JP5116093B2 - Sheet post-processing device - Google Patents

Description

  BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet post-processing apparatus that performs post-processing such as bookbinding, punching, and stamping on a sheet transported from an image forming apparatus such as a copying machine or a printer, and particularly, in a limited space of the image forming apparatus. The present invention relates to a sheet post-processing apparatus in which a plurality of trays for storing sheet bundles are arranged, and a tray for stacking and storing sheet bundles is switched and used in accordance with a post-processing mode.

  The sheet post-processing apparatus is provided with a processing tray at a paper discharge port of an image forming apparatus such as a copying machine or a printer. The processing tray is equipped with a post-processing apparatus such as a stapling apparatus, a punching apparatus, or a stamp apparatus. It is widely used as a device that performs post-processing on a series of sheets that are carried out, and stores the processed sheets in a downstream stacking tray.

  As an example of such a sheet post-processing apparatus, a post-processing apparatus is installed on the downstream side of the image forming apparatus, a first tray that stores sheets unloaded from the image forming apparatus without post-processing, and post-processing An apparatus including a second tray that stores applied sheets (bundles) is known (see, for example, Patent Document 1). In the sheet post-processing apparatus disclosed herein, the first and second trays are selectively switched to the processing tray disposed upstream of the paper discharge tray.

  As another example of the sheet post-processing apparatus, there is known a layout configuration in which a paper discharge port is disposed above the image forming unit and an image reading unit is further disposed above (see, for example, Patent Document 2). ). In this sheet post-processing apparatus, a configuration is disclosed in which a post-processing unit for stapling the stacked sheet bundle is disposed at a paper discharge port between the image forming unit and the image reading unit.

  In the unit configuration in the sheet post-processing apparatus disclosed in Patent Document 1, since the apparatus housing is connected in order of the image forming apparatus and then the post-processing apparatus, installation space is required, and the entire system becomes large. .

For this reason, Patent Document 2 intends to reduce the installation space of the system by adopting a layout configuration in which the post-processing unit is mounted on the image forming unit.
Japanese Patent Laid-Open No. 11-11783 JP 2006-248686 A

  However, the configuration disclosed in Patent Document 1 has a problem that the entire system is enlarged as described above. Further, in the unit configuration of Patent Document 1, the staple position for binding sheets (bundles) stacked on the tray and the folding blade (folding knife) for folding the sheet bundles are arranged at the same position. Since the layout configuration of the apparatus becomes complicated, the assembly work of the apparatus at the time of manufacture becomes complicated, and the product reliability is difficult.

  For this reason, it is conceivable that the post-processing unit is mounted on the image forming unit so that the center of the sheet bundle is stapled, and the sheet bundle is folded and stored in the paper discharge tray. In this layout configuration, the storage of processed sheets, that is, the discharge and storage of stapled sheets, the discharge and storage of folded sheets, the discharge and storage of unprocessed sheets, and the sheet discharge mechanism are provided. A new problem of complexity will arise.

  For this reason, the present invention has been made in view of various problems that the above-described conventional sheet post-processing apparatus has, and provides a sheet post-processing apparatus having a compact configuration while reducing the size of the system. It is the purpose.

In order to solve the above-described problems, the present invention provides a paper discharge port for discharging a sheet conveyed in a predetermined conveyance direction, and a downstream of the paper discharge port with respect to the conveyance direction. A folding unit having a sheet folding means for performing a folding process on the paper sheet; a folding processing path provided in the folding unit for introducing a sheet discharged from the paper discharge port into the sheet folding means; A sheet placing surface provided in the folding unit and configured to stack sheets discharged from the paper discharge port; a shift unit that moves the folding unit up and down; and an abutting part that regulates the lifting of the folding unit; The folding unit includes: a first position where a sheet discharged from the sheet discharge port is placed on the sheet placement surface without passing through the folding processing path; and a sheet discharged from the sheet discharge port. Sheet The sheet folding means is configured to freely move up and down between the second position introduced into the folding processing path, and the sheet folding means performs the folding process on the sheet introduced into the folding processing path, and the sheet the configured to discharge the sheet stacking surface, wherein the shifting means, stacking the sheets stacked on said sheet stacking surface, by pressing on the abutment part, on the sheet stacking surface The present invention provides a sheet post-processing apparatus characterized by strengthening the crease of the sheet.

Here, the folding unit is characterized by comprising the sheet stacking surface on the upper surface.

The processing tray in the sheet post-processing apparatus is provided with an alignment unit that aligns the sheets at a predetermined alignment position, and a sheet bundle unloading unit that unloads the aligned sheet bundle, and the sheet bundle unloading unit includes: The sheet on the processing tray is transferred to the folding unit.

  Further, the processing tray is provided with post-processing means for binding the end portions of the sheet bundle aligned by the aligning means.

  According to the present invention, when sheets such as single sheets, post-processing sheets such as binding and folding, interrupts, overflow (interrupt printing, etc.) sheets are separately stored in a plurality of trays, they are placed on the same placement surface. Since the number of trays can be reduced, the entire tray unit can be configured to be small and compact.

  Furthermore, in addition to reducing the number of trays, the tray unit with a built-in folding processing mechanism can be configured to be thin and compact so that it can selectively face the paper exit of the image forming apparatus. A lifting mechanism that selectively allows a plurality of tray units configured in a plurality of stages to face a paper discharge port can be configured in a small size and at low cost.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a schematic diagram showing an entire image forming system equipped with a sheet post-processing apparatus according to an embodiment of the present invention, and FIGS. 2 and 3 are schematic cross-sectional views of the sheet post-processing apparatus.

[Image forming system]
As shown in FIG. 1, the image forming system includes a sheet feeding device A, an image forming device B, a sheet post-processing device (hereinafter simply referred to as “post-processing device”) C, a document reading device D, and a document conveying device E. ing.

  The document transport device E transports the documents set on the document tray one by one onto the platen of the document reading device D and transports them onto the paper discharge tray. At this time, the image reading device D reads the document passing over the platen by the document conveying device E by the reading unit. The reading unit includes a lamp, a plurality of mirrors, a lens, and an image sensor. Then, the light irradiated by the lamp of the reading unit is reflected by the document surface, guided to the image sensor through a plurality of mirrors and lenses, and the image is read by the image sensor. The document image data read by the image sensor is subjected to predetermined image processing and transferred to the exposure control unit of the image forming apparatus B.

  The exposure control unit of the image forming apparatus B outputs laser light corresponding to the image signal. The laser beam is irradiated onto the photosensitive drum while being scanned by the polygon mirror. An electrostatic latent image corresponding to the scanned laser beam is formed on the photosensitive drum. The electrostatic latent image formed on the photosensitive drum is developed by a developing device and visualized as a toner image.

  On the other hand, a sheet on which an image is formed is conveyed from any cassette of the sheet feeding apparatus A including a plurality of cassettes to the transfer unit of the image forming apparatus B. Then, the toner image visualized in the transfer unit is transferred to the sheet conveyed from the sheet feeding device A to form an image. The sheet after the transfer is subjected to a fixing process in a fixing unit. Then, the sheet that has passed through the fixing unit is conveyed to the post-processing apparatus C.

  The sheet conveyed to the post-processing apparatus C is subjected to post-processing such as binding and folding by the processing unit 9 and is discharged to the storage unit 10.

[Post-processing device C]
Next, a sheet post-processing apparatus according to an embodiment of the present invention will be described based on FIG. 1, FIG. 2, and FIG.

  As shown in FIG. 1, the post-processing apparatus C of the present invention is disposed between the image forming apparatus B and the document reading apparatus D, and is provided with a processing unit 9 having a binding device on one end side in the horizontal direction. The storage unit 10 for storing the post-processed sheet is disposed. That is, this image forming system has a so-called in-cylinder carry-out function for storing the sheet discharged to the storage unit 10 in a space between the image forming apparatus B and the document reading apparatus D.

  FIG. 2 is a schematic cross-sectional view illustrating each functional unit of the post-processing apparatus C. As illustrated in FIG. 2, the post-processing apparatus C receives a sheet from the image forming apparatus B and conveys the sheet. A processing tray 14 for processing sheets fed by the section 11, an alignment section 12 for aligning sheets on the processing tray 14, a gripper / staple section 13 for performing staple processing on the aligned sheets, and a plurality of stack trays. And a saddle portion (sheet bundle folding portion) 15 which is provided on the lower surface side of one stack tray and performs stapling processing and folding processing on the sheet.

  Below, the detail of each function part of the post-processing apparatus C is demonstrated based on FIG.

(Transport section 11)
The conveyance unit 11 is provided with a conveyance path 20 that is continuous with the paper discharge port of the image forming apparatus B, and a conveyance roller pair 21 that conveys the sheet along the conveyance path 20. A carry-out roller pair 22 is provided at the carry-out port 20 c of the conveyance path 20, and the carry-out roller pair 22 sequentially carries out the sheets to the processing tray 14 disposed below the conveyance path 20. The conveyance path 20 includes a pair of guide plates 20a and 20b that guide the sheet.

  In the present embodiment, the sheet carried out by the carry-out roller pair 22 is placed in a state of being stretched between the processing tray 14 and a sheet placing surface or a folding processing path of a stack tray described later, Predetermined processing is performed.

(Alignment unit 12)
In the aligning unit 12, a stopper member 31 that aligns one end of the sheet carried out on the processing tray 14 and a top surface of the sheet carried out on the processing tray 14 are brought into contact with the upper surface of the sheet carried out from the pair of carry-out rollers 22. The forward and reverse rotation of the shift roller 30 for feeding the sheet in the unloading direction and the direction different from the unloading direction, and the end of the sheet on the processing tray 14 in the sheet width direction (perpendicular to the sheet unloading direction). An alignment member 32 (see FIG. 5) is provided.

  The stopper member 31 is configured to be rotatable about a support shaft 31a, and can move to a vertical alignment position and a substantially horizontal retraction position. The shift roller 30 is provided on one end side of an arm member 33 that is rotatably provided with a support shaft 33a having a polygonal cross section as a fulcrum, and the processing tray 14 is rotated by the rotation of the arm member 33. It is configured to be movable to a contact position that contacts the upper surface of the upper sheet and a retracted position that is retracted from the upper surface of the sheet. Further, the arm member 33 is configured to be movable in the sheet width direction along the support shaft 33a, and the shift roller 33 slides in the sheet width direction by the movement of the arm member 33.

  When the leading edge of the sheet is unloaded onto the processing tray 14, the shift roller 30 moves from the retracted position to the contact position before the trailing edge of the sheet has passed through the unloading roller pair 22, and further rotates to process the trailing edge of the sheet. The sheet is conveyed until it is discharged onto the tray 14. At that time, that is, while the shift roller 30 is rotating (forward rotation) in the sheet conveyance direction, the gripper unit 40 described later prevents the preceding sheet or the preceding sheet bundle stacked on the processing tray 14 from being fed together. The preceding sheet or the preceding sheet bundle is sandwiched. When the trailing edge of the sheet is discharged onto the processing tray 14, the rotation of the shift roller 30 is stopped. Thereafter, the gripper unit 40 releases the above-mentioned clamping, and the shift roller 30 continues to reversely rotate and feeds the sheet discharged onto the processing tray 14 in the direction opposite to the carry-out direction, that is, the direction toward the stopper member 31. The sheet fed by the shift roller 30 abuts against the stopper member 31 at the alignment position, and the feeding direction end is aligned. When the end in the sheet feeding direction is aligned, the rotation of the shift roller 30 is stopped, and the shift roller 30 is slid toward the alignment member 32 in a state where the shift roller 30 is in contact with the upper surface of the sheet. At this time, since the outer peripheral surface of the shift roller 30 is a high friction member such as urethane rubber, the sheet also slides toward the alignment member 32 following the sliding movement of the shift roller 30. The shift roller 30 slides and stops until one end in the width direction of the sheet comes into contact with the alignment member 32. As a result, the widthwise ends of the sheets are aligned. When the sheet alignment operation is completed, the arm member 33 rotates upward, and the shift roller 30 moves to a retracted position away from the upper surface of the sheet. At this time, the gripper unit 40 holds the preceding sheet or the preceding sheet bundle so that the sheet or the preceding sheet bundle stacked and aligned on the processing tray 14 does not move. Then, the arm member 33 and the shift roller 30 slide to the initial position at the approximate center of the processing tray 14 along the sheet width direction of the support shaft 33a, and the same alignment as when the next sheet is carried out onto the processing tray 14. Perform the action.

(Gripper / staple section 13)
Next, the gripper / staple unit 13 will be described. FIG. 4 is a schematic view showing an operation state in which the gripper unit 40 clamps a sheet bundle, and FIG. 5 is a plan view showing a configuration of the gripper / staple unit. As shown in these drawings, the gripper / staple unit 13 grips the sheet bundle aligned on the processing tray 14 and moves the sheet bundle moved to the staple processing position by the gripper unit 40. And a staple unit 41 for binding.

  The gripper unit 40 includes a pair of grip arms 44 (44a, 44b) for gripping the sheet bundle aligned on the processing tray 14. As shown in FIG. 4, the pair of grip arms 44 are provided so as to be fixed and support the lower surface of the sheet bundle and the fixed grip arm 44 a so as to oppose the upper surface of the sheet bundle. It consists of a movable grip arm 44b. Further, the gripper unit 40 is configured to be movable in the sheet feeding direction (arrow a in FIG. 5), and the sheet bundle can be gripped by the grip arm pair 44 and moved to the staple position. The gripper unit 40 of the present embodiment is provided with three grip arm pairs 44 as shown in FIG. 5, and these three grip arm pairs 44 are arranged at positions spaced apart by a predetermined interval in the seat width direction. .

  In the staple unit 41, a staple head and an anvil block are incorporated, a needle-like staple is bent into a U-shape and press-fitted into a sheet bundle, and a leading end thereof is bent by the anvil block to bind the sheet bundle. In the present embodiment, a staple head is attached to one of the upper and lower lever members whose base ends are supported by each other, and an anvil block is attached to the other, and the upper and lower lever members are reciprocated from the separated position to the pressure contact position by the drive cam member. A typical stapling unit is used.

  As shown in FIG. 5, a guide rail 43 for moving the staple unit 41 in the sheet width direction (arrow b in FIG. 5) is provided on the base 42 at the bottom of the post-processing apparatus C. The guide rail 43 is formed longer than the width of the maximum sheet, and can bind both ends of the sheet.

  With the above-described configuration, after the sheet bundle aligned on the processing tray 14 is gripped by the grip arm pair 44 of the gripper unit 40, the gripper unit 40 moves in the sheet feeding direction and moves the sheet bundle to the staple position. At this time, the above-described stopper member 31 has moved to a retracted position that does not hinder the movement of the sheet bundle by the gripper unit 40.

  Then, the sheet bundle moved to the staple position by the gripper unit 40 is subjected to a binding process at its end by the staple unit 41. Note that the binding process can be performed by an end binding process that performs a binding process on one side of a sheet bundle and a two-point binding process that performs a binding process at two predetermined positions at the end in the sheet conveyance direction. , And one of the end binding and the two-point binding is executed.

  The sheet bundle subjected to the binding process is again gripped by the grip arm pair 44 of the gripper unit 40. The gripper unit 40 moves in a direction different from the previous sheet feeding direction, that is, toward the storage unit 10 while the sheet bundle is gripped by the grip arm pair 44. Accordingly, the sheet bundle moves so as to be pushed out toward the storage unit 10 side. When the sheet bundle is moved to the storage unit 10, the gripper unit 40 releases the grip of the sheet bundle by the grip arm pair 44 and moves to an intermediate position between the stopper member 31 and the staple position until the next sheet bundle is processed. stand by.

(Storage part 10, saddle part 15)
Next, the storage unit 10 will be described with reference to FIG. A plurality of stack trays are arranged in the storage unit 10 on the downstream side of the processing tray 14 described above. In this embodiment, the first stack tray 50 and the second stack tray 51 are configured to be selectively connected to the processing tray 14.

  The first stack tray 50 includes a sheet placement surface 50a on which folded sheets are stacked and stored. Further, the second stack tray 51 is constituted by a tray member having a sheet placement surface 51 a continuous with the processing tray 14.

  On the lower surface side of the first stack tray 50, the sheet stack of the sheets stacked and aligned between the processing tray 14 and the folding processing path 60 is bound and then folded, and the sheet stacking surface of the first stack tray 50 is folded. A saddle unit (sheet bundle folding unit) 53 configured to be accommodated in 50a is provided.

  That is, the first stack tray 50 stores the folded sheet bundle from the saddle unit 53 that performs the binding process and the folding process on the sheet bundle, and the sheet bundle subjected to the end binding or the two-point binding by the staple unit 41. The In addition, the second stack tray 51 stores a sheet bundle that has been stapled by the staple unit 41 or bound at two places. Of course, the two stack trays can also store sheet bundles that are not bound or folded.

(Raising and lowering the stack tray)
The first and second stack trays 50 and 51 are supported on the frame of the post-processing apparatus C connected to the processing tray 14 so that the first and second stack trays 50 and 51 can be moved up and down independently.

  FIG. 6 is a schematic diagram for explaining, for example, an elevating mechanism as shift means for moving the stack tray up and down, FIG. 6 (a) is a longitudinal sectional view thereof, and FIG. 6 (b) is a partial plan view thereof. . The first stack tray 50 incorporating the saddle unit 53 and the second stack tray 51 are attached to the first and second support plates 71a and 71b, respectively.

  Two pinions 73a and 73b are attached to the surface of the first support plate 71a opposite to the surface to which the first stack tray 50 is attached. Each of the two pinions 73a and 73b meshes with racks 72a and 72b that are spaced apart in the horizontal direction. Then, when any one of the pinions 73a and 73b is rotationally driven by the motor 74, the support plate 71a moves along the racks 72a and 72b, and the first stack tray 50 moves up and down accordingly.

  The lifting mechanism for the second stack tray 51 has the same configuration as the first stack tray 50. That is, the two pinions 73c and 73d on the opposite surface of the second support plate 71b that supports the second stack tray 51 mesh with the racks 72a and 73b, respectively, and rotate one of the pinions 73c and 73d. As a result, the second stack tray 51 moves up and down.

  Each rack 72 a and 72 b is attached to a tray frame 70 provided in the storage unit 10.

  FIG. 7 is a view for explaining the raising / lowering position of the stack tray of the post-processing apparatus C. FIG. In FIG. 7A, the stack trays 50 and 51 are moved to positions where the sheets discharged from the processing tray 14 can be received from the sheet carry-in port 60 a of the first stack tray 50. In FIG. 7B, the stack trays 50 and 51 are moved to positions where the sheet discharged from the processing tray 14 can be received by the sheet placement surface 50 a of the first stack tray 50. In FIG. 7C, the stack trays 50 and 51 are moved to positions where the sheet discharged from the processing tray 14 can be received by the sheet placement surface 51 a of the second stack tray 51. This elevating mechanism moves these stack trays up and down based on a sheet processing mode signal from the outside.

(First stack tray 50)
Next, the configuration of the first stack tray 50 and the saddle unit 53 will be described in detail.

  As shown in FIG. 3, the saddle unit 53 includes, for example, a staple head unit 61 and an anvil unit 62 serving as a saddle stitch binding unit that binds the folding processing path 60 and the center (fold position) of the sheet bundle to the folding processing path 60. Further, a folding blade 63 and a pair of folding rollers 64 are provided on the downstream side of the staple head unit 61. That is, the first stack tray 50 has a sheet placement surface 50a formed by molding such as resin on the upper surface thereof, and has a folding processing path 60, a staple head unit 61, an anvil unit 62, and a bottom portion thereof. For example, a space for forming, as a unit, a folding blade 63 and a pair of folding rollers 64 as sheet folding means is formed. With this configuration, the user's fingers are prevented from touching the internal staple head unit 61, the anvil unit 62, the folding blade 63, and the folding roller 64 from the outside.

  Further, as described above, the first stack tray 50 is configured to be movable up and down in the storage unit 10. Accordingly, the first stack tray 50 is discharged from the processing tray 14 at a position (FIG. 7A) for receiving the sheet discharged from the processing tray 14 from the sheet carry-in port 60a of the saddle unit 53. The sheet can be moved to a position (FIG. 7B) for receiving the sheet on the sheet placement surface 50a according to post-processing applied to the sheet.

  In the first stack tray 50, the sheet bundle folded by the above-described sheet folding means (for example, the folding blade 63 and the folding roller pair 64) is stacked on the sheet placement surface 50a at regular intervals (for example, a certain number of copies). Every time, the sheet bundle on the sheet stacking surface 50a is raised against the top plate 70a (see FIG. 3) of the tray frame 70 as an abutting portion for restricting the raising of the stack tray. In this way, by sandwiching the sheet between the sheet placement surface 50a and the top plate 70a of the tray frame 70, the fold portion of the sheet bundle that has been folded and stacked on the sheet placement surface 50a is further strongly folded, The spread of folds can be prevented.

(Saddle stitching / Folding part)
In the folding processing path 60, a staple head unit 61 and an anvil unit 62, a folding conveyance roller pair 65, a folding blade (folding knife) 63, and a folding conveyance roller pair 66 are arranged in this order from the carry-in entrance 60a side. Further, a pair of folding rollers 64 is disposed at a position facing the folding blade 63 across the sheet.

  The staple head unit 61 that inserts staples into the sheet bundle carried into the folding processing path 60 includes a former member that bends a needle (blank) accommodated in a needle cartridge into a U-shape, and the needle as a sheet. And a drive cam and a drive motor for operating the driver member. The staple head unit 61 is supported so as to be movable in the sheet width direction, and is configured to bind two places (a plurality of places) of the sheet bundle in the sheet width direction.

  On the other hand, the anvil unit 62 that bends the needle tip is constituted by a stay member having a bending groove for bending the needle tip. In particular, the apparatus shown in FIG. 3 is provided with a plurality of folding grooves in the sheet width direction. The plurality of bending grooves are configured to bind together a plurality of preset positions in cooperation with the staple head unit 61.

  Further, the folding blade 63 folds and conveys the sheet bundle that has been subjected to the binding process (saddle stitching process) at substantially the center of the sheet so as to be folded into a booklet shape from the center (center folding), for example. It is arranged at a position between the roller pair 66. The folding blade 63 is supported so as to reciprocate so as to insert the sheet bundle into the nip position of the pair of folding rollers 64 from a direction orthogonal to the sheet bundle (see FIG. 9).

  The pair of folding rollers 64 is disposed in pressure contact with each other at a position facing the folding blade 63 via the sheet bundle. One folding roller 64a of the pair of folding rollers 64 is connected to a drive motor, and the other folding roller 64b is configured to be driven by one folding roller 64a (see FIG. 8). In the present embodiment, as shown in FIG. 8, the other folding roller 64b revolves with respect to one folding roller 64a to deflect the pressure contact direction. That is, the other folding roller 64b is moved in the direction along the sheet placement surface 50a from the first position (the position of the other folding roller 64b shown by the solid line in FIG. 8) that coincides with the sheet insertion direction by the folding blade 63. The sheet is revolved in the clockwise direction in the drawing to the second position (the position of the other folding roller 64b indicated by the broken line in FIG. 8) for carrying out the sheet. Accordingly, as shown in FIG. 8, the discharge direction of the folded sheet bundle is deflected by the angle θ, and the folded sheet bundle is smoothly discharged between the preceding sheet bundle and the sheet placing surface 50a.

  In addition, 60b shown in FIG. 8 is an overrun opening of the sheet, and temporarily guides the leading end of the sheet conveyed from the folding processing path 60 to the outside of the saddle unit 53. The folding processing path 60 is configured to be supported (bridge supported) across the processing tray 14 and the folding processing path 60 in a state of being connected to the processing tray 14. Accordingly, the processing tray 14 can be configured to be short and compact with respect to the sheet length, and at the same time, the sheet bundle is gripped by the gripper unit 40 and the sheet bundle is placed at the saddle stitching position SP2 (see FIG. 8). Can be transported.

  Further, the first stack tray 50 is formed with a paper discharge port 50b for discharging the sheet from the pair of folding rollers 64 to the sheet placement surface 50a.

(Saddle 15)
Next, a configuration for carrying out a sheet (folded sheet) folded by the folding blade 63 from the sheet discharge outlet 50b in the first stack tray 50 described above will be described.

  A folded sheet from the folding processing path 60 to the sheet placement surface 50a through the paper discharge outlet 50b is configured to be carried out from below to above in a substantially U-shaped path. A sheet placement surface 50 a is arranged on the folding processing path 60, and the sheet folded by the folding processing path 60 is configured so that the conveyance direction is reversed by the saddle unit 53.

  That is, in FIG. 2, the sheet is conveyed from the processing tray 14 in the left direction in the figure, but the folded sheet loading direction is reversed in the right direction in the figure at the paper discharge port 50b. This state will be described with reference to FIG.

  First, as shown in FIG. 8, a sheet discharge stopper 67 is disposed on the sheet placement surface 50a to restrict the position of the leading end (folded end side) of the folded sheet. The paper discharge stopper 67 is configured to be movable in the direction of arrow c in FIG. And it moves to the optimal position according to a sheet size by the drive means not shown, and changes the position of the folding sheet accommodated on the sheet | seat mounting surface 50a.

  Further, as shown in FIG. 8, in the vicinity of the discharge port 50 b formed on the sheet placement surface 50 a, when the folded sheet is carried into the sheet placement surface 50 a, the rear end side of the folded sheet is lifted upward, A movable lever member 68 is provided for reliably discharging the sheet from the discharge port 50b onto the sheet placement surface 50a. The movable lever member 68 is disposed so as to straddle the pair of folding rollers 64, and one end of the movable lever member 68 is axially supported by the support shaft 68a, and is configured to be rotatable around the support shaft 68a. An eject roller 69 is provided at the other end of the movable lever member 68.

  The movable lever member 68 operates when the rear end of the folded sheet conveyed to the paper discharge port 50 b by the folding roller pair 64 passes through the folding roller pair 64. Specifically, as shown in FIG. 8, an eject roller 69 provided at the end of the movable lever member 68 rotates about the support shaft 68a in the direction of the arrow d in FIG. The folded sheet is pushed up and guided onto the sheet placement surface 50 a of the first stack tray 50.

  The eject roller 69 is connected to a drive motor (not shown), and rotates in the clockwise direction in the drawing to prevent the sheet bundle from moving in the direction opposite to the discharge stopper 67 side by the rotation of the movable lever member 68. To do.

(Saddle stitching, center folding)
Next, saddle stitching and center folding operations will be described. First, the aligning unit 12 executes alignment operation to align the sheet bundle P that is stacked across the processing tray 14 and the folding processing path 60 by the pair of carry-out rollers 22. The aligned sheet bundle P is gripped by the gripper unit 40 and transferred so as to be pushed out from the processing tray 14 so that the approximate center of the sheet bundle P is positioned at the saddle stitching position SP2.

  When the center of the sheet bundle P reaches the saddle stitching position SP2, the staple head unit 61 is operated, and saddle stitching processing is performed at two predetermined locations by the staple head unit 61 and the anvil unit 62. When the saddle stitching process is completed, gripping of the gripper unit 40 with respect to the sheet bundle P is released, and one roller of the pair of folding conveyance rollers 65 is pressed against the other roller. At the same time, one roller of the folding conveyance roller pair 66 is pressed against the other roller. As a result, the sheet bundle P is sandwiched between the folding conveyance roller pair 65 and the folding conveyance roller pair 66. Then, the conveying roller pair 65 is driven and conveyed until the approximate center of the sheet bundle P reaches the folding position FP (see FIG. 8).

  When the approximate center of the sheet bundle reaches the folding position FP, the folding blade 63 is actuated as shown in FIG. As a result, the folding blade 63 moves forward toward the nip portion of the pair of folding rollers 64 while pressing the central portion of the sheet bundle P. That is, the folding blade 63 moves forward toward the sheet placement surface 50a side of the first stack tray 50, and the saddle stitching portion of the central portion of the sheet bundle P is formed by the folding roller pair 64 as shown in FIG. Press to push into the nip. At this time, the folding roller pair 64 also rotates simultaneously with the operation of the folding blade 63.

  The sheet bundle P is sandwiched between the folding roller pair 64 from the center by the pushing operation of the folding blade 63 into the nip portion of the folding roller pair 64 and the rotating operation of the folding roller pair 64, and is conveyed toward the paper discharge port 50b. Is done. The folding blade 63 moves forward until the tip portion reaches a predetermined position that has passed through the nip position of the folding roller pair 64, and when the sheet bundle P is sandwiched between the folding roller pair 64, the folding blade 63 moves backward and returns to a predetermined standby position. . At this time, the folding and conveying roller pair 65 and the folding and conveying roller pair 66 are separated from each other, and the nipping of the sheet bundle is released.

  When the folding blade 63 moves backward, passes through the nip position of the pair of folding rollers 64 and is separated from the sheet bundle P, the other roller 64b of the pair of folding rollers 64 is moved relative to one roller 64a as shown in FIG. Revolve to deflect the direction of pressure contact. As a result, the discharge direction of the sheet bundle P by the folding roller pair 64 changes, and the sheet bundle is smoothly discharged onto the sheet placement surface 50a of the first stack tray 50. Then, when the trailing end of the discharged sheet bundle passes the folding roller pair 64, the above-described movable lever member 68 is operated. The movable lever member 68 pushes up the rear end side of the sheet bundle by an eject roller 69 provided at the end of the movable lever member 68 while rotating, and the sheet bundle P is moved onto the sheet placement surface 50 a of the first stack tray 50. To guide. Then, after the movable lever member 68 is rotated from the initial first position to the second position for pushing up the sheet bundle P, the movable lever member 68 is rotated back to the first position again and enters a standby state.

  Then, when the next sheet bundle is aligned on the processing tray 14, the same saddle stitching and center folding operations are executed, and the preceding sheet bundle discharged onto the sheet placement surface 50a of the first stack tray 50 is processed. Insert and stack subsequent sheet bundles below.

(Second stack tray 51)
The above-described second stack tray 51 is configured to have a shape capable of stacking sheets by molding such as resin. In the second stack tray 51, a level sensor 80 for detecting the stacking height position of the sheets is attached to the frame on the processing unit 9 side. The position of the second stack tray 51 is lowered in accordance with the amount of sheets stacked on the sheet placement surface 51a.

  As described above in detail, according to the present invention, when a single sheet, a post-processing sheet such as binding or folding, a sheet such as an interrupt or an overflow is stored separately in a plurality of trays, the folded sheet and the folding process are performed. Since sheets that are not to be stacked are stacked on the same sheet placement surface, the number of trays can be reduced, and the tray unit can be configured to be small and compact and inexpensive.

  Since the number of trays can be reduced as described above, the entire tray unit can be made compact and compact. In addition, it is possible to configure a lifting mechanism that allows a plurality of tray units configured in a plurality of upper and lower stages to selectively face a paper discharge port in a small and inexpensive manner.

  In addition, this invention is not limited to the said embodiment, A various deformation | transformation is possible based on the meaning of this invention, and these are not excluded from the scope of the present invention.

  BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet post-processing apparatus that performs post-processing such as bookbinding, punching, and stamping on a sheet transported from an image forming apparatus such as a copying machine or a printer, and particularly, in a limited space of the image forming apparatus. The present invention has industrial applicability with respect to a sheet post-processing apparatus in which a plurality of trays for storing sheet bundles are arranged and the trays for stacking and storing sheet bundles are switched in correspondence with the post-processing mode.

1 is a schematic diagram illustrating an entire image forming system equipped with a sheet post-processing apparatus according to an embodiment of the present invention. It is a cross-sectional schematic diagram of the sheet post-processing apparatus according to an embodiment of the present invention. It is a cross-sectional schematic diagram which shows the detail of the sheet | seat post-processing apparatus of FIG. FIG. 3 is a schematic diagram illustrating an operation state in which a gripper unit clamps a sheet bundle in the sheet post-processing apparatus of FIG. 2. FIG. 3 is a plan view showing a configuration of a gripper / staple unit of the sheet post-processing apparatus of FIG. 2. It is a schematic diagram which shows the raising / lowering mechanism of the stack tray of the sheet | seat post-processing apparatus of FIG. It is a schematic diagram which shows the raising / lowering position of the stack tray of the sheet | seat post-processing apparatus of FIG. FIG. 3 is a schematic diagram illustrating a configuration and operation of a saddle unit of the sheet post-processing apparatus of FIG. 2. FIG. 4 is a schematic diagram illustrating a half-folding operation in a saddle unit of the sheet post-processing apparatus of FIG. 2.

Explanation of symbols

A sheet feeding device B image forming device C sheet post-processing device D document reading device E document transport device 9 processing unit 10 storage unit 11 transport unit 12 alignment unit 13 gripper / staple unit 14 processing tray 15 saddle unit (sheet bundle folding unit)
20 Transport path 20a, 20b Guide plate 20c Unloading port 21 Conveying roller pair 22 Unloading roller pair 30 Shift roller 31 Stopper members 31a, 33a, 68a Support shaft 32 Alignment member 33 Arm member 40 Gripper unit 41 Staple unit 42 Base 43 Guide rail 44 Grip arm pair 44a Fixed grip arm 44b Movable grip arm 50 First stack tray 50a, 51a Sheet placement surface 50b Paper discharge port 51 Second stack tray 53 Saddle unit (sheet bundle folding unit)
60 Folding path 60a Sheet carry-in port 61 Staple head unit 62 Anvil unit 63 Folding blade 64 Folding roller pair 64a, 64b Folding roller 65 Folding conveyance roller pair 66 Folding conveyance roller pair 67 Discharge stopper 68 Movable lever member 69 Eject roller 70 Tray Frame 70a Top plate 71a First support plate 71b Second support plate 72a, 72b Rack 73a, 73b, 73c, 73d Pinion 80 Level sensor

Claims (4)

A discharge port for discharging a sheet conveyed in a predetermined conveyance direction;
A folding unit that is provided downstream of the paper discharge port with respect to the transport direction and includes a sheet folding unit that performs a folding process on the sheet discharged from the paper discharge port;
A folding processing path that is provided in the folding unit and introduces a sheet discharged from the sheet discharge port into the sheet folding unit;
A sheet mounting surface provided in the folding unit and configured to stack sheets discharged from the discharge port;
Shift means for moving the folding unit up and down;
An abutting part that regulates the rise of the folding unit;
With
The folding unit discharges the sheet discharged from the sheet discharge port from a first position where the sheet is mounted on the sheet mounting surface without passing through the folding processing path and the sheet discharge port. The second position where the sheet is introduced into the folding processing path is configured to be movable up and down,
The sheet folding means is configured to perform the folding process on a sheet introduced into the folding processing path and to discharge the sheet to the sheet placement surface,
The shift means strengthens the folds of the sheets stacked on the sheet mounting surface by pressing the sheets stacked on the sheet mounting surface against the abutting portion. Post-processing device.   The sheet post-processing apparatus according to claim 1, wherein the folding unit includes the sheet placement surface on an upper surface. A processing tray disposed at the paper discharge port and for aligning sheets conveyed in a predetermined conveyance direction,
The processing tray is provided with an alignment unit that aligns the sheets at a predetermined alignment position, and a sheet bundle unloading unit that unloads the aligned sheet bundle,
The sheet post-processing apparatus according to claim 1, wherein the sheet bundle carrying-out means transfers a sheet on the processing tray to the folding unit.   The sheet post-processing apparatus according to claim 3, wherein a post-processing unit that binds an end portion of the sheet bundle aligned in the alignment unit is disposed in the processing tray.

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