JP2018030727A - Sheet processing apparatus and image forming system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a duplicate fold from arising in a second sheet folding process when the folding process is performed by a nip-reverse method.SOLUTION: A sheet processing apparatus includes: a first folding roller pair 2 that folds a sheet P; a forward-reverse roller pair 3 that conveys downstream the sheet P folded by the first folding roller pair 2; and a second folding roller pair 4 that further folds the sheet P folded by the first folding roller pair 2. The forward-reverse roller pair 3 is rotatable in a forward-reverse direction when driven for conveying, and when not driven, it is locked in one rotation direction but rotatable in the other rotation direction.SELECTED DRAWING: Figure 17

Description

  The present invention relates to a paper processing apparatus and an image forming system, and particularly to a sheet-like recording medium (referred to as “paper” in this specification) such as paper, transfer paper, printing paper, and OHP sheet that has been carried in. The present invention relates to a sheet processing apparatus that performs a folding process, and an image forming system including the sheet processing apparatus and an image forming apparatus such as a copying machine, a printer, a facsimile, or a digital multifunction peripheral.

  As a sheet processing apparatus that performs a folding process on a sheet conveyed from an image forming apparatus, for example, a technique described in Japanese Patent Laid-Open No. 2006-117383 (Patent Document 1) is known. According to this technique, a first stop member capable of moving a position provided in the second transport path to stop the leading edge of the paper, a first transport roller that forms a fold by sandwiching a paper sheet in the first stop member, and a first transport roller. A pair of transport rollers formed by two transport rollers, a second stop member capable of moving a position provided in the first transport path to stop the paper that has passed through the pair of transport rollers, and the second stop member It has a pair of conveyance rollers formed by a second conveyance roller and a third conveyance roller that form a fold by sandwiching the bending of the sheet. By controlling the stop position of the second stop member 10, a four-fold is formed. It is characterized by a paper processing device.

  In this technology, a special path branched from the transport path for transporting the paper transported from the upstream apparatus to the downstream apparatus for performing the folding process and a stopper are provided so that the front end of the paper is abutted and folded. The processing is performed. That is, in the folding process, the sheet is brought into contact with the stopper through this dedicated path, the folding position is adjusted and the bending is formed, and the formed bending is nipped at the folding portion and folded.

  On the other hand, for example, a technique described in Japanese Patent Application Laid-Open No. 2007-277006 (Patent Document 2) is also known. In the method of folding a medium with a folding device, this technique includes a rotatable folding cylinder, a first rotatable press member that engages with the folding cylinder to form a first folding pinch, The folding device includes a second rotatable press member that engages with the stacking cylinder to form a second folded pinch and a medium feeding means, and the medium is fed by the first pinch and the second pinch by the feeding means. Feed toward the middle cylinder, turn the cylinder in the first direction into the first pinch, direct the medium, form slack in the medium between the feeding means and the cylinder, and reverse the cylinder in the first direction By rotating in the second direction, the slack is moved into the second pinch and folded.

  That is, conventionally, as disclosed in Japanese Patent Application Laid-Open No. 2004-260, as a method of folding, when an image-formed sheet is received and folding processing such as tri-folding and Z-folding is performed, the operation is performed according to the paper size. Folding is possible only by adjusting the folding position by abutting the leading edge of the sheet against a possible leading edge abutting member (hereinafter referred to as a stopper method) and the conveyance amount adjustment by the conveying means as disclosed in Patent Document 2. Two methods, a method of performing position adjustment (hereinafter referred to as a sandwiching and reversing method), are generally used.

  In the stopper method described in Patent Document 1, the leading end of the folded portion of the paper is abutted against the stopper, and at the time of the second folding process, the first folding side paper portion formed during the first folding process. (Peller part) is always stopped. For this reason, after the bending of the paper generated during the second folding process is nipped by the second folding roller pair, the paper portion (peller portion) on the first folding side starts to move after the bending is eliminated. Pc is unlikely to occur. However, a mechanism for moving the paper leading edge abutting member according to the paper length is required, and since the installation space for this mechanism is essential, it is difficult to reduce the size of the apparatus.

  On the other hand, the holding and reversing method described in Patent Document 2 is excellent in terms of miniaturization because the folding position is adjusted only by adjusting the conveyance amount. However, during the second paper folding process in the three-folding or Z-folding in which the paper folding process is performed twice, the upstream conveying means (hereinafter referred to as the first folding roller pair) and the downstream conveying means (hereinafter referred to as the positive folding means) It is necessary to feed the sheet in a direction opposite to each other to form a deflection on the sheet. In this case, the first folding roller pair conveys the sheet in the downstream direction, and the forward / reverse roller pair conveys the sheet in the upstream direction. Then, a second folding process is performed on the sheet on which the second folding roller pair positioned downstream of the forward / reverse roller pair is bent. At that time, there are cases where two folds are attached as referred to as box folding or box folding.

  FIGS. 28 to 31 are explanatory views showing a mechanism of occurrence of box breakage. The direction in which the first folding roller pair 2 and the forward / reverse rotation roller pair 3 are opposite to each other during the second paper folding process in the three-folding or Z-folding in which the paper folding process is performed twice (the first folding roller pair 2 is in the downstream direction) In addition, the forward / reverse roller pair 3 conveys the sheet P in the upstream direction), forms a bend Pt1 on the sheet P, and performs the second folding process by the second folding roller pair 4. For this reason, the first folding side paper portion (peller portion) P1a including the leading edge P1 of the paper P formed during the first folding process by the conveyance of the pair of forward and reverse rollers 3 is before the bending Pt2 of the second folding portion disappears. In some cases, the second folding roller pair 4 may be drawn into the nip (FIG. 29). When the second folding process is performed in this state (FIG. 30), a so-called box break Pc in which two fold lines Pc1 and Pc2 are formed occurs (FIG. 31).

  In order to prevent the occurrence of the box breakage Pc, the front end P1 of the paper P formed at the time of the first folding process is stopped before the nip of the second folding roller pair 4 (the forward / reverse roller pair 3 is stopped). (FIG. 32) The second folding roller pair 4 and the forward / reverse rotation roller pair 3 pull the paper P at the moment when the bending Pt2 of the second folding portion disappears (FIG. 33). Therefore, the forward / reverse rotation roller pair 3 may be rotated at the moment when the bending Pt <b> 2 of the second folding portion disappears to eliminate the tension. However, there is also a problem of inertia, and it is not realistic to eliminate the tension by rotating the forward / reverse rotation roller pair 3 as described above in terms of dynamics and control, and the sheet P with such a mechanism is not practical. It is difficult to eliminate the tension.

  Accordingly, the problem to be solved by the present invention is to prevent box folding during the second sheet folding process when folding is performed by the sandwich reversal method.

  In order to solve the above problems, the present invention provides a first conveying member pair for folding a sheet, a second conveying member pair for conveying the sheet folded by the first conveying member pair downstream, and the first A third conveying member pair that further folds the sheet folded by one conveying member pair, and the second conveying member pair can be rotated forward and backward when driven and rotated in one direction when not driven. It features a paper processing device that is locked in direction and rotatable in the other rotational direction. Note that problems, configurations, and effects other than those described above will be clarified in the following description of embodiments.

  According to the present invention, when the folding process is performed by the sandwiching reversal method, it is possible to prevent the box from being folded during the second sheet folding process.

1 is a diagram showing a schematic configuration of an image forming system according to Example 1 in an embodiment of the present invention. 2 is a diagram illustrating a schematic configuration of another form of the image forming system in Embodiment 1. FIG. It is a figure which shows the folding mechanism of the folding processing apparatus in FIG.1 and FIG.2. 1 is a block diagram illustrating a control configuration of an image forming system in Embodiment 1. FIG. FIG. 6 is an operation explanatory diagram illustrating an initial state before a sheet is conveyed from the image forming apparatus side. FIG. 6 is an operation explanatory diagram illustrating a state when a sheet is carried into the first transport path from the state of FIG. 5. FIG. 7 is an operation explanatory diagram illustrating a state when the leading edge of the sheet is conveyed from the second sheet detection sensor until reaching a first protrusion amount from the state of FIG. 6. FIG. 8 is an operation explanatory diagram illustrating a state in which the second conveying member pair is rotated in the reverse rotation while the first conveying member is rotated in the conveying direction from the state of FIG. 7 to make a crease. FIG. 9 is an operation explanatory diagram illustrating a state when the sheet on which the first fold is formed by the first fold roller pair is transported to the second transport path from the state of FIG. 8. FIG. 10 is an operation explanatory diagram illustrating a state in which the sheet is transported along the second transport path from the state of FIG. 9, sandwiched between the forward and reverse roller pairs and transported downstream. It is operation | movement explanatory drawing which shows the state which reversely rotates a normal / reverse rotation roller pair from the state of FIG. 10, and conveys it to the 2nd folding roller pair side. It is operation | movement explanatory drawing which shows the state in which 2nd folding is given by the 2nd folding roller pair from the state of FIG. 11, and it is conveyed downstream. It is a flowchart which shows the control procedure of the operation | movement of each part at the time of Z folding. It is a figure which shows notionally the structure of the drive part main body of the normal / reverse rotation roller pair which has a play (idling area | region). It is an operation principle explanatory view showing a state when the forward / reverse rotation roller pair starts to rotate when there is no play in the idling region. FIG. 16 is an operation principle explanatory diagram showing a state when a predetermined amount of paper is conveyed from the state of FIG. FIG. 11 is an operation principle explanatory view showing that it is easy for the driving member to idle and pull out the sheet when the leading end of the sheet is nipped and pulled by the nip of the second folding roller pair. FIG. 10 is an operation explanatory diagram showing that the sheet bending portion is nipped between the second folding roller pair, the excess bending on the downstream side is eliminated, and the sheet is conveyed without being bent while being folded. FIG. 10 is an operation explanatory diagram illustrating a state in which the forward / reverse roller pair is rotating before the sheet conveyed by the first folding roller pair enters the nip of the forward / reverse roller pair. FIG. 20 is an operation explanatory diagram showing a state in which the forward / reverse roller pair holds the sheet from the state of FIG. 19 and further conveys the sheet to a preset position. FIG. 21 is an operation explanatory diagram illustrating a state when the paper stop position is determined based on the detection output of the third paper detection sensor from the state of FIG. 20. FIG. 22 is an operation explanatory diagram illustrating a state in which the drive member is moved in the idling region and the drive member is idling after the forward / reverse roller pair is stopped at the position illustrated in FIG. 21. It is operation | movement explanatory drawing which shows the state which stopped the drive part main body from the state of FIG. FIG. 10 is an operation explanatory diagram showing a state when driving a pair of forward and reverse rollers after a preset time has elapsed before the sheet is pulled by the second folding roller pair and play of the driving member is eliminated. FIG. 6 is a schematic configuration diagram illustrating a pair of forward and reverse rollers according to a second embodiment. It is a figure which shows the operation | movement of the normal / reverse rotation roller pair when the motor is rotating in the normal rotation direction and the schematic configuration of the drive mechanism in the third embodiment. It is a figure which shows the operation | movement of a normal / reverse rotation roller pair when the motor is rotating in the reverse rotation direction and the schematic configuration of the drive mechanism in the third embodiment. A state in which the first folding roller pair and the forward / reverse roller pair in the conventional clamping determination method are conveyed in the opposite direction, the sheet is bent, and the second folding process is performed by the second folding roller pair. It is operation | movement explanatory drawing shown. FIG. 29 is an operation explanatory diagram illustrating a state in which the sheet portion on the first folding side from the state of FIG. 28 is drawn into the nip of the second folding roller pair before the bending of the second folding portion is eliminated. It is operation | movement explanatory drawing which shows a state when a 2nd folding process is performed from the state of FIG. It is operation | movement explanatory drawing which shows a state when a 2nd folding process is performed in the state of FIG. 30, and box breakage generate | occur | produced. FIG. 10 is an operation explanatory diagram showing a state when the leading edge of the paper formed during the first folding process is stopped before the nip of the second folding roller pair in order to prevent the occurrence of box breakage. FIG. 33 is an operation explanatory diagram illustrating a state in which the sheet is pulled between the second folding roller pair and the forward / reverse roller pair from the state of FIG. 32.

  In the present invention, when the second folding is performed, the drive unit of the forward / reverse roller pair is provided with a play that can be conveyed upstream and downstream as it continues to rotate, and free to play in the other direction (upstream direction). When the reverse roller is stopped, it is locked in the downstream direction so that it can be easily pulled out when pulled from the upstream side, and the forward / reverse roller is rotated before play is eliminated to prevent box breakage. And

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1 is a diagram showing a schematic configuration of an image forming system according to Example 1 of the embodiment of the present invention. In FIG. 1, an image forming system 1 according to the present embodiment basically includes an image forming apparatus 200, a folding processing apparatus 100, and a post-processing apparatus 300. The folding processing apparatus 100 is provided between the front-stage image forming apparatus 200 and the rear-stage post-processing apparatus 300. A sheet on which an image is formed by the image forming apparatus 200 is conveyed to the folding processing apparatus 100, subjected to a predetermined folding process by the folding processing apparatus 100, and further sent to the post-processing apparatus 300. In the post-processing device 300, post-processing such as alignment processing, binding processing, or bookbinding processing is performed on the folded paper or the paper that is not pressed.

  FIG. 2 is a diagram illustrating a schematic configuration of an image forming system according to another embodiment of the present embodiment. In FIG. 2, the folding processing apparatus 100 is a so-called in-body installation type provided in a paper discharge unit in the image forming apparatus 200. In the image forming system 1 shown in FIG. 2, the folding processing apparatus 100 is installed in the in-body sheet discharge unit 200 a of the image forming apparatus 200, and the sheet discharge tray 400 only protrudes from the installation area of the image forming apparatus 200. The system is greatly miniaturized compared to the configuration of FIG.

  FIG. 3 is a diagram illustrating a folding mechanism of the folding processing apparatus 100 in FIGS. 1 and 2.

  The folding apparatus 100 includes two conveyance paths, a first conveyance path W1 and a second conveyance path W2, and the first to third plurality of conveyance members F1, F2 along the two conveyance paths W1, W2. , F3 are arranged. The second transport member F2 is disposed so as to sandwich the first transport path W1 and the second transport path W2, and has a function of folding and transferring the paper P from the first transport path W1 to the second transport path W2.

  The first conveying member F1 is composed of a first conveying roller pair R1. The second transport member F2 includes first to fourth transport rollers R2, R3, R4, and R5. The 3rd conveyance member F3 is comprised from 2nd conveyance roller pair R6. The first and second transport roller pairs R1 and R6 (first transport member F1 and third transport member F3) are driven by first and third drive motors M1 and M3, respectively, to apply a transport force to the paper P.

  The first conveying roller pair R1 is provided on the entrance side of the folding processing apparatus 100 in the first conveying path W1, receives paper from the preceding image forming apparatus 200, is driven by the first drive motor M1, and is downstream of the folding processing apparatus 100. The sheet P is conveyed to the side.

  In the present embodiment, the second conveyance path W2 is not shown, but the end W2a on the downstream side in the sheet conveyance direction (discharge side) joins on the downstream side of the first conveyance path W1, and the end on the upstream side in the sheet conveyance direction The part W2b joins the upstream side of the first conveying roller pair R1, or is in the open state shown in FIG. And it is connected by the 2nd conveyance path W2 and the communication path W2c in the installation location of the 2nd conveyance member F2 downstream of the 1st conveyance roller pair R1 of the 1st conveyance path W1.

  In the second conveying member F2, the first and second conveying rollers R2, R3 are opposed to each other with the first conveying path W1 interposed therebetween, and a second nip N2 is formed therebetween. Further, the second and third transport rollers R3, R4 are arranged to face each other between the first transport path W1 and the second transport path W2, and a third nip N3 is formed between them. The path guided by the third nip N3 functions as a communication path W2c that guides the sheet from the first transport path W1 to the second transport path W2. Further, the second and fourth transport rollers R3 and R5 face each other with the second transport path W2 interposed therebetween, and a fourth nip N4 is formed between them.

  The first to fourth transport rollers R2 to R5 are driven by a second drive motor M2 that drives the second transport roller R3. That is, the second drive member F2 is driven by the second drive motor M2. The second drive motor M2 can rotate in both forward and reverse directions. By changing the direction of rotation, the second drive motor M2 conveys the paper P and performs a folding process. Note that the second transport member F2 may be formed of not only a pair of transport rollers but also an adhesive transport roller pair or a suction belt.

  In the second conveying member F2, the second conveying roller R3 is a driving conveying roller, and the first, third, and fourth conveying rollers R2, R4, and R5 are driven conveying rollers that rotate in contact with the second conveying roller R3, respectively. It is. The second conveying roller R3 and the third conveying roller R4 constitute the first folding roller pair 2, and the second conveying roller R3 and the fourth conveying roller R5 constitute the second folding roller pair 4.

  The first, third and fourth transport rollers R2, R4, R5 are respectively given elastic force toward the second transport roller R3 by first to third compression springs (elastic members) S2, S3, S4, respectively. Contact with the second transport roller R3 is maintained. Thereby, the driving force is obtained from the second transport roller R3, and the other three transport rollers R2, R4, R5 are driven.

  The first conveying roller pair R1 includes a driving conveying roller R1a and a driven conveying roller R1b, and a driving force is applied to the driving conveying roller R1a from the first driving motor M1. The driven transport roller R1b is given elastic force to the drive transport roller R1a side by the first compression spring S1, contacts at the first nip N1, and is driven in that state. The second conveying roller pair R6 includes a driving conveying roller R6a and a driven conveying roller R6b, and a driving force is applied to the driving conveying roller R6a in a state synchronized with the gear mechanism from the third driving motor M3. The driven conveyance roller R6b is given an elastic force to the drive conveyance roller R6a side by the fifth compression spring S5, contacts at the fifth nip N5, and is driven in that state.

  The first sheet detection sensor SN1 is immediately before the first conveyance roller pair R1 in the first conveyance path W1, and the second sheet detection sensor SN2 is immediately after the first and second conveyance rollers R2 and R3 nips. A third sheet detection sensor SN3 is disposed in the immediate vicinity of the second conveyance roller pair R6 on the conveyance path W2 on the side away from the fourth conveyance roller R5. The first sheet detection sensor SN1 functions as an entrance sheet detection sensor, and the second sheet detection sensor SN2 functions as a discharged sheet detection sensor.

  FIG. 4 is a block diagram showing a control configuration of the image forming system in this embodiment.

  In FIG. 4, the folding processing apparatus 100 includes a control circuit on which a microcomputer having a CPU 100a, an I / O interface 100b, and the like is mounted. Signals from the CPU of the image forming apparatus 200, each switch of the operation panel 201, and each sheet detection sensor (not shown) are input to the CPU 100a via the communication interface 100c. The CPU 100a executes predetermined control based on a signal input from the image forming apparatus 200 side. Further, the CPU 100a controls the drive of the solenoid and the motor via the driver and the motor driver, and acquires the paper detection sensor information in the apparatus from the interface. Further, for example, a motor driver is controlled by a motor driver via the I / O interface 100b for a control target, and paper detection sensor information is acquired from the paper detection sensor.

  The control is executed based on the program defined by the program code while the CPU 100a reads the program code stored in the ROM (not shown), develops 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 100a shown in FIG.

  5 to 12 are operation explanatory views showing an outline of the operation of each part in the case of Z-folding. FIG. 13 is a flowchart showing the control procedure of the operation of each unit.

  FIG. 5 shows an initial state before the sheet is conveyed from the image forming apparatus 200 side. From the state of FIG. 5, as shown in FIG. 6, the paper P is carried into the first transport path W1 from the image forming apparatus 200 side. When the first paper detection sensor (entrance paper detection sensor) SN1 detects the leading edge P1 of the paper P (step S101), the first drive motor M1 that is the first transport member F1 starts to rotate (in the direction of arrow R1). When the paper P enters the first nip N1 of the first transport roller pair R1, the paper P is transported to the downstream second transport member F2 side by the first transport roller pair R1 (step S102). The sheet P having the leading end reached the first conveying member F2 is nipped by the second nip N2 between the first and second conveying rollers R2 and R3 and further conveyed downstream.

  Then, at the time when the sheet is transported to just before the second nip N2 between the second transport roller R3 and the third transport roller R4 (step S103), the second drive motor M2 is driven, and the second transport member F1 is moved in the direction of the arrow in FIG. (Step S104). Whether or not the sheet has been conveyed to the position immediately before the second nip N2 is determined from, for example, the rotation speed of the first drive motor M1 that drives the first conveyance member F1 (or the linear speed of the first conveyance roller pair R1) and the conveyance time. I can judge.

  After the second conveying member F1 starts to rotate in the direction of the arrow in FIG. 7 in step S104, the amount of protrusion (first protrusion amount) Δ1 from the position of the second sheet detection sensor SN2 is determined in order to set the folding position. (Step S105). The Z-folding is performed by folding outward (first folding) from the leading end P1 of the sheet P in the sheet transport direction at a quarter position of the entire length of the sheet, and folding inward (second folding) at a position of 1/2 of the total length. The position in FIG. 8 is a position where a fold line P3 is formed at a position ¼ from the front end P1 of the paper P. The setting of this position is also performed by the CPU 100a or referring to the ROM table.

  That is, the paper P is transported from when the leading edge P1 of the paper P is detected by the second paper detection sensor SN2 until the leading edge P1 of the paper P reaches the first protrusion amount Δ1. The first protrusion amount Δ1 is determined from the sheet length and the folding method, and is determined by the rotation amount of the first transport roller R2. When the leading edge P1 of the sheet P reaches the protrusion amount Δ1 (step S105: YES), the second conveying member F2 (third conveying roller R3) is temporarily stopped (step S106). At that time, when the leading edge P1 of the paper P is detected by the second paper detection sensor SN2, the second drive motor M2 decelerates, and the paper P is conveyed to the first protrusion amount Δ1, and stops at that position. . This deceleration enables highly accurate stop position control.

  To set the first movement amount Δ1, the CPU 100a receives data on the length in the transport direction of the paper P from the image forming apparatus 200 before starting the job (before image formation on the paper P), and the data The amount of movement is automatically calculated based on, and the calculation result is used. Even if it is not calculated, the relationship between the paper size and the movement amount can be tabulated in advance and stored in the ROM, and the movement amount can be set according to the paper size.

  Next, while the first transport member F1 is rotated in the transport direction, the second transport member F2 (second transport roller R3) is rotated in the reverse direction with respect to the transport direction up to FIG. 7 as shown in FIG. Step S107). The first protrusion amount Δ1 can also be determined based on the transport amount of the first transport member F1 from the position of the first paper detection sensor SN1.

  The sheet P is transported in the reverse direction by the reverse rotation of the second transport member F2 (second drive motor M2). On the other hand, since the first conveying member F1 rotates in the direction continued from FIG. 6 and conveys the paper P, bending is formed in the third nip N3 as in the case of folding in two (FIG. 8). This bending enters the third nip N3 and the first folding is performed. Thereby, the first fold line P3 is formed. The first folded paper P is transported to the second transport path W2 as shown in FIG.

  The sheet P is transported along the downward gradient of the second transport path W2, and is sandwiched and transported by the fifth nip N5 of the second transport roller pair R6 that has started rotating in the direction of the arrow as shown in FIG. (Step S107). Then, when the leading end (first fold P3) of the paper P is detected by the third paper detection sensor SN3 (step S108) and reaches a position protruding from the position by the second protrusion amount Δ2, the third transport member F3 (second transport roller pair R6: third drive motor M3) stops (step S109). As shown in FIG. 11, when the sheet P is conveyed in the direction of the arrow by the second folding roller pair 4 (second and fourth conveying rollers R3 and R5 pair), the driving member 3a4 moves in the idling region 3a. Then, the drive member 3a4 is idled until there is no play (step S110).

  Next, the sheet P is pulled by the second folding roller pair 4, and after the preset time elapses before the play of the driving member 3a4 is eliminated, the reverse rotation of the forward / reverse roller pair 3 (second conveying roller pair R6) is started. (Step S111). The operations in steps S110 and S111 and the mechanism for performing this operation will be described later. Note that the second protrusion amount Δ2 can also be set as a protrusion amount from the fifth nip N5.

  Similar to the first protrusion amount Δ1, the second protrusion amount Δ2 is determined from the sheet length and the folding method, and the rotation amount of the forward / reverse roller pair 3 (second transport roller pair R6) (driving of the third drive motor M3). Step number). In order to perform such control, in the present embodiment, the first to third drive motors M1, M2, M3 are constituted by stepping motors. Each of the drive motors M1, M2, and M3 can be configured by a motor other than the stepping motor, for example, a DC motor. In that case, a control method corresponding to the employed motor type is taken. For example, when a DC motor is used, the protrusion amount or drive stop timing is controlled based on the number of encoder pulses counted.

  When a DC motor is used to drive the pair of forward and reverse rollers 3, for example, a DC motor as disclosed in JP 2012-213308 and its driving device may be used. If such a DC motor is used, the forward / reverse operation can be quickly performed, and the productivity can be improved. Further, the step-out motor does not step out with respect to the load fluctuation. Further, by correcting the positional deviation due to load fluctuation or the like by feedback control, it is possible to always rotate at an accurate position. As a result, it can be folded at an accurate position, and high folding quality can be guaranteed.

  Further, the reverse rotation of the forward / reverse roller pair 3 (second conveying roller pair R6) is such that the first folding roller pair 2 (second and third conveying rollers R3, R4) maintains the rotation direction shown in FIGS. It is executed in the state. As a result, as shown in FIG. 11, the sheet P is bent (Pt1 described later) in the communication path W2c on the downstream side of the third nip N3.

  When the second and third conveyance members F2 and F3 shown in FIG. 11 are continuously driven in the rotational direction, the bending (Pt1 described later) is caused by the second folding roller pair 4 (second conveyance roller R3 and fourth conveyance roller R5). ) 4th nip N4, and the paper P is transported in the direction of the end W2a on the paper discharge side of the second transport path W2. In the course of this conveyance, the second fold is applied as shown in FIG. The second folded paper P is further transported from the paper discharge side end W2a to the post-processing apparatus 300 in the subsequent stage through the first transport path W1. Alternatively, the paper is discharged to the paper discharge tray 400.

  In FIG. 12, the third paper detection sensor SN3 detects the passage of the rear end of the paper P (step S112), and after passing through the fourth nip N4, the second and third transport members F2, F3 (first 2 and the third drive motors M2 and M3) stop rotating (step S113). Further, as shown in FIG. 19, the first drive motor M1 stops rotating at a timing after the first sheet detection sensor SN1 detects the trailing edge of the sheet and after the trailing edge of the sheet is separated from the first nip N1.

  The outline of Z-folding in this embodiment is as described above. In this embodiment, in order to avoid the above-described box folding phenomenon, the rotating mechanism of the forward / reverse rotating roller pair 3 that rotates forward or backward or this rotating mechanism is driven. A predetermined play (idling region) is provided in the drive mechanism, and control is performed as in steps S110 and S111.

  That is, the forward / reverse roller pair 3 (a) can transport the paper P upstream and downstream. (B) When the forward / reverse roller pair 3 is stopped, the forward / reverse roller pair 3 does not move due to the paper P being scraped (the position where the paper P is stopped). (C) It has three basic functions of idling during forward / reverse operation of the forward / reverse roller pair 3.

  The function (b) is for ensuring the folding position accuracy. The function of (c) is to make it possible to easily pull out when pulled from the second folding roller pair 4 in order to avoid the box breaking phenomenon. For the function (c), in the present embodiment, a play (idling region) 3a that idles in any part of the drive mechanism during forward / reverse operation of the forward / reverse roller pair 3 is provided.

  FIG. 14 is a diagram conceptually showing the configuration of the drive unit main body 3a1 of the pair of forward and reverse rollers 3 having this play (idling region) 3a. As shown in FIG. 14A, the forward / reverse roller pair 3 includes a driving member 3a4 that transmits the driving force of the driving unit main body 3a1, the driving shaft 3a2, and the driving shaft 3a2 to the driven unit 3a3 of the roller main body 3a. When the member 3a4 idles in the space 3a5 in the drive unit main body 3a1 and hits the driven unit 3a3, the driving force can be transmitted to the drive unit main body 3a1 side in one direction. In the other direction, the drive unit body 3a1 is locked, and the drive unit body 3a1 does not rotate.

  For example, when the drive shaft 3a2 rotates in the clockwise direction (arrow CW direction) in the state shown in FIG. 14A, the drive unit main body 3a1 rotates in the clockwise direction (arrow CW direction) as it is. On the other hand, when the drive shaft 3a2 rotates in the illustrated counterclockwise direction (arrow CCW direction) in the state of FIG. 14A, the drive shaft 3a2 and the drive member 3a4 are idled to the position shown in FIG. 14B. Even if the driving member 3a4 pushes the driven portion 3a3 to transmit the driving force, the driving portion main body 3a1 is locked in this direction, and the driving portion main body 3a1 does not rotate. In other words, the drive unit main body 3a1 is idled while the drive member 3a4 is positioned in the space 3a5 without contacting the driven unit 3a3.

  That is, the drive member 3a4 is positioned in the idling region 3a until the drive shaft 3a2 rotates in the clockwise direction (arrow CW direction) from the state of FIG. 14B until the drive member 3a4 hits the side surface of the driven portion 3a3. Therefore, the driving force is not transmitted and the driving unit main body 3a1 does not rotate (FIG. 14 (c)). Then, when there is no play in the idle region 3a and the driving member 3a4 hits the driven portion 3a3, the driving force is transmitted to the driving portion main body 3a1, and the driving portion main body 3a1 starts to rotate (FIG. 14D). ).

  In FIG. 14, the mechanism provided with the idling region 3 a is provided in the drive unit main body 3 a 1 that drives the forward / reverse rotation roller pair 3, but may be provided on another drive mechanism, for example, on the gear side. Furthermore, it is possible to provide a drive force transmission path from the drive shaft of the motor that transmits the drive force to the gear to the gear. In any case, it can be provided in the driving force transmission path from the driving source to the pair of forward and reverse rollers 3. The forward / reverse roller pair 3 rotates in synchronization with the rotation of the drive unit main body 3a1. Therefore, the rotation operation of the drive unit main body 3a1 is equivalent to the rotation operation of the forward / reverse rotation roller pair 3.

  15 to 18 are explanatory views showing the principle of conveyance operation of the pair of forward and reverse rollers 3 having the play shown in FIG. When the paper P is transported from the first folding roller pair 2, the forward / reverse roller pair 3 is rotated in the direction of transporting the paper P downstream. If the forward / reverse rotation roller pair 3 continues to rotate, there is no play in the idle rotation region 3a, and the forward / reverse rotation roller pair 3 starts rotating when play is eliminated, so that the paper P can be conveyed downstream (see FIG. 15). A predetermined amount of paper P is conveyed, the forward / reverse roller pair 3 is rotated reversely (FIG. 16), and the leading end P1 of the paper P is stopped before the fourth nip N4 of the second folding roller pair 4.

  At this time, the forward / reverse roller pair 3 is stopped and locked in one (downstream direction) rotation direction. As a result, the pair of forward and reverse rollers 3 does not move due to the paper P being squeezed, and the paper P is not sent downstream from the stopped position. Further, since the play (idle region 3a) is free in the other (upstream direction) rotation direction, the leading end P1 of the paper P is pinched by the fourth nip N4 of the second folding roller pair 4 and pulled. Can be easily pulled out (FIG. 17).

  Further, when the sheet bending portion Pt1 is nipped between the second folding roller pair 4, the downstream excessive bending Pt2 is eliminated. Pulled out from. At that time, the forward / reverse roller pair 3 can be idled when the paper P moves in the upstream direction, and therefore can be pulled out without load (FIG. 18). 4 is conveyed.

  16 to 18, the leading end P1 of the paper P and the paper portion (peller portion) P1a on the first folding side are guided to the nip along the guide plate 4a extending to the nip of the second folding roller pair 4. , Pinched at the nip and pulled. For this reason, no paper jam or bending occurs between the leading edge P1 of the paper P and the second folding roller pair 4.

  19 to 24 are operation explanatory views showing an example of the operation of the forward / reverse roller pair 3 in the present embodiment. The operating principle is as described with reference to FIGS.

  First, before the sheet P conveyed by the first folding roller pair 2 enters the nip of the forward / reverse roller pair 3, the forward / reverse roller pair 3 rotates in the direction of the arrow shown in FIG. The paper P is further transported, and after the forward / reverse roller pair 3 holds the paper P, it is transported to a preset position (FIG. 20). At this time, the third paper detection sensor SN3 is provided at the peripheral position of the forward / reverse rotation roller pair 3 as described above, and the paper stop position is determined based on the detection output of the third paper detection sensor SN3 (FIG. 21). . Instead of the sheet detection sensor SN3, the sheet stop position can be determined by pulse count control of the third drive motor M3, encoder pulse output of the DC motor, or the like.

  After the forward / reverse roller pair 3 is stopped at the position shown in FIG. 21, the drive member 3a4 moves in the idle rotation region 3a, and the drive member 3a4 (drive unit main body 3a1) is idled until there is no play (FIG. 22). Then, the drive unit main body 3a1 is stopped again (FIG. 23). The idling is in a direction opposite to the rotation direction until the forward / reverse roller pair 3 is stopped. Also at this time, the third sheet detection sensor SN3 (which may be provided separately) is used as in the case of the stop in the downstream conveyance shown in FIG. 21, or the pulse count control of the third drive motor M3, the encoder of the DC motor The paper stop position is determined by output or the like.

  In this state, the forward / reverse roller pair 3 locks the rotation of the paper P in the downstream direction, so the forward / reverse roller pair 3 does not move due to the paper P being squeezed, and the paper P is located downstream from the stopped position. Not sent. Thereafter, the sheet P is pulled by the second folding roller pair 4, and after a preset time before the play of the driving member 3a4 is eliminated, the forward / reverse roller pair 3 is driven (FIG. 24). At this time, the rotational speed of the forward / reverse roller pair 3 is set equal to or higher than the rotational speed of the second folding roller pair 4. Thus, the sheet P is not pulled between the second folding roller pair 4 and the forward / reverse roller pair 3.

  In consideration of the efficiency of paper processing, it is desirable that the idling region 3a is small because the play operation time is short.

  FIG. 25 is a diagram illustrating a schematic configuration of the forward / reverse roller pair 3 according to Example 2 of the present embodiment.

  The forward / reverse roller pair 3 according to the second embodiment includes a pair of first and second drive rollers 3a and 3b, and first and second driven gears 8a and 8b that drive the drive rollers 3a and 3b. The first and second transmission mechanisms 9a and 9b for transmitting the driving force of the first and second driven gears 8a and 8b to the first and second driving rollers 3a and 3b, and the first driven gear 8a are provided. A drive gear 7 for driving and a drive motor (not shown) for driving the drive gear 7 are included. The second driven gear 8b meshes with the first driven gear 8a and rotates in synchronization with the rotation of the drive gear 7, and this rotational driving force is transmitted to the first and second drive rollers 3a and 3b, respectively. In this embodiment, the driving gear 7 is provided with the play mechanism shown in FIG.

  The other parts are constructed in the same manner as in Example 1 and function in the same manner.

  As in the present embodiment, in the configuration in which the drive unit main body 3a1 is provided with a play (idling region) 3a, if one of the pair of forward / reverse rollers 3 is a driven roller, there is a concern that the paper P may be rotated against the strain of the paper P. For this reason, it is necessary to prevent the paper P from rotating (locking) even if it is pushed by the paper sheet P. In this embodiment, the two rollers are configured as drive rollers. The play of the drive unit main body 3a1 may be provided in the drive gear 7 or in the upstream gear.

  26 and 27 are diagrams showing a schematic configuration of the forward / reverse roller pair 3 according to Example 3 of the present embodiment.

  In the present embodiment, in the drive configuration of the forward / reverse rotation roller pair 3, the same effect as in the configuration in which the play 3a is provided in the drive section main body 3a1 in the first and second embodiments using the one-way clutch 10 and the electromagnetic clutch 11 is provided. It ’s what you get.

  That is, in the third embodiment, the one-way clutch 10 and the electromagnetic clutch 11 are connected to the first driven gear 8 a in the second embodiment, and the drive mechanism of the motor 12 is connected to the one-way clutch 10 and the electromagnetic clutch 11. Other configurations are the same as those of the second embodiment.

  With this configuration, when the motor 12 is rotating in the forward rotation direction (the clockwise direction shown in FIG. 26: the arrow CW direction), the forward / reverse roller pair 3 rotates in the direction of transporting the paper P upstream. . At that time, the electromagnetic clutch 11 is in an OFF state. In the stopped state, since the one-way clutch 10 is provided, the sheet P is rotated when the sheet P is pulled in the upstream direction, and is locked when the sheet P is conveyed in the downstream direction.

  When the motor 12 is rotating in the reverse rotation direction (counterclockwise direction shown in FIG. 27: arrow CCW direction), the electromagnetic clutch 11 is turned on. As a result, the forward / reverse roller pair 3 rotates in the reverse direction (the direction in which the paper P is conveyed downstream), and the one-way clutch 10 side gear does not rotate. Therefore, the functions (a) to (c) which are basic functions of the forward / reverse rotation roller pair 3 can be obtained with certainty, and the box breaking phenomenon can be avoided.

  Other parts are configured in the same manner as in the first and second embodiments and function in the same manner.

  According to the present embodiment, an operation equivalent to the mechanism in which the idling region (play) 3 a is provided in the drive unit can be realized by combining the existing one-way clutch 10 and the electromagnetic clutch 11.

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

  1) The first folding roller pair 2 that folds the paper P (second conveying roller R3 and third conveying roller pair 4 pair: first conveying member pair) and the first folding roller pair 2 The forward / reverse roller pair 3 (second transport roller pair R6: second transport member pair) that transports the paper P downstream and the first folding roller pair 2 (first transport member pair) folded. And a second folding roller pair 4 (second conveying roller R3 and fourth conveying roller R5 pair: third conveying member pair) that further folds the paper P, and the forward / reverse roller pair 3 is forward / reverse during conveyance driving. Since it can rotate and is locked in one rotational direction and non-driven, it can rotate in the other rotational direction, so that the basic performances (a) to (c) can be exhibited. This makes it possible to prevent the box from being folded during the second paper folding process when the folding process is performed by the sandwiching inversion method.

  2) A first transport roller pair R1 (fourth transport member pair) that transports the paper P, a first transport roller R2 that receives the paper P transported by the first transport roller pair R1, and transports the paper P to the subsequent stage. In the state where the sheet P is held by the two conveying rollers R3 (fifth conveying member pair), the first conveying roller pair R1, the first conveying roller R2, and the second conveying roller R3 pair, the first conveying Since the roller R2 and the second conveying roller R3 pair are rotated in the opposite directions, the portion corresponding to the fold of the paper P can be reliably guided to the nip of the first folding roller pair 2.

  3) Since the rotatable range is set in advance, the next reverse conveying operation can be performed reliably after idling.

  4) In the preset rotatable range, the forward / reverse roller pair 3 (second conveying member pair) is stopped, and the second folding roller pair 4 (third conveying member pair) is the paper. Deflection Pt2 of the paper P generated between the forward / reverse roller pair 3 (second conveying member pair) and the second folding roller pair 4 (third conveying member pair) when conveying P downstream. Since the rotation range is sufficient to eliminate the bending, it is possible to guarantee idling that only eliminates the bending that occurs during the second folding process, and reliably prevents the box folding phenomenon that occurs during the second folding process. It can be avoided.

  5) When the sheet P is folded by the second folding roller pair 4 (third conveying member pair), the forward / reverse roller pair 3 (second conveying member pair) is in a stopped state, and thus the first The sheet P can be reliably pulled in by the nip of the two-fold roller pair 4.

  6) The sheet P is conveyed by the second folding roller pair 4 (third conveying member pair), and the forward / reverse roller pair 3 (second conveying member pair) is pulled by the sheet P along with this conveyance. Thus, after the preset time before the idling is completed, the forward / reverse roller pair 3 is driven, so that the second folding roller pair 4 is bent while folding the paper P. The sheet P can be pulled out from the forward / reverse roller pair 3 without load in the absence of load.

  7) When the forward / reverse roller pair 3 (second transport member pair) is driven to rotate, the transport speed of the paper P is the paper P of the second folding roller pair 4 (third transport member pair). Therefore, the sheet P is not pulled between the forward / reverse roller pair 3 and the second folding roller pair 4. This prevents the paper P from being damaged due to pulling.

  8) The forward / reverse roller pair 3 (second conveying member pair) includes a driving member 3a4 rotating concentrically with the driving shaft 3a2, a driven portion 3a3 driven by the driving member 3a4, and the driving member 3a4. Since the drive unit main body 3a1 (drive unit) including the idling region 3a that idles is provided, the functions (b) and (c) can be reliably exhibited.

  9) Since the forward / reverse roller pair 3 (second conveying member pair) is configured as a driving roller, there is no fear of rotating against the edge of the paper P, and the function (b) can be surely exhibited. it can.

  10) Each of the forward / reverse roller pair 3 (second conveying member pair) is a drive roller, and a one-way clutch 10 is provided at the drive portion of one drive roller of the forward / reverse roller pair 3, and the other drive roller is driven. Since the electromagnetic clutch 11 is provided in the part, the functions (a) to (c) which are basic functions of the forward / reverse rotation roller pair 3 can be obtained with certainty.

  11) Since the image forming system 1 includes the folding processing apparatus 100 (paper processing apparatus) and the image forming apparatus 200 having any one of the above configurations 1) to 10), the above described 1) to 10). It is possible to provide a system that exhibits the effect.

  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.

DESCRIPTION OF SYMBOLS 1 Image forming system 2 1st folding roller pair (1st conveyance member pair)
3 Forward / reverse roller pair (second conveying member pair)
3a idling region 3a1 drive unit main body 3a2 drive shaft 3a3 driven unit 3a4 drive member 4 second folding roller pair (third conveying member pair)
DESCRIPTION OF SYMBOLS 10 One-way clutch 11 Electromagnetic clutch 100 Folding processing apparatus 200 Image forming apparatus P Paper Pt2 Deflection R1 1st conveyance roller pair (4th conveyance member pair)
R2 First transport roller R3 Second transport roller R4 Third transport roller R5 Fourth transport roller R6 Second transport roller pair

JP 2006-117383 A JP 2007-277006 A

The present invention relates to a sheet processing apparatus and an image forming system, and particularly to sheet-like recording media (referred to as “paper” in the present specification) such as paper, transfer paper, printing paper, and OHP sheet. The present invention relates to a sheet processing apparatus that performs a folding process, and an image forming system including the sheet processing apparatus and an image forming apparatus such as a copying machine, a printer, a facsimile, or a digital multifunction peripheral.

  As a sheet processing apparatus that performs a folding process on a sheet conveyed from an image forming apparatus, for example, a technique described in Japanese Patent Laid-Open No. 2006-117383 (Patent Document 1) is known. According to this technique, a first stop member capable of moving a position provided in the second transport path to stop the leading edge of the paper, a first transport roller that forms a fold by sandwiching a paper sheet in the first stop member, and a first transport roller. A pair of transport rollers formed by two transport rollers, a second stop member capable of moving a position provided in the first transport path to stop the paper that has passed through the pair of transport rollers, and the second stop member It has a pair of conveyance rollers formed by a second conveyance roller and a third conveyance roller that form a fold by sandwiching the bending of the sheet. By controlling the stop position of the second stop member 10, a four-fold is formed. It is characterized by a paper processing device.

  In this technology, a special path branched from the transport path for transporting the paper transported from the upstream apparatus to the downstream apparatus for performing the folding process and a stopper are provided so that the front end of the paper is abutted and folded. The processing is performed. That is, in the folding process, the sheet is brought into contact with the stopper through this dedicated path, the folding position is adjusted and the bending is formed, and the formed bending is nipped at the folding portion and folded.

  On the other hand, for example, a technique described in Japanese Patent Application Laid-Open No. 2007-277006 (Patent Document 2) is also known. In the method of folding a medium with a folding device, this technique includes a rotatable folding cylinder, a first rotatable press member that engages with the folding cylinder to form a first folding pinch, The folding device includes a second rotatable press member that engages with the stacking cylinder to form a second folded pinch and a medium feeding means, and the medium is fed by the first pinch and the second pinch by the feeding means. Feed toward the middle cylinder, turn the cylinder in the first direction into the first pinch, direct the medium, form slack in the medium between the feeding means and the cylinder, and reverse the cylinder in the first direction By rotating in the second direction, the slack is moved into the second pinch and folded.

  That is, conventionally, as disclosed in Japanese Patent Application Laid-Open No. 2004-260, as a method of folding, when an image-formed sheet is received and folding processing such as tri-folding and Z-folding is performed, the operation is performed according to the paper size. Folding is possible only by adjusting the folding position by abutting the leading edge of the sheet against a possible leading edge abutting member (hereinafter referred to as a stopper method) and the conveyance amount adjustment by the conveying means as disclosed in Patent Document 2. Two methods, a method of performing position adjustment (hereinafter referred to as a sandwiching and reversing method), are generally used.

An object of the present invention is to solve is to make it so that no break boxes during the second paper folding process.

To solve the above problems, the present invention includes a first conveying member pairs folding seat, and a second conveying member pair for conveying the sheet folded by the first conveying member pairs downstream, said first A third conveying member pair that further folds the sheet straddling between the conveying member pair and the second conveying member pair, and the second conveying member pair is formed by the third conveying member pair. A sheet processing apparatus that idles when a sheet is conveyed is characterized. Note that problems, configurations, and effects other than those described above will be clarified in the following description of embodiments.

According to the present invention, box folding can be prevented from occurring during the second paper folding process.

1 is a diagram showing a schematic configuration of an image forming system according to Example 1 in an embodiment of the present invention. 2 is a diagram illustrating a schematic configuration of another form of the image forming system in Embodiment 1. FIG. It is a figure which shows the folding mechanism of the folding processing apparatus in FIG.1 and FIG.2. 1 is a block diagram illustrating a control configuration of an image forming system in Embodiment 1. FIG. FIG. 6 is an operation explanatory diagram illustrating an initial state before a sheet is conveyed from the image forming apparatus side. FIG. 6 is an operation explanatory diagram illustrating a state when a sheet is carried into the first transport path from the state of FIG. 5. FIG. 7 is an operation explanatory diagram illustrating a state when the leading edge of the sheet is conveyed from the second sheet detection sensor until reaching a first protrusion amount from the state of FIG. 6. FIG. 8 is an operation explanatory diagram illustrating a state in which the second conveying member pair is rotated in the reverse rotation while the first conveying member is rotated in the conveying direction from the state of FIG. 7 to make a crease. FIG. 9 is an operation explanatory diagram illustrating a state when the sheet on which the first fold is formed by the first fold roller pair is transported to the second transport path from the state of FIG. 8. FIG. 10 is an operation explanatory diagram illustrating a state in which the sheet is transported along the second transport path from the state of FIG. 9, sandwiched between the forward and reverse roller pairs and transported downstream. It is operation | movement explanatory drawing which shows the state which reversely rotates a normal / reverse rotation roller pair from the state of FIG. 10, and conveys it to the 2nd folding roller pair side. It is operation | movement explanatory drawing which shows the state in which 2nd folding is given by the 2nd folding roller pair from the state of FIG. 11, and it is conveyed downstream. It is a flowchart which shows the control procedure of the operation | movement of each part at the time of Z folding. It is a figure which shows notionally the structure of the drive part main body of the normal / reverse rotation roller pair which has a play (idling area | region). It is an operation principle explanatory view showing a state when the forward / reverse rotation roller pair starts to rotate when there is no play in the idling region. FIG. 16 is an operation principle explanatory diagram showing a state when a predetermined amount of paper is conveyed from the state of FIG. FIG. 11 is an operation principle explanatory view showing that it is easy for the driving member to idle and pull out the sheet when the leading end of the sheet is nipped and pulled by the nip of the second folding roller pair. FIG. 10 is an operation explanatory diagram showing that the sheet bending portion is nipped between the second folding roller pair, the excess bending on the downstream side is eliminated, and the sheet is conveyed without being bent while being folded. FIG. 10 is an operation explanatory diagram illustrating a state in which the forward / reverse roller pair is rotating before the sheet conveyed by the first folding roller pair enters the nip of the forward / reverse roller pair. FIG. 20 is an operation explanatory diagram showing a state in which the forward / reverse roller pair holds the sheet from the state of FIG. 19 and further conveys the sheet to a preset position. FIG. 21 is an operation explanatory diagram illustrating a state when the paper stop position is determined based on the detection output of the third paper detection sensor from the state of FIG. 20. FIG. 22 is an operation explanatory diagram illustrating a state in which the drive member is moved in the idling region and the drive member is idling after the forward / reverse roller pair is stopped at the position illustrated in FIG. 21. It is operation | movement explanatory drawing which shows the state which stopped the drive part main body from the state of FIG. FIG. 10 is an operation explanatory diagram showing a state when driving a pair of forward and reverse rollers after a preset time has elapsed before the sheet is pulled by the second folding roller pair and play of the driving member is eliminated. FIG. 6 is a schematic configuration diagram illustrating a pair of forward and reverse rollers according to a second embodiment. It is a figure which shows the operation | movement of the normal / reverse rotation roller pair when the motor is rotating in the normal rotation direction and the schematic configuration of the drive mechanism in the third embodiment. It is a figure which shows the operation | movement of a normal / reverse rotation roller pair when the motor is rotating in the reverse rotation direction and the schematic configuration of the drive mechanism in the third embodiment. A state in which the first folding roller pair and the forward / reverse roller pair in the conventional clamping determination method are conveyed in the opposite direction, the sheet is bent, and the second folding process is performed by the second folding roller pair. It is operation | movement explanatory drawing shown. FIG. 29 is an operation explanatory diagram illustrating a state in which the sheet portion on the first folding side from the state of FIG. 28 is drawn into the nip of the second folding roller pair before the bending of the second folding portion is eliminated. It is operation | movement explanatory drawing which shows a state when a 2nd folding process is performed from the state of FIG. It is operation | movement explanatory drawing which shows a state when a 2nd folding process is performed in the state of FIG. 30, and box breakage generate | occur | produced. FIG. 10 is an operation explanatory diagram showing a state when the leading edge of the paper formed during the first folding process is stopped before the nip of the second folding roller pair in order to prevent the occurrence of box breakage. FIG. 33 is an operation explanatory diagram illustrating a state in which the sheet is pulled between the second folding roller pair and the forward / reverse roller pair from the state of FIG. 32.

In the stopper system described in Patent Document 1 shown as a conventional example, the leading end of the folded portion of the sheet is abutted against the stopper, and the first folding process is performed at the first folding process. The folding-side paper portion (peller portion) is always stopped. For this reason, after the bending of the paper generated during the second folding process is nipped by the second folding roller pair, the paper portion (peller portion) on the first folding side starts to move after the bending is eliminated. Pc is unlikely to occur. However, a mechanism for moving the paper leading edge abutting member according to the paper length is required, and since the installation space for this mechanism is essential, it is difficult to reduce the size of the apparatus.

On the other hand, the holding and reversing method described in Patent Document 2 is excellent in terms of miniaturization because the folding position is adjusted only by adjusting the conveyance amount. However, during the second paper folding process in the three-folding or Z-folding in which the paper folding process is performed twice, the upstream conveying means (hereinafter referred to as the first folding roller pair) and the downstream conveying means (hereinafter referred to as the positive folding means) It is necessary to feed the sheet in a direction opposite to each other to form a deflection on the sheet. In this case, the first folding roller pair conveys the sheet in the downstream direction, and the forward / reverse roller pair conveys the sheet in the upstream direction. Then, a second folding process is performed on the sheet on which the second folding roller pair positioned downstream of the forward / reverse roller pair is bent. At that time, there are cases where two folds are attached as referred to as box folding or box folding.

FIGS. 28 to 31 are explanatory views showing a mechanism of occurrence of box breakage. The direction in which the first folding roller pair 2 and the forward / reverse rotation roller pair 3 are opposite to each other during the second paper folding process in the three-folding or Z-folding in which the paper folding process is performed twice (the first folding roller pair 2 is in the downstream direction) In addition, the forward / reverse roller pair 3 conveys the sheet P in the upstream direction), forms a bend Pt1 on the sheet P, and performs the second folding process by the second folding roller pair 4. For this reason, the first folding side paper portion (peller portion) P1a including the leading edge P1 of the paper P formed during the first folding process by the conveyance of the pair of forward and reverse rollers 3 is before the bending Pt2 of the second folding portion disappears. In some cases, the second folding roller pair 4 may be drawn into the nip (FIG. 29). When the second folding process is performed in this state (FIG. 30), a so-called box break Pc in which two fold lines Pc1 and Pc2 are formed occurs (FIG. 31).

In order to prevent the occurrence of the box breakage Pc, the front end P1 of the paper P formed at the time of the first folding process is stopped before the nip of the second folding roller pair 4 (the forward / reverse roller pair 3 is stopped). (FIG. 32) The second folding roller pair 4 and the forward / reverse rotation roller pair 3 pull the paper P at the moment when the bending Pt2 of the second folding portion disappears (FIG. 33). Therefore, the forward / reverse rotation roller pair 3 may be rotated at the moment when the bending Pt <b> 2 of the second folding portion disappears to eliminate the tension. However, there is also a problem of inertia, and it is not realistic to eliminate the tension by rotating the forward / reverse rotation roller pair 3 as described above in terms of dynamics and control, and the sheet P with such a mechanism is not practical. It is difficult to eliminate the tension.

Therefore, in the present invention, when the second folding is performed, the drive unit of the pair of forward and reverse rollers is provided with a play that can be conveyed upstream and downstream as it continues to rotate, and free to play in the other direction (upstream direction). When the forward / reverse roller is stopped, it is locked in the downstream direction so that it can be easily pulled out when pulled from the upstream side, and the forward / reverse roller is rotated before play is eliminated to prevent box breakage. It is characterized by.

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1 is a diagram showing a schematic configuration of an image forming system according to Example 1 of the embodiment of the present invention. In FIG. 1, an image forming system 1 according to the present embodiment basically includes an image forming apparatus 200, a folding processing apparatus 100, and a post-processing apparatus 300. The folding processing apparatus 100 is provided between the front-stage image forming apparatus 200 and the rear-stage post-processing apparatus 300. A sheet on which an image is formed by the image forming apparatus 200 is conveyed to the folding processing apparatus 100, subjected to a predetermined folding process by the folding processing apparatus 100, and further sent to the post-processing apparatus 300. In the post-processing device 300, post-processing such as alignment processing, binding processing, or bookbinding processing is performed on the folded paper or the paper that is not pressed.

  FIG. 2 is a diagram illustrating a schematic configuration of an image forming system according to another embodiment of the present embodiment. In FIG. 2, the folding processing apparatus 100 is a so-called in-body installation type provided in a paper discharge unit in the image forming apparatus 200. In the image forming system 1 shown in FIG. 2, the folding processing apparatus 100 is installed in the in-body sheet discharge unit 200 a of the image forming apparatus 200, and the sheet discharge tray 400 only protrudes from the installation area of the image forming apparatus 200. The system is greatly miniaturized compared to the configuration of FIG.

  FIG. 3 is a diagram illustrating a folding mechanism of the folding processing apparatus 100 in FIGS. 1 and 2.

  The folding apparatus 100 includes two conveyance paths, a first conveyance path W1 and a second conveyance path W2, and the first to third plurality of conveyance members F1, F2 along the two conveyance paths W1, W2. , F3 are arranged. The second transport member F2 is disposed so as to sandwich the first transport path W1 and the second transport path W2, and has a function of folding and transferring the paper P from the first transport path W1 to the second transport path W2.

  The first conveying member F1 is composed of a first conveying roller pair R1. The second transport member F2 includes first to fourth transport rollers R2, R3, R4, and R5. The 3rd conveyance member F3 is comprised from 2nd conveyance roller pair R6. The first and second transport roller pairs R1 and R6 (first transport member F1 and third transport member F3) are driven by first and third drive motors M1 and M3, respectively, to apply a transport force to the paper P.

  The first conveying roller pair R1 is provided on the entrance side of the folding processing apparatus 100 in the first conveying path W1, receives paper from the preceding image forming apparatus 200, is driven by the first drive motor M1, and is downstream of the folding processing apparatus 100. The sheet P is conveyed to the side.

  In the present embodiment, the second conveyance path W2 is not shown, but the end W2a on the downstream side in the sheet conveyance direction (discharge side) joins on the downstream side of the first conveyance path W1, and the end on the upstream side in the sheet conveyance direction The part W2b joins the upstream side of the first conveying roller pair R1, or is in the open state shown in FIG. And it is connected by the 2nd conveyance path W2 and the communication path W2c in the installation location of the 2nd conveyance member F2 downstream of the 1st conveyance roller pair R1 of the 1st conveyance path W1.

  In the second conveying member F2, the first and second conveying rollers R2, R3 are opposed to each other with the first conveying path W1 interposed therebetween, and a second nip N2 is formed therebetween. Further, the second and third transport rollers R3, R4 are arranged to face each other between the first transport path W1 and the second transport path W2, and a third nip N3 is formed between them. The path guided by the third nip N3 functions as a communication path W2c that guides the sheet from the first transport path W1 to the second transport path W2. Further, the second and fourth transport rollers R3 and R5 face each other with the second transport path W2 interposed therebetween, and a fourth nip N4 is formed between them.

  The first to fourth transport rollers R2 to R5 are driven by a second drive motor M2 that drives the second transport roller R3. That is, the second drive member F2 is driven by the second drive motor M2. The second drive motor M2 can rotate in both forward and reverse directions. By changing the direction of rotation, the second drive motor M2 conveys the paper P and performs a folding process. Note that the second transport member F2 may be formed of not only a pair of transport rollers but also an adhesive transport roller pair or a suction belt.

  In the second conveying member F2, the second conveying roller R3 is a driving conveying roller, and the first, third, and fourth conveying rollers R2, R4, and R5 are driven conveying rollers that rotate in contact with the second conveying roller R3, respectively. It is. The second conveying roller R3 and the third conveying roller R4 constitute the first folding roller pair 2, and the second conveying roller R3 and the fourth conveying roller R5 constitute the second folding roller pair 4.

  The first, third and fourth transport rollers R2, R4, R5 are respectively given elastic force toward the second transport roller R3 by first to third compression springs (elastic members) S2, S3, S4, respectively. Contact with the second transport roller R3 is maintained. Thereby, the driving force is obtained from the second transport roller R3, and the other three transport rollers R2, R4, R5 are driven.

  The first conveying roller pair R1 includes a driving conveying roller R1a and a driven conveying roller R1b, and a driving force is applied to the driving conveying roller R1a from the first driving motor M1. The driven transport roller R1b is given elastic force to the drive transport roller R1a side by the first compression spring S1, contacts at the first nip N1, and is driven in that state. The second conveying roller pair R6 includes a driving conveying roller R6a and a driven conveying roller R6b, and a driving force is applied to the driving conveying roller R6a in a state synchronized with the gear mechanism from the third driving motor M3. The driven conveyance roller R6b is given an elastic force to the drive conveyance roller R6a side by the fifth compression spring S5, contacts at the fifth nip N5, and is driven in that state.

  The first sheet detection sensor SN1 is immediately before the first conveyance roller pair R1 in the first conveyance path W1, and the second sheet detection sensor SN2 is immediately after the first and second conveyance rollers R2 and R3 nips. A third sheet detection sensor SN3 is disposed in the immediate vicinity of the second conveyance roller pair R6 on the conveyance path W2 on the side away from the fourth conveyance roller R5. The first sheet detection sensor SN1 functions as an entrance sheet detection sensor, and the second sheet detection sensor SN2 functions as a discharged sheet detection sensor.

  FIG. 4 is a block diagram showing a control configuration of the image forming system in this embodiment.

  In FIG. 4, the folding processing apparatus 100 includes a control circuit on which a microcomputer having a CPU 100a, an I / O interface 100b, and the like is mounted. Signals from the CPU of the image forming apparatus 200, each switch of the operation panel 201, and each sheet detection sensor (not shown) are input to the CPU 100a via the communication interface 100c. The CPU 100a executes predetermined control based on a signal input from the image forming apparatus 200 side. Further, the CPU 100a controls the drive of the solenoid and the motor via the driver and the motor driver, and acquires the paper detection sensor information in the apparatus from the interface. Further, for example, a motor driver is controlled by a motor driver via the I / O interface 100b for a control target, and paper detection sensor information is acquired from the paper detection sensor.

  The control is executed based on the program defined by the program code while the CPU 100a reads the program code stored in the ROM (not shown), develops 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 100a shown in FIG.

  5 to 12 are operation explanatory views showing an outline of the operation of each part in the case of Z-folding. FIG. 13 is a flowchart showing the control procedure of the operation of each unit.

  FIG. 5 shows an initial state before the sheet is conveyed from the image forming apparatus 200 side. From the state of FIG. 5, as shown in FIG. 6, the paper P is carried into the first transport path W1 from the image forming apparatus 200 side. When the first paper detection sensor (entrance paper detection sensor) SN1 detects the leading edge P1 of the paper P (step S101), the first drive motor M1 that is the first transport member F1 starts to rotate (in the direction of arrow R1). When the paper P enters the first nip N1 of the first transport roller pair R1, the paper P is transported to the downstream second transport member F2 side by the first transport roller pair R1 (step S102). The sheet P having the leading end reached the first conveying member F2 is nipped by the second nip N2 between the first and second conveying rollers R2 and R3 and further conveyed downstream.

  Then, at the time when the sheet is transported to just before the second nip N2 between the second transport roller R3 and the third transport roller R4 (step S103), the second drive motor M2 is driven, and the second transport member F1 is moved in the direction of the arrow in FIG. (Step S104). Whether or not the sheet has been conveyed to the position immediately before the second nip N2 is determined from, for example, the rotation speed of the first drive motor M1 that drives the first conveyance member F1 (or the linear speed of the first conveyance roller pair R1) and the conveyance time. I can judge.

  After the second conveying member F1 starts to rotate in the direction of the arrow in FIG. 7 in step S104, the amount of protrusion (first protrusion amount) Δ1 from the position of the second sheet detection sensor SN2 is determined in order to set the folding position. (Step S105). The Z-folding is performed by folding outward (first folding) from the leading end P1 of the sheet P in the sheet transport direction at a quarter position of the entire length of the sheet, and folding inward (second folding) at a position of 1/2 of the total length. The position in FIG. 8 is a position where a fold line P3 is formed at a position ¼ from the front end P1 of the paper P. The setting of this position is also performed by the CPU 100a or referring to the ROM table.

  That is, the paper P is transported from when the leading edge P1 of the paper P is detected by the second paper detection sensor SN2 until the leading edge P1 of the paper P reaches the first protrusion amount Δ1. The first protrusion amount Δ1 is determined from the sheet length and the folding method, and is determined by the rotation amount of the first transport roller R2. When the leading edge P1 of the sheet P reaches the protrusion amount Δ1 (step S105: YES), the second conveying member F2 (third conveying roller R3) is temporarily stopped (step S106). At that time, when the leading edge P1 of the paper P is detected by the second paper detection sensor SN2, the second drive motor M2 decelerates, and the paper P is conveyed to the first protrusion amount Δ1, and stops at that position. . This deceleration enables highly accurate stop position control.

  To set the first movement amount Δ1, the CPU 100a receives data on the length in the transport direction of the paper P from the image forming apparatus 200 before starting the job (before image formation on the paper P), and the data The amount of movement is automatically calculated based on, and the calculation result is used. Even if it is not calculated, the relationship between the paper size and the movement amount can be tabulated in advance and stored in the ROM, and the movement amount can be set according to the paper size.

  Next, while the first transport member F1 is rotated in the transport direction, the second transport member F2 (second transport roller R3) is rotated in the reverse direction with respect to the transport direction up to FIG. 7 as shown in FIG. Step S107). The first protrusion amount Δ1 can also be determined based on the transport amount of the first transport member F1 from the position of the first paper detection sensor SN1.

  The sheet P is transported in the reverse direction by the reverse rotation of the second transport member F2 (second drive motor M2). On the other hand, since the first conveying member F1 rotates in the direction continued from FIG. 6 and conveys the paper P, bending is formed in the third nip N3 as in the case of folding in two (FIG. 8). This bending enters the third nip N3 and the first folding is performed. Thereby, the first fold line P3 is formed. The first folded paper P is transported to the second transport path W2 as shown in FIG.

  The sheet P is transported along the downward gradient of the second transport path W2, and is sandwiched and transported by the fifth nip N5 of the second transport roller pair R6 that has started rotating in the direction of the arrow as shown in FIG. (Step S107). Then, when the leading end (first fold P3) of the paper P is detected by the third paper detection sensor SN3 (step S108) and reaches a position protruding from the position by the second protrusion amount Δ2, the third transport member F3 (second transport roller pair R6: third drive motor M3) stops (step S109). As shown in FIG. 11, when the sheet P is conveyed in the direction of the arrow by the second folding roller pair 4 (second and fourth conveying rollers R3 and R5 pair), the driving member 3a4 moves in the idling region 3a. Then, the drive member 3a4 is idled until there is no play (step S110).

  Next, the sheet P is pulled by the second folding roller pair 4, and after the preset time elapses before the play of the driving member 3a4 is eliminated, the reverse rotation of the forward / reverse roller pair 3 (second conveying roller pair R6) is started. (Step S111). The operations in steps S110 and S111 and the mechanism for performing this operation will be described later. Note that the second protrusion amount Δ2 can also be set as a protrusion amount from the fifth nip N5.

  Similar to the first protrusion amount Δ1, the second protrusion amount Δ2 is determined from the sheet length and the folding method, and the rotation amount of the forward / reverse roller pair 3 (second transport roller pair R6) (driving of the third drive motor M3). Step number). In order to perform such control, in the present embodiment, the first to third drive motors M1, M2, M3 are constituted by stepping motors. Each of the drive motors M1, M2, and M3 can be configured by a motor other than the stepping motor, for example, a DC motor. In that case, a control method corresponding to the employed motor type is taken. For example, when a DC motor is used, the protrusion amount or drive stop timing is controlled based on the number of encoder pulses counted.

  When a DC motor is used to drive the pair of forward and reverse rollers 3, for example, a DC motor as disclosed in JP 2012-213308 and its driving device may be used. If such a DC motor is used, the forward / reverse operation can be quickly performed, and the productivity can be improved. Further, the step-out motor does not step out with respect to the load fluctuation. Further, by correcting the positional deviation due to load fluctuation or the like by feedback control, it is possible to always rotate at an accurate position. As a result, it can be folded at an accurate position, and high folding quality can be guaranteed.

  Further, the reverse rotation of the forward / reverse roller pair 3 (second conveying roller pair R6) is such that the first folding roller pair 2 (second and third conveying rollers R3, R4) maintains the rotation direction shown in FIGS. It is executed in the state. As a result, as shown in FIG. 11, the sheet P is bent (Pt1 described later) in the communication path W2c on the downstream side of the third nip N3.

  When the second and third conveyance members F2 and F3 shown in FIG. 11 are continuously driven in the rotational direction, the bending (Pt1 described later) is caused by the second folding roller pair 4 (second conveyance roller R3 and fourth conveyance roller R5). ) 4th nip N4, and the paper P is transported in the direction of the end W2a on the paper discharge side of the second transport path W2. In the course of this conveyance, the second fold is applied as shown in FIG. The second folded paper P is further transported from the paper discharge side end W2a to the post-processing apparatus 300 in the subsequent stage through the first transport path W1. Alternatively, the paper is discharged to the paper discharge tray 400.

  In FIG. 12, the third paper detection sensor SN3 detects the passage of the rear end of the paper P (step S112), and after passing through the fourth nip N4, the second and third transport members F2, F3 (first 2 and the third drive motors M2 and M3) stop rotating (step S113). Further, as shown in FIG. 19, the first drive motor M1 stops rotating at a timing after the first sheet detection sensor SN1 detects the trailing edge of the sheet and after the trailing edge of the sheet is separated from the first nip N1.

  The outline of Z-folding in this embodiment is as described above. In this embodiment, in order to avoid the above-described box folding phenomenon, the rotating mechanism of the forward / reverse rotating roller pair 3 that rotates forward or backward or this rotating mechanism is driven. A predetermined play (idling region) is provided in the drive mechanism, and control is performed as in steps S110 and S111.

  That is, the forward / reverse roller pair 3 (a) can transport the paper P upstream and downstream. (B) When the forward / reverse roller pair 3 is stopped, the forward / reverse roller pair 3 does not move due to the paper P being scraped (the position where the paper P is stopped). (C) It has three basic functions of idling during forward / reverse operation of the forward / reverse roller pair 3.

  The function (b) is for ensuring the folding position accuracy. The function of (c) is to make it possible to easily pull out when pulled from the second folding roller pair 4 in order to avoid the box breaking phenomenon. For the function (c), in the present embodiment, a play (idling region) 3a that idles in any part of the drive mechanism during forward / reverse operation of the forward / reverse roller pair 3 is provided.

  FIG. 14 is a diagram conceptually showing the configuration of the drive unit main body 3a1 of the pair of forward and reverse rollers 3 having this play (idling region) 3a. As shown in FIG. 14A, the forward / reverse roller pair 3 includes a driving member 3a4 that transmits the driving force of the driving unit main body 3a1, the driving shaft 3a2, and the driving shaft 3a2 to the driven unit 3a3 of the roller main body 3a. When the member 3a4 idles in the space 3a5 in the drive unit main body 3a1 and hits the driven unit 3a3, the driving force can be transmitted to the drive unit main body 3a1 side in one direction. In the other direction, the drive unit body 3a1 is locked, and the drive unit body 3a1 does not rotate.

  For example, when the drive shaft 3a2 rotates in the clockwise direction (arrow CW direction) in the state shown in FIG. 14A, the drive unit main body 3a1 rotates in the clockwise direction (arrow CW direction) as it is. On the other hand, when the drive shaft 3a2 rotates in the illustrated counterclockwise direction (arrow CCW direction) in the state of FIG. 14A, the drive shaft 3a2 and the drive member 3a4 are idled to the position shown in FIG. 14B. Even if the driving member 3a4 pushes the driven portion 3a3 to transmit the driving force, the driving portion main body 3a1 is locked in this direction, and the driving portion main body 3a1 does not rotate. In other words, the drive unit main body 3a1 is idled while the drive member 3a4 is positioned in the space 3a5 without contacting the driven unit 3a3.

  That is, the drive member 3a4 is positioned in the idling region 3a until the drive shaft 3a2 rotates in the clockwise direction (arrow CW direction) from the state of FIG. 14B until the drive member 3a4 hits the side surface of the driven portion 3a3. Therefore, the driving force is not transmitted and the driving unit main body 3a1 does not rotate (FIG. 14 (c)). Then, when there is no play in the idle region 3a and the driving member 3a4 hits the driven portion 3a3, the driving force is transmitted to the driving portion main body 3a1, and the driving portion main body 3a1 starts to rotate (FIG. 14D). ).

  In FIG. 14, the mechanism provided with the idling region 3 a is provided in the drive unit main body 3 a 1 that drives the forward / reverse rotation roller pair 3, but may be provided on another drive mechanism, for example, on the gear side. Furthermore, it is possible to provide a drive force transmission path from the drive shaft of the motor that transmits the drive force to the gear to the gear. In any case, it can be provided in the driving force transmission path from the driving source to the pair of forward and reverse rollers 3. The forward / reverse roller pair 3 rotates in synchronization with the rotation of the drive unit main body 3a1. Therefore, the rotation operation of the drive unit main body 3a1 is equivalent to the rotation operation of the forward / reverse rotation roller pair 3.

  15 to 18 are explanatory views showing the principle of conveyance operation of the pair of forward and reverse rollers 3 having the play shown in FIG. When the paper P is transported from the first folding roller pair 2, the forward / reverse roller pair 3 is rotated in the direction of transporting the paper P downstream. If the forward / reverse rotation roller pair 3 continues to rotate, there is no play in the idle rotation region 3a, and the forward / reverse rotation roller pair 3 starts rotating when play is eliminated, so that the paper P can be conveyed downstream (see FIG. 15). A predetermined amount of paper P is conveyed, the forward / reverse roller pair 3 is rotated reversely (FIG. 16), and the leading end P1 of the paper P is stopped before the fourth nip N4 of the second folding roller pair 4.

  At this time, the forward / reverse roller pair 3 is stopped and locked in one (downstream direction) rotation direction. As a result, the pair of forward and reverse rollers 3 does not move due to the paper P being squeezed, and the paper P is not sent downstream from the stopped position. Further, since the play (idle region 3a) is free in the other (upstream direction) rotation direction, the leading end P1 of the paper P is pinched by the fourth nip N4 of the second folding roller pair 4 and pulled. Can be easily pulled out (FIG. 17).

  Further, when the sheet bending portion Pt1 is nipped between the second folding roller pair 4, the downstream excessive bending Pt2 is eliminated. Pulled out from. At that time, the forward / reverse roller pair 3 can be idled when the paper P moves in the upstream direction, and therefore can be pulled out without load (FIG. 18). 4 is conveyed.

  16 to 18, the leading end P1 of the paper P and the paper portion (peller portion) P1a on the first folding side are guided to the nip along the guide plate 4a extending to the nip of the second folding roller pair 4. , Pinched at the nip and pulled. For this reason, no paper jam or bending occurs between the leading edge P1 of the paper P and the second folding roller pair 4.

  19 to 24 are operation explanatory views showing an example of the operation of the forward / reverse roller pair 3 in the present embodiment. The operating principle is as described with reference to FIGS.

  First, before the sheet P conveyed by the first folding roller pair 2 enters the nip of the forward / reverse roller pair 3, the forward / reverse roller pair 3 rotates in the direction of the arrow shown in FIG. The paper P is further transported, and after the forward / reverse roller pair 3 holds the paper P, it is transported to a preset position (FIG. 20). At this time, the third paper detection sensor SN3 is provided at the peripheral position of the forward / reverse rotation roller pair 3 as described above, and the paper stop position is determined based on the detection output of the third paper detection sensor SN3 (FIG. 21). . Instead of the sheet detection sensor SN3, the sheet stop position can be determined by pulse count control of the third drive motor M3, encoder pulse output of the DC motor, or the like.

  After the forward / reverse roller pair 3 is stopped at the position shown in FIG. 21, the drive member 3a4 moves in the idle rotation region 3a, and the drive member 3a4 (drive unit main body 3a1) is idled until there is no play (FIG. 22). Then, the drive unit main body 3a1 is stopped again (FIG. 23). The idling is in a direction opposite to the rotation direction until the forward / reverse roller pair 3 is stopped. Also at this time, the third sheet detection sensor SN3 (which may be provided separately) is used as in the case of the stop in the downstream conveyance shown in FIG. 21, or the pulse count control of the third drive motor M3, the encoder of the DC motor The paper stop position is determined by output or the like.

  In this state, the forward / reverse roller pair 3 locks the rotation of the paper P in the downstream direction, so the forward / reverse roller pair 3 does not move due to the paper P being squeezed, and the paper P is located downstream from the stopped position. Not sent. Thereafter, the sheet P is pulled by the second folding roller pair 4, and after a preset time before the play of the driving member 3a4 is eliminated, the forward / reverse roller pair 3 is driven (FIG. 24). At this time, the rotational speed of the forward / reverse roller pair 3 is set equal to or higher than the rotational speed of the second folding roller pair 4. Thus, the sheet P is not pulled between the second folding roller pair 4 and the forward / reverse roller pair 3.

  In consideration of the efficiency of paper processing, it is desirable that the idling region 3a is small because the play operation time is short.

  FIG. 25 is a diagram illustrating a schematic configuration of the forward / reverse roller pair 3 according to Example 2 of the present embodiment.

  The forward / reverse roller pair 3 according to the second embodiment includes a pair of first and second drive rollers 3a and 3b, and first and second driven gears 8a and 8b that drive the drive rollers 3a and 3b. The first and second transmission mechanisms 9a and 9b for transmitting the driving force of the first and second driven gears 8a and 8b to the first and second driving rollers 3a and 3b, and the first driven gear 8a are provided. A drive gear 7 for driving and a drive motor (not shown) for driving the drive gear 7 are included. The second driven gear 8b meshes with the first driven gear 8a and rotates in synchronization with the rotation of the drive gear 7, and this rotational driving force is transmitted to the first and second drive rollers 3a and 3b, respectively. In this embodiment, the driving gear 7 is provided with the play mechanism shown in FIG.

  Other parts are configured in the same manner as in the first embodiment and function in the same manner.

  As in the present embodiment, in the configuration in which the drive unit main body 3a1 is provided with a play (idling region) 3a, if one of the pair of forward / reverse rollers 3 is a driven roller, there is a concern that the paper P may be rotated against the strain of the paper P. For this reason, it is necessary to prevent the paper P from rotating (locking) even if it is pushed by the paper sheet P. In this embodiment, the two rollers are configured as drive rollers. The play of the drive unit main body 3a1 may be provided in the drive gear 7 or in the upstream gear.

  26 and 27 are diagrams showing a schematic configuration of the forward / reverse roller pair 3 according to Example 3 of the present embodiment.

  In the present embodiment, in the drive configuration of the forward / reverse rotation roller pair 3, the same effect as in the configuration in which the play 3a is provided in the drive section main body 3a1 in the first and second embodiments using the one-way clutch 10 and the electromagnetic clutch 11 is provided. It ’s what you get.

  That is, in the third embodiment, the one-way clutch 10 and the electromagnetic clutch 11 are connected to the first driven gear 8 a in the second embodiment, and the drive mechanism of the motor 12 is connected to the one-way clutch 10 and the electromagnetic clutch 11. Other configurations are the same as those of the second embodiment.

  With this configuration, when the motor 12 is rotating in the forward rotation direction (the clockwise direction shown in FIG. 26: the arrow CW direction), the forward / reverse roller pair 3 rotates in the direction of transporting the paper P upstream. . At that time, the electromagnetic clutch 11 is in an OFF state. In the stopped state, since the one-way clutch 10 is provided, the sheet P is rotated when the sheet P is pulled in the upstream direction, and is locked when the sheet P is conveyed in the downstream direction.

  When the motor 12 is rotating in the reverse rotation direction (counterclockwise direction shown in FIG. 27: arrow CCW direction), the electromagnetic clutch 11 is turned on. As a result, the forward / reverse roller pair 3 rotates in the reverse direction (the direction in which the paper P is conveyed downstream), and the one-way clutch 10 side gear does not rotate. Therefore, the functions (a) to (c) which are basic functions of the forward / reverse rotation roller pair 3 can be obtained with certainty, and the box breaking phenomenon can be avoided.

  Other parts are configured in the same manner as in the first and second embodiments and function in the same manner.

  According to the present embodiment, an operation equivalent to the mechanism in which the idling region (play) 3 a is provided in the drive unit can be realized by combining the existing one-way clutch 10 and the electromagnetic clutch 11.

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

  1) The first folding roller pair 2 that folds the paper P (second conveying roller R3 and third conveying roller pair 4 pair: first conveying member pair) and the first folding roller pair 2 The forward / reverse roller pair 3 (second transport roller pair R6: second transport member pair) that transports the paper P downstream and the first folding roller pair 2 (first transport member pair) folded. And a second folding roller pair 4 (second conveying roller R3 and fourth conveying roller R5 pair: third conveying member pair) that further folds the paper P, and the forward / reverse roller pair 3 is forward / reverse during conveyance driving. Since it can rotate and is locked in one rotational direction and non-driven, it can rotate in the other rotational direction, so that the basic performances (a) to (c) can be exhibited. This makes it possible to prevent the box from being folded during the second paper folding process when the folding process is performed by the sandwiching inversion method.

  2) A first transport roller pair R1 (fourth transport member pair) that transports the paper P, a first transport roller R2 that receives the paper P transported by the first transport roller pair R1, and transports the paper P to the subsequent stage. In the state where the sheet P is held by the two conveying rollers R3 (fifth conveying member pair), the first conveying roller pair R1, the first conveying roller R2, and the second conveying roller R3 pair, the first conveying Since the roller R2 and the second conveying roller R3 pair are rotated in the opposite directions, the portion corresponding to the fold of the paper P can be reliably guided to the nip of the first folding roller pair 2.

  3) Since the rotatable range is set in advance, the next reverse conveying operation can be performed reliably after idling.

  4) In the preset rotatable range, the forward / reverse roller pair 3 (second conveying member pair) is stopped, and the second folding roller pair 4 (third conveying member pair) is the paper. Deflection Pt2 of the paper P generated between the forward / reverse roller pair 3 (second conveying member pair) and the second folding roller pair 4 (third conveying member pair) when conveying P downstream. Since the rotation range is sufficient to eliminate the bending, it is possible to guarantee idling that only eliminates the bending that occurs during the second folding process, and reliably prevents the box folding phenomenon that occurs during the second folding process. It can be avoided.

  5) When the sheet P is folded by the second folding roller pair 4 (third conveying member pair), the forward / reverse roller pair 3 (second conveying member pair) is in a stopped state, and thus the first The sheet P can be reliably pulled in by the nip of the two-fold roller pair 4.

  6) The sheet P is conveyed by the second folding roller pair 4 (third conveying member pair), and the forward / reverse roller pair 3 (second conveying member pair) is pulled by the sheet P along with this conveyance. Thus, after the preset time before the idling is completed, the forward / reverse roller pair 3 is driven, so that the second folding roller pair 4 is bent while folding the paper P. The sheet P can be pulled out from the forward / reverse roller pair 3 without load in the absence of load.

  7) When the forward / reverse roller pair 3 (second transport member pair) is driven to rotate, the transport speed of the paper P is the paper P of the second folding roller pair 4 (third transport member pair). Therefore, the sheet P is not pulled between the forward / reverse roller pair 3 and the second folding roller pair 4. This prevents the paper P from being damaged due to pulling.

  8) The forward / reverse roller pair 3 (second conveying member pair) includes a driving member 3a4 rotating concentrically with the driving shaft 3a2, a driven portion 3a3 driven by the driving member 3a4, and the driving member 3a4. Since the drive unit main body 3a1 (drive unit) including the idling region 3a that idles is provided, the functions (b) and (c) can be reliably exhibited.

  9) Since the forward / reverse roller pair 3 (second conveying member pair) is configured as a driving roller, there is no fear of rotating against the edge of the paper P, and the function (b) can be surely exhibited. it can.

  10) Each of the forward / reverse roller pair 3 (second conveying member pair) is a drive roller, and a one-way clutch 10 is provided at the drive portion of one drive roller of the forward / reverse roller pair 3, and the other drive roller is driven. Since the electromagnetic clutch 11 is provided in the part, the functions (a) to (c) which are basic functions of the forward / reverse rotation roller pair 3 can be obtained with certainty.

  11) Since the image forming system 1 includes the folding processing apparatus 100 (paper processing apparatus) and the image forming apparatus 200 having any one of the above configurations 1) to 10), the above described 1) to 10). It is possible to provide a system that exhibits the effect.

  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.

DESCRIPTION OF SYMBOLS 1 Image forming system 2 1st folding roller pair (1st conveyance member pair)
3 Forward / reverse roller pair (second conveying member pair)
3a idling region 3a1 drive unit main body 3a2 drive shaft 3a3 driven unit 3a4 drive member 4 second folding roller pair (third conveying member pair)
DESCRIPTION OF SYMBOLS 10 One-way clutch 11 Electromagnetic clutch 100 Folding processing apparatus 200 Image forming apparatus P Paper Pt2 Deflection R1 1st conveyance roller pair (4th conveyance member pair)
R2 First transport roller R3 Second transport roller R4 Third transport roller R5 Fourth transport roller R6 Second transport roller pair

JP 2006-117383 A JP 2007-277006 A

Claims (11)

A first pair of conveying members for folding paper;
A second conveying member pair that conveys the sheet folded by the first conveying member pair downstream;
A third conveying member pair that further folds the paper folded by the first conveying member pair;
The sheet processing apparatus, wherein the second conveying member pair is capable of rotating in the forward and reverse directions during conveyance driving, locked in one rotation direction when not driven, and rotatable in the other rotation direction. The sheet processing apparatus according to claim 1,
A fourth pair of conveying members for conveying the paper;
A fifth conveyance member pair that receives the sheet conveyed by the fourth conveyance member pair and conveys it to the subsequent stage; and
A sheet processing apparatus, wherein the fifth conveying member pair is rotated in a reverse direction while the sheet is held by the fourth conveying member pair and the fifth conveying member pair. In the paper processing apparatus according to claim 1 or 2,
The sheet processing apparatus is characterized in that the rotatable range is set in advance. The sheet processing apparatus according to claim 3.
The preset rotatable range is such that when the second conveying member pair stops and the third conveying member pair conveys the paper downstream, the second conveying member pair and the third conveying range. A sheet processing apparatus having a rotation range sufficient to eliminate the bending of the sheet generated between the pair of conveying members. The sheet processing apparatus according to claim 4, wherein
When the sheet is folded by the third conveying member pair, the second conveying member pair is in a stopped state. The sheet processing apparatus according to claim 5, wherein
The sheet is conveyed by the third conveying member pair, and the second conveying member pair is pulled by the sheet along with the conveyance to start idling, and a preset time before the idling ends. After the elapse of time, the second conveying member pair is rotationally driven in the pulling direction. The sheet processing apparatus according to claim 6.
The conveyance speed of the sheet when the second conveyance member pair is rotationally driven is set to be equal to or higher than the conveyance speed of the sheet of the third conveyance member pair. Paper processing device. The sheet processing apparatus according to any one of claims 1 to 7,
The second conveying member pair includes a drive unit that includes a drive member that rotates concentrically with the drive shaft, a driven unit that is driven by the drive member, and an idle region in which the drive member idles. A paper processing apparatus. The paper processing apparatus according to any one of claims 1 to 8,
Each of the second conveying member pairs is a driving roller. The paper processing apparatus according to any one of claims 1 to 8,
Each of the second conveying member pairs is a driving roller,
A sheet processing apparatus, wherein a drive unit of one drive roller of the second conveying member pair is provided with a one-way clutch, and a drive unit of the other drive roller is provided with an electromagnetic clutch. An image forming system comprising the sheet processing apparatus according to claim 1.