to fifth conveying members R1, R2, R3, R4, R5) starts to rotate (step 102). When the paper P reaches the first transport member R1, the transport force is applied by the first transport member R1, and is transported toward the second transport member R2 and the third transport member R3 (see FIG. 4). In the figure, the step is indicated by “S”.

  When the leading edge P1 of the sheet is detected by the second sheet detecting sensor SN2 (step 103: YES), the CPU 6a starts counting the transport amount (number of drive pulses of the pulse motor) of the leading edge P1 by a counter (not shown) (step 104). Then, when the predetermined count value is reached, that is, when the sheet P is conveyed by a length desired to be creased after the front end P1 of the sheet P is detected by the second detection means SN2 (step 105: YES), the first to first values are obtained. The fifth transport members R1, R2, R3, R4, and R5 are stopped (step 106). Thereafter, the third drive motor M3 and the fourth drive motor M4 (the third transport member R3 and the fifth transport member R5) are reversed (step 107), and the folding process including the third transport member R3 and the fourth transport member R4 is performed. The paper P is bent toward the part (see FIG. 5).

  The bending of the paper P is sandwiched between the third transport member R3 and the fourth transport member R4 to form a crease, and then the creased paper is downstream by the first to fifth transport members R1, R2, R3, R4, and R5. It is conveyed to the side (see FIG. 6).

  Since the creased sheet P needs to be discharged again onto the sheet discharge tray T by the fifth transport member R5, when the leading edge P1 of the sheet P being folded is detected by the third detection unit SN3 (step S1). 108: YES), the fourth drive motor M4 is stopped to stop the reverse rotation of the fifth transport member R5, and the fourth drive motor M4 is further driven to switch the fifth transport member R5 to the downstream transport direction rotation. (Step 109).

  Next, when the folded portion Pf that has become the paper leading edge P1 passes through the nip of the third and fourth transport members R3, R4 (step 110: YES), the first and second drive motors M1, M2 are driven to drive the first. Then, sheet conveyance by the second conveying members R1 and R2 is started (step 111). Then, the conveyance is continued until the third sheet detection sensor SN3 detects the sheet trailing edge P2 after the folding process, and when the sheet trailing edge P2 is detected (step 112: YES), the sheet is conveyed by a predetermined amount and discharged to the discharge tray T. The sheet P that has been folded upward is discharged. Thereafter, the first to fourth drive motors M1 to M4 (paper conveyance by the first to fifth conveyance members R1 to R5) are stopped (see FIG. 7).

  In the basic configuration of the present embodiment shown in FIG. 2, the folding device 6 is positioned on the downstream side of the image forming apparatus PR, receives the sheet P sent from the transport member R as it is, and transports it to the downstream side. ing. When the folding process is performed in the folding device 6, the third and fifth transport members R3 and R5 are reversed, so that a certain processing time is required. However, since the image forming apparatus PR forms an image at a constant speed and continues to convey the paper P at a constant speed, the paper P is stopped or conveyed in the reverse direction because the folding apparatus 6 performs the folding process. Even during this time, the paper P is sent to the folding processing section side by the transport member R and the first transport member R1. In this way, when the paper trailing edge P2 side is further transported while the paper P is in the folding process, paper jam (paper jam) occurs in the first transport path W1.

  Further, when the succeeding paper P-2 is fed while the preceding paper P-1 is being folded, the next paper P-2 is added to the preceding paper P-1 being folded. A paper jam occurs due to a collision in one conveyance path W1 or a collision with a stopped conveyance member. When a paper jam occurs, the image forming system 100 stops, and it is necessary to take out all the paper P positioned in the conveyance path in the image forming apparatus PR and the folding apparatus 6. Then, it is necessary to start again from the image formation on the preceding paper P-1. When paper jam occurs in this way, not only the user's effort, but also the production efficiency is significantly reduced.

  Therefore, in the first embodiment, even when the paper P is continuously conveyed during the folding process, the conveyance of the paper is not hindered. Therefore, in this embodiment, as shown in FIG. 9, the guide member that forms the first transport path W1 between the first and second transport members R1 and R2 is configured by the first elastic material F1. With this configuration, even if the second to fifth transport members R2, R3, R4, and R5 are stopped for the folding process after receiving the paper P as shown in FIG. 10, the transport member of the image forming apparatus PR. The paper P continued to be conveyed by R can be received by the first conveying member R1 and conveyed toward the stopped second conveying member R2 to bend the paper P so that no paper jam occurs. Other parts are the same as the basic configuration of the folding device 6 shown in FIG.

  9 is a diagram showing a schematic configuration of the folding device 6 according to the first embodiment, FIGS. 10 to 12 are operation explanatory views showing basic operations of the folding device 6 in the first embodiment, and FIG. FIG. 14 is a flowchart showing the processing procedure of the subroutine of FIG.

  Hereinafter, the operation of the folding process in the first embodiment executed in the folding device 6 will be described with reference to FIGS.

  In FIG. 13, steps 201 to 205 are processed in the same procedure as the processing procedure of the basic folding apparatus 6 shown in FIG. 8, and perform the same operation (see FIG. 10). When the conveyance is finished up to the folding position in step 205 (step 205: YES), the second, third and fourth drive motors M2, M3, M4 are stopped, and the second to fifth conveyance members R2, R3, R4, R5 are moved. Stop (step 206). However, since the first transport member R1 is not stopped, the sheet P is sandwiched between the nips of the second transport member R2, and the state where the sheet rear end P2 side is transported by the first transport member R1 is maintained in this state. .

  When the trailing edge P2 of the sheet passes through the nip of the conveying member R of the image forming apparatus PR and is detected by the first sheet detecting means SN1 (step 207 to step 11), the first drive motor M1 is stopped and the first conveying member R1 The conveyance of the paper P is stopped (step 207-step 12: see FIG. 11). In this state, the sheet P bends between the first conveying member R1 and the second conveying member R2, and the bending Pd is absorbed by the first elastic member F1 of the guide member being elastically deformed or allowed to be bent. Step 207 is a sheet trailing edge check routine based on the detection result of the sheet trailing edge P2 of the first sheet detection sensor SN1, and is a routine of step 11 and step 12 in FIG. In this embodiment, the guide member is constituted by the elastic material F1 in order to absorb or allow the bending Pd. However, for example, a space is formed so that the bending is brought out from the space. Also good.

  Next, as in step 107, the third and fourth drive motors M3, M4 are reversed to start the rotation of the third to fifth drive members R3, R4, R5 in the reverse direction (step 208—see FIG. 12). . Then, the sheet trailing edge check (step 209) based on the detection result of the sheet trailing edge P2 of the first sheet detection sensor SN1 again and the sheet leading edge check (step 210) based on the detection result of the sheet leading edge P1 of the third sheet detection sensor SN3. To check whether or not the folding portion Pf has passed through the nips of the third and fourth conveying members R3 and R4 (step 211).

  In the sheet leading edge check routine based on the detection result of the sheet leading edge P1 of the third sheet detecting sensor SN3, processing as shown in FIG. 14B is executed. That is, when the third sheet detection sensor SN3 detects the sheet leading end P1 (step 21), in other words, the sheet P is conveyed in the reverse direction, and after the sheet leading end P1 passes through the nip of the fifth conveying member R5, the fourth drive is performed. The motor M4 is stopped, and further rotation in the transport direction is started. As a result, the fifth transport member R5 rotates in the paper transport direction to prepare for the next transport after the paper P is removed.

  When the folding portion Pf passes through the nip between the third and fourth transport members R3 and R4 (step 211: YES), the processing from step 212 to step 214 similar to step 111 to step 113 in FIG. And as shown in FIG. 7, the paper P is conveyed downstream.

  By processing in this way, even if the paper P is transported by the first transport member R1, it can be sent to the downstream side, and the folding process is performed without hindering the transport of the paper P from the image forming apparatus PR side. Can do.

  In some cases, the length of the paper P to be processed is long, or the folding device 6 is mounted on a model in which the conveyance speed of the image forming apparatus PR is fast. In such a case, the bending Pd of the sheet P that can be continued by being conveyed while the sheet P is stopped during the folding process becomes larger than the bending Pd shown in FIG. It may become impossible to absorb. The present embodiment is an example corresponding to such a case.

  FIG. 15 is a diagram illustrating a schematic configuration of the folding device 6 according to the second embodiment. In this embodiment, as shown in FIG. 15, the guide member between the second conveying member R2 that stops during the folding process and the first conveying member R1 on the upstream side, the conveying member R1 and the conveying member R of the image forming apparatus. Each of the guide members between the first and second elastic members F1 and F2 is composed of the first elastic member F1 and the second elastic member F2, and the first conveying member R1 upstream of the second conveying member R2 stopped during the folding process. Was made slower than the conveying speed of the conveying member R of the image forming apparatus PR. Other parts are the same as the basic configuration of the folding device 6 shown in FIG.

  16 and 17 are explanatory diagrams of the operation of the folding device 6 in the second embodiment. With the configuration as shown in FIG. 15, the deflection Pd of the paper P is changed between the first transport member R1 and the second transport member R2 as shown in FIG. 17 with respect to the paper P transported as shown in FIG. And between the conveying member R and the first conveying member R1, the first bending Pd1 and the second bending Pd2 can be formed. In addition, since the deflection Pd can be dispersed (Pd1, Pd2), the stop time of the second transport member R2 can be increased. As a result, it is possible to take much time for the folding process. In other words, the deflection of the paper can be dispersed and the conveyance difference can be absorbed. Therefore, it is possible to cope with a model in which the conveyance speed of the image forming apparatus PR is faster.

  In FIG. 17, when the sheet trailing edge P2 passes through the nip of the conveying member R while the folding process is stopped, the conveying member R continues to be conveyed (rotated) while the sheet trailing edge P2 is in contact with the conveying member R. However, in order to eliminate problems such as contamination of the conveying member R adhering to the trailing edge P2, the trailing edge P2 of the sheet does not pass through the nip of the conveying member R while the folding process is stopped. It is desirable to mount the image forming apparatus PR at a high conveyance speed.

  Hereinafter, the operation of the folding process in the second embodiment executed in the folding device 6 will be described with reference to FIGS. 16 to 18A and 18B.

  In FIG. 18A, steps 301 to 305 are processed in the same procedure as steps 101 to 105 of the basic folding apparatus 6 shown in FIG. 8 and perform the same operations (see FIG. 16). When the conveyance to the folding position is completed in step 305 (step 305: YES), the paper size information sent from the image forming apparatus PR side is determined (step 306). This determination is made on the basis of whether or not bending can be absorbed only by the first elastic material F1, and whether or not both the first and second elastic materials F1 and F2 need to absorb bending.

Whether or not bending can be absorbed only by the first elastic material F1, or whether both of the first and second elastic materials F1 and F2 need to absorb bending,
Paper length <Conveying fee up to the folding position + Maximum deflection amount of the first elastic material F1 (1)
Judgment is made based on whether or not

  In step 306, if the expression (1) is established, it is determined that the bending can be absorbed only by the first elastic material F1, and the processing in and after step 307 is executed. If the expression (1) is not established, the first and second elastic materials are determined. It is determined that both the materials F1 and F2 need to absorb the deflection, and the processing after step 316 is executed.

  That is, when the expression (1) is established, the processing from step 307 to step 315 is executed. Since the processing from step 307 to step 315 is the same as the processing from step 207 to step 214 in the first embodiment, description thereof will be omitted.

If the expression (1) is not established, the second to fourth drive motors M2, M3, and M4 are stopped, and the rotations of the second to fifth drive members R2, R3, R4, and R5 are stopped. At the same time, the rotational speed of the first drive motor M1 is decelerated and the transport speed of the first transport member R1 is decreased. When the conveyance speed VR1 of the first conveyance member R1 is VR2, the conveyance speed of the second conveyance member R2 is VR2, and the conveyance speed of the conveyance member R is VR,
VR2 <VR1 <VR (2)
Is set so that

  In the basic configuration shown in FIG. 2, the conveying speed of the conveying member R, the first conveying member R1, and the second conveying member R2 is the same, and the conveying speed from the image forming apparatus PR is maintained and carried into the folding device 6. Is done. On the other hand, in this embodiment, the conveyance speed relationship (2) is set. This setting is performed by the CPU 6a in the folding device 6.

  In step 316, the second to fourth drive motors M2, M3, and M4 (second to fifth transport members R2, R3, R4, and R5) are stopped, and the speed relationship is set as shown in equation (2). 3 and the fourth drive motors M3, M4 (third, fourth and fifth transport members R3, R4, R5) start to reverse, and transport the paper P in the direction opposite to the paper P loading direction (step) 317). Next, the processing from step 319 to step 322 is executed. Since the processing from step 318 to step 322 is the same as the processing from step 210 to step 214 in the first embodiment, description thereof will be omitted.

  The first and second embodiments are examples corresponding to the paper P that is continuously conveyed during the folding process, but in the third embodiment, the paper P continuously sent from the image forming apparatus PR is used as the preceding paper during the folding process. This is an example corresponding to the case of catching up.

  FIG. 19 is a diagram illustrating a schematic configuration of the folding device 6 according to the third embodiment. In this embodiment, a switchback path W3 and a branch claw B1 are provided in the first transport path W1 with respect to the basic configuration shown in FIG. The switchback path W3 is branched from the first transport path W1 between the second transport member R2 that stops during the folding process and the first transport member R1 upstream thereof, and a branch claw B1 is provided at the branch point. . The branch claw B1 may be driven and controlled by a driving source such as a motor or a solenoid. In this embodiment, the branch claw B1 always applies an elastic force by an elastic material such as a spring, and always feeds the paper P to the switchback path W3. The position configuration leads to Further, the branch claw B1 itself may be made of an elastic material so that the paper P is always guided to the switchback path W3. Other parts are the same as the basic configuration of FIG.

  20 to 26 are operation explanatory views showing the operation of the folding device 6 in the third embodiment.

  In the third exemplary embodiment, the paper sheet P sent from the image forming apparatus PR is branched downstream by the first to fifth transport members R1, R2, R3, R4, and R5, and the paper trailing edge P2 is provided at the branching portion B1. (See FIGS. 20 and 21). When the paper rear end PR exceeds the branch claw B1, the branch claw B1 is positioned so as to guide the paper rear end P2 to the switchback path by the action of the elastic material (the state shown in FIGS. 20 to 21). Then, by rotating the second to fifth transport members R2, R3, R4, and R5 in the direction opposite to the transport direction, the sheet rear end P2 is guided to the switchback path W3 (see FIG. 22).

  At this time, if the sheet is returned to the position where the crease is desired and the second conveying member R2 is stopped, the sheet P is bent to the nip between the third and fourth conveying members R3 and R4, and the creasing process is performed. (See FIG. 23). After the crease is formed, the sheet is conveyed downstream by the third to fifth conveying members R3, R4, and R5. At this time, even if the next sheet P-2 catches up with the preceding sheet P-1 after the folding process (see FIG. 23), the trailing edge P-1b of the preceding sheet P-1 that has been retracted to the switchback path W3 Then, the next paper P-2 can be conveyed downstream in a state where the leading edge P-2a of the next paper P-2 is overlapped. For this reason, the conveyance of the preceding paper P-1 and the next paper P-2 after the folding process does not interfere with each other (see FIG. 24).

  Then, the third to fifth transport members R3, R4, R5 are moved from the position where the rear end P-1b of the folded preceding paper P-1 exceeds the nip of the second transport member R2 to the next sheet P-2. The speed is increased to a speed faster than the transport speed and transported downstream (see FIG. 25). Further, when the trailing edge P-1b of the preceding paper P-1 exceeds the nip of the third and fourth transport members R3, R4, the third and fourth transport members R3, R4 are reversed and rotated in the transport direction, If the transport speed is matched with the transport speed of the next paper P-2, the next paper P-2 can be received while discharging the preceding paper P-1 by the fifth transport member R5 (see FIG. 26).

  In these operations, the trailing edge P-1b of the preceding paper P-1 exceeds the nip of the conveying member R of the image forming apparatus PR until it is retracted to the switchback path W3 (FIGS. 20, 21, and FIG. 22), when the conveying speed of the first to fifth conveying members R1, R2, R3, R4, R5 is increased more than the conveying speed of the conveying member R of the image forming apparatus PR, the next sheet P is temporarily stored. -2 can increase the time between papers. Thereby, it is possible to earn time until the next sheet P-2 catches up during the folding process of the preceding sheet P-1.

  27A, 27B, and 27C are flowcharts illustrating the processing procedure in the third embodiment.

  In FIG. 27A, steps 401 to 404 are processed in the same procedure as steps 101 to 104 of the basic folding device 6 shown in FIG. 8, and the first sheet detection sensor SN1 detects the sheet trailing edge P2. (Step 405: see FIG. 20). Then, after detecting the trailing edge P-1b of the preceding paper P-1 by the first paper detection sensor SN1, in order to set the paper conveyance amount, the conveyance amount of the preceding paper P-1 is set in the same manner as in Step 104. . Since the carry amount is set by the count value of the drive pulse of the drive motor after detecting the paper trailing edge P-1b, counting is started when the paper trailing edge is detected in step 405 (step 406).

  Next, acceleration of all of the first to fourth drive motors M1 to M4 (first to fifth transport members R1 to R5) is started (step 407), and the trailing edge P-1b of the preceding paper P-1 is determined. Transport to a position beyond the branching claw B1 (step 408: YES-FIG. 21). Then, the driving of the first to fourth drive motors M1 to M4 (first to fifth transport members R1 to R5) is stopped at a position beyond the branch claw B1 (step 409).

  From this position, the second to fourth drive motors M2 to M4 (second to fifth transport members R2 to R5) are reversed (step 410). As a result, the trailing edge P-1b of the preceding paper P-1 is guided to the switchback path W3 (see FIG. 22). If the preceding paper P-1 reaches the position where the crease is desired (step 411: YES), the second drive motor M2 (second transport member R2) is stopped (step 412). In response to this, the preceding paper P-1 is bent to the nip of the third and fourth transport members R3, R4, and the crease process is performed (see FIG. 23).

  Next, until the first sheet detection sensor SN1 detects the leading edge P-2a of the next sheet P-2, the sheet detection operation by the first sheet detection sensor SN1 is repeated (step 413 to step 31: NO), and the first sheet detection is performed. When the sensor SN1 detects the leading edge P-2a of the next paper P-2 (step 413-step 31: YES), the first drive motor M1 is driven to transport the next paper P-2 by the first transport member R1. Is started (step 413-step 32). The processing content of step 413 is the SN1 paper leading edge check processing shown in FIG.

  Then, the paper detection operation by the third paper detection sensor SN3 is repeated until the third paper detection sensor SN3 detects the leading edge P-1a of the preceding paper P-1 that has been conveyed in the reverse direction in Step 410 (Step 414 to Step 21). : NO), when detected (step 414-step 21: YES), the fourth drive motor M4 (fifth transport member R5) is stopped and the transport direction rotation in the paper discharge direction is started (step 414-step 22). ). The processing content of step 413 is the processing shown in FIG.

  The processes of step 413 and step 414 are repeated until the folding portion Pf of the preceding paper P-1 passes through the nips of the third and fourth transport members R3 and R4 (step 415: NO), and the second paper P-2 is processed. The transport by the first transport member R1 is started, the leading edge P-1a of the preceding paper P-1 comes out of the nip of the fifth transport member R5, the fifth transport member R5 starts to rotate in the transport direction, and further the preceding paper P- After the first folding portion Pf passes through the nip between the third and fourth transport members R3 and R4, the process proceeds to step 416.

  In step 416, the driving of the second drive motor M2 stopped in step 412 is started, and the sheet conveyance by the second conveying member R2 is started. At this time, if the transport members R3 and R4 of the preceding paper P-1 are rotated in the transport direction and the transport speed is matched with the transport speed of the next paper P-2 as described above, the next paper P-2 can be received. Yes (see FIG. 24).

  Alternatively, the driving of the second to fourth drive motors M2, M3, M4 (second to fifth transport members R2, R3, R4, R5) is started and increased to a speed faster than the transport speed of the next sheet P-2. If the conveyance of the preceding paper P-1 to the downstream side is started along the second conveyance path W2, the time between the next paper P-2 can be temporarily extended as described above.

  After the processing in step 416, the same processing as in steps 413 and 414 is executed in step 417 and step 418. Further, in step 419, the SN2 sheet trailing edge check in steps 41 and S42 shown in FIG. Execute.

  The SN2 paper trailing edge check routine of step 419 is executed based on the detection output of the second paper detection sensor SN2, and the second and third drive motors M2, M3 (second to fourth transport members R2, R3, R4). This is a routine for switching the drive in the direction opposite to the transport direction to the drive in the transport direction. That is, when the preceding sheet P-1 is conveyed in the direction opposite to the conveying direction from the image forming apparatus PR and the folding process to the preceding sheet P-1 is performed, the leading edge of the preceding sheet P-1 at the time of carrying in When the second sheet detection sensor SN2 detects the trailing edge of the sheet that has been P-1a, the preceding sheet P may come out of the nip between the third and fourth conveying members R3 and R4 if the sheet is fed by a predetermined amount from that timing. I understand.

  Therefore, the second sheet detection sensor SN2 repeatedly detects the trailing edge of the sheet (here, the leading edge P-1a) (step 419-step 41: NO), and a predetermined amount based on the detected timing (step 419-step 41: YES). After the sheet is transported and the sheet comes out of the nip between the third and fourth transport members R3 and R4, the second and second sheets are transported to the discharge tray T side along the first transport path W1. The three drive motors M2 and M3 are driven in the transport direction (steps 419 to 42). As a result, the second and third transport members R2 and R3 rotate in a direction to transport the next paper P-2 to the discharge tray T side along the first transport path W1 (see FIG. 26).

  When the check in step 419 is completed, it is confirmed whether or not the fifth transport member R5 is rotating in the transport direction (paper discharge direction) (step 420). If not, the process returns to step 418 and the subsequent processing is performed. repeat. If it is rotating in the transport direction, it waits until the third sheet detection sensor SN3 detects the trailing edge P-1b of the preceding sheet P-1 (step 421), and if the trailing edge P-1b is detected, the next sheet is detected. It is confirmed whether there is P-2 (step 422). If there is the next paper P-2, if the speed is increased and transported in step 416 in step 437, the transport speed of the first to fourth drive motors M1 to M4 (first to fifth transport members R1 to R5) will be described. To the original speed. Then, the processing after step 403 is repeated.

  If there is no next sheet P-2, the first to fourth drive motors M1 to M4 (first to fifth conveying members R1 to R5) convey the preceding sheet P-1 by a predetermined amount and then stop (step 423). .

  Furthermore, when the time between sheets of the paper P continuously fed from the image forming apparatus PR is short and cannot be handled by the configuration shown in the third embodiment, the second transport member R2 is separated and the second transport member R2 is separated. In this case, it is possible to prevent paper jam from occurring. Example 4 is this example.

  28 and 29 are diagrams illustrating a schematic configuration of the folding device 6 according to the fourth embodiment. The fourth embodiment is an example in which the driven-side transport roller of the second transport member R2 can be separated from the drive-side transport roller by a separation mechanism with respect to the third embodiment shown in FIG.

  In FIG. 28, the rotation shaft of the transport roller R2a on the driven side of the second transport member R2 is coupled to one end of the link L1, and the other end of the link L1 is coupled to an eccentric position of the cam K1. The cam K1 is rotationally driven by the fifth drive motor M5, and the cam K1 can move the driven-side transport roller R2a in the vertical direction in the drawing relative to the drive-side transport roller R2b by the link member L1. Thus, as shown in FIG. 29, the driven-side transport roller R2a is separated from the drive-side transport roller R2b, and the nip of the second transport member R2 can be released.

  FIG. 30 is an operation explanatory diagram showing a state when the next paper P-2 catches up during the folding process of the preceding paper P-1 and an overlapping portion occurs. Comparing the states of the preceding sheet P-1 and the next sheet P-2 in FIGS. 30 and 24, the rear end P-1b of the preceding sheet P-1 and the leading end P- of the next sheet P-2 are shown in FIG. There is much overlap with 2a. However, if the crease process of the preceding paper P-1 is finished and the third and fourth transport members R3 and R4 are ready to be transported downstream, the nip of the second transport member R2 is separated. The paper P-1 can be transported at a faster speed downstream. Therefore, as shown in FIG. 25, it is possible to widen the time between the next sheet P-2 caught up during the folding process, and the next sheet P-2 is received by the third conveying member R3 for the folding process. There will be room for time.

  Further, after the trailing edge P-1b of the preceding paper P-1 reaches the branch claw B1, the transport amount that is switched back and transported to the switchback path W3 is proportional to the distance at which a crease is made from the paper leading edge P-1a. Therefore, the longer the paper length (the length in the transport direction), the longer the time required for switchback, and the time between sheets with the next paper P-2 becomes clogged. On the other hand, when the paper length is short, the switchback time is short, so the time between papers with the next paper P-2 is less clogged.

  For this reason, when the paper length is long and the gap between the next paper P-2 is clogged and it is necessary to transport the folded preceding paper P-1 to the downstream more quickly, the second transport member R2 Perform separation. On the other hand, the paper length is short, the time between the next paper P-2 is sufficient, and the rear end P-1b of the folded preceding paper P-1 passes through the nip of the second conveying member R2. Even if the speed is increased downstream, if there is a margin between the sheets P2 and the next sheet P-2, the power consumption can be reduced and the operation can be reduced if the second conveying member R2 is not separated. It is possible to reduce sound and improve the durability of the driving parts.

  30 and 31 are explanatory diagrams of the operation of the folding device 6 in the fourth embodiment. Hereinafter, the operation of the folding process according to the fourth embodiment will be described with reference to FIGS. 27A, 27B, and 27C.

  In the fourth embodiment, step 401 in FIG. 27A to step 415 in FIG. 27B are processed in the same manner as in the third embodiment and operate in the same manner. Then, after the determination process of step 415, when the second transport member R2 is separated, the process proceeds to the process of step 424 in FIG. 27C.

  In step 424, the fifth drive motor M5 is driven to operate the separation mechanism, and the second transport member R2 is separated as described above (see FIG. 30). When the preceding paper P-1 is transported at an increased speed, the third drive motor (the third and fourth drive members R3, R4) is accelerated to the second transport path W2 for the preceding paper P-1. (Step 425).

  Next, the processing from step 426 to step 429 is executed. Since the processing from step 426 to step 429 is the same as the processing from step 417 to step 420n in the third embodiment, description thereof is omitted here.

  In step 429, the fifth transport member R5 is rotated in the transport direction (step 429: YES), and when the transport speed of the fifth transport member R5 is increased, the fourth drive motor M4 is increased to advance the speed. The conveyance of the paper P-1 is started (step 430). When the second paper detection sensor SN2 detects the trailing edge of the preceding paper P-1 (paper leading edge P-1a at the time of carry-in) (step 431: YES), the second and third drive motors M2 and M3 (first) are detected. 2 thru | or 4th conveyance member R2, R3, R4), a predetermined amount of preceding paper P-1 is conveyed, and the rear end of the preceding paper P-1 passes the nip of 3rd and 4th conveyance member R3, R4 Then, the second and third drive motors M2 and M3 are stopped, and rotation in the transport direction is started (step 432).

  Next, the second drive motor M2 (second transport member R2) is rotated in the transport direction, the fifth drive motor M5 is driven to release the separated state of the second transport member R2, and the driven transport roller R2a is driven. A nip is made on the side conveying roller R2b (step 433: see FIG. 31). Thereafter, the processing from Step 434 to Step 436 similar to Step 321 to Step 423 of the third embodiment is executed, and the processing is terminated.

  If it is determined in step 435 that there is the next sheet P-2, the process proceeds to step 438. If the speed is increased, the first to fourth drive motors M1, M2, M3, which have been increased, are increased. The speed of M4 (first to fifth transport members R1, R2, R, 3, R4, and R5) is returned to the original, and the processing after step 403 is executed.

  As described above, according to the present embodiment, the following effects are obtained.

(1) A second transport member R2 (first transport member) that transports the paper P and the paper P transported by the second transport member R2 (first transport member) are received and transported to the subsequent stage. In a state where the paper P is held by the third transport member R3 (second transport member), the second transport member R2 (first transport member), and the third transport member R3 (second transport member), A fourth transport member R4 (third transport member) that rotates the third transport member R3 (second transport member) in the reverse direction to fold the paper P, and the second transport member R2 (first transport member). First elastic material F1 [and second elastic material F2] or switchback path W3 (paper conveyance permission means) that permits conveyance of the paper P in parallel with the folding process on the upstream side of the member) in the paper conveyance direction. Therefore, it can accept paper that continues to be conveyed during the folding process. And, also, even if that would catch up the next sheet, it can folding process without interfering with the conveyance of the sheet, also it is possible to accept the next sheet.

  In addition, since it is only provided in the paper transport permission means in the transport path upstream of the second transport member R2 (first transport member) in the paper transport direction, it can be applied to a paper processing apparatus having a miniaturized folding function. Even small ones can maintain productivity.

(2) Since the sheet transport permission means is a bend absorbing portion that absorbs the bend Pd of the sheet P being transported, the effect of (1) can be obtained with a simple configuration in which a portion for absorbing the bend Pd is provided. it can.

(3) Since the sheet transport permitting means is a switchback path W3 (retraction path) for retracting the sheet P being transported, the switchback path W3 that has been used in the past is used in a simple configuration. An effect can be obtained.

(4) Since the bending absorbing portion is made of the first elastic material F1 (elastic deformation portion) provided on the conveyance guide member, the bending Pd of the paper P can be absorbed by the elastic deformation of the first elastic material F1.

(5) The elastic deformation portion is between the first transport member R1 (fourth transport member) and the second transport member R2 (first transport member), and the first transport member R1 (fourth transport member). Since the first and second elastic members F1 and F2 are provided on the upstream side in the paper conveyance direction of the conveyance member), the bending Pd of the paper P can be absorbed at a plurality of locations. As a result, it is possible to reliably handle large-size paper P.

(6) Since the bending absorbing portion is a space provided in the conveyance guide member, it is possible to deal with it by simply providing a space and letting out the bending Pd to the outside.

(7) Since a fifth drive motor M5 for separating the nip of the second transport member R2 (first transport member), a separation mechanism (separation means) such as a cam K1 and a link L1 is provided. The nip of the second conveying member R2 (first conveying member) is opened, and the leading edge P-2a of the next sheet P-2 can be fed to the end of the second conveying member R2 without causing a paper jam.

(8) Since whether or not the separation operation of the separation mechanism (separation means) is set according to the paper size, the effect (7) can be obtained by separating the paper when the paper size is larger than a predetermined size. Can do.

(9) Since the sheet processing apparatuses (1) to (8) are provided, the image forming system 100 having the effects of the sheet processing apparatuses (1) to (8) can be constructed in a small size. The image forming system 100 here includes a folding device 6 and an image forming device PR as paper processing devices.

(10) The second transport member R2 (first transport member) that transports the paper P and the paper P transported by the second transport member R2 (first transport member) are received and transported to the subsequent stage. In a state where the paper P is held by the third transport member R3 (second transport member), the second transport member R2 (first transport member), and the third transport member R3 (second transport member), A fourth transport member R4 (third transport member) that rotates the third transport member R3 (second transport member) in the reverse direction to fold the paper P, and the second transport member R2 (first transport member). A first elastic member F1 (and second elastic member F2) or a switchback path W3 (paper conveyance permission unit) that permits conveyance of the sheet in parallel with the folding process on the upstream side of the member) in the sheet conveyance direction. A paper folding method in the folding device 6, wherein the preceding paper P- Alternatively, the second sheet P-2 is conveyed and folded in the direction opposite to the conveying direction by the third conveying member R3 (second conveying member) while being conveyed using the sheet conveying permission means, so that the (1 ) Can be obtained.

  In the description of the effects in the above-described embodiment, the constituent elements in the claims are indicated in parentheses for each part of the present embodiment, or a reference numeral is attached, and the correspondence between the two is clarified.

  Furthermore, the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit of the present invention, and all the technical matters included in the technical idea described in the claims are all included. The subject of the present invention. The above-described embodiments show preferred examples, but those skilled in the art can realize various alternatives, modifications, variations, and improvements from the contents disclosed in the present specification. These are included in the technical scope described in the appended claims.

6 Folding device 100 Image forming system F1 1st elastic material F2 2nd elastic material M5 5th drive motor P paper P-1 preceding paper P-2 secondary paper P-2a (next paper) tip
Pd Deflection PR Image forming apparatus R1 First transport member (fourth transport member)
R2 Second transport member (first transport member)
R3 Third transport member (second transport member)
R4 Fourth transport member (third transport member)
K1 Cam L1 Link W3 Switchback path

JP 2007-277006 A

Claims (10)

A first conveying member that conveys a preceding sheet conveyed from another device upstream in the sheet conveying direction ;
A second conveying member that receives the preceding sheet conveyed by the first conveying member and conveys the preceding sheet; and
A third conveying member that folds the preceding sheet by rotating the second conveying member in a reverse direction while holding the preceding sheet by the first conveying member and the second conveying member;
While the succeeding sheet is continuously conveyed from the other apparatus at a constant speed, the preceding sheet is allowed to be conveyed in parallel with the folding process on the upstream side of the first conveying member in the sheet conveying direction. Paper transport permission means;
A paper processing apparatus. The sheet processing apparatus according to claim 1,
A sheet processing apparatus, which is a deflection absorbing unit that absorbs the deflection of the preceding sheet being conveyed by a space that can be stored by the sheet conveyance permission unit. The sheet processing apparatus according to claim 1,
A sheet processing apparatus, which is a retreat path for retreating the preceding sheet being conveyed by the sheet conveyance permission unit. The sheet processing apparatus according to claim 2,
A sheet processing apparatus, wherein the bending absorbing portion is an elastically deforming portion provided on a conveyance guide member. The sheet processing apparatus according to claim 4,
A fourth conveying member further upstream of the first conveying member in the sheet conveying direction;
A paper processing apparatus in which the elastic deformation portion is provided between the first transport member and the fourth transport member and on the upstream side in the paper transport direction of the fourth transport member. The sheet processing apparatus according to claim 2,
The paper processing apparatus in which the space portion is provided on the conveyance guide member. The sheet processing apparatus according to claim 3,
A sheet processing apparatus including a separating unit that separates a nip of the first conveying member. The sheet processing apparatus according to claim 7,
A sheet processing apparatus in which whether or not the separating operation of the separating unit is possible is set according to a sheet size.   An image forming system comprising the sheet processing apparatus according to claim 1. A first conveying member that conveys a preceding sheet conveyed from another device upstream in the sheet conveying direction ;
A second conveying member that receives the preceding sheet conveyed by the first conveying member and conveys the preceding sheet; and
A third conveying member that folds the preceding sheet by rotating the second conveying member in a reverse direction while holding the preceding sheet by the first conveying member and the second conveying member;
While the succeeding sheet is continuously conveyed from the other apparatus at a constant speed, the preceding sheet is allowed to be conveyed in parallel with the folding process on the upstream side of the first conveying member in the sheet conveying direction. Paper transport permission means;
A paper folding method in a paper processing apparatus comprising:
Paper, characterized in that folding the while conveying the sheet of paper or the rear row of the preceding using paper conveying permissible means, and conveying the leading the paper of the second conveying member in the opposite direction Folding method.