JP4302280B2 - Folded sheet stacking apparatus and image forming apparatus equipped with the apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a sheet stacking apparatus that stacks folded sheets or sheet bundles, and an image forming apparatus such as a copying machine, a printer, a facsimile, and a composite device including the apparatus.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, there is a type of image forming apparatus in which a sheet post-processing device is provided in a main body. In the image forming apparatus main body, the sheet post-processing apparatus receives a plurality of sheets on which images are formed in a sequentially stacked state, aligns them into a sheet bundle, and binds the central portion of the sheet bundle with a stapler. The sheet bundle is folded in half at the center of the sheet bundle, and the sheet bundle is formed into a document bound in a shape like a weekly magazine and discharged to a discharge tray.
[0003]
In such a sheet post-processing apparatus, the sheet folding device receives and conveys the conveyed sheet bundle by a pair of sheet folding rotating bodies, and a position where an intermediate portion of the sheet faces a portion where the sheet folding rotating bodies are in contact with each other When the sheet folding member comes into contact with the sheet folding member, the sheet pushing member pushes between the sheet folding members, and the sheet folding member pair is rotated to fold the sheet bundle into two.
[0004]
However, the folded sheet bundle discharged to the discharge tray is sequentially discharged and stacked on the discharge tray with the folded side first, but the folded side is higher than the open end, so the folded side is higher. It will be stacked in an unstable state.
[0005]
As a discharge tray for coping with such a problem, there is a discharge tray 85 shown in FIG. The discharge tray 85 supports the open end Pb of the folded sheet bundle P with a projection 85a protruding on the discharge tray, and the sheet bundle P can be leveled and stacked in a stable state. ing.
[0006]
There is also a discharge tray 86 shown in FIG. The discharge tray 86 is configured such that the moving member 87 moves in accordance with the number of stacked sheet bundles. By moving the moving member 87, the stacking position of the sheet bundles is sequentially shifted like a roof tile and the sheets are moved. The bundles are loaded in a flat manner and are loaded in a stable state.
[0007]
Sheets include plain paper, substitutes for plain paper resin, and cardboard.
[0008]
[Problems to be solved by the invention]
However, the discharge tray 85 in FIG. 18 increases in proportion to the number of stacked sheet bundles, and accordingly, a large space is required above the discharge tray.
[0009]
Further, the discharge tray 86 in FIG. 19 needs to be lengthened in proportion to the number of stacked sheet bundles, and accordingly requires a large stacking area.
[0010]
In the above description, the case where the folded sheet is a sheet bundle has been described, but the same problem occurs when a single folded sheet is stacked and stacked.
[0011]
SUMMARY An advantage of some aspects of the invention is that it provides a sheet stacking apparatus including a discharge tray that does not require a large stack space for folded sheets, and an image forming apparatus including the sheet stacking apparatus.
[0012]
[Means for Solving the Problems]
  Achieve the above objectivesForOf the present inventionFoldThe sheet stacking apparatus has a discharge tray in which a concave portion for receiving the end portion of the folded sheet discharged with the folded end portion first is formed at a downstream end in the discharge direction of the folded sheet.A stopper member provided at the downstream end of the discharge tray and receiving the end of the folded sheet discharged to the discharge tray, the stopper member being displaceable in the discharge direction, and the stopper member in the discharge direction. And an elastic member that regulates the amount of displacement of the stopper member in the discharge direction.
[0014]
  The initial position of the stopper member is set to a position for receiving the maximum size folded sheet.
  The upper end of the stopper member can be tilted in the discharge direction, with the lower portion serving as a fulcrum by a rotating shaft.
  The stopper member is linearly movable in the discharge direction along the guide rail.
[0015]
In order to achieve the above object, an image forming apparatus of the present invention includes an image forming unit that forms an image on a sheet, a sheet folding device that folds a sheet on which an image is formed by the image forming unit, and creates a folded sheet; And any one folded sheet stacking apparatus that receives folded sheets created by the sheet folding apparatus.
[0016]
In order to achieve the above object, an image forming apparatus of the present invention includes an image forming unit that forms an image on a sheet, a sheet bundle binding device that binds a sheet on which an image is formed by the image forming unit in a bundle, and the above A sheet folding device that folds the sheet bundle bound by the sheet bundle binding device to create a folded sheet bundle, and any one folded sheet stacking device that receives the folded sheet bundle created by the sheet folding device. ing.
[0017]
(Function)
The discharge tray receives and stacks the folded sheets sequentially discharged one after another with the folded end first. At this time, the folded end portion of the folded sheet is swollen, but the discharge tray receives the swollen portion of the lowermost folded sheet by the concave portion. For this reason, the discharge tray alleviates the difference in thickness between the swelled portion of the folded sheet and the open end of the folded sheet, and supports the folded sheets stacked and stacked in a substantially horizontal state.
[0018]
When the discharge tray sequentially receives the folded sheets that are sequentially discharged with the folded end first, the folded sheet that has been stacked first is folded by the contact resistance between the folded sheets. The sheet may be moved downstream in the folded sheet discharge direction. In such a case, the stopper member provided on the downstream side of the discharge tray in the folded sheet conveyance direction is displaced downstream in the folded sheet discharge direction while receiving the moved folded sheet. As a result, the folded sheets are stacked with their positions slightly shifted to the downstream side in the folded sheet discharge direction without overlapping the swollen portions in the vertical direction, and are substantially horizontally supported by the discharge tray.
[0019]
In addition, since the discharge tray can be displaced when taking out the folded sheet, it does not interfere with taking out the folded sheet.
[0020]
The folded sheet in the description of the above operation includes both cases when the number of sheets is one, and when the sheets are bundles of sheets. Therefore, the folded sheet in the claims includes both cases where the number of sheets is one and the sheets are bundled.
[0021]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0022]
(Copier body)
A main body of a copying machine as an example of an image forming apparatus provided with a sheet post-processing apparatus having a folding unit (sheet folding apparatus) for folding a sheet according to the present invention will be described with reference to FIG.
[0023]
The main body 1 of the copying machine 20 includes a platen glass 906 as a document placement table, a light source 907, a lens system 908, a paper feeding unit 909, an image forming unit 902, and the like. An automatic document feeder 940 that automatically feeds the document D to the platen glass 906 is provided at the top of the main body 1.
[0024]
The sheet feeding unit 909 includes cassettes 910 and 911 that store recording sheets S and are detachable from the main body 1, and a deck 913 disposed in a pedistyle 912. An image forming unit (image forming unit) 902 includes a cylindrical photosensitive drum 914, a developing unit 915 disposed around the photosensitive drum 914, a transfer charger 916, a separation charger 917, a cleaner 918, a primary charger 919, and the like. I have. On the downstream side of the image forming unit 902, a conveying device 920, a fixing device 904, a pair of paper discharge rollers 1a and 1b, and the like are disposed.
[0025]
The operation of each mechanism in the main body 1 of the copying machine 20 will be described.
[0026]
When a paper feed signal is output from the control device 921 provided in the main body 1, the sheet S is fed from the cassettes 910 and 911 or the deck 913. On the other hand, the light reflected from the light source 907 on the document D placed on the platen glass 906 is applied to the photosensitive drum 914 through the lens system 908. The photosensitive drum 914 is charged in advance by a primary charger 919, and an electrostatic latent image is formed by irradiation with light, and then the electrostatic latent image is developed by a developing device 915 to form a toner image. .
[0027]
The sheet S fed from the sheet feeding unit 909 is corrected in skew by the registration roller 901 and further sent to the image forming unit 902 at the same timing. In the image forming unit 902, the toner image on the photosensitive drum 914 is transferred to the fed sheet S by the transfer charger 916. The sheet S to which the toner image has been transferred is charged to a polarity opposite to that of the transfer electric device 916 by the separation charger 917 and separated from the photosensitive drum 914.
[0028]
The separated sheet S is conveyed to the fixing device 904 by the conveying device 920, and the transfer image is permanently fixed on the sheet S by the fixing device 904. The sheet S on which the image is fixed is discharged from the main body 1 to the outside by a pair of discharge rollers 1a and 1b.
[0029]
In this way, an image is formed on the sheet S fed from the sheet feeding unit 909 and is discharged to the sheet post-processing apparatus 2.
[0030]
(Sheet post-processing equipment)
(Sheet acceptance and alignment of sheet post-processing equipment)
In FIG. 1, a sheet post-processing apparatus (also called “finisher”) 2 is provided on the side of a main body 1 of a copying machine.
[0031]
A paper discharge roller 1a provided on the main body 1 of the copying machine 20 and a paper discharge roller 1b pressed against the paper discharge roller 1a constitute a paper discharge roller pair. The conveyance guide pair 3 receives the sheets discharged from the paper discharge roller pair 1 a and 1 b of the copying machine 20 and guides them into the sheet post-processing apparatus 2. The sheet detection sensor 4 detects a sheet conveyed in the conveyance guide 3. The sheet detection of the sheet detection sensor 4 determines the alignment timing and the like, and also functions to detect whether the sheet is jammed (not jammed) in the conveyance guide 3. The discharge roller pair 6 rotates and sandwiches and conveys the sheet in the conveyance guide 3.
[0032]
The processing tray 8 receives and stacks sheets discharged one after another by the discharge roller pair 6. The processing tray 8 is provided with a pair of alignment plates 9 that guide the both ends of the width of the sheet discharged by the discharge roller pair 6 and perform width alignment. As shown in FIG. 2, the alignment plates 9 and 9 are arranged on both ends in the width direction intersecting with the sheet conveying direction. Each alignment plate 9, 9 has a rack 16 integral with the alignment plate 9 that meshes with a pin-on 15 provided on the shaft of an alignment motor 14 formed of a stepping motor disposed below the processing tray 8. The aligning motor 14 and the back aligning motor 14 are provided in the processing tray 8 so as to move appropriately in the sheet width direction.
[0033]
In FIG. 1, a carry-in guide 7 is a guide for guiding the sheet discharged from the discharge roller pair 6 into the processing tray 8. A paddle 17 is provided below the carry-in guide 7. The paddle 17 is formed in a semicircular shape from a rubber material or the like having a certain elasticity in order to ensure the carry-in of the sheet, is in contact with the upper surface of the sheet, and rotates about the shaft 17a. Yes. Further, the paddle 17 is formed by integrally forming fins 17b extending radially around the shaft 17a and a paddle surface 17c. The paddle 17 is easily deformed as the sheets are stacked on the processing tray 8, and gives an appropriate conveying force to the sheets.
[0034]
The processing tray 8 is further provided with a first pulley 10 provided on the first pulley shaft 10a and a second pulley 11 provided on the second pulley shaft 11a on the left and right in FIG. . A transfer belt 12 is stretched between the first pulley 10 and the second pulley 11, and an extrusion claw 13 is projected from a part of the outer periphery of the transfer belt 12.
[0035]
Further, a lower conveying roller 18 is coaxially provided on the first pulley shaft 10a. Above the lower conveyance roller 18, a position where the conveyance upper roller 19 is pressed against the lower conveyance roller 18 (a dotted line position in FIG. 1), and a separation position away from the conveyance lower roller 18 (solid line in FIG. 1). Is provided to move between.
[0036]
The stopper 21 is discharged onto the processing tray 8 by the discharge roller pair 6 and falls due to its own weight, and further receives and regulates the end of the sheet that moves by rotation on the paddle 17. One end of the stopper 12 is supported by the first pulley shaft 10a, and is always protruded by a spring (not shown) or the like to a position that regulates the end of the seat.
[0037]
(Stapler unit for sheet post-processing equipment)
The stapler unit (sheet bundle binding device) 30 is unitized as indicated by a two-dot chain line in FIG. 1, and can be pulled out from the sheet post-processing device 2. The stapler unit 30 has a needle driving head unit 31 having a needle cartridge (not shown) on the lower side across the conveyance path, and an anvil unit 33 for bending a needle driven from the needle driving head unit 31 on the upper side. Yes. The needle driving head unit 31 and the anvil unit 33 are movable in a direction (front and back direction on the paper surface) intersecting the sheet conveyance direction (from the right side to the left side in FIG. 1). The guide rods 33 and 34 are provided up and down so as to guide the movement (shift movement) of the anvil unit 32 and the driving head unit 31 in the direction intersecting the sheet conveying direction, respectively. The screw shafts 35 and 36 are screw shafts for shifting the anvil unit 32 and the driving head unit 31. The anvil drive shaft 37 and the head drive shaft 38 are drive shafts for causing the anvil unit 32 and the driving head unit 31 to perform a needle driving operation and a needle bending operation, respectively. The conveyance guide 39 guides a sheet bundle conveyed in the stapler unit 30.
[0038]
(Folding unit of sheet post-processing device (sheet folding device))
The sheet bundle folding unit 50 is unitized as shown by a two-dot chain line in FIG. 1 and can be pulled out from the sheet post-processing apparatus 2 in the same manner as the stapler unit 30. The sheet bundle conveyance guide 53 guides a sheet bundle conveyed between the conveyance upper roller 19 and the conveyance lower roller 18 positioned on the entry side of the stapler unit 30. The bundle conveying upper roller 51 is provided on the entry side of the folding unit 50. The lower conveying roller 52 is disposed to face the bundle conveying roller pair 51. The bundle conveying upper roller 51 moves between the position pressed against the bundle conveying lower roller 52 (the position indicated by the solid line in FIG. 1) and the position separated (the position indicated by the one-dot chain line in FIG. 1). Yes. The upper bundle conveying roller 51 is moved until the leading end portion of the sheet bundle passes through the upper bundle conveying roller 51 and the lower bundle conveying roller 52 by the upper conveying roller 19 and the lower conveying roller 18 positioned on the entry roller side of the stapler unit 30. In this state, the roller is separated from the lower conveyance roller 52 (the position indicated by the one-dot chain line in FIG. 1), and then moved to the position in contact with the lower bundle conveyance roller 52 (the position indicated by the solid line in FIG. 1). .
[0039]
When the bundle detection sensor 54 that detects the end of the sheet bundle detects the leading edge of the sheet bundle, the bundle conveyance upper roller 51 is pressed against the bundle conveyance upper roller 52 and the folding position in the sheet bundle conveyance direction is set and controlled. To be used. The thrust plate 55 is a stainless steel plate having a tip thickness of about 0.25 mm. The pair of folding rollers (sheet folding rotating body pair) 57a and 57b are cylindrical rollers having partial flat portions extending in a direction intersecting the sheet bundle conveying direction, and are respectively urged and rotated in a pressing direction. It is like that.
[0040]
The pushing plate 55 is positioned almost directly above the pair of folding rollers 57a and 57b, and the leading edge thereof moves to the vicinity of the nip between the pair of folding rollers 57a and 57b. In addition, around the pair of folding rollers 57a and 57b, substantially arc-shaped backup guides 59a and 59b for guiding the conveyance of the sheet bundle are provided together with the conveyance guide 53. The backup guides 59a and 59b are linked to the sheet bundle of the folding roller pairs 57a and 57b when the leading edge of the thrusting plate 55 moves to the vicinity of the nip of the folding roller pairs 57a and 57b in conjunction with the vertical movement of the thrusting plate 55. It moves to open the peripheral surface. The sheet bundle guide 56 guides the sheet bundle conveyed by being sandwiched between the bundle conveyance upper roller 51 and the bundle conveyance lower roller 52, and the leading end portion (downstream end portion) of the sheet bundle is the sheet bundle passage 58. To hang down. Of the bundle discharge roller pair 60a, 60b, the roller indicated by reference numeral 60a is a driving roller, and the roller indicated by reference numeral 60b is a driven roller.
[0041]
The bundle stack tray 80 for folded sheet bundles is folded by the folding operation of the pair of folding rollers 57a and 57b and stacks the sheet bundles discharged by the pair of bundle discharge rollers 60a and 60b. The folded sheet presser 81 presses the sheet bundle discharged into the bundle stacking tray 80 by a spring or its own weight.
[0042]
12 to 14 show a folded sheet stacking device 79 which is a feature of the present invention. The folded sheet stacking device 79 is formed at the bottom 80a of the bundle stacking tray 80 (discharge tray), and has a recess 82 that absorbs the bulge on the folding side of the sheet bundle, and a rotating shaft provided near the exit of the bundle stacking tray 80. A bundle stopper (stopper member) 83 that is biased substantially vertically by a spring 84 and tiltable in the direction of arrow H with 83a as a fulcrum is provided.
[0043]
The sheet bundle passage 58 is formed as a space in which the sheet bundle can move between the frame of the sheet post-processing apparatus 2 and the bundle stacking tray 80.
[0044]
The raising / lowering tray 90 moves up and down along the frame of the sheet post-processing apparatus 2 and moves between the position of the solid line and the position of the two-dot chain line in FIG. The elevating tray 90 can be moved up and down by engaging the elevating tray support portion 92 with a part of a belt that is rotated by driving means such as an elevating tray motor 155 (see FIG. 16). The paper surface sensor 93 detects the top surface of the sheet on the lifting tray 90. The trailing edge guide 94 guides the trailing edge of the sheet on the lifting tray 91 that moves up and down in the vertical direction. The auxiliary tray 91 is provided so as to be able to be pulled out from the elevating tray 90, and is used in a state of being pulled out when a large-sized sheet or the like is stacked.
[0045]
Detailed configurations of the processing tray 8 of the sheet post-processing apparatus 2 and the folding unit 50 of the stapler unit 30 will be described with reference to FIG.
[0046]
FIG. 2 is a plan view of the processing tray 8 portion. The first pulley 10 and the second pulley 11 are located on both sides of the substantially center in the sheet width direction with the transfer belt 12 stretched. On the first pulley shaft 10a, two conveyance lower rollers 18 are provided on both sides of the approximate center in the sheet width direction. The lower conveyance roller 18 is a tire-type hollow roller.
[0047]
Two first pulleys 10 for rotating the transfer belt 12 as described above are arranged on the first pulley shaft 10a. The first pulley 10 is driven and rotated by the counterclockwise rotation of the first pulley shaft 10a in FIG. 1 by a one-way clutch 75 interposed between the first pulley 10 and the first pulley shaft 10a. In the direction rotation, the drive is cut and stopped. The first pulley shaft 10a is connected to a motor shaft 70a of a stepping motor 70 as a conveyance drive source via a pulley 73, a timing belt 74, and gear pulleys 72 and 71 fixed to the first pulley shaft 10a.
[0048]
Therefore, when the stepping motor 70 rotates the sheet on the processing tray 8 in the direction of moving in the stapling direction of FIG. 1 (the direction of arrow B in FIGS. 1 and 2), the lower conveying roller fixed to the first pulley shaft 10a. 18 is driven to rotate, but the driving force is not transmitted to the transfer belt 12 by the one-way clutch 75, and the transfer belt 12 is in a stopped state. When the stepping motor 70 is rotated so as to move the sheet toward the lifting tray 90, the lower conveying roller 18 and the transfer belt 12 are both rotated in the direction of the lifting tray 90 (the arrow A direction in FIGS. 1 and 2).
[0049]
The transfer belt 12 will be described with reference to FIG. An extruding claw 13 is provided on the transfer belt 12 stretched between the first pulley 10 and the second pulley 11 with the one-way clutch 75 interposed on the first pulley shaft 10a. In order to locate the home position (HP position in FIG. 3) of the push-out pawl 13, the push-out pawl sensor 76 and the push-out pawl detection arm 77 of the push-out pawl 13 that engage with the push-out pawl 13 are provided on the lower surface of the processing tray 8. Is provided. The position at which the pushing claw 13 is moved by the transfer belt 12 to push the pushing claw detection arm 77 and the pushing claw sensor 76 is switched from OFF to ON is defined as a home position (HP). The positional relationship at this time is shown in FIG. If the nip between the lower conveyance roller 18 and the upper conveyance roller 19 is P, the length from the nip P to the stopper 21 is L1, and the length along the conveyance belt 12 from the nip P to the pushing claw 13 is L2. L1 <L2).
[0050]
By operation of a cam or the like (not shown), the transport upper roller 19 is lowered and pressed toward the transport lower roller 18 side. Thereafter, when the conveyance stepping motor 70 is rotated and the first pulley rotation shaft 10a is rotated counterclockwise (in the direction of arrow A in FIGS. 1 and 2), the conveyance lower roller 18 is rotated, and the sheet bundle is also rotated. It moves in the direction of the lifting tray 90 (arrow A direction).
[0051]
The transport upper roller 19 is also rotated by a stepping motor 70 (see FIG. 2). Accordingly, the sheet bundle moves from the position of the stopper 21 entering the stapler unit 30 side in the direction of the arrow A due to the rotation of the lower conveyance roller 18 and the upper conveyance roller 19. As the belt 12 rotates, the pushing claw 13 hits and is conveyed to the lifting tray 90 while being pushed by the pushing claw 13 in the direction of the arrow A in each figure. In this case, since the length relationship is (Ll <L2), the pushing claw 13 is pushed up from the lower side (the right end side in FIG. 3) of the sheet bundle, and the sheet bundle is always in the vertical state. The end will be pushed out. As a result, extra stress or the like is not generated when the sheet bundle is transferred.
[0052]
When performing the binding process, the push-out claw 13 moves counterclockwise from the position HP in FIG. 3 and moves the sheet bundle moved from the stopper 21 by the roller pairs 18 and 19 that convey the sheet bundle synchronously. Extrude after handed over.
[0053]
On the other hand, when the sheets carried into the processing tray 8 are not bound by the stapler unit 30, there is no need to carry the sheet bundle to the position of the stopper 21, so the conveyance stepping motor 70 is driven and pushed out in advance. The claw 13 is moved from the HP position in FIG. 3 toward the lift tray 90 from the nip point between the lower conveyance roller 18 and the upper conveyance roller 19 (movement standby position corresponding to (L2 + α), PreHP position in FIG. 3). Move it to. This (L2 + α) can be set by counting the number of steps of the stepping motor 70. Therefore, in the case of a sheet that does not require a binding process, the sheet post-processing apparatus 2 moves the pushing claw to the PreHP position in advance without transferring the sheet to the stopper 21, stacks it, and bundles it on the lifting tray 90. Therefore, it is possible to cope with a copying machine main body having a high processing speed.
[0054]
As shown in FIG. 3, when the position of the PreHP of the push-out claw 13 is a position where the carry-in guide 7 and the upper end of the push-out claw 13 overlap each other, it is ensured that the sheets carried in one by one are The stack can be stacked at the position of the push-out claw 13 in the position. If it does in this way, after that, the extrusion nail | claw 13 can discharge | emit a sheet bundle to the raising / lowering tray 90 rapidly.
[0055]
(Detailed description of the stapler unit)
4 and 5, the stapler unit 30 includes left and right unit frames 40 and 41, guide rods 33 and 34 provided between the frames 40 and 41, screw shafts 35 and 36, drive shafts 37 and 38, An anvil unit 32 is provided above, and a driving head unit 31 is provided below. The driving head unit 31 is engaged with the screw shaft 36, and the head unit 31 moves in the left-right direction in FIG. The anvil unit 32 has a similar mounting configuration. The screw shaft 36 is continuous with the stapler slide motor 42 via a gear outside the unit frame 41. The driving of the stapler slide motor 42 is also transmitted to the anvil unit 32 by the timing belt 43. For this reason, the head unit 31 and the anvil unit 32 move in a direction (the left-right direction in FIG. 4) intersecting the sheet conveying direction without shifting the vertical position.
[0056]
Therefore, if the stapler slide motor 42 is driven according to the width of the sheet to control the head unit 31 and the anvil unit 32 to move to predetermined positions, the slur needle can be driven freely at an arbitrary position. .
[0057]
Further, driving force such as movement of a head for driving a needle (not shown) in the head unit 31, movement of the needle, and folding movement of the needle in the anvil unit 32 is performed by the coupling device 44 from the sheet post-processing device 2 side. It is transmitted to the anvil unit 32 side by the timing belt 45 on the unit frame 40 side. The moving arm 23 (see FIG. 5) and the stopper 21 are connected by a connecting pin 23c, a connecting lever 22, and a connecting pin 21a. The stopper 21 is supported by the pulley shaft 10a.
[0058]
Based on FIG. 4 and FIG. 5, a description will be given of a configuration in which the stopper 21 that moves the head unit 31 in the sheet width direction to the staple path passage of the stopper 21 that sets the needle driving position at the end of the sheet bundle moves into and out of the staple path passage. A stopper engaging protrusion 24 capable of engaging the stopper 21 with the moving arm 23 is provided below the driving head unit 31 shown in FIG. As the head unit 31 moves, the stopper engaging protrusion 24 engages with the moving arm protrusion 23b, so that the moving arm 23 rotates counterclockwise about the rotation shaft 23a as shown in FIG. Move to the position of the two-dot chain line. Therefore, the stopper 21 does not interfere with the movement of the head unit 31 and the anvil unit 32 in the sheet width direction.
[0059]
(Detailed description of folding unit)
The folding unit 50 will be described with reference to FIGS.
[0060]
FIG. 6 is a diagram of the folding unit frame 49 of the folding unit (sheet folding device) 50. Since the folding unit 50 is provided in the sheet post-processing apparatus 2 so that it can be pulled out, the rear frame in FIG. 6 is also formed in the same shape. The folding unit frame 49 of the folding unit 50 is provided with a folding roller driving shaft 61 as a rotating shaft of the folding roller 57a and a driving shaft 69a of the bundle discharge roller 60a. The drive shaft 62 of one folding roller 57b is attached to a folding roller holder 63 that rotates about the driving shaft 69b of the bundle discharge roller 60b. A tension spring 67 having a tension of about 5 kg is stretched between the folding roller holder 63 and the folding unit frame 49. The folding unit frame 49 is formed with a hole or frame guide 64 that allows the folding roller drive shaft 62 to move by the folding roller holder 63.
[0061]
Therefore, when the sheet bundle is folded and conveyed by the pair of folding rollers 57a and 57b, a constant pressure can be applied to the sheet bundle by the tension spring 67, and a reliable folding operation can be performed.
[0062]
The folding unit frame 49 is formed with a veneer frame guide 65 as a long hole for guiding the movement of the rollers 66, 66 erected on the support holder 110 that supports the veneer 55. The veneer frame guide 65 allows the veneer plate 55 to move toward the pair of folding rollers 57a and 57b.
[0063]
The folding unit frame 49 is further provided with a drive shaft 111 that rotatably supports a cam plate 114 that moves the thrust plate 55.
[0064]
The folding unit frame 49 is also provided with an upper roller shaft 101 for conveying the sheet bundle into the folding unit 50 and an upper roller shaft 101 for the bundle conveying lower roller 51 and a lower roller shaft 103 for the lower bundle conveying roller 52. The folding unit frame 49 is provided with a mechanism for positioning the bundle conveying upper roller 51 at a position separated from the bundle conveying lower roller 52 until the sheet bundle is carried into the folding unit 50.
[0065]
The upper roller shaft 101 of the bundle conveying roller pair 51 and 52 is supported by the bearing holder 102. A cam follower 112 is erected on one end of the bearing holder 102. The cam follower 112 is engaged with an upper roller moving cam 68 that is rotatably attached to the folding unit frame 49. A tension spring 104 having a tension of about 300 g is stretched between the other end of the bearing holder 102 and the lower roller shaft 103. The tension spring 104 always urges the bundle conveying upper roller 51 toward the bundle conveying lower roller 52 side. The rotation of the upper roller moving cam 68 causes the bearing holder 102 to move up and down against or against the tension spring 104, and bring the bundle conveying upper roller 51 into a position where it is pressed against the position separated from the bundle conveying lower roller 52. It is designed to move.
[0066]
FIG. 7 is a view showing a mechanism for performing the folding operation, and is provided inside the folding unit frame 49 shown in FIG.
[0067]
A cam plate 114 is fixed to the cam drive shaft 111, and the cam plate 114 is rotationally driven according to the rotation of the shaft 111. In the cam plate 114, a cam follower 116 erected substantially at the center of an operation arm 115 that can be rotated about a shaft 113 enters a cam groove 114 b of the cam plate 114. A thrust plate 55 is attached to the distal end side of the operating arm 115 via a support holder 110.
[0068]
Therefore, when the cam plate 114 is rotationally driven, the operating arm 115 also moves up and down, and the thrust plate 55 attached to the working arm 115 also moves up and down. The thickness of the thrust plate 55 that presses the sheet bundle is formed of a stainless material of about 0.25 mm. Next, the support holder 110 that supports the thrust plate 55 is interlocked with backup guides 59a and 59b that guide the periphery of the pair of folding rollers 57a and 57b.
[0069]
The backup guides 59a and 59b are arranged so as to cover the outer peripheral surfaces of the cylindrical folding roller pairs 57a and 57b extending in the crossing direction in the sheet conveying direction, and are folded around the shafts 61 and 62 of the folding roller pairs 57a and 57b. The roller pair 57a, 57b is rotatable with respect to the outer peripheral surface.
[0070]
Lever pieces 119 and 120 are provided on the outer peripheral ends of the backup guides 59a and 59b, respectively. The backup guides 59a and 59b are pulled by a pulling 121. The lever pieces 119 and 120 are in contact with and supported by operating pieces 117 and 118 which are divided into two portions of the support holder 110. Accordingly, when the backup guides 59a and 59b are in the state shown in FIG. 7A, the backup guides 59a and 59b are positioned so as to cover the outer peripheral surface of the folding roller pairs 57a and 57b on the conveyance path side, It can be guided in a state where it is sufficiently in contact with the surface, and further functions as a guide for backing up (supporting) the sheet bundle. The backup guides 59a and 59b normally function as a lower bundle conveyance guide together with a bundle conveyance guide.
[0071]
When the sheet bundle folding operation is performed, the lever pieces 119 and 120 are pushed up as the operating pieces 117 and 118 of the support holder 110 are lowered as shown in FIG. As a result, the backup guides 59a and 59b are rotated about the shafts 61 and 62 against the pulling 121 so that the outer peripheral surfaces of the pair of folding rollers 57a and 57b are surely brought into contact with the sheet bundle.
[0072]
A drive transmission system of the folding unit 50 will be described. The drive transmission system includes a rotation and separation system for the bundle conveying upper roller 51 and the bundle conveying lower roller 52 shown in FIGS. 8 and 9, and a drive transmission system for moving the folding roller pairs 57a and 57 and the thrust plate 55 shown in FIG. And divided. All of these transmission systems are provided in a frame on the back side of the folding unit frame 49 shown in FIG.
[0073]
The driving system for the bundle conveying upper roller 51 and the conveying lower roller 52 shown in FIGS. 8 and 9 is folded via gears 127 and 128 from a conveying motor 162 provided on the sheet post-processing apparatus 2 side that can be rotated forward and backward. Input to the gear pulley 129 on the unit 50 side. Since the one-way clutch 123 is interposed between the gear pulley 129 and the shaft 113 that drives the upper roller moving cam 68, the upper roller can be rotated only in one direction (rotation in the direction opposite to the arrow in FIG. 8). The moving cam 68 rotates and moves the bundle conveying upper roller 51 up and down. Drive from the gear pulley 129 is transmitted by the pulleys 130 and 131 to the bundle conveying upper roller shaft 101 and the lower roller shaft 103 via the timing belt 135. One-way clutches 124 and 125 are interposed between the pulleys 130 and 131 and the shafts 101 and 103, and the shafts 101 and 103 are rotationally driven by driving the pulleys 130 and 131 (in the direction of the arrow in FIG. 8). .
[0074]
Further, a timing belt 135 is stretched so as to rotationally drive the bundle discharge roller pair 60a, 60b via the idle pulleys 132, 133.
[0075]
When the gear pulley 129 in FIG. 8 rotates in the direction of the arrow, the bundle conveying upper roller 51 and the bundle conveying lower roller 52 rotate in the direction in which the sheet bundle is conveyed into the folding unit 50. When the gear pulley 129 rotates in the direction opposite to the illustrated arrow, the upper roller moving cam 68 rotates as described above, and the bundle conveying upper roller 51 is separated from or pressed against the bundle conveying lower roller 52. Although not shown, these operations are controlled by detecting a flag protrusion provided on the shaft 113 with a sensor or the like.
[0076]
FIG. 10 is a diagram showing a drive transmission system of the pair of folding rollers 57a and 57b, which is attached to a frame on the back side of the drive system shown in FIGS.
[0077]
The driving of the stapling / folding motor 170 (see FIG. 16) from the sheet post-processing device 2 side is received by the coupling device 137. Although not shown, the stapling / folding motor 170 is normally rotated to drive the coupling device 44 of the stapler unit in FIG. 4 and to rotate the coupling device 137 by reverse rotation.
[0078]
The driving force from the coupling device 137 is transmitted to the gear 139 that rotates the folding roller 57a (see FIG. 7) and also to the gear 142 by the gear 138 provided on the coaxial 61. Yes. This gear 142 is transmitted by a gear 141 to a shaft 111 that drives a cam plate 114 that operates an operating arm 115 that moves a thrust plate 55. Although not shown, the position of the cam plate 114 is known by detecting a flag protrusion fixed to the shaft 111 with a sensor.
[0079]
Next, the sheet folding operation of the folding unit 50 will be described with reference to FIG.
[0080]
In order to perform stapling (saddle stitching) at the approximate center of the sheet bundle in the processing tray 8 in the conveyance direction, the sheet is carried in with the bundle conveyance upper roller 51 and the bundle conveyance lower roller 52 separated from each other. Thereafter, the leading edge of the sheet bundle is detected, and the binding process is performed when the center of the sheet bundle in the conveyance direction is determined. Thereafter, the upper roller moving cam 68 (see FIG. 6) is rotated to press the bundle conveying lower roller 52 against the bundle conveying upper roller 51, and the bundle conveying upper portion 51 is moved up until the center in the sheet conveying direction is directly below the abutting plate 55. The roller 51 and the bundle conveyance lower roller 52 are driven to convey the sheet bundle. At this time, since the backup guides 59a and 59b are in a position covering the circumferential surface of the folding roller and back up (support) the lower surface of the sheet, the sheet bundle is conveyed smoothly. When the substantially center of the sheet bundle conveyance direction reaches directly below the abutting plate 55, the bundle detection sensor 54 detects this and temporarily stops driving the bundle conveyance upper roller 51 and the bundle conveyance lower roller 52. In this state, the sheet bundle is suspended by the bundle conveying upper roller 51 and the bundle conveying lower roller 52 as shown in FIG.
[0081]
As a result, the sheet bundle is aligned by its own weight. Since the sheet bundle is suspended, a sheet path is simply provided in a portion downstream of the thrust plate 55 without providing a mechanism such as a sheet stopper. Further, since the downstream portion of the thrust plate 55 is inclined downward, the folding unit 50 and the entire sheet post-processing apparatus 2 can be made compact.
[0082]
When the sheet bundle reaches the state shown in FIG. 11A, the folding roller drive shaft 61 is driven to rotate. When the folding roller drive shaft 61 rotates, both the folding roller pair 57a and 57b rotate, and the cam plate 114 (see FIG. 7) also rotates to move the thrust plate 55 to the nip of the folding roller pair 57a and 57b. The pair of folding rollers 57a and 57b rotate while folding the sheet bundle and discharge it to the bundle stacking tray 80.
[0083]
When the pushing plate 55 pushes the half position (intermediate part, L / 2) of the length (L) of the sheet bundle toward the folding roller pair 57a, 57b, the upper roller shaft 101 of the bundle conveying upper roller 51; Although the lower roller shaft 103 of the bundle conveying lower roller 52 is stopped, one-way clutches 124 and 125 (see FIG. 8) are interposed between the bundle conveying upper roller 51 and the bundle conveying lower roller 52 and the shafts 101 and 103. Therefore, while the sheet bundle is folded by the thrust plate 55, the bundle conveyance upper roller 51 and the bundle conveyance lower roller 52 are pulled by the sheet bundle and follow and rotate, thereby hindering the folding of the sheet bundle. There is no such thing. Accordingly, the sheet bundle is smoothly folded by the folding roller pairs 57a and 57b. Thereafter, the bundle conveying upper roller 51 and the bundle conveying lower roller 52 rotate to rotate the bundle discharging roller pair 60a and 60b, and the sheet bundle is discharged from the folding unit 50 to the bundle stacking tray 80.
[0084]
(Control block circuit)
FIG. 16 is a schematic block diagram relating to control of the sheet post-processing apparatus 2. The control block 149 is a central processing unit (CPU), a ROM that stores in advance control means executed by the CPU, a RAM that stores operation data of the CPU, control data received from the main body 1 of the copying machine 20, and the like. It is configured.
[0085]
Various 1 / 0s are provided in the control block 149. An arrow pointing to the control block 149 side is an input side, and an arrow pointing away from the control block 149 is an output side.
[0086]
A circuit related to sheet alignment includes a front alignment HP sensor 151 that sets a home position (HP) of an alignment plate 9 that aligns both ends of the sheet with the processing tray 8, and a back alignment HP sensor 152. The alignment plates 9 and 9 (see FIG. 2) stand by at the positions of the front alignment HP sensor 151 and the back alignment HP sensor 152 until the first sheet is carried into the processing tray 8. The front alignment motor 14 is a pulse motor that moves the front alignment plate 9, and the rear alignment motor 14 is a pulse motor that moves the rear alignment plate 9. The alignment plate 9 is moved by the respective alignment motors 14, and the width alignment according to the width of the sheet bundle can be performed. Further, the alignment plate 9 can be freely shifted (job) in the direction intersecting with the conveyance direction for each sheet bundle for each sheet bundle.
[0087]
Next, a circuit related to the lifting tray 90 includes a paper surface sensor 93 that detects the uppermost surface of the sheet on the lifting tray 90, a lifting clock sensor 150 that detects the amount of rotation of the lifting tray motor 155 by an encoder, and the lifting tray 90. An upper limit switch 153 and a lower limit switch 154 that regulate the up-and-down movement range are provided. This circuit drives the lifting tray 90 by controlling the lifting tray motor 155 in accordance with input signals from the sensors 93 and 150 and the switches 153 and 154.
[0088]
A circuit related to detecting a stacked sheet as to whether or not a sheet or a sheet bundle is stacked in the lift tray 90 and the folded sheet discharge stacker 80 is a lift tray paper sensor 156 that detects the presence or absence of the lift tray 90. And a detection sensor folded sheet stacker paper sensor 157 in the folded sheet discharge stacker 80. These sensors 156 and 157 are also used as sensors that warn the operator when sheets remain before the sheet post-processing apparatus is activated or when a sheet bundle is not removed after a predetermined time has elapsed.
[0089]
A circuit related to opening of the door of the sheet post-processing apparatus 2 and detection of a door opening / closing apparatus that detects whether or not the main body 1 of the sheet post-processing apparatus is properly installed in the main body 1 of the image forming apparatus 20 is a front door sensor 158. And a joint switch 159 for detecting whether or not the sheet post-processing 2 is correctly mounted on the copying machine main body 1.
[0090]
A circuit related to the sheet conveyance operation and the sheet bundle conveyance operation in a state where the sheets are stacked detects on the conveyance guide 3 that the sheet has been conveyed from the main body 1 of the copying machine 20 to the sheet post-processing apparatus 2. The sheet detection sensor 4, the processing tray sheet detection sensor 160 that detects the presence or absence of a sheet on the processing tray 8, the position for driving the staple needle to the center in the conveyance direction of the sheet conveyed from the processing tray 8, and the staple needle In order to determine the position at which the sheet is bent at the same position as the driving position, the center binding position and center binding folding position sensors 95 and 95 for detecting the leading end of the sheet bundle in the conveyance direction, and the sheet bundle on the processing tray 8 are moved up and down the tray 90. A push-out claw sensor 76 for detecting the home position of the push-out claw 13 provided on the transfer belt 12 that is moved to the side; A bundle conveying upper roller HP sensor 161 that detects the home position of the bundle conveying upper roller 51 at a position separated from the bundle conveying lower roller 52 at the entrance of the folding unit 50, and based on a signal from each sensor, The conveyance motor 162 and the stepping motor 70 are controlled. The rotational force of the conveyance motor 162 is transmitted to the conveyance roller pair 5, the discharge roller pair 6, the bundle conveyance upper roller 51, the bundle conveyance lower roller 52, and the bundle discharge roller pairs 60a and 60b. The upper roller moving cam 68 that moves the bundle conveying roller pair 51 is rotated by the reverse rotation of the conveying motor 162. The rotational force of the stepping motor 70 is transmitted to the lower pulley 18, the upper roller 19, and the first pulley 10 that circulates the transfer belt 12 disposed on the processing tray 8.
[0091]
The circuit related to the control of the paddle 17 includes a paddle HP sensor 163 that detects the rotational position of the paddle 17, and a transport upper HP sensor 164 that detects a position where the transport upper roller 19 is separated from the transport lower roller 18. The paddle motor 165 is controlled based on signals from the sensors 163 and 164.
[0092]
A circuit related to the control of the staple / folding operation includes a staple HP sensor 166 that detects that the driving head unit 31 and the anvil unit 32 in the stapler unit 30 can be stapled, and a staple in the driving head unit 31. A staple sensor 167 for detecting whether or not the needle is set, and a staple slide for detecting whether or not the needle head unit 31 and the anvil unit 32 are in the initial position (position in FIG. 4) when shifting in the sheet conveying direction. The HP sensor 168, the staple / folding clock sensor 171 for detecting the rotation direction of the staple / folding motor 170 for switching the driving of the stapler unit 30 and the folding unit 50 between forward and reverse, and the stapler unit 30 and the folding unit 50 are operable. In state And a safety switch 172 for detecting that, these sensors, by a switch or the like, stapled slide motor 42, and controls the stapling / folding motor 170.
[0093]
The stapler slide motor 42 transmits a rotational force to a guide screw shaft 36 that moves the driving head unit 31 and the anvil unit 32 in a direction intersecting the sheet conveying direction. The stapling / folding motor 170 drives the coupling device 44 (see FIG. 4) of the stapler unit 30 by one-way rotation in forward and reverse driving, and the coupling device 137 (see FIG. 10) in the folding unit 50 by the other rotation. It is like that.
[0094]
Next, operations in each processing mode of the sheet post-processing apparatus 2 will be described.
[0095]
As a basic processing mode,
(1) Non-staple mode: a mode in which sheets are stacked on the lifting tray 90 without binding processing;
(2) Side stapling mode: a mode in which one or a plurality of places are stacked on the lifting / lowering tray 90 at the end (side) in the sheet conveyance direction;
(3) Saddle step mode: a mode in which a half of the sheet length in the sheet conveyance direction is bound at a plurality of positions, a sheet is folded and bound at the bound position, and the bundled stacker 80 is stacked.
There are three.
[0096]
[(1) Non-staple mode]
When this mode is selected, first, the control block 149 drives the stepping motor 70 that circulates the transfer belt 12 to move the pushing claw 13 at the home position (HP position) in FIG. The sheet is moved to a preform position (FIG. 3, PreHP position) which is the sheet stacking reference position, and stopped. At the same time, the conveyance motor 162 is driven to rotate the conveyance roller pair 5 and the discharge roller pair 6 to wait for the sheet to be discharged from the discharge rollers 1 a and lb of the main body 1 of the copying machine 20. When the sheet is discharged, the conveyance roller pair 5 and the discharge roller pair 6 convey the sheet to the processing tray 8. The sheet detection sensor 4 detects the sheet and measures the start timing of the alignment motors 14 and 14 that move the alignment plate 9 and the paddle motor 165 that rotates the paddle 17.
[0097]
The control block 149 drives the alignment motors 14 and 14 and the paddle motor 165 while the sheets are discharged and stacked on the processing tray 8. By this driving, the aligning plates 9 and 9 are moved in the width direction intersecting the sheet conveying direction to align both ends of the sheet, and the paddle 17 is rotated at the PreHP position so that the sheet end abuts against the pushing claw 13 and is aligned. This operation is repeated each time a sheet is discharged to the processing tray 8 respectively. When a predetermined number of sheets are aligned on the extrusion claw 13, the control block 149 stops the rotation of the conveyance motor 162 and the paddle motor 165 and restarts the stepping motor 70 that drives the transfer belt 12. As a result, the sheet bundle moves to the lifting tray 90 side (the direction of arrow A in FIG. 1). The moved sheet bundle is stacked on the lifting tray 90. As the sheet bundle is discharged, the control block 149 lowers the elevating tray motor 155 by a certain amount in the direction in which the elevating tray 90 descends, and then raises until the paper surface sensor 93 detects the uppermost sheet. Drive in the direction to stop and wait until the next sheet bundle is placed.
[0098]
[(2) Side staple mode]
When this mode is selected, the control block 149 drives the conveyance motor 162 to rotate the conveyance roller pair 5 and the discharge roller pair 6, and discharges the sheet from the main body 1 of the copying machine 20 to the processing tray 8. To load. The control block 149 drives the alignment motors 14 and 14 and the paddle motor 165 while the sheets are discharged and stacked. Thus, the sheet is aligned at both ends in the width direction by the alignment plates 9 and 9 and the sheet end is transferred to the stopper 21 and stopped. This is repeated a specific number of times.
[0099]
In a state where the sheet bundle is regulated by the stopper 21, the conveyance upper roller 19 is moved to the conveyance lower roller 18 side, and the sheet bundle is sandwiched between the conveyance upper roller 19 and the conveyance lower roller 18. Thereafter, the control block 149 drives and rotates the staple / folding motor 170 in the staple operation direction to perform the binding process by the driving head unit 31 and the anvil unit 32 in order to perform the binding process. When binding processing is performed at a plurality of positions on the sheet edge, the staple slide motor 42 is driven and moved, and then binding processing is performed.
[0100]
When this binding process is completed, the sheet bundle after the binding process is moved by the stepping motor 70 to the lifting tray 90 side (in the direction of arrow A in FIG. 1) with the lower transport roller 18, the upper transport roller 19, and the transfer belt 12. As a result, the sheet bundle is transferred from the lower conveyance roller 18 and the upper conveyance roller 19 in the order of the push-out pawl 13 and stacked on the lifting tray 90. Subsequent operations of the lifting tray 90 are the same as those in the non-staple mode described above, and a description thereof will be omitted.
[0101]
[(3) Saddle step mode]
This mode is a mode for performing a binding process and a folding process to a substantially central position of the sheet length in the sheet conveyance direction. Since the operation of stacking sheets discharged from the image forming apparatus 1 on the processing tray 8 is the same as that in the above-described side staple mode, description of the operation is omitted.
[0102]
After the sheets are aligned and stacked on the processing tray 8, the transport upper roller 19 is lowered toward the transport lower roller 18, and the sheet bundle is sandwiched between the transport upper roller 19 and the transport lower roller 18. Next, the control block 149 drives the staple slide motor 42 to retract the stopper 21 from the sheet bundle conveyance path and transfer the sheet bundle in the direction of arrow B in FIG. By this driving, the stopper engaging protrusion 24 of the driving head unit 31 is also moved as shown in FIGS. 4 and 5, and is engaged with the moving arm 23, so that the stopper 21 is moved and the moving region of the head unit 31 and the anvil unit 32 is moved. Evacuate from. The driving head unit 31 and the anvil unit 32 are stopped at a driving setting position in a direction that is in the direction of the sheet movement. Subsequently, the control block 149 rotates the stepping motor 70 in the direction opposite to the non-staple mode or the side staple mode. By this driving, the sheet bundle is transferred in the direction opposite to the lifting tray 90 (the direction of arrow B in FIG. 1). When the bundle detection sensor 54 in the folding unit 50 detects the leading end of the sheet bundle in the transport direction by this transport, the transport upper roller 19 and the transport lower roller 18 are based on the transport direction sheet length information sent in advance. The sheet bundle is conveyed to a position where the substantially central part in the sheet conveying direction coincides with the binding position and stops.
[0103]
When the stepping motor 70 rotates in the reverse direction, the one-way clutch 75 is interposed between the first pulley 10 that stretches the transfer belt 12 and the first pulley shaft 10a. The transfer belt 12 and the push-out claw 13 remain stopped without being transmitted.
[0104]
Next, the control block 149 rotates the staple / folding motor 170 that drives the head drive shaft 38 and the anvil drive shaft 37 in the direction in which they are operated, and performs the binding process. When binding a plurality of locations, the stapler slide motor 42 is driven and the binding is performed after the screw shafts 35 and 36 are moved to a predetermined position in a direction intersecting the sheet conveying direction.
[0105]
When the sheet bundle is conveyed to the binding processing position, the position of the sheet bundle in the conveyance direction leading end is determined by the bundle conveyance lower roller 52 in the folding unit 50 and the bundle conveyance upper roller 51 which is already separated from the bundle conveyance roller. It is in the position that passed.
[0106]
In order to perform the folding process after the binding process is completed, first, the transport motor 162 shown in FIG. 8 is reversely rotated to rotate the upper roller moving cam 68 shown in FIGS. By this rotation, the bearing holder 102 moves, the bundle conveying upper roller 51 is lowered to the bundle conveying lower roller 52 side, and the sheet bundle is held between the tension springs 104.
[0107]
Next, the conveyance upper roller 19 in the processing tray 8 is lifted from the sheet bundle, and the nipping of the sheet bundle is released. Next, the bundle conveying upper roller 51 and the bundle conveying lower roller 52 are driven by the conveying motor 162 to convey the sheet bundle further downstream. During this conveyance, the conveyance motor 162 is stopped while decelerating from the signal of the bundle detection sensor 54 and the sheet length information so that the central portion of the sheet bundle in the conveyance direction, that is, the binding processing position becomes the folding position. The sheet bundle is sandwiched between the bundle conveyance upper roller 51 and the bundle conveyance lower roller 52 and is suspended in the conveyance path.
[0108]
When the stapling / folding motor 170 is driven in the direction opposite to the binding process, as shown in FIG. 7B, the pair of folding rollers 57a and 57b rotate in the direction to sandwich the sheet bundle and the thrust plate 55 is lowered. . At the same time, the backup guides 59a and 59b also move so as to open the folding roller peripheral surface on the sheet bundle side. After the pushing plate 55 moves so as to sandwich the pair of folding rollers 57a and 57b that rotate the sheet bundle, the sheet bundle is wound around the pair of folding rollers 57a and 57b. Subsequently, the pushing plate 55 moves away from the sheet bundle, and the sheet bundle is further folded by the folding roller pairs 57a and 57b. At this stage, the bundle conveyance upper roller 51, the bundle conveyance lower roller 52, and the bundle discharge roller pair 60a, 60b are rotated in a direction in which the sheet bundle can be discharged to the bundle stacking tray 80 by the conveyance motor 162. On the other hand, the pair of folding rollers 57a and 57b stops when the thrust plate 66 rises and is detected by the thrust plate Hp sensor 169. The sheets conveyed between the bundle discharge roller pair 60a and 60b are discharged to the bundle stacking tray 80 and stacked. The folded sheet bundle is prevented from being opened by being pressed by the folded sheet presser 81 so as to prevent the next folded sheet bundle from being carried in.
[0109]
The bundle conveying upper roller 51 moves away from the bundle conveying lower roller 52 and moves upward when the time during which the sheet bundle can be discharged by the bundle discharge rollers 60a and 60b has elapsed, and moves upward. Prepare for the import of.
[0110]
(Characteristic part of the present invention)
As described above, the folded sheet stacking device 79 according to the present invention is formed in the bottom 80a of the bundle stacking tray (discharge tray) 80 in FIGS. 12 to 14 and absorbs the bulge on the folding side of the sheet bundle. And a bundle stopper (stopper member) 83 that can be tilted in the direction of arrow H by being urged almost vertically by a spring 84 with a rotating shaft 83a provided near the outlet of the bundle stacking tray 80 as a fulcrum. .
[0111]
As shown in FIG. 13, the sheet bundle P discharged by the bundle discharge roller pair 60a and 60b has its bulge portion Pa on the folding side of the sheet bundle P dropped into the recess 82, and the bulge portion Pa and the open end Pb are separated. The difference in thickness is alleviated and the stacking tray 80 is loaded almost horizontally. Thus, the folded sheet stacking device 79 can stack the sheet bundle in a stable state and improve stackability.
[0112]
When the sheet bundle is sequentially stacked in the bundle stacking tray 80, as shown in FIG. 14, the sheet bundle moves in the sheet bundle discharge direction (left direction in the figure) due to the contact resistance between the sheet bundles. It is pushed by the sheet bundle and opens outward against the spring 84. As a result, the bulging portion Pa of the sheet bundle is displaced outward, so that the difference in thickness between the bulging portion Pa and the open end Pb is reduced. Further, the folded sheet stacking device 79 can stack the sheet bundle in a stable state by reducing the stack height of the entire sheet bundle. In addition, the bulge portion Pa side of the stacked sheet bundle comes into contact with the bundle stopper 83 and has a shape along the inclined bundle stopper 83 with the amount of movement restricted, so that the conventional discharge tray 86 shown in FIG. Unlike the case, the movement amount of the sheet bundle is small, and the stacking space for the sheet bundle can be reduced accordingly. Further, since the sheet bundle moves, the open end Pb of the already stacked sheet bundle is not turned by a newly ejected sheet, and the sheet bundle is wrinkled or bent. There is nothing.
[0113]
The bundle stopper 83 is tilted. However, as shown in FIG. 15, the bundle stopper 83 may be a bundle stopper (stopper member) 89 that moves linearly on the guide rail 89 a against the tension spring 88. Good. Even in this case, the same advantages as when the tilting bundle stopper 83 is used are produced.
[0114]
Further, since the bundle stoppers 83 and 89 are tilted or moved, there is no hindrance when taking out the sheet bundle.
[0115]
Further, the initial position of the bundle stoppers 83 and 89 is set to a position for receiving the maximum size folded sheet. With this setting, the folded sheets of any size are not stacked out of the bundle stacking tray 80 in a folded state.
[0116]
Note that the saddle stitch mode of the present embodiment shows a case in which the binding process and the folding process are performed in a series, but it goes without saying that the saddle stitch mode can also be used when only the folding process is performed without performing the binding process. It goes without saying that the apparatus can stack a bundle of sheets that are not subjected to binding processing but are only folded.
[0117]
【The invention's effect】
Since the sheet stacking apparatus according to the present invention has a recess formed in the discharge tray, the difference in thickness between the bulged portion of the folded sheet and the open end of the folded sheet is alleviated, and stacking is performed without raising only one side. The folded sheets can be stacked on the discharge tray in a substantially horizontal and stable state.
[0118]
When a stopper member that can be displaced downstream in the folded sheet conveyance direction is provided on the discharge tray, when the folded sheet previously stacked is moved downstream in the folded sheet discharge direction by the folded sheet stacked later, The stopper member is displaced downstream in the folded sheet discharge direction while receiving the moved folded sheet, and the folded sheets do not overlap in the vertical direction between the swelled portions, and somewhat on the downstream side in the folded sheet discharge direction. Since the sheets are stacked out of position, the folded sheets can be stacked on the discharge tray in a substantially horizontal and stable state. Further, since the folded sheets can be supported while being slightly shifted in the folded sheet discharge direction, the folded sheet stacking space can be reduced.
[0119]
If the position of the stopper member is set to receive the maximum size folded sheet, the folded sheet of any size will protrude from the output tray and be stacked in a folded state. There is no.
[0120]
Since the image forming apparatus of the present invention includes the sheet stacking apparatus having excellent stackability, the number of sheets that can form an image on the sheet can be increased at one time, and the image forming efficiency is improved. Can be made.
[Brief description of the drawings]
FIG. 1 is a front sectional view of a sheet post-processing apparatus equipped with a folded sheet stacking apparatus according to an embodiment of the present invention.
FIG. 2 is a view of a processing tray portion of the sheet post-processing apparatus as viewed from above.
FIG. 3 is an enlarged view of a transfer belt portion of the sheet post-processing apparatus.
FIG. 4 is a view of the stapler unit of the sheet post-processing apparatus as viewed from the sheet conveying direction.
FIG. 5 is an operation explanatory view of a stopper of the sheet post-processing apparatus.
FIG. 6 is a front view of the frame of the folding unit of the sheet post-processing apparatus.
FIG. 7 is an operation explanatory diagram of the folding unit of the sheet post-processing apparatus. (A) It is the state figure before sheet | seat bending.
(B) It is a state figure in the middle of sheet bending.
FIG. 8 is a view of a folding unit driving mechanism of the sheet post-processing apparatus.
FIG. 9 is a diagram of a driving mechanism of a folding unit of the sheet post-processing apparatus.
FIG. 10 is a diagram of a driving mechanism of a folding unit of the sheet post-processing apparatus.
FIG. 11 is an explanatory view of the sheet bundle folding operation by the thrust plate of the folding unit of the sheet post-processing apparatus. (A) It is the state figure before sheet | seat bending.
(B) It is a state figure in the middle of sheet bending.
FIG. 12 is a front sectional view of the folded sheet stacking apparatus according to the embodiment of the present invention.
13 is a diagram illustrating a stacked state of sheet bundles when the number of folded sheet bundles is small in the folded sheet stacking apparatus of FIG.
14 is a diagram illustrating a stacking state of sheet bundles when the number of folded sheet bundles is large in the folded sheet stacking apparatus of FIG.
FIG. 15 is a front sectional view of a sheet stacking apparatus according to another embodiment of the present invention.
FIG. 16 is a schematic control block diagram of the sheet post-processing apparatus.
FIG. 17 is a schematic front cross-sectional view of a copier equipped with a folded sheet stacking device in the main body.
FIG. 18 is a schematic front view of a conventional folded sheet stacking apparatus.
FIG. 19 is a schematic front view of a conventional folded sheet stacking apparatus. FIG. 6A is a state diagram when the number of folded sheets is small.
FIG. 6B is a state diagram when the number of folded sheets is large.
[Explanation of symbols]
P sheet, sheet bundle
Pa Swelled part of folded side of folded sheet or sheet bundle
Pb Open end of folded sheet or sheet bundle
1. Body of copier (image forming device)
2 Sheet post-processing equipment
20 Copying machine (image forming device)
21 Stopper
30 Stapler unit (sheet bundle binding device)
31 Driving head unit
32 Anvil Unit
50 Folding unit (sheet folding device)
60 Bundle discharge roller
60a Roller, bundle discharge roller pair
60b Pair of driven roller and bundle discharge roller
79 Folded sheet stacking device
80 Bundle stack tray (discharge tray)
80a bottom
81 Folding sheet presser
82 recess
83 Bundle stopper (stopper member)
83a Bundle stopper fulcrum
84 Spring
88 Tension spring
89 Bundle stopper (stopper member)
89a guide rail
149 Control block
902 Image forming unit (image forming unit)

Claims (6)

A discharge tray formed with a recessed portion for receiving the end portion of the folded sheet discharged first with the folded end portion at the downstream end in the discharge direction of the folded sheet ;
A stopper member that is provided at the downstream end of the discharge tray and receives the end of the folded sheet discharged to the discharge tray, and is displaceable in the discharge direction;
A folded sheet stacking apparatus comprising: an elastic member that urges the stopper member in a direction opposite to the discharging direction to restrict a displacement amount of the stopper member in the discharging direction . 2. The folded sheet stacking apparatus according to claim 1 , wherein an initial position of the stopper member is set to a position for receiving a folded sheet having a maximum size. 3. The folded sheet stacking apparatus according to claim 1, wherein an upper end portion of the stopper member can be tilted in the discharge direction with a lower portion as a fulcrum by a rotating shaft. The folded sheet stacking apparatus according to claim 1 or 2, wherein the stopper member is linearly movable along the guide rail in the discharge direction. Image forming means for forming an image on a sheet;
A sheet folding apparatus that folds a sheet on which an image is formed by the image forming unit to create a folded sheet;
An image forming apparatus comprising: the folded sheet stacking apparatus according to claim 1, which receives a folded sheet created by the sheet folding apparatus. Image forming means for forming an image on a sheet;
A sheet bundle binding device that binds the sheets on which images are formed by the image forming unit in a bundle;
A sheet folding device that creates a folded sheet bundle by folding the sheet bundle bound by the sheet bundle binding device;
The folded sheet stacking apparatus according to any one of claims 1 to 4, which receives a folded sheet bundle created by the sheet folding apparatus;
An image forming apparatus comprising:

Images