Sheet post-processing device

Abstract

To provide a sheet post-processing device that can suppress the occurrence of sheet post-processing defects while minimizing the increase in manufacturing costs.SOLUTION: Provided is a sheet post-processing device comprising stapling means, a moving table, a base member, and moving drive means. The stapling means drives a stapler needle into a sheet bundle inserted into a sheet insertion recess. The moving table moves together with the stapling means in a sheet width direction, which is perpendicular to a sheet insertion direction of the sheet bundle into the sheet insertion recess. The base member freely supports the moving table. The moving drive means moves the moving table in the sheet width direction. The sheet post-processing device moves the stapling means via the moving table by the moving drive means to drive the stapler needle into the sheet bundle for binding processing. The center of gravity of the stapling means is located away from a support point of the base member to the moving table in the sheet insertion direction.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a sheet post-processing device.

Background Art

[0002] A conventional sheet post-processing device includes stapling means, a moving table, a base member, and moving drive means. The stapling means has a sheet insertion recess into which a sheet bundle obtained by stacking a plurality of sheets is inserted, and drives stapler needles into the sheet bundle inserted into the sheet insertion recess. The moving table moves integrally with the stapling means in the sheet width direction orthogonal to the sheet insertion direction of the sheet bundle into the sheet insertion recess. The base member supports the moving table movably. The moving drive means moves the moving table in the sheet width direction.

[0003] The moving drive means moves the stapling means in the sheet width direction via the moving table, drives the stapler needles into a predetermined position of the sheet bundle, and performs binding processing.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] In the configuration of Patent Document 1, the moving table that moves integrally with the stapling means may float with respect to the base member, and there is a possibility that defects in paper post-processing may occur. Further, when a member for preventing the moving table from floating is provided, the number of parts may increase and the manufacturing cost may increase.

[0006] In view of the above problems, the present invention provides a sheet post-processing device capable of suppressing the occurrence of defects in paper post-processing while suppressing an increase in manufacturing cost.

Means for Solving the Problem

[0007] A first configuration of the present invention for achieving the above object is a sheet post-processing apparatus including staple means, a moving table, a base member, and moving drive means. The staple means has a sheet insertion recess into which a sheet bundle obtained by stacking a plurality of sheets is inserted, and drives staple pins into the sheet bundle inserted into the sheet insertion recess. The moving table moves integrally with the staple means in the sheet width direction orthogonal to the sheet insertion direction of the sheet bundle into the sheet insertion recess. The base member supports the moving table movably. The moving drive means moves the moving table in the sheet width direction. The sheet post-processing apparatus performs a stapling process by driving the staple means via the moving table by the moving drive means and driving the staple pins into the sheet bundle. The center of gravity of the staple means is located away from the support point of the base member with respect to the moving table in the sheet insertion direction.

Advantages of the Invention

[0008] According to the first configuration of the present invention, it is possible to provide a sheet post-processing apparatus that can suppress the occurrence of defects in paper post-processing while suppressing an increase in manufacturing cost.

Brief Description of the Drawings

[0009]

Figure 1

Figure 2

Figure 3

Modes for Carrying Out the Invention

[0010] Hereinafter, with reference to the drawings, a multifunction printer 100 as an embodiment of the image forming apparatus of the present invention will be described. FIG. 1 is a schematic cross-sectional view for explaining the outline of a multifunction printer main body 101 and a sheet post-processing apparatus 1 that constitute the multifunction printer 100 as an embodiment of the present invention. As shown in FIG. 1, the multifunction printer 100 of the present embodiment includes a multifunction printer main body 101 as an image forming apparatus main body having an image forming unit (not shown) that forms an image on a sheet, and a sheet post-processing apparatus 1.

[0011] The multifunction printer main body 101 includes an image forming unit (not shown) that forms an image on a sheet such as paper, and a main body discharge unit 102 that discharges the sheet on which the image has been formed (printed) by the image forming unit to the sheet post-processing apparatus 1 or the like.

[0012] As shown in FIG. 1, the sheet post-processing apparatus 1 conveys the sheet T on which an image has been formed in the multifunction printer main body 101 and discharged from the multifunction printer main body 101 from a loading unit 60 provided at the upper part of the right side surface of the sheet post-processing apparatus 1 into the housing 11 of the sheet post-processing apparatus 1. Then, predetermined post-processing such as stapling and folding is performed on the conveyed sheet T.

[0013] The sheet post-processing apparatus 1 includes a sheet folding unit 2, a stapling unit 3, a punching unit 4, a main discharge tray 51, and a sub-discharge tray 52. The sheet post-processing apparatus 1 also includes a loading unit 60, a first conveyance path L1, a second conveyance path L2, a third conveyance path L3, a first branching unit P1, a second branching unit P2, a third branching unit P3, a first merging unit Q1, a main discharge unit 61, a sub-discharge unit 62, a retraction drum 71, various switching members, and various rollers or roller pairs.

[0014] First, the configuration related to the conveyance of the sheet T will be described. The loading unit 60 is a part where the sheet T discharged from the main body discharge unit 102 of the multifunction printer main body 101 is loaded. The first conveyance path L1 conveys the sheet T loaded from the loading unit 60 to the main discharge unit 61. The sheet T discharged from the main discharge unit 61 is discharged to the main discharge tray 51.

[0015] The second conveyance path L2 branches off from the first conveyance path L1 at the first branch portion P1. The second conveyance path L2 conveys the sheet T conveyed by the first branch portion P1 to the sub-discharge portion 62. The sheet T discharged from the sub-discharge portion 62 is discharged to the sub-discharge tray 52.

[0016] The third conveyance path L3 branches off from the first conveyance path L1 at the second branch portion P2 and extends to the sheet folding processing unit 2. The second branch portion P2 is located on the downstream side of the first branch portion P1 in the first conveyance path L1. The fourth conveyance path L4 branches off from the third conveyance path L3 at the third branch portion P3, curves along the periphery of the retraction drum 71, and merges into the first conveyance path L1 at the first merging portion Q1. The first merging portion Q1 is located between the first branch portion P1 and the second branch portion P2 in the first conveyance path L1.

[0017] The first intermediate roller pair 80 is disposed in front of the first branch portion P1 in the first conveyance path L1. The first intermediate roller pair 80 sends out the sheet T conveyed in front of the first branch portion P1 in the first conveyance path L1 to the downstream side.

[0018] The first switching claw 72 is provided at the first branch portion P1 and switches the conveyance destination of the sheet T conveyed in the first conveyance path L1 to either the first conveyance path L1 as it is or the second conveyance path L2. The second switching claw 73 is provided at the second branch portion P2 and switches the conveyance destination of the sheet T conveyed in the first conveyance path L1 to either the first conveyance path L1 as it is or the third conveyance path L3.

[0019] The punch portion 4 is disposed to face the region between the loading portion 60 and the first branch portion P1 in the first conveyance path L1. The punch portion 4 performs a punching process on the sheet T at a predetermined timing.

[0020] The main discharge unit roller pair 81 is disposed near the main discharge unit 61 at the terminal end of the first conveyance path L1. The main discharge unit roller pair 81 sends out the sheet T that conveys the terminal end of the first conveyance path L1 to the main discharge tray 51. Also, when sending out the sheet T to the stapling unit 3, the main discharge unit roller pair 81 separates and releases the nip. Then, the sheet is sent out to the stapling unit 3 by a sheet sending-out mechanism (not shown).

[0021] The main discharge tray 51 receives the sheet T discharged from the main discharge unit 61 by the main discharge unit roller pair 81. The main discharge tray 51 mainly receives the bundle of sheets T discharged from the main discharge unit 61 after stapling is performed in the stapling unit 3. The main discharge tray 51 is configured to sequentially descend from the uppermost position as the number of bundles of the discharged sheets T increases. Then, when the bundle of sheets T is removed from the main discharge tray 51, the main discharge tray 51 ascends and returns to the reference position.

[0022] Note that the sheet T discharged without any particular post-processing in the sheet post-processing apparatus 1 or the sheet T subjected only to punching processing can also be received by the main discharge tray 51.

[0023] The sub-discharge unit roller pair 82 is disposed near the sub-discharge unit 62 at the terminal end of the second conveyance path L2. The sub-discharge unit roller pair 82 sends out the sheet T that conveys the terminal end of the second conveyance path L2 to the sub-discharge tray 52. The sub-discharge tray 52 receives the sheet T discharged from the sub-discharge unit 62 by the sub-discharge unit roller pair 82. The sub-discharge tray 52 mainly receives the sheet T discharged without any particular post-processing in the sheet post-processing apparatus 1 or the sheet T subjected only to perforation processing.

[0024] The sheet folding processing unit 2 is disposed at the lower part of the housing 11. The sheet folding processing unit 2 is arranged at the lowermost part of the housing 11 of the sheet post-processing device 1. The sheet folding processing unit 2 is provided on the downstream side of the third conveyance path L3, and mainly, a bundle of sheets T on which staple processing has been performed is introduced. Therefore, the sheet folding processing unit 2 mainly performs folding processing on the bundle of sheets T. When the folding processing is selected by the user, folding processing such as double folding and triple folding is performed on the bundle of sheets T, and the bundle is discharged to the lower discharge tray 224 provided at the lower part of one side surface of the housing 11 of the sheet post-processing device 1.

[0025] The staple processing unit 3 performs stacking processing for stacking a plurality of sheets T to form a bundle of sheets T. The staple processing unit 3 can perform various staple processing such as end binding for binding the ends of the stacked bundle of sheets T with staples. For example, for end binding, there are included center end binding for binding two locations along the longitudinal direction near the center of the tip of the bundle of sheets T, and diagonal end binding for binding one corner of the tip of the bundle of sheets T at an angle of 45°. The bundle of sheets T on which stacking processing or end binding has been performed is discharged from the main discharge unit 61 by the main discharge unit roller pair 81.

[0026] The retraction drum 71 conveys the sheet T that branches from the first conveyance path L1 and conveys the third conveyance path L3 to the fourth conveyance path L4 and circulates it via the first conveyance path L1. Thereby, the sheet T can be temporarily retracted. When continuously performing staple processing on a plurality of bundles of sheets T, the retraction drum 71 winds one sheet and a plurality of sheets of the next bundle of sheets T around the surface of the retraction drum 71 and waits while the previous bundle of sheets T is being stapled by the staple processing unit 3. Due to the function of this retraction drum 71, it is not necessary to temporarily stop the discharge of the sheet T from the multi-functional machine main body 101 during staple processing, and productivity is improved.

[0027] Next, with reference to FIG. 2, the details of the structure of the stapling processing unit 3 in the sheet post-processing apparatus 1 of the present embodiment will be described. FIG. 2 is a perspective view of the stapling processing unit 3, and FIG. 3 is a side cross-sectional view of the stapling processing unit 3. The stapling processing unit 3 according to the present embodiment is arranged above the housing 11 of the sheet post-processing apparatus 1. The stapling processing unit 3 is provided on the downstream side of the first conveyance path L1. A sheet bundle T obtained by stacking a plurality of sheets is introduced into the stapling processing unit 3.

[0028] The stapling processing unit 3 moves a stapler (stapling means) 31 to drive stapler needles into the sheet bundle T to perform stapling processing (binding processing). When stapling processing is selected by the user, the stapling processing unit 3 performs stapling processing on the sheet bundle T. The sheet bundle T on which stapling processing has been performed is discharged to a main discharge tray 51 provided at the upper part of one side surface of the housing 11 of the sheet post-processing apparatus 1.

[0029] In the following description, for convenience, the "sheet" shall include the sheet bundle T. Also, the direction in which the sheet bundle T is inserted into the sheet insertion recess 313 of the stapling processing unit 3 or the direction in which the sheet bundle T is conveyed from the sheet insertion recess 313 is referred to as the "sheet insertion direction D1". Among the sheet insertion direction D1, the direction approaching the sheet insertion recess 313 is referred to as the "insertion downstream direction D11", and the direction separating from the sheet insertion recess 313 is referred to as the "insertion upstream direction D12". The sheet insertion direction D1 is inclined with respect to the vertical direction (the vertical direction of the sheet post-processing apparatus 1).

[0030] The direction orthogonal to the sheet insertion direction D1 is referred to as the "sheet width direction D2". Among the sheet width direction D2, the front side of the sheet post-processing apparatus 1 (the front side of the paper surface in FIG. 1) is referred to as the "front direction D21", and the back side of the sheet post-processing apparatus 1 (the back side of the paper surface in FIG. 1) is referred to as the "back direction D22".

[0031] The direction orthogonal to the sheet insertion direction D1 and the sheet width direction D2 (in other words, the direction orthogonal to the D1-D2 plane) is referred to as the "sheet thickness direction D3". Among the sheet thickness direction D3, the upward direction is referred to as the "thickness upward direction D31", and the downward direction is referred to as the "thickness downward direction D32".

[0032] The stapling processing unit 3 includes a stapler (stapling means) 31, a moving table 32, a base member 33, and a moving drive means 34. That is, the sheet post-processing device 1 includes a stapler (stapling means) 31, a moving table 32, a base member 33, and a moving drive means 34.

[0033] The stapler (stapling means) 31 drives stapler pins SP into a sheet bundle T obtained by stacking a plurality of sheets. The sheet insertion recess 313 is into which the sheet bundle T obtained by stacking a plurality of sheets is inserted. The moving table 32 moves integrally with the stapler (stapling means) 31 in the sheet width direction D2. The base member 33 supports the moving table 32 movably. The moving drive means 34 moves the moving table 32 in the sheet width direction D2. The center of gravity of the stapling means is located away from the support point of the base member with respect to the moving table in the sheet insertion direction.

[0034] The stapler (stapling means) 31 includes a stapler main body portion 311 having a clincher, a stitcher 312, and a sheet insertion recess 313. The stapler 31 sandwiches the sheet bundle T inserted into the sheet insertion recess 313 between the stitcher 312 and the clincher, and drives stapler pins into this sheet bundle T. The stapler 31 in the present embodiment can perform an oblique end binding process by driving the stapler pins SP in a state inclined by a predetermined angle in the D1-D2 plane with respect to the sheet insertion direction D1 of the sheet T near the corner of the sheet bundle T.

[0035] The base member 33 supports the moving table 32 so as to be movable in the sheet width direction D2. The base member 33 is mainly composed of a sheet metal member. The base member 33 includes a substantially rectangular main surface portion 335. The main surface portion 335 extends in the D1-D2 plane, and the length in the sheet width direction D2 is longer than the length in the sheet insertion direction D1.

[0036] The main surface portion 335 is inclined with respect to the vertical direction (the up-down direction of the sheet post-treatment device 1). The main surface portion 335 is provided with a guide groove 331 and a movement groove 334. The guide groove 331 and the movement groove 334 are grooves extending along the sheet width direction D2. The guide groove 331 is located on the upstream side in the insertion direction D12 with respect to the movement groove 334. The movement groove 334 is located at a substantially central portion of the main surface portion 335 in the sheet insertion direction D1. The movement groove 334 extends longer in the sheet width direction D2 than the guide groove 331.

[0037] The moving table 32 is a table extending in the D1-D2 plane. A stapler 31 is mounted and held on the moving table 32. The moving table 32 moves linearly in the sheet width direction D2 with respect to the base member 33 and integrally with the stapler 31. The moving table 32 rotates about a virtual rotation axis extending in the sheet thickness direction D3.

[0038] A pair of wheels (not shown) and a wheel 327 are provided on the moving table 32. The wheels (not shown) are arranged at intervals in the sheet width direction D2 on the upstream side in the insertion direction D12 of the moving table 32. The wheel 327 is arranged at the center in the sheet width direction D2 on the downstream side in the insertion direction D11 of the moving table 32. The wheels (not shown) and the wheel 327 are rotatable with respect to the base portion of the moving table 32. The wheels (not shown) and the wheel 327 rotate in contact with the upper surface of the main surface portion 335 of the base member 33. Thereby, the moving table 32 can move smoothly along the guide groove 331 on the main surface portion 335 of the base member 33.

[0039] At this time, the load on the stapler 31 becomes the largest at the contact point between the wheel 327 disposed on the end side in the insertion downstream direction D11 and the base member 33 (support point P of the base member 33 with respect to the moving table). In the present embodiment, the center of gravity G of the stapler 31 is located away from the support point P in the sheet insertion direction D1.

[0040] More specifically, it is preferable that the center of gravity G of the stapler 31 is located in the region S in a cross section orthogonal to the sheet width direction D2. The region S is a trapezoidal region surrounded by a one-dot chain line in FIG. 3 and is surrounded by a first virtual line H1 and a second virtual line H2. The region S is located vertically below Z2 than the lower end of the sheet insertion recess 313. Further, the first virtual line H1 extends in the sheet thickness direction D3 through the lower end of the sheet insertion recess 313. The second virtual line H2 extends in the vertical direction Z1 through the support point P. That is, the center of gravity G of the stapler 31 is located between the first virtual line H1 and the second virtual line H2.

[0041] The moving table 32 sandwiches the base member 33 between itself and the first slider 35 via the moving groove 334 of the base member 33. The first slider 35 is guided by the moving groove 334 along the direction in which the moving groove 334 extends and is movable.

[0042] Further, the moving table 32 sandwiches the base member 33 between itself and a second slider (not shown) via the guide groove 331 of the base member 33. The second slider (not shown) is guided by the guide groove 331 along the direction in which the guide groove 331 extends and is movable.

[0043] The first slider 35 has wheels 353. The wheels 353 rotate in contact with the lower surface of the main surface portion 335 of the base member 33. Thereby, the first slider 35 can move smoothly along the moving groove 334 on the lower surface of the main surface portion 335 of the base member 33.

[0044] The second slider (not shown) has wheels (not shown). The wheels of the second slider (not shown) contact and rotate on the lower surface of the main surface portion 335 of the base member 33. As a result, the second slider can move smoothly along the guide groove 331 on the lower surface of the main surface portion 335 of the base member 33.

[0045] The movement driving means 34 is composed of a moving table linear movement driving means, a moving table rotation driving means, and a staple means inclination holding means. The moving table linear movement driving means linearly moves the moving table 32 in the sheet width direction D2. The moving table rotation driving means rotates the moving table 32 so that the stapler 31 is inclined to a position where the staple needle SP can be driven in at a predetermined angle with respect to the sheet insertion direction D1. The staple means inclination holding means mechanically holds the moving table 32 so as to maintain the inclined state of the stapler 31.

[0046] The movement driving means 34 has a motor 361. The motor 361 is a driving source that rotationally drives a pulley (not shown) via a shaft (not shown) or the like. The motor 361 is fixed, for example, on the upper surface of the main surface portion 335 of the base member 33 on the back direction D22 side.

[0047] The motor 361 becomes a driving source that moves the stapler 31 in the sheet width direction D2 and rotates the stapler 31 about a virtual rotation axis extending in the sheet thickness direction D3 via a pulley, an endless belt, the moving table 32, and the like.

[0048] After linearly moving the stapler 31 in the sheet width direction D2 by the movement driving means 34, the stapler 31 can be rotated. Then, the stapler 31 drives the staple needle SP into the vicinity of the corner of the sheet bundle T at a predetermined angle with respect to the sheet insertion direction D1 and the sheet width direction D2, and performs an oblique end binding process.

[0049] At this time, the center of gravity G of the stapler 31 is located away from the support point P in the sheet insertion direction D1, and a force that presses the moving table 32, which moves integrally with the stapler 31, toward the base member 33 acts with the support point P as a fulcrum. Thereby, it is possible to prevent the moving table 32 from rising with respect to the base member 33. Further, it is possible to cause a defect in the post-processing of the paper only by changing the position of the center of gravity of the stapler 31, and it is possible to suppress an increase in manufacturing cost.

[0050] Further, by arranging the center of gravity G of the stapler 31 between the first virtual line H1 and the second virtual line H2 and arranging it below the lower end of the sheet insertion recess 313 in the vertical direction Z2, it is possible to prevent the moving table 32 from rising with respect to the base member 33.

[0051] The present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the scope of the claims. For example, each configuration of the above-described embodiment can be partially omitted or arbitrarily combined so as to be different from the above. For example, in the present embodiment, a sheet post-processing apparatus that performs diagonal edge binding processing has been described, but the present invention also includes a sheet post-processing apparatus that performs only parallel binding processing without rotating the stapler 31.

Industrial Applicability

[0052] The present invention can be used in an image forming apparatus including a sheet post-processing apparatus.

Explanation of Reference Numerals

[0053] 1 Sheet post-processing apparatus 2 Sheet folding processing unit 3 Staple processing unit 4 Punch unit 11 Housing 31 Stapler 32 Moving table 33 Base member 34 Moving drive means 35 First slider 51 Main discharge tray 52 Sub discharge tray 60 Loading section 61 Main discharge section 62 Sub discharge section 71 Retraction drum 72 First switching claw 73 Second switching claw 80 First intermediate roller pair 81 Main discharge section roller pair 82 Sub discharge section roller pair 100 Multifunction device 101 Multifunction device main body 102 Main body discharge section 224 Lower discharge tray 311 Stapler main body section 312 Stitcher 313 Sheet insertion recess 327 Wheel 331 Guide groove 334 Movement groove 335 Main surface 353 Wheel 361 Motor D1 Sheet insertion direction D11 Downstream insertion direction D12 Upstream insertion direction D2 Sheet width direction D21 Front direction D22 Rear direction D3 Sheet thickness direction D31 Upward thickness direction D32 Downward thickness direction G Center of gravity L1 First conveyance path L2 Second conveyance path L3 Third conveyance path L4 Fourth conveyance path H1 First virtual line H2 Second virtual line P Support point P1 First branch section P2 Second branch section P3 Third branch section Q1 First confluence section S Area SP Stapler needle T Sheet bundle Upper side in the vertical direction Z1 Lower side in the vertical direction Z2

Claims

1. A sheet post-processing device having a sheet insertion recess into which a stack of sheets obtained by performing a stacking process on a plurality of sheets is inserted, and stapling means for driving stapler pins into the stack of sheets inserted into the sheet insertion recess, a moving table that moves integrally with the stapling means in a sheet width direction orthogonal to a sheet insertion direction of the stack of sheets into the sheet insertion recess, a base member that movably supports the moving table, and moving drive means for moving the moving table in the sheet width direction, wherein the moving drive means moves the stapling means via the moving table to drive the stapler pins into the stack of sheets to perform a binding process, and a center of gravity of the stapling means is located away from a support point of the base member with respect to the moving table in the sheet insertion direction.

2. The center of gravity of the stapling means is located between a first virtual line extending in a sheet thickness direction orthogonal to the sheet insertion direction and the sheet width direction through a lower end of the sheet insertion recess, and a second virtual line extending in a vertical direction through the support point. The sheet post-processing device according to claim 1.

3. The center of gravity of the stapling means is located below the lower end of the sheet insertion recess in the vertical direction. The sheet post-processing device according to claim 1 or claim 2.

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