JP2013014431A - Sheet processing apparatus, image forming apparatus, and sheet folding method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sheet processing apparatus which performs fold reinforcing processing more properly than a conventional sheet processing apparatus having a fold reinforcing unit, and to provide an image forming apparatus and sheet folding method.SOLUTION: The sheet processing apparatus includes: a folding unit that folds a sheet bundle including a plurality of sheets to form a fold; a fold reinforcing roller that nips the fold of the sheet bundle having the fold formed thereon and conveyed to a fold reinforcing position, reciprocatingly moves along the direction of the fold, and reinforces the fold of the sheet bundle; a detection sensor that is arranged along a sheet conveyance direction between the folding unit and the fold reinforcing roller, and measures a folding height of sheet bundle at the fold reinforcing position; and a controller that reciprocatingly moves the fold reinforcing roller, on the basis of a result measured by the detection sensor.

Description

  Embodiments described herein relate generally to a sheet processing apparatus that performs a folding process on a printed sheet, an image forming apparatus that uses the sheet processing apparatus, and a sheet folding method.

  Installed on the downstream side in the sheet conveying direction of an image forming apparatus such as a copying machine, a printer, or a multifunction peripheral (MFP (Multi-Functional Peripheral)), and performs post-processing such as punching processing and binding processing on a printed sheet. There is a sheet processing apparatus. In addition to the punching and binding functions, the sheet post-processing device has a folding function that folds a part of the sheet, and saddle stitching / center folding that folds the sheet at the center after stapling the center of the sheet. It has a processing function. The saddle stitching / center folding function can produce a booklet from a plurality of printed sheets.

  In the saddle stitching / half-folding process, the sheet post-processing apparatus binds the center portion of the sheet with a staple or the like, and then folds the binding portion into a sheet with a pair of rollers called folding rollers. For example, the sheet post-processing apparatus applies a plate-like member called a folding blade to the binding portion of the sheet bundle and pushes it into the nip portion of the pair of folding rollers to fold the sheet bundle.

  However, the time during which the folded portion of the sheet bundle is pressed by the nip portion of the folding roller is short, and the entire folding portion is simultaneously pressed by the nip portion of the folding roller, so that the pressure is distributed over the entire fold. For this reason, the fold formed by the folding roller is not sufficiently pressurized, and is particularly incomplete when the number of sheets is large or a thick sheet is included in the sheet bundle. There is a case.

  In order to cope with this problem, there is a technique that includes a folding unit having a folding roller and reinforces a fold formed by the folding roller with a folding roller. The fold-increasing rollers include, for example, a pair of rollers that can move along the folds of the sheet bundle. The folding unit nips the folds of the sheet bundle at the nip portion of the folding roller, and reinforces the folds of the sheet bundle by moving the folding roller along the fold while applying pressure to the nip portion. The folding roller of the folding unit normally stands by at a home position slightly separated from the end of the sheet bundle. During the folding process, the folding roller moves from the home position, reciprocates along the fold of the sheet bundle, and returns to the home position again when the folding process is completed.

  In particular, Patent Document 1 discloses an apparatus that performs the number of reciprocating movements of a folding roller with respect to one sheet bundle (hereinafter referred to as the number of foldings) a plurality of times. The sheet processing apparatus changes the number of folds of the fold-in roller according to the sheet size and sheet type (thickness) included in the sheet bundle. Since this apparatus determines the number of times of folding according to the sheet size and the type (thickness) of the sheet, even if it is actually insufficient, the folding process is completed and the sheet bundle is discharged.

JP 2010-18440 A

  SUMMARY OF THE INVENTION An object of the present invention is to provide a sheet processing apparatus, an image forming apparatus, and a sheet folding method that perform a folding process more appropriately than a sheet processing apparatus having a conventional folding unit.

  In order to achieve the above object, a sheet processing apparatus according to an embodiment includes a folding unit that folds a sheet bundle composed of a plurality of sheets to form a fold, and a sheet bundle in which a fold is formed and conveyed to a folding position. On the other hand, sandwiched between the folds of the sheet bundle, reciprocating along the direction of the folds, and disposed between the fold increasing roller that reinforces the folds of the sheet bundle and the folding unit and the fold increasing roller along the sheet conveying direction, A detection sensor that measures the folding height of the sheet bundle at the folding position, and a controller that reciprocates the folding roller based on the measurement result of the detection sensor.

FIG. 2 is a block diagram illustrating a hardware configuration of the image forming apparatus and the sheet processing apparatus according to the first embodiment. Schematic for demonstrating the structure of the sheet processing apparatus of 1st Embodiment. The schematic perspective view for demonstrating the whole structure of the fold-in unit of 1st Embodiment. The schematic sectional drawing for demonstrating the support part of 1st Embodiment. FIG. 3 is a perspective external view showing a structural example of a roller unit according to the first embodiment. Schematic for demonstrating the drive part of 1st Embodiment. Schematic for demonstrating the mechanism of the up-down drive of the upper roller of 1st Embodiment. Schematic for demonstrating the detection sensor of 1st Embodiment. 6 is a flowchart for explaining folding processing of the sheet processing apparatus according to the first embodiment. 9 is a flowchart for explaining folding processing of the sheet processing apparatus according to the second embodiment. Schematic for demonstrating the roller unit of 3rd Embodiment. 10 is a flowchart illustrating control of a sheet processing apparatus according to a third embodiment. Schematic for demonstrating the modification of the roller unit of 3rd Embodiment.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
(First embodiment)

  FIG. 1 is a block diagram illustrating a hardware configuration of the image forming apparatus and the sheet processing apparatus. The image forming apparatus 100 includes a control unit 102, a storage device 108, a communication interface (communication I / F) 110, an operation panel 112, a scanner unit 114 that reads an original, and a printer unit (image forming unit) that forms an image. ) 116. Each component of the image forming apparatus 100 is connected via a bus 118.

  The control unit 102 includes a processor 104 including a CPU (Central Processing Unit) or an MPU (Micro Processing Unit), and a memory 106. The memory 106 is a semiconductor memory, for example, and includes a ROM (Read Only Memory) that stores a control program and the like, and a RAM (Random Access Memory) that provides a temporary work area to the processor 104. The control unit 102 controls the operation panel 112, the scanner unit 114, and the printer unit 116 based on various programs stored in the ROM or the storage device 108. The control unit 102 has a function of correcting or expanding image data. The control unit 102 communicates with the control unit 202 of the sheet processing apparatus 200.

  The storage device 108 stores application programs and an OS. The application program includes a program that executes a function of the multifunction peripheral such as a copy function, a print function, a scanner function, a facsimile function, and a network file function. The application program further includes an application for a Web client (Web browser) and other applications.

  The storage device 108 temporarily stores image data of a document read by the scanner unit 114 or image data acquired via the communication I / F 110. In addition, the storage device 108 appropriately stores software updates, protected electronic documents, text data, account information, policy information, and the like. The storage device 108 may be, for example, a magnetic storage device such as a hard disk drive, an optical storage device, a semiconductor storage device (flash memory, etc.), or any combination of these storage devices.

  The communication I / F 110 is an interface connected to an external device. The communication I / F 110 is connected to an external device via an appropriate wireless or wired connection such as IEEE 802.15, IEEE 802.11, IEEE 802.3, IEEE 1284, such as Bluetooth (registered trademark), infrared connection, or optical connection. The communication I / F 110 may further include a USB connection unit to which a USB standard connection terminal is connected, a parallel interface, and the like. The control unit 102 communicates with a user terminal, a USB device, and other external devices via the communication I / F 110.

  The operation panel 112 includes a touch panel display unit and various operation keys. The operation keys include, for example, a numeric keypad, a reset key, a stop key, and a start key. The display unit displays instruction items related to printing conditions such as sheet size, number of copies, print density setting, or finishing (binding, folding), for example. An instruction for the displayed item is input from the display unit.

  The scanner unit 114 includes a built-in scanning reading unit that reads a document as an image, a document placing table, and an automatic document feeder that transports the document to a reading position. The scanning reading unit of the scanner unit 114 reads a document set on a document table or an automatic document feeder.

  The printer unit 116 includes a known image forming unit including a photosensitive drum, for example, and a developing unit using toner, for example. The printer unit 116 forms an image corresponding to the image data of the document read by the scanner unit 114 by these units or an image corresponding to the image data sent from the user terminal on the sheet.

  The sheet processing apparatus 200 includes a control unit 202, a finisher unit 220, and a saddle unit unit 240. The control unit 202 (controller) includes a processor 204 including a CPU (Central Processing Unit) or an MPU (Micro Processing Unit), and a memory 206. The memory 206 is a semiconductor memory, for example, and includes a ROM (Read Only Memory) that stores a control program and the like, and a RAM (Random Access Memory) that provides a temporary work area to the processor 204. The control unit 202 communicates with the control unit 102 of the image forming apparatus 100. The control unit 202 controls the finisher unit 220 and the saddle unit unit 240 based on information received from the control unit 102 and various programs stored in a ROM or the like. Further, the saddle unit 240 according to the present embodiment includes a stapler 252, a folding unit 258, and a folding unit 300.

  FIG. 2 is a schematic diagram for explaining the configuration of the sheet processing apparatus.

  The sheet processing apparatus 200 processes a sheet discharged from the image forming apparatus 100 according to an input instruction from the operation panel 112 or an instruction from a user terminal. The sheet processing apparatus 200 includes an entrance roller 210, a branch member 212, a finisher unit 220, and a saddle unit unit 240. The entrance roller 210 carries the sheet carried out from the image forming apparatus 100 into the sheet processing apparatus 200. The branching member 212 is a finisher unit 220 or a saddle unit unit according to the processing content input via the display unit of the operation panel 112 of the image forming apparatus 100 shown in FIG. Switch to 240. The finisher unit 220 sorts the sheet bundle or binds the end of the sheet bundle, for example. The finisher unit 220 may be, for example, a post-processing device described in the specification and drawings of Japanese Patent Application Laid-Open No. 2007-76862.

  The saddle unit 240 binds or folds the sheet bundle. The saddle unit 240 includes a plurality of transport rollers 242, a carry-out roller 244, a carry-out roller sensor 245, a stacking unit 246, a stapler 252, a folding unit 258, a folding unit 300, a discharge roller 264, and a sheet bundle stacking tray 266. The conveyance roller 242 conveys the sheet toward the stacking unit 246. The carry-out roller 244 carries out the sheet to the stacking unit 246. The carry-out roller sensor 245 detects the conveyed sheet.

  The stacking unit 246 includes a stack tray 248, a stacker 250, and a sensor 251. The stacking unit 246 temporarily stacks sheets in a standing position. The stack tray 248 supports the sheet surface. The stacker 250 receives the lower end of the sheet. The stacker 250 supports the lower end of the sheets stacked in a standing position, and aligns (vertically aligns) the position of the end of the sheet in the transport direction. The sheets stacked on the stacking unit 246 are also aligned in the sheet width direction, which is a direction intersecting the sheet conveyance direction. The sheet width alignment (lateral alignment) is omitted. The sensor 251 detects that the sheet has been conveyed to the stacker 250.

  The stacker 250 moves up and down along the stack tray 248. The stacker 250 adjusts the position of the sheet bound by the stapler 252 and the position of the sheet folded by the folding unit 258. In this embodiment, as an example, a position where a sheet is bound and a position where the sheet is folded are described as a central portion in the sheet conveyance direction.

  A plurality of (for example, two) staplers 252 are arranged in the sheet width direction. The stapler 252 has a stapler head 254 and an anvil 256. The stapler head 254 and the anvil 256 bind the sheet bundle.

  When the stapler 252 binds the sheet bundle, the stacker 250 moves so that the position where the sheets are bound comes to the position where the folding unit 258 is folded. When the stacker 250 stops, the folding unit 258 starts folding.

  The folding unit 258 has a folding plate 260 and a folding roller pair 262. The folding plate 260 stands by at a position that does not hinder the conveyance of the sheet. When the position to be creased comes to the front of the folding plate 260, the folding plate 260 moves toward the folding roller pair 262. The front end of the folding plate 260 pierces the sheet bundle and pushes it toward the nip portion of the rotating folding roller pair 262. The pair of folding rollers 262 folds the sheet pressed by the folding plate 260 with nipping and conveying. The sheet bundle on which the folds are formed by the folding unit 258 is further conveyed to the folding unit 300 provided on the downstream side thereof.

  The folding unit 300 moves while pressing the crease in a direction orthogonal to the conveying direction of the sheet bundle (a direction along the crease line) to reinforce the crease formed by the folding unit 258 (folding process). The folding unit 300 will be described later. The sheet bundle whose creases are strengthened by the folding unit 300 is discharged to the sheet bundle stacking tray 266 by the discharge roller 264.

  FIG. 3 is a schematic perspective view for explaining the overall structure of the folding unit 300. The folding unit 300 includes a support unit 400, a folding roller unit 500 (hereinafter simply referred to as the roller unit 500), a driving unit 600, and a detection member 560. The support part 400 is a part of the structural member of the entire folding unit 300, and supports the roller unit 500 so as to be slidable in the crease direction (width direction intersecting the sheet bundle conveyance direction). The roller unit 500 moves along the fold of the sheet bundle folded by the folding roller pair 262 located upstream, and pressurizes the fold of the sheet bundle to strengthen the fold of the sheet bundle. The drive unit 600 includes a drive motor 602. The driving unit 600 drives the roller unit 500 along the fold line of the sheet bundle. The detection member 560 detects whether or not the roller unit 500 is in the home position. The detection member 560 may be, for example, a microsensor or a microactuator.

  The support part 400 is demonstrated using FIG. 3 and FIG. FIG. 4 is a schematic cross-sectional view for explaining the support portion 400. FIG. 4A shows a state where the roller unit 500 is at the home position. FIG. 4B shows a state in which the roller unit 500 moves and reinforces the fold of the sheet bundle. The support unit 400 includes a frame 402, a conveyance guide 414, flexible members 416 and 418, and a support shaft 420.

  The frame 402 includes a top plate 404, left and right side plates 406 and 407, a bottom plate 408, a back plate 410, and a sheet bundle mounting table 412. The top plate 404 has a support hole 405 extending in the longitudinal direction. The support hole 405 slidably holds a support roller 528 for maintaining the posture provided in the upper part of the roller unit 500 shown in FIG. The side plates 406 and 407 support the support shaft 420. The support shaft 420 slidably supports the roller unit 500. The support shaft 420 is inserted into a through hole 512 of the roller unit 500 described later. The position of the roller unit 500 (excluding position change in the moving direction) and the three-axis posture are regulated by the support shaft 420 and the through hole 512, and the support hole 405 and the support roller 528, and are constant during the movement of the roller unit 500. Retained.

  The conveyance guide 414 is disposed between the side plates 406 and 407. The conveyance guide 414 has a bottom plate 415. A flexible member 416 is attached to the bottom plate 415. The flexible member 416 is a belt-like member formed of a resin member such as a film-like polyethylene terephthalate (PET). Below the flexible member 416 is a flexible member 418 and a sheet placement table 412. The flexible member 418 is attached to the sheet mounting table 412 so as to face the flexible member 416.

  When the folds of the sheet bundle P are strengthened, the folds of the sheet bundle P are nipped by the folding position (folding roller 502) between the flexible members 416 and 418 as shown in FIG. Position). That is, a fold-increasing roller 502 (upper roller 503 and lower roller 504), which will be described later, presses the fold of the sheet bundle P via the flexible members 416 and 418, thereby strengthening the fold. By using the flexible members 416 and 418, generation of scratches and wrinkles on the crease and the vicinity thereof is prevented.

  Next, control for conveying the sheet bundle to the folding position will be described. The support unit 400 includes a sheet bundle detection sensor 422. In the present embodiment, the sheet bundle detection sensor 422 is disposed on the sheet mounting table 412. The sheet bundle detection sensor 422 may be a micro sensor or a micro actuator, for example. Driving of the sheet bundle in the conveyance direction is performed by a folding roller motor (not shown) that rotates the folding roller pair 262. The control unit 202 controls the conveyance of the sheet bundle by controlling the rotation speed and rotation amount of the folding roller motor. That is, the control unit 202 controls the rotation of the folding roller motor based on a signal output from the sheet bundle detection sensor 422 and indicating that the fold of the sheet bundle has been detected, and stops the sheet bundle at the additional folding position. For example, when the control unit 202 receives a signal indicating sheet bundle detection from the sheet bundle detection sensor 422, the controller 202 drives the folding roller motor for a predetermined number of pulses, and then stops the folding roller motor, thereby increasing the position of the sheet bundle. Stop at.

  Further, the folding unit 300 has a detection sensor 800 for detecting the height of the folded sheet bundle. The detection sensor 800 will be described later.

  Next, the structure of the roller unit 500 will be described. FIG. 5 is a perspective external view showing a structural example of the roller unit 500, as viewed from the sheet bundle conveyance direction (the direction of arrow A in FIG. 3).

  The roller unit 500 includes a folding roller 502. The roller unit 500 includes a unit support portion 510 and a unit frame 520. The unit support portion 510 has a through hole 512 into which the support shaft 420 is inserted, and a connection portion 514 that connects to a unit drive belt of the drive portion 600 described later. A unit frame 520 is attached above the unit support portion 510.

  The unit frame 520 has a folding roller 502. The unit frame 520 includes an upper frame 522, a lower frame 524, a frame plate 526 that fixes the upper frame 522 and the lower frame 524, an upper link member 530, and a lower link member 540. Further, the unit frame 520 has a support roller 528 for maintaining the posture of the roller unit 500.

  The upper link member 530 is rotatably attached to the upper frame 522 via the upper link shaft 531. The lower link member 540 is rotatably attached to a side surface of the lower frame 524 via a lower link shaft 541 (see FIG. 3) fixed to the lower frame 524. The upper link member 530 and the lower link member 540 are spring-coupled by a spring 550. One end of the spring 550 is locked in the hook hole 532 of the upper link member 530, and the other end of the spring 550 is locked in the notch 542 of the lower link member 540. FIG. 5 shows the spring 550 in a free state in which the other end of the spring 550 is removed from the notch 542. However, when the other end of the spring 550 is actually locked to the notch 542, the upper link member 530 and A tensile force of the spring 550 is applied between the lower link member 540 and the lower link member 540.

  The upper link member 530 rotatably supports an upper roller 503 that is one of the folding increase rollers 502. The upper roller shaft of the upper roller 503 is fixed to the upper link member 530. The upper frame 522 has a hollow portion, and the upper roller 503 on which the upper link member 530 is supported is accommodated in the hollow portion. When the roller unit 500 is located at the home position, the upper roller 503 is located away from the lower roller 504. When the roller unit 500 starts to move away from the home position, the upper link member 530 starts to rotate downward around the upper link shaft 531 by being pulled by the spring 550. Thereby, the upper roller 503 rotatably attached to the upper link member 530 is lowered. The upper roller 503 moves from a position away from the lower roller 504 to a position in contact with the lower roller 504.

  The upper link member 530 includes a conveyance guide roller 534 that presses the conveyance guide 414 downward during the folding process. When the roller unit 500 leaves the home position, the conveyance guide roller 534 descends in the same manner as the upper roller 503 and presses the bottom plate 415 of the conveyance guide 414 from above (see FIGS. 4A and 4B). The lowering of the conveyance guide roller 534 is realized by the same mechanism as the lowering of the upper roller 503 described later. The conveyance guide 414 holds the sheet bundle from above and prevents lateral deviation of the sheet bundle.

  On the other hand, the lower frame 524 has a hollow portion similar to the upper frame 522, and the lower roller 504, which is the other of the additional rollers 502, is accommodated in the hollow portion. The lower frame 524 rotatably supports the lower roller 504. The rotation shaft of the lower roller 504 is fixed to the lower frame 524 (that is, fixed to the unit frame 520). Therefore, even when the roller unit 500 moves, the position of the lower roller 504 in the height direction (or the thickness direction of the sheet bundle) does not change. In the present embodiment, the position of the upper end of the lower roller 504 is adjusted to a position substantially equal to the position of the flexible member 418. Accordingly, when the roller unit 500 moves, the lower roller 504 rotates while contacting the lower surface of the flexible member 418 (see FIG. 4B).

  As shown in FIG. 3, the lower link member 540 has a guide roller 544 that freely rotates. The guide roller 544 is a part of a configuration for causing the upper roller 503 to move up and down. The vertical movement of the upper roller 503 will be described later.

  Between the upper roller 503 and the lower roller 504, a pressing force due to the pulling force of the spring 550 works mutually. During the folding process, the sheet bundle is sandwiched between the upper roller 503 and the lower roller 504 via the flexible members 416 and 418. Therefore, the fold of the sheet bundle is strengthened by the pressing force between the upper roller 503 and the lower roller 504.

  Next, the structure of the drive unit 600 will be described. FIG. 6 is a schematic diagram for explaining the configuration of the drive unit 600. FIG. 6 is a view seen from the direction of arrow A in FIG. 3 and also shows the roller unit 500 in the home position. In addition, the structural members of the support part 400 are partially omitted for convenience of explanation. In the present embodiment, the home position of the roller unit 500 is set to a position that does not interfere even with a sheet bundle having the maximum processable size. On the other hand, of the range in which the roller unit 500 can move in the crease direction (the width direction intersecting the sheet bundle conveyance direction), the farthest position from the home position is the maximum size that can be processed by the nip portion of the folding roller 502. Is set in a range that does not pass through the end of the sheet bundle.

  The drive unit 600 includes a drive motor 602 that is a drive source of the folding unit 300. The drive motor 602 is a DC motor, for example, and the control unit 202 controls the rotation direction and the rotation speed. The driving force by the driving motor 602 is transmitted to the pulley 606 via the motor belt 604, and further transmitted from the gear 607 of the pulley 606 to the driving pulley 610 via the gear 608. The driving pulley 610 suspends the unit driving belt 614 together with the driven pulley 612.

  The unit driving belt 614 moves between the driving pulley 610 and the driven pulley 612 by the driving force of the driving motor 602. The unit drive belt 614 has a rack on the surface. The rack of the unit drive belt 614 is fitted with the connection portion 514 at the lower part of the roller unit 500. The unit drive belt 614 moves the roller unit 500 in the crease direction. When the rotation direction of the drive motor 602 is reversed, the moving direction of the unit drive belt 614 is reversed. Thereby, the roller unit 500 reciprocates.

  The control unit 202 of the sheet processing apparatus 200 shown in FIG. 1 controls the movement amount and movement speed of the unit drive belt 614, that is, the movement amount and movement speed of the roller unit 500 by controlling the rotation of the drive motor 602. The rotation amount and rotation speed of the drive motor 602 are detected by a pulse signal sequence output from an encoder sensor 616 disposed in the vicinity of the drive motor 602. The control unit 202 controls the rotation of the drive motor 602 based on the detected rotation amount and rotation speed. The drive motor 602 may be a pulse motor. In this case, the control unit detects the rotation speed by counting pulses directly output from the drive motor 602.

  Next, a mechanism for driving the upper roller 503 up and down will be described with reference to FIGS. 3, 6, and 7. FIG. 7 is a diagram for explaining a mechanism for driving the upper roller 503 up and down. As described above, the upper link member 530 and the lower link member 540 of the roller unit 500 are connected by the spring 550 at a position farthest from the respective rotation shafts (upper link shaft 531 and lower link shaft 541). Further, the lower link member 540 has a guide roller 544 that freely rotates.

  The support part 400 shown in FIGS. 3 and 4 includes a guide rail 700 having an L-shaped cross section as shown in FIGS. 6 and 7. The guide rail 700 has a first guide part 701 inclined near the home position and a second guide part 702 other than the first guide part 701. The second guide part 702 is arranged in parallel with the fold direction of the sheet bundle. In FIG. 7, an area where the first guide portion 701 is provided is an inclined area A1, and an area where the second guide portion 702 is provided is an effective drive area A2. The height in the moving direction of the upper link shaft 531 and the lower link shaft 541 of the roller unit 500 that moves in the inclined area A1 and the effective drive area A2 is constant.

  As shown in FIG. 7, in the inclined area A1, the roller unit 500 starts moving from the home position. When the roller unit 500 is driven by the drive belt 614 and leaves the home position, the guide roller 544 comes into contact with the bottom surface of the first guide portion 701 of the guide rail 700. Thereafter, the guide roller 544 descends along the bottom surface of the first guide portion 701. As the guide roller 544 descends, the lower link member 540 rotates counterclockwise in FIG. 7 about the lower link shaft 541. The upper link member 530 is also pulled by the spring 550 and rotates counterclockwise about the upper link shaft 531. As a result, the upper roller 503 between the upper link shaft 531 and the hook hole 532 of the spring 550 gradually descends while the roller unit 500 moves the first guide portion 701, and the upper roller 503 and the lower roller The interval with 504 gradually approaches. The upper roller 503 and the lower roller 504 come into contact with each other in the vicinity of the region where the first guide portion 701 ends. At this time, pressure (pressing) that presses each other acts between the upper roller 503 and the lower roller 504. This pressing is based on the pulling force by the spring 550.

  In the second guide portion 702 of the guide rail 700 (that is, the effective driving area A2), the upper roller 503 and the lower roller 504 apply pressure to the folds of the sheet bundle while maintaining the above-mentioned pressure, and strengthen the folds. The unit 500 moves while strengthening the crease along the crease, and temporarily stops at the end of the sheet bundle opposite to the home position. After that, while continuing to strengthen the crease, move on the return path and return to the home position. Note that the position of the end opposite to the home position (turning position) where the roller unit 500 stops and turns back may be determined based on sheet size information, or may be constant for all sheet sizes. good. In the present embodiment, it is determined based on sheet size information.

  The control unit 202 of the sheet processing apparatus 200 controls the driving start timing of the roller unit 500 at the home position. When the sheet bundle is conveyed to the folding unit 300, the control unit 202 determines whether or not the leading end portion of the folded sheet bundle has been conveyed to the folding position based on a signal from the sheet bundle detection sensor 422. . When the leading end of the sheet bundle, that is, the crease is conveyed to the folding position, the control unit 202 stops conveying the sheet bundle. Subsequently, the control unit 202 starts the movement (outward path) of the roller unit 500 from the home position. When the roller unit 500 moves from the home position, the detection member 560 shown in FIG. 3 changes from on to off.

  The control unit 202 moves the roller unit 500 in the crease direction by a predetermined amount from the position where the detection member 560 is turned off, and moves the roller unit 500 at the position of the sheet bundle end (folding position) opposite to the home position. Stop. The control unit 202 obtains the amount of movement of the roller unit 500 based on the number of pulses of the encoder of the drive motor 602 and the like. When the roller unit 500 stops at the turn-back position, the control unit 202 counts the stop time. When the stop time has elapsed for a predetermined time, the control unit 202 moves the roller unit 500 in the opposite direction (return path). The control unit 202 stops the roller unit 500 at the home position based on a signal from the detection member 560. The above-described operation is the flow of the folding process (first time). When the folding process is performed by reciprocating the roller unit 500 a plurality of times with respect to one sheet bundle, the operation control of the roller unit 500 is repeated.

  FIG. 8 is a schematic diagram for explaining the detection sensor 800. In FIG. 8, the roller unit 500 is omitted. The detection sensor 800 detects the folding height of the sheet bundle. The detection sensor 800 may be a general displacement sensor such as an optical type, an ultrasonic type, a laser focus type, or a contact type. For example, the detection sensor 800 detects a physical change amount up to the surface of the sheet bundle with an element, and calculates the change amount as a distance. By this calculation, the distance from the sensor to the sheet bundle can be calculated, and the folding height of the sheet bundle can be measured. In the present embodiment, the detection sensor 800 is disposed between the folding roller pair 262 and the roller unit 500, as shown in FIG. For example, the detection sensor 800 is attached to the frame 402 of the support unit 400. Here, the folding height of the sheet bundle (hereinafter referred to as the folding height) means the thickness of the sheet bundle that is creased by the folding roller pair 262. The detection sensor 800 is preferably disposed at a position where the folding height of the sheet bundle changes as the folds of the sheet bundle are reinforced by the roller unit 500 in the sheet conveyance direction. For example, the detection sensor 800 is disposed at a position where the swelling of the sheet bundle folded by the folding roller pair 262 can be detected.

(Folding control)
In the sheet processing apparatus 200 according to the present embodiment, the folding process is controlled based on the folding height of the sheet bundle.

  FIG. 9 is a flowchart for explaining the folding process of the sheet processing apparatus 200 according to the present embodiment. The sheet processing apparatus 200 measures the folding height of the sheet bundle folded by the folding unit 258. Alternatively, the sheet processing apparatus 200 measures the folding height of the sheet bundle after the roller unit 500 of the folding unit 300 reciprocates along the fold of the sheet bundle to strengthen the fold. The sheet processing apparatus 200 determines whether or not to execute the folding increase process based on the folding height of the sheet bundle.

  In ACT 901, the control unit 202 controls the rotation of the folding roller motor that drives the folding roller pair 262 of the folding unit 258 to convey the sheet bundle to the folding position by controlling the rotation of the folding roller pair 262 of the folding unit 258. The control unit 202 reciprocates the roller unit 500 to perform the first folding process (ACT 902). Note that the first fold-in process here means that the roller unit 500 reciprocates once along the fold of the sheet bundle to strengthen the fold. It is not limited to performing once. For example, the reciprocation of the roller unit 500 may be performed a plurality of times as the first folding process.

  The control unit 202 measures the folding height of the sheet bundle whose creases are reinforced by the roller unit 500 via the detection sensor 800 (ACT 903). The control unit 202 determines whether or not the measured folding height of the sheet bundle is below a threshold value (ACT 904).

  The folding height of the sheet bundle varies depending on the number of sheets and the sheet type. Therefore, the threshold value of the present embodiment is an ideal folding height obtained experimentally in advance, and is held in the memory 206 in a data format such as a lookup table, for example. The control unit 202 acquires sheet processing information such as the type of sheets to be processed and the number of sheets per bundle from the image forming apparatus 100. The control unit 202 sets an appropriate threshold based on the sheet processing information.

  If the measured folding height of the sheet bundle is below a preset threshold value (YES in ACT 904), the control unit 202 executes the first folding process, and then further moves the roller unit 500 back and forth. The folding process is terminated without performing the process (ACT 905).

  On the other hand, if the measured folding height of the sheet bundle exceeds a preset threshold value (No in ACT 904), the control unit 202 reciprocates the roller unit 500 and performs the second folding increase process again. Implement (ACT906). The control unit 202 again measures the folding height of the sheet bundle whose creases are strengthened by the roller unit 500 via the detection sensor 800 (ACT 903), and whether or not the measured folding height of the sheet bundle exceeds the threshold value. Is determined (ACT 904). In this second folding process, the roller unit 500 may be reciprocated once or a plurality of times, similarly to the first folding process described above.

  In the above description, the sheet bundle folded by the folding unit 258 is subjected to folding processing once by the ACT 902 (first folding processing), but the sheet processing apparatus 200 according to the present embodiment performs this processing. It is not limited. For example, the control unit 202 may not perform the process of ACT902. That is, when the sheet bundle folded by the folding unit 258 is conveyed to the folding unit 300, the control unit 202 measures the folding height of the sheet bundle folded by the folding unit 258, and measures the measured sheet. It may be determined whether or not the folding height of the bundle exceeds a threshold value, and based on the result, it may be determined whether or not the folding increase process is performed.

According to the sheet processing apparatus 200 of the above embodiment, the actual folding height of the sheet is measured, and when the folding height exceeds a preset threshold, the folding process of the roller unit 500 is added. Thus, an appropriate folding height can be obtained.
(Second Embodiment)

  The folding control according to the second embodiment will be described. In the second embodiment, information on the folding height of the sheet bundle before and after the folding process is further used. FIG. 10 is a flowchart for explaining the folding process of the sheet processing apparatus 200 according to the second embodiment.

  In ACT 1001, the control unit 202 controls the rotation of the folding roller motor that drives the pair of folding rollers 262 of the folding unit 258 to convey the sheet bundle to the folding position by controlling the rotation of the folding roller pair 262 of the folding unit 258. The control unit 202 reciprocates the roller unit 500, and performs the first folding process as in the first embodiment (ACT 1002).

  The control unit 202 measures the folding height of the sheet bundle whose creases are reinforced by the roller unit 500 via the detection sensor 800 (ACT 1003). The control unit 202 determines whether or not the measured folding height of the sheet bundle is below a threshold value (ACT 1004). If the measured folding height of the sheet bundle is below a preset threshold value (YES in ACT 1004), the control unit 202 terminates the folding increase process without performing any further reciprocation processing of the roller unit 500. (ACT1005).

  On the other hand, when the measured folding height of the sheet bundle exceeds a preset threshold value (No in ACT 1004), the control unit 202 reciprocates the roller unit 500 and again performs the folding increase process (second time) (Folding process) is performed (ACT 1006). The control unit 202 again measures the folding height of the sheet bundle whose folds are reinforced by the roller unit 500 via the detection sensor 800 (ACT 1007).

  In ACT 1008, the control unit 202 compares the folding height of the sheet bundle measured in ACT 1003 with the folding height of the sheet bundle measured in ACT 1007. That is, the control unit 202 compares the difference between the folding height of the sheet bundle after performing the first folding process in ACT 1003 and the folding height of the sheet bundle after performing the second folding process in ACT 1006. To do.

When the difference in folding height of the sheet bundle before and after the additional folding process (second folding process) in ACT 1006 is greater than a predetermined value (No in ACT 1008), the process of the control unit 202 is as follows. Return to the processing of ACT1004. On the other hand, when the difference in the folding height of the sheet bundle before and after the execution of the additional folding process is smaller than the predetermined value (ACT 1008: Yes), the measured folding height of the sheet bundle is larger than the threshold value. Even so, no further reciprocation process of the roller unit 500 is performed, and the folding process is terminated (ACT 1005). Here, the difference in the folding height of the sheet bundle before and after the additional folding process is smaller than the predetermined value means that the folding height changes much despite the additional folding process. It means no. Therefore, after that, even if additional folding processing is performed, it is determined that the folding height does not change so much, so the control unit 202 ends the folding processing. According to the sheet processing apparatus 200 of the present embodiment, the same effects as those of the first embodiment can be obtained, and an excessive increase in processing time can be appropriately prevented.
(Third embodiment)

  The sheet processing apparatus 200 according to the third embodiment determines whether or not the folding process by the roller unit 500 of the folding unit 300 can be executed.

  The roller unit 500 normally moves along the fold line of the sheet bundle folded by the folding unit 258. That is, the folding roller 502 of the roller unit 500 moves in the width direction intersecting the sheet conveyance direction of the folded sheet bundle, rides on the end portion of the sheet bundle, and then moves along the crease. The fold increase roller 502 reinforces the crease with a strong pressing force. Here, for example, when the sheet processing information from the image forming apparatus 100 indicates that the type of sheet to be processed is plain paper, but the actual sheet is thick paper or the like, depending on the number of sheets, the sheet bundle The folding height may exceed the specification range. In this case, the folding roller 502 of the roller unit 500 cannot ride on the end of the sheet bundle and may stop.

  Therefore, the sheet processing apparatus 200 according to the present embodiment determines whether or not the sheet bundle folded by the folding unit 258 can execute the folding process before the folding roller 502 of the roller unit 500 rides on the sheet bundle. . FIG. 11 is a schematic diagram for explaining a roller unit 500 according to the third embodiment. The same components as those in the other embodiments are denoted by the same reference numerals, and description thereof is omitted.

  FIG. 11A is a schematic diagram for explaining a roller unit 500 according to the third embodiment. In FIG. 11A, the sheet bundle folded by the folding unit 258 is conveyed in the direction of arrow B. The roller unit 500 includes a detection unit 900 for determining whether or not the sheet bundle can be folded. The detection unit 900 is attached to the upper frame 522 of the roller unit 500. The detection unit 900 includes a sensor 902 and an actuator 904 each having a light emitting unit and a light receiving unit.

  11B and 11C are schematic views of the roller unit 500 viewed from the direction of arrow C in FIG. In FIGS. 11B and 11C, the illustration of the unit support portion 510, the upper frame 522, and the lower frame 524 is omitted for the sake of explanation.

  In FIG. 11B, the roller unit 500 moves from the home position, which is a standby position, in the fold direction of the sheet bundle folded by the folding unit 258 (in the direction of arrow D). The detection unit 900 is positioned closer to the sheet bundle than the folding roller 502 in a state where the roller unit 500 stands by at the home position.

  The actuator 904 of the detection unit 900 is similarly projected from a rotation shaft 906, a first member 908 protruding from the rotation shaft 906, and a position away from the first member 908 in the circumferential direction of the rotation shaft 906. Two members 910. The first member 908 contacts the end of the sheet bundle when the folding height of the sheet bundle P conveyed to the folding position is equal to or higher than the height H. The second member 910 has a protrusion at the tip at a right angle to the protruding direction. The second member 910 rotates clockwise around the rotation shaft 906 as the roller unit 500 advances in the arrow D direction with the first member 908 contacting the end of the sheet bundle. As the second member 910 rotates, the protruding portion at the tip of the second member blocks between the light emitting unit and the light receiving unit of the sensor 902. As shown in FIGS. 11B and 11C, the roller unit 500 moves from the home position, which is a standby position, in the fold direction of the sheet bundle. The detection unit 900 moves together with the roller unit 500 in the fold direction of the sheet bundle.

  FIG. 12 is a flowchart for explaining control of the sheet processing apparatus 200 according to the third embodiment.

  In ACT 1201, the control unit 202 conveys the sheet bundle to the folding position via the folding roller pair 262. When the sheet bundle is conveyed to the folding position, the control unit 202 starts the folding process of the roller unit 500 and moves the roller unit 500 from the home position in the crease direction.

  In ACT 1203, the control unit 202 determines whether or not the folding height of the sheet bundle exceeds a predetermined value H. For example, the control unit 202 detects an ON / OFF signal from the detection unit 900.

  The detection unit 900 attached to the roller unit 500 reaches the end in the width direction of the sheet bundle P prior to the folding roller pair 502. Here, when the folding height of the sheet bundle P is equal to or less than the predetermined value H, the first member 908 does not contact the end portion and the upper surface of the sheet bundle. Therefore, the signal of the detection unit 900 indicates ON. On the other hand, when the folding height of the sheet bundle P exceeds a predetermined value H, the first member 908 contacts the end of the sheet bundle. When the first member 908 comes into contact with the end portion of the sheet bundle, the second member 910 rotates around the rotation shaft 906, and the protruding portion blocks between the light emitting portion and the light receiving portion of the sensor 902. That is, the signal of the detection unit 900 indicates OFF.

  When the folded height of the sheet bundle does not exceed the predetermined value H (No in ACT 1203), that is, when the detection unit 900 is ON, the control unit 202 continues to move the roller unit 500 in the fold direction, and folds the sheet unit. Increase processing is executed (ACT 1204). When the folding process is completed, the control unit 202 discharges the sheet bundle (ACT 1205).

  On the other hand, when the folding height of the sheet bundle exceeds the predetermined value H (Yes in ACT 1203), that is, when the detection unit 900 is turned off, the control unit 202 stops the movement of the roller unit 500 in the crease direction. (ACT 1206). For example, the control unit 202 stops the movement of the roller unit 500 in the crease direction before the folding roller 502 hits the end of the sheet bundle. In ACT 1207, the control unit 202 returns the roller unit 500 to the home position. Subsequently, the control unit 202 discharges the sheet bundle (ACT 1205). That is, when the folding height of the sheet bundle exceeds a predetermined value H, the control unit 202 discharges the sheet bundle without executing the folding increase process.

  In addition, the control unit 202 notifies the user that the sheet bundle has been discharged via the operation panel 112 without executing the folding process.

  According to the sheet processing apparatus 200 of the above-described embodiment, the roller unit 500 cannot get over the sheet bundle and is prevented from stopping as a jam. Therefore, the user does not need to perform an operation such as jam release, which is convenient.

  The detection unit 900 may be configured not only to detect the folding height of the sheet but also to detect the home position of the roller unit 500. For example, as shown in FIGS. 13A and 13B, when a protrusion 920 is provided on a support portion (not shown) and the roller unit 500 is at the home position, the protrusion 920 is a sensor 902 of the detection unit 900. It is good also as a structure which interrupts | blocks between the light emission part and light-receiving part. When the roller unit 500 starts moving in the crease direction, the sensor 902 that moves together with the roller unit 500 does not detect the protrusion 920. When the folding height of the sheet bundle exceeds the predetermined value H, the sensor 902 that has stopped detecting the protrusion 920 next detects the protrusion of the second member 910 of the actuator 904. Since the sheet processing apparatus 200 detects the home position of the roller unit 500 using the detection unit 900 instead of the detection member 560, the number of sensors can be reduced.

  According to at least one embodiment described above, more appropriate folding processing can be performed.

  Note that the entity that executes each operation of the above-described embodiment is an entity relating to a computer, such as hardware, a complex of hardware and software, software, software being executed, and the like. For example, the subject that performs the operation is a process, processor, object, executable file, thread, program, and computer executed on the processor, but is not limited thereto. In addition, a process or thread may perform a plurality of subjects that perform an operation.

  Although several embodiments of the present invention have been described, these embodiments are presented by way of example and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the scope of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalents thereof.

DESCRIPTION OF SYMBOLS 100 Image forming apparatus 116 Image forming part 200 Sheet processing apparatus 202 Control part 258 Folding unit 262 Folding roller pair 300 Folding unit 500 Roller unit 502 Folding roller 503 Upper roller 504 Lower roller 600 Drive part 800 Detection sensor

Claims (7)

A folding unit that folds a sheet bundle of a plurality of sheets to form a crease;
A fold-increasing roller that sandwiches the folds of the sheet bundle and reciprocates along the direction of the folds to reinforce the folds of the sheet bundle with respect to the sheet bundle that has been formed and conveyed to the folding position. When,
A detection sensor that is disposed between the folding unit and the folding roller along a sheet conveying direction and measures a folding height of the sheet bundle at the folding position;
A controller that reciprocates the folding roller based on the measurement result of the detection sensor;
A sheet processing apparatus comprising:   The sheet processing apparatus according to claim 1, wherein when the folding height of the sheet bundle exceeds a threshold, the controller reciprocates the folding roller.   The controller reciprocates the folding roller until the folding height of the sheet bundle falls below the threshold value, and discharges the sheet bundle when the folding height of the sheet bundle falls below the threshold value. The sheet processing apparatus according to claim 2.   The sheet processing apparatus according to claim 2 or 3, wherein the controller receives sheet processing information and sets the threshold based on the sheet processing information.   The controller compares the folding height of the sheet bundle before and after the folding process with the folding roller, and if the difference in folding height is less than a predetermined value, the folding height of the sheet bundle is the threshold value. 5. The sheet processing apparatus according to claim 2, wherein the sheet bundle is discharged regardless of whether or not the value is less than. An image forming unit that prints an image on a sheet;
A sheet processing apparatus that bundles printed sheets to form a sheet bundle and folds the sheet bundle to form a crease, and an image forming apparatus comprising:
The image forming apparatus according to claim 1, wherein the sheet processing apparatus is the sheet processing apparatus according to claim 1. A sheet folding method executed by a sheet processing apparatus including a folding unit for folding a sheet bundle, a detection sensor for measuring the folding height of the sheet bundle, and a folding roller,
The sheet bundle is folded by the folding unit to form a crease,
Conveying the sheet bundle formed with folds in the folding unit;
The sheet bundle is stopped at a folding position where a fold is strengthened by the folding roller,
Measure the folding height of the sheet bundle stopped at the folding position with the detection sensor arranged between the folding unit and the folding roller,
A sheet folding method comprising reinforcing the fold by reciprocating the fold-increasing roller along a fold of the sheet bundle formed by the folding unit based on a measurement result by the detection sensor.

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