JP2003026368A - Method and device for post-processing of sheet and image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To preclude defective workmanship of book binding with sheets of paper transported upon a sheet placing table by a wind-in belt likely to occur with a deformation of the sheet trailing edge when sheet abuts to a trailing edge abutting member. SOLUTION: A post-processing device according to the invention works with two processes, the first aligning process in which a sheet discharge belt 75 is rotated in the regular direction by a driving means so that a sheet discharging pawl 76 is stopped in the specified position upstream about the transporting direction of the abutting surface of the trailing edge abutting member 72, and the sheet S carried in to the sheet placing table 71 is moved with rotation of the wind-in belt 16 and abutted to the abutting surface portion of the pawl 76 to generate pre-alignment, and the second aligning process in which the belt 75 is rotated in the reverse direction so that the pawl 76 is retreated from over the table 71, and the sheets S stacked on the table 71 are abutted to the abutting surface of the trailing edge abutting member 72 situated under so that alignment is established.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic copying machine,
Receiving sheets discharged from image forming devices such as printers, facsimiles, and multifunction devices having these functions,
The present invention relates to a sheet post-processing apparatus having a function of stacking in a sheet storage unit, performing post-processing such as binding processing, and discharging the sheet to a sheet discharge unit.

[0002]

2. Description of the Related Art A large number of sheets on which images are recorded by a main body of an image forming apparatus such as a copying machine, a printer, a facsimile, and a complex machine of these are gathered for each number of prints, and bound by a binding means for binding. A paper post-processing device is provided. The sheet post-processing device is connected to and driven by the print function of the main body of the image forming apparatus.

As a sheet post-processing device for binding a bundle of a plurality of sheets as a set, Japanese Patent Laid-Open No. 2-276
691, No. 8-319054, Japanese Examined Patent Publication No. 5-4199
No. 1 publications and the like are disclosed.

[0004]

The conventional sheet post-processing apparatus for binding processing has the following problems.

FIG. 13 is a cross-sectional view of the sheet storage section 70 in the conventional sheet post-processing apparatus. Entrance conveyance roller 15
The sheet S sandwiched between A and 15B and conveyed to the sheet storage unit 70 is conveyed to the upper side of the sheet mounting table 71 and goes up (conveying direction a). The rear end of the sheet S is the entrance transport roller 15
After passing through the nipping positions of A and 15B, the sheet S turns downward due to its own weight (conveying direction b), slides down on the sheet stacking table 71, and is rolled up by the rotating sheet winding member 16 so as to slide and contact. Then, the trailing edge of the sheet comes into contact with the abutting surface of the lower sheet trailing edge abutting member 72 to stop and align.

The pair of paper rear end abutting members 72 abut on both ends of the rear end of the paper S in the width direction to align and align them.

At least one paper winding member 16 is rotatably supported inside the pair of paper rear end abutting members 72 in the width direction. The paper winding member 16 is arranged near the central portion of the paper placing table 71. The paper take-in member 16 is a belt or an impeller installed between a drive pulley and a driven pulley.

The sheet S slides down on the sheet mounting table 71 and abuts on the abutting surface portions of the sheet trailing edge abutting member 72 located near both ends in the sheet width direction. The paper winding member 16 which is located in the vicinity and rotates allows the sliding contact and movement.

At the rear end of the sheet S, the vicinity of both ends in the sheet width direction abuts the abutting surface of the sheet rear end abutting member 72, but the vicinity of the center in the sheet width direction rotates. As a result, the trailing edge of the sheet S is swollen and deformed as shown in the figure, and the binding process is performed in this deformed state. Therefore, the binding position of the bundle of sheets after the binding process from the rear end of the sheet is displaced from the predetermined position, and the rear end of the sheet becomes uneven. In particular, when a large number of sheets S are stacked on the sheet mounting table 71 and binding processing is performed, defective binding positions and uneven sheet trailing edges are significant.

[0010]

The above problems can be solved by a sheet post-processing method, a sheet post-processing apparatus, and an image forming apparatus of the present invention.

(1) The sheet discharged from the main body of the image forming apparatus is conveyed and stacked on the sheet mounting table, and the sheet is abutted against the abutting surface of the sheet rear end abutting member arranged below the sheet mounting table. In the sheet post-processing method, in which the sheets are brought into contact with each other to be aligned and aligned, the sheets are bound by the binding means, and then the sheets are discharged by the sheet discharging means, the sheet discharging means is rotatably stretched between a plurality of pulleys. A discharge belt, a discharge claw that is formed integrally with the discharge belt, and that rotates the discharge belt to press the trailing end portion of the bound sheet bundle in the transport direction to discharge the sheet bundle; and the discharge belt. Drive means for rotating in the normal and reverse directions, and before the sheets are stacked and aligned on the sheet mounting table, the discharge belt is rotated in the forward direction by the drive means to move the discharge claws to the rear end of the sheet. Abutment of abutting member Stop at a predetermined position above the vertical surface and bring the paper into contact with the paper abutting surface of the discharge claw to pre-align it, and then rotate the discharge belt in the reverse direction so that the discharge claw is placed on the paper table. A sheet post-processing method, in which the sheets stacked on the sheet tray are brought into contact with the abutting surface of the sheet trailing edge abutting member below and aligned.

(2) The sheets discharged from the main body of the image forming apparatus are conveyed and stacked on the sheet mounting table, the sheets are positioned and aligned at a predetermined position, the sheets are bound by the binding means, and then discharged to the outside of the apparatus. In the sheet post-processing apparatus, a discharge belt rotatably stretched between a plurality of pulleys is formed integrally with the discharge belt, and the rotation of the discharge belt causes the binding direction of the bundle of sheets to be bound. Discharging means including a discharging claw for pressing the rear end portion to discharge the sheet bundle and a driving means for rotating the discharging belt in the forward and reverse directions, and arranged below the sheet stacking table and contacting the sheets. The sheet trailing edge abutting member for positioning and aligning is arranged above the sheet trailing edge abutting member, slidably contacts the sheet and is driven to rotate, and guides the sheet to abut the sheet trailing edge abutting member. Abut the contact surface And a sheet guide member for driving the discharge belt to rotate forward by the drive unit to stop the discharge claw at a predetermined position above the abutting surface of the sheet rear end abutting member. The first aligning step of moving the sheet carried into the sheet mounting table by the rotation of the sheet, and abutting it against the sheet abutting surface of the discharge claw to pre-align it, and the discharge belt is driven in the reverse rotation direction to remove the discharge claw. A second aligning step of retreating from the sheet stacking table and aligning the sheets stacked on the sheet stacking table by abutting against the abutting surface of the sheet trailing edge abutting member below. Paper post-processing device.

(3) An image forming apparatus comprising an image forming apparatus main body including an image writing means, an image forming means, and a sheet conveying means, and the sheet post-processing apparatus described in (2) above.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION Next, a sheet post-processing apparatus of the present invention,
An image forming apparatus including a sheet post-processing apparatus will be described with reference to the drawings.

[One Embodiment of Image Forming Apparatus] FIG. 1 is an overall configuration diagram of an image forming system including an image forming apparatus main body A, an image reading apparatus B, and a sheet post-processing apparatus (hereinafter also referred to as a post-processing apparatus) FS. is there.

The image forming apparatus main body A has a charging means 2, an image exposing means (writing means) 3, a developing means 4, and a transfer means 5 around a rotating image carrier (hereinafter referred to as a photoconductor) 1.
A, an electrostatic latent image forming means 5B, a separation claw 5C, and a cleaning means 6 are arranged in the image forming portion. The charging means 2 uniformly charges the surface of the photoconductor 1 and then the laser beam from the exposing means 3 The latent image is formed by performing exposure scanning based on the image data read from the image forming device, and the latent image is reversely developed by the developing means 4 to form a toner image on the surface of the photoconductor 1.

On the other hand, the paper S fed from the paper storage means 7A is sent to the transfer position. At the transfer position, the toner image is transferred onto the paper S by the transfer means 5A. After that, the electric charge on the back surface of the sheet S is erased by the charge eliminating unit 5B, separated from the photoconductor 1 by the separation claw 5C, conveyed by the intermediate conveying unit 7B, and subsequently heated and fixed by the fixing unit 8, and then discharged from the sheet discharging unit 7C. Is discharged.

When images are formed on both sides of the paper S,
The sheet S heated and fixed by the fixing unit 8 is branched from the normal sheet discharge path by the conveyance path switching plate 7D, switched back and turned upside down in the reverse conveyance 7E, and then discharged to the outside of the apparatus by the sheet discharge unit 7C. It The paper S discharged from the paper discharge unit 7C is sent to the receiving unit 11 of the post-processing device FS.

On the other hand, the surface of the photoconductor 1 after the image processing is cleaned by the cleaning means 6 downstream of the separation claw 5C to remove the developer remaining on the surface, to prepare for the next image formation.

An operation unit 9 for selecting and setting an image forming mode and a sheet post-processing mode is arranged on the upper front side of the image forming apparatus main body A.

On the upper part of the image forming apparatus main body A, an image reading apparatus B equipped with an automatic document feeder of a moving original reading type is installed.

[Post-Processing Device] FIG. 2 is an overall configuration diagram showing the transport path of the sheet S in the post-processing device FS according to the present invention.

In the post-processing apparatus FS, the first sheet feeding means 20A, the second sheet feeding means 20B and the fixed sheet discharging table 30 are arranged in the upper stage of the figure, and the punching means 40, the shift means 50 and the sheet discharging means are arranged in the middle stage. 60 are arranged in series on the same plane which is almost horizontal,
A binding processing unit (also referred to as a paper storage unit) 70 and a folding processing unit 80 are arranged in series on the lower stage in the same plane forming an inclined surface.

On the left side surface of the post-processing device FS in the drawing,
Shifted sheet S and edge-stitched sheet bundle S
An elevating and discharging tray 91 for stacking a and a fixed discharging tray 92 for stacking a processed sheet bundle Sb that has been folded in three or two are arranged.

The post-processing apparatus FS is installed with its position and height adjusted so that the receiving section 11 for the sheet S carried out from the image forming apparatus main body A coincides with the sheet discharging section 7C of the image forming apparatus main body A.

In the receiving section 11, the sheet S subjected to the image forming process from the image forming apparatus main body A, the interleaving sheet K1 for separating the sheet bundle supplied from the first sheet feeding means 20A, and the second sheet feeding means 20B. The cover sheet K2 supplied from

(Paper feeding means) Interleaving paper K1 accommodated in the paper feeding tray of the first paper feeding means 20A
Are separated and fed by the paper feed unit 21, and the transport roller 2
It is sandwiched by 2, 23, 24 and introduced into the receiving unit 11. Further, the cover sheet K2 stored in the sheet feeding tray of the second sheet feeding unit 20B is separated and fed by the sheet feeding section 25, nipped by the transport rollers 23 and 24, and introduced into the receiving section 11. .

(Punching means) A punching means 40 is arranged on the downstream side of the receiving section 11 in the sheet conveying direction. The punching means 40 has a movable punch that is driven up and down, and a fixed die that fits into the blade of the punch.

(Paper branching means) A paper branching means composed of switching means G1 and G2 is provided on the downstream side of the punching means 40 in the paper carrying direction. The switching means G1 and G2 are selectively driven by driving a solenoid (not shown) to one of the three paper conveyance paths, that is, the first conveyance path for discharging the upper stage, the second conveyance path in the middle stage, and the third conveyance path in the lower stage. Branch.

(Simple paper discharge) When this paper transport is set, the switching means G1 moves to the second
The transport path and the third transport path are shut off, and only the first transport path is opened.

The sheets S passing through the first conveying path are nipped by the conveying rollers 31 and ascended, discharged by the discharge rollers 32, placed on the fixed sheet discharge table 30, and sequentially stacked. A maximum of about 200 sheets of paper S can be stacked on the fixed paper output tray 30.

(Shift processing) When this transport mode is set, the switching means G1 retracts upward, the switching means G2 shuts off the third transport path, opens the second transport path, and allows the sheet S to pass. to enable.
The sheet S passes through a sheet passage formed between the switching means G1 and G2.

The image-formed sheet S discharged from the image forming apparatus main body A, the interleaf sheet K1 fed from the first sheet feeding means 20A, or the cover sheet fed from the second sheet feeding means 20B. The sheet K2 passes through the intermediate sheet passage of the switching units G1 and G2, is shifted by the shift unit 50 in the direction orthogonal to the sheet transport direction, and is then transported.

The shift means 50 carries out a shift process for changing the paper discharge position of the paper S in the carrying width direction every predetermined number of sheets. The shift-processed sheets S are discharged by the sheet discharging unit 60 to the up-and-down sheet discharge tray 91 outside the machine and sequentially placed. The elevating and discharging tray 91 is configured to sequentially descend when discharging a large number of sheets S, and a maximum of about 3000 sheets (A4, A4
It is possible to store the sheet S of B5).

(Binding Processing) FIG. 3 is a sectional view of the post-processing unit 10 including the binding processing section 70 and the folding processing section 80.

When the binding process or the folding process is set in the operation section 9, the image-formed sheet S sent to the receiving section 11 of the post-processing apparatus FS after being subjected to the image forming processing in the image forming apparatus main body A is After passing through the punching means 40, it is sent to the third conveying path below the switching means G2, is sandwiched by the conveying rollers 12, and is conveyed downward.

When a sheet S of a size larger than A4 or B5 is conveyed in the third conveying path, the solenoid S
D1 is driven, and the sheet S passes through the sheet passage 13A on the left side of the switching unit G3 in the figure, is nipped by the conveying rollers 14, and is conveyed downward. The sheet S has a pair of inlet conveyance rollers 15 that are formed of inlet conveyance rollers 15A and 15B located further downstream.
Are sandwiched and fed by a sheet of paper, discharged to the upper space of the inclined sheet stacking table (intermediate stacker) 71, contact the sheet stacking table 71 or the upper surface of the sheet S stacked on the sheet stacking table 71, and obliquely upward. Be transported. After the trailing end of the sheet S in the traveling direction is discharged from the nipping position of the transport rollers 14, the sheet S starts to descend due to its own weight, and the sheet loading table 71
The sheet is conveyed on the inclined surface of the sheet and is bound by the stapling means (stapling means) 7
The trailing edge of the sheet S contacts the sheet abutting surface of the sheet trailing edge abutting member 72 for edge binding in the vicinity of 00, and the sheet stops. 16
Is an endless belt-shaped paper winding member (hereinafter referred to as a winding belt) 16 that is rolled into contact with the leading edge of the paper S and is fed to the paper rear end abutting member 72.
Is. The winding belt 16 may be a rotatable impeller.

In the third transport path, small size sheets S of A4, B5 size or the like are efficiently and continuously transported to improve copy productivity, and movable switching means G3,
A paper passage 13B parallel to the paper passage 13A on the left side of the switching means G3 in the drawing is provided.

Solenoid S connected to switching means G3
When D1 is driven, the passage 13A is closed and the passage 13B is closed.
Open up.

The leading end portion of the first small-sized sheet S sent out from the conveying roller 12 passes through the sheet passing path 13B and comes into contact with the peripheral surfaces of the inlet conveying rollers 15A and 15B in the rotation stopped state. Stop.

Next, the energization of the solenoid SD1 is turned off, the leading end of the switching means G3 swings clockwise, the paper passage 13B is closed, and the paper passage 13A is opened. The leading edge of the second sheet S sent out from the transport roller 12 is
After passing through the sheet passing path 13A, it comes into contact with the peripheral surfaces of the entrance conveying rollers 15A and 15B in the rotation stopped state and stops. Therefore,
1 near the nipping position of the entrance conveyance rollers 15A and 15B.
The leading end portions of the second sheet S and the second sheet S overlap and stop, and the standby state is set.

At a predetermined timing, the entrance conveyance rollers 15A and 15B are driven and rotated, and the two sheets S are nipped and conveyed at the same time, and ejected onto the sheet placing table 71. After the third sheet, the entrance conveying rollers 15A and 15B discharge the sheets S one by one.

Reference numeral 73A denotes a pair of upstream side width aligning members movably provided on both side surfaces of the sheet mounting table 71. The width alignment member 73A is movable in a direction orthogonal to the sheet transport direction, and is opened wider than the sheet width when the sheet S is received on the sheet mounting table 71. When the sheet S is conveyed on the sheet mounting table 71 and comes into contact with the sheet rear end abutting member 72 and stops, the width alignment member 73A causes the sheet S to move.
The side edges of the sheet bundle Sa are tapped to align the width of the sheet bundle Sa (width alignment). At this stop position, when a predetermined number of sheets S are stacked and aligned on the sheet mounting table 71, the binding means 7
The binding process is performed by 00 to bind the sheet bundle Sa.

A notch is formed in a part of the sheet stacking surface of the sheet stacking table 71, and the discharge belt 75 wound around the drive pulley 74A and the driven pulley 74B is rotatably driven. A discharge claw 76 is formed integrally with the discharge belt 75, and the tip end portion thereof draws an elliptical locus X as shown by a dashed line in the figure. The bound paper bundle Sa is held on the trailing edge of the paper S by the discharge claws 76 of the discharge belt 75, is placed on the discharge belt 75, and slides on the placement surface of the sheet placement table 71 to be slanted. It is pushed up and the sheet discharging means 6
The discharge roller 61 moves to the nip position of 0. The sheet bundle Sa nipped by the rotating discharge rollers 61 is moved up and down by the lift tray 9
1 is discharged and loaded (see FIG. 2).

FIG. 4 shows the case where various binding processes are executed.
7 is a plan view showing the arrangement of a sheet bundle Sa and a binding unit 700. FIG. FIG. 4A is a plan view showing a flat stitching process in which the staples SP are stapled at two locations in the center in the vicinity of the side edges of the sheet bundle Sa, and FIG. FIG. 4 is a plan view showing an edge stitching process of striking a staple SP at a position.
FIG. 7C is a plan view showing a saddle stitching process of striking the staples SP at two central portions of the sheet bundle Sa.

(Saddle Stitching Processing) As shown in FIG. 3, the sheet stacking table 7 on which the sheet bundle Sa is mounted
1, the binding processing unit 70, and the folding processing unit 80 are arranged on the pedestal of the post-processing unit 10 and can be pulled out to the front side of the post-processing device FS by being guided by the slide rails R1 and R2.

The binding means 700 is constructed in a two-part structure of a stapling mechanism 701 and a staple receiving mechanism 702, and a sheet passage 77A through which the sheet S can pass is formed in the middle thereof.

Two sets of the binding means 700 are arranged in the direction orthogonal to the sheet conveying direction, and can be moved in the direction orthogonal to the sheet conveying direction by the driving means (not shown).

When the side-to-side binding mode is set, the binding needles SP are struck by the two sets of binding means 700 at the two central locations in the sheet width direction of the sheet bundle Sa (see FIG. 4A).

When the edge binding mode is set, the binding means 700 goes straight and the sheet bundle S corresponding to the sheet size.
The binding needle SP is hit at one location of the corner portion of a (see FIG. 4B). When the saddle-stitching and center-folding process is set, the staples SP are struck at two central portions of the sheet bundle Sa (see FIG. 4C).

When the saddle stitching process is set, the stitching means 70
The paper trailing edge abutting member 72 near the 0 stapling position (stitching position of the binding needle) is retracted from the transport path, and at the same time, a sheet abutting member 78 for both saddle stitching and center folding downstream from it is passed through the paper path 77A. The paper path 77B is blocked by moving in the direction of the extension surface of the paper.

The saddle-stitching stopper unit having the sheet abutting member 78, when the sizes (length in the carrying direction) of the cover sheet K2 and the sheet S are set or detected, the lower end of the sheet bundle Sa to be saddle-stitched. It moves to the position where it abuts the section and stops.

After the cover sheet K2 is placed at a predetermined stop position on the sheet placing table 71, the sheet S carried out from the image forming apparatus main body A is transferred from the receiving section 11 of the post-processing apparatus FS to the third section.
After passing through the transport path, the cover sheets K2 placed on the sheet placing table 71 are sequentially stacked on the upper surface of the sheet K2, and the leading end of the sheet S abuts on the sheet abutting member 78 to be positioned.

After the final sheet S is positioned and placed on the sheet placing table 71, the saddle stitching process by the binding means 700 is performed on the sheet bundle Sa including the cover sheet K2 and all the pages of the sheet S. By this saddle-stitching process, the binding needle SP is driven into the central portion of the cover sheet K2 and the sheet S in the transport direction. The staple SP is driven from the staple driving mechanism 701 on the staple driving side toward the staple receiving mechanism 702 on the staple clinching side.

(Folding Process) As shown in FIG. 3, a folding process unit 80 is arranged diagonally below the binding process unit 70. After the saddle stitching process, the sheet abutting member 78 linearly moves in the downstream direction of conveyance of the sheet bundle Sa to open the passage downstream of the sheet passage 77A. The movable sheet abutting member 78 regulates the stop position of the sheet bundle Sa at the time of saddle stitching processing at the upper position, and regulates the stop position of the sheet bundle Sa at the time of center folding processing at the lower position.

The sheet bundle Sa composed of the cover sheet K2 and the sheet S subjected to the saddle stitching is conveyed in the sheet passage 81A formed by the guide plate 81 obliquely downward, and the sheet abutting member 7 is pushed.
The end of the sheet bundle Sa in the transport direction comes into contact with 8 and stops at a predetermined position. The sheet abutting member 78 can be moved to a predetermined position by the result of setting or detecting the sheet size and the driving unit.

A sheet mounting table 71 of the post-processing unit 10,
The paper passages 77A, 77B, 81A are formed on substantially the same plane and form a steep slope of about 70 degrees.

The folding processing section 80 includes a protrusion plate 82, a pair of first folding lower rollers 83, a first folding upper roller 84, and a second folding upper roller 84.
Folding roller 85, transport belt 86, transport switching member 8
7 and the like, and enables the folding process and the tri-folding process of the sheet bundle Sa.

(Drive system of binding processing section) FIG. 5 is a block diagram of a drive system for driving the rotation of the discharge belt 75 and the swing of the discharge roller 61, and FIG. 6 is a sheet storage section 70 and the discharge roller 61. FIG.

The motor M1 includes a belt B1, a pulley P1,
The upper roller 61A of the discharge roller 61 is driven and rotated through the belt B2, and the lower roller 61B of the discharge roller 61 is driven and rotated through the belt B3, the pulley P2, and the belt B4. Further, the motor M1 includes a belt B3 and a pulley P.
2, drive belt 74A via belt B5 and pulley P3
Is driven and rotated to rotate one discharge belt 75.

The gear 74D fixed to the shaft end of the rotary shaft 74C of the drive pulley 74A meshes with the cam member 74E and rotates. The cam member 74E has a cam-shaped test portion. When the sensor PS1 detects this portion to be inspected, the standby position when the discharge claw 76 fixed to the discharge belt 75 rotated by the motor M1 is stopped is set.

The motor M2 moves the two upstream side width matching members 73A via the belt 731 in accordance with the sheet width. The motor M3 translates and rotationally moves the two binding units 700 via the belt 703 to set them at the binding position. The motor M4 moves the downstream width matching member 73B via the belt 732.

Further, the paper trailing edge abutting member 72 is driven by a motor (not shown) to block and open the paper passage 77B. The paper abutting member 78 is also driven by a motor (not shown), moves in the paper passages 77B and 81A, and is installed at a predetermined position.

In FIG. 5, the motor M5 drives and rotates the entrance conveying rollers 15A and 15B and rotates the winding belt 16.

(Conveyance of Sheet Bundle After Stitching Process) FIG. 7A is a sectional view of the vicinity of the discharge belt 75 showing a state in which the sheet bundle Sa after the end stapling process is discharged.

The trailing end portion of the end-stitched sheet bundle Sa, which is positioned and stacked on the sheet mounting table 71, is rotated in the arrow direction by the forward rotation of the motor M1 capable of forward and reverse rotation. Discharge claw 7 fixed to one end of belt 75
The sheet is held by 6 and slides on the sheet mounting table 71, is pushed forward in the direction of the outlined arrow diagonally above and is ejected.

Standby position HP of the discharge claw 76 during edge binding processing
1 is below the sheet stacking table 71, and the discharge belt 75
After the start of the rotation of the sheet bundle Sa, the sheet bundle Sa is swiftly set to the position where the rear end portion of the sheet bundle Sa is pressed. The standby position HP1 described above
Is arbitrarily positioned at a predetermined position when detected by a photo sensor (not shown) and timed by a timer.

FIG. 7B shows a sheet bundle Sa after saddle stitching processing.
FIG. 9 is a cross-sectional view of the vicinity of a discharge belt 75 showing a state in which is conveyed to the folding processing unit 80 in the next step.

The rear end of the saddle-stitched bundle of sheets Sa positioned and stacked on the sheet mounting table 71 in the sheet discharge direction is one end of a discharge belt 75 which is rotated in the arrow direction by the reverse rotation of the motor M1. By the rearward push of the discharge claw 76 fixed to the sheet stack and the own weight of the sheet bundle Sa, the sheet is slid on the sheet mounting table 71 and is pushed obliquely downward in the direction of the outlined arrow to be conveyed to the folding processing unit 80 in the next step. .

Standby position HP of the discharge claw 76 during saddle stitching processing
2 is set to a position where the rear end portion of the sheet bundle Sa of the maximum size is quickly pressed after the discharge belt 75 starts rotating in the arrow direction. The standby position HP2 can be arbitrarily set to a predetermined position by detection by a photo sensor (not shown) and timing processing by a timer.

(Discharge Belt and Discharge Claw) The discharge belt 75 is a timing belt having a tooth profile and has an endless shape. A discharge claw 76 is integrally formed on a part of the outer peripheral portion of the discharge belt 75. The discharge belt 75 and the discharge claw 76 have a width of 6 mm, for example, and are made of urethane rubber. The discharge claw 76 formed of urethane rubber has an advantage that when the slide claw 76 is in sliding contact with the rear end of the sheet bundle Sa, it has less scratches than chloroprene rubber (CR) or the like used in the conventional discharge claw. .

That is, when the discharging claw 76 moves on the sheet mounting table 71 while slidingly contacting the rear end portion of the sheet stack Sa and the discharging claw 76 retracts from the upper surface of the sheet mounting table 71, the discharging claw 76 moves the sheet stack Sa. There are very few scratches when moving by sliding on the bottom side of the.

FIG. 8 is a partial sectional view showing the rotation of the discharge claw 76 of the discharge belt 75, and FIG. 8A shows a state before the discharge belt 75 starts discharging the sheet bundle Sa.
(B) shows a state in which the sheet bundle Sa is discharged by the discharge belt 75.

The discharging claw 76 is formed integrally with a part of the outer peripheral portion of the discharging belt 75, and has a sheet abutting surface portion 76A, an upper end regulating portion 76B, a connecting portion 76C, a reinforcing portion 76D, a slit portion (cutting portion) 76E, It is formed of an inclined surface portion 76F and the like.

The sheet abutting surface portion 76A presses the rear end portion of the sheet bundle Sa and conveys it to the sheet discharging means 60. The upper end regulation portion 76B regulates curl generated at the rear end portion on the upper surface side of the bundle of many sheets Sa.

The connecting portion 76C is a connecting portion that connects the outer peripheral portion of the discharge belt 75 and the discharge claw 76, and is connected to at least one tooth portion 75A of the discharge belt 75 and has a thick shape. The connecting portion 76C having this thick shape is
It has sufficient strength required when the rear end of the sheet bundle Sa is pressed to be conveyed and discharged. Also, this connecting portion 76
C is set to a minimum length in which the discharge belt 75 has little bending when the drive pulley 74A and the driven pulley 74B rotate.

The reinforcing portion 76D is a sheet abutting surface portion 76A.
Is a thickened portion for reinforcing the back portion of the sheet, and is sufficient to prevent deformation by the pressing force when the discharging claw 76 presses the rear end of the sheet bundle Sa to convey and discharge the sheet. Have strength.

A slit portion 76E is formed between the bottom portion of the reinforcing portion 76D and the flat portion of the outer peripheral surface of the discharge belt 75. The slit portion 7E is, for example, a narrow gap having a slit width δ of about 0.5 mm, and is pressed against the flat portion of the outer peripheral surface of the discharge belt 75 when the sheet abutting surface portion 76A of the discharge claw 76 presses the sheet bundle Sa. To prevent the discharge claws 76 from falling.

The discharge belt 75 is provided at the bottom of the slit portion 76E.
Below the flat portion of the outer peripheral surface, there are a plurality of tooth portions 75B corresponding to the bottom portion of the reinforcing portion 76D.
Serves as reinforcement when the discharge claw 76 is pressed.

(Inlet Conveying Roller Pair, Paper Storage Section, Paper Ejection Means) FIG. 9 is a sectional view of the inlet conveyance roller pair 15, the paper storage section 70, and the paper ejection means 60.

The sheet S carried into the third carrying path shown in FIG. 3 is sent out after being pinched by the pair of entrance carrying rollers 15 after the passage of the leading end or the trailing end of the paper is detected by the sensor PS2. The sheet is discharged into the space above the inclined sheet placing table 71, and the sheet placing table 71 or the sheet placing table 7 is discharged.
The sheet S stacked on the sheet 1 is brought into contact with the upper surface of the sheet S and is conveyed in an upper conveying direction a. After the trailing end of the sheet S in the traveling direction is discharged from the nipping position of the transport rollers 14, the sheet S turns downward due to its own weight, and travels in the transport direction b on the inclined surface of the sheet mounting table 71, and the winding belt The leading edge of the sheet slides by 16, and the trailing edge of the sheet S abuts against the sheet abutting surface of the sheet trailing edge abutting member 72 to stop.

The sheet discharging means 60 arranged above the sheet mounting table 71 has an upper roller 61A and a lower roller 6 which are driven and rotated.
1B and. The upper roller unit 62 holding the upper roller 61A is connected to a disk 67 and a crank lever 66 which are rotated by a motor M6 through a gear train, and is swingable around a support shaft 64.

Large size paper (for example, A3 size paper,
(8.5 × 14 inch size paper) S is introduced onto the paper table 71, a drive source (not shown) is driven, and the upper roller unit 62 is centered on the support shaft 64 via the disc 67 and the crank lever 66. The upper roller 61A.
Is moved upward from the nipping position with the lower roller 61B, the paper passage is opened, and the leading end of the large-sized paper can be inserted.

(Inlet Conveying Roller Pair and Winding Belt) FIG. 10 is a plan sectional view showing the vicinity of the inlet conveying roller pair 15.

The two entrance conveying rollers 15A driven and rotated by the motor M5 (see FIG. 5) press-contact each of the two entrance conveying rollers 15B to be driven to rotate. The entrance transport rollers 15A and 15B are symmetrically arranged at substantially the same distance with respect to the center line CL of the sheet S in the width direction.

A concave roller 17A having an outer peripheral surface with a concave curved surface is provided in the vicinity of the central portion of the rotary shaft 15C of the entrance conveying roller 15A.
Is fixed. Rotation shaft 15 of entrance conveyance roller 15B
A convex roller 17B having a convex curved outer peripheral surface is fixed near the center of C. Concave roller 17A and convex roller 1
By sandwiching the sheet S with 7B and transporting it, a corrugation is formed in the central portion of the sheet width of the sheet S.

The toothed pulley P4 formed integrally with the convex roller 17B rotates together with the rotating shaft 15C to rotate the winding belt 16 which winds the toothed pulleys P4, P5 and P6.

On the shaft near both ends of the rotary shaft 15C, 2
The individual entrance conveyance assisting rollers 18 are symmetrically arranged at substantially the same distance with respect to the center line CL. Entrance conveyance auxiliary roller 18
Has a plurality of protrusions on the outer peripheral surface. The entrance conveyance auxiliary roller 18 does not have a driven roller and rotates independently. The rotating entrance conveyance auxiliary roller 18 slidably contacts the rear end of the sheet S descending on the sheet mounting table 71 and pushes it out to abut the abutting surface of the sheet rear end abutting member 72.

The paper trailing edge abutting member 72 is a binding means 70.
It is swingably supported on the side wall of No. 0 and is continuously swung by a drive source (not shown) to block and open the sheet passage 77B. Two
Individual sheet rear end abutting member 72, two sets of binding means 700
Are symmetrically arranged at substantially the same distance with respect to the center line CL.

(Abutting Alignment of Rear Edge of Sheet) FIG. 11A is a sectional view of the first aligning step showing the abutting of the rear edge of the sheet by the discharge claw 76 of the discharge belt 75.
FIG. 11B is a cross-sectional view of the second alignment step showing the sheet rear end abutting by the sheet rear end abutting member 72. FIG. 12 is a block diagram showing control of the first alignment process and the second alignment process.

(First Alignment Step) In the operation unit 9, sheet size, edge stitching processing, saddle stitching processing, folding processing, simple paper ejection, shift processing, cover attaching processing, punching processing, etc. are selected,
Is set.

The control means 100 includes sensors PS1 and PS.
2 detection signals are input. Further, the control means 100 is preset with a preset value of the number of sheets for switching the sheet abutting means described later. The control means 100 controls the driving of the motors M1 to M6 by these input signals and detection signals.

In the operation section 9 of the image forming apparatus main body A,
When the end-stitching process is selected and set, the control means 100 drives the motor M1 to rotate in the forward direction to rotate the discharge belt 75 in the counterclockwise direction in the figure before loading and aligning the sheets S on the sheet mounting table 71. Then, the discharge claw 76 is stopped at a stop position of a predetermined distance L on the upstream side in the transport direction from the sheet abutting surface portion 72A of the sheet rear end abutting member 72. The predetermined distance L is 1 to 5 mm (see FIG. 11 (a)).

After the discharging claw 76 is stopped at the predetermined position of the predetermined distance L, the sheet S nipped and conveyed by the pair of entrance conveying rollers 15 descends on the sheet placing table 71 by its own weight,
The trailing edge of the sheet is conveyed by being slid by the rotating winding belt 16, and the sheet abutting surface portion 76A of the ejection claw 76
Abut and stop. Similarly, the succeeding sheets S are brought into contact with the sheet abutting surface portion 76A of the ejection claw 76, stopped and stacked, and the sheet bundle is aligned.

The winding belt 16 arranged in the lower part of the sheet mounting table 71 and the sheet abutting surface portion 7 of the discharge claw 76.
6A is disposed in the vicinity of the center line CL of the sheet S and is in a position facing the center line CL, the end portion of the sheet S slid by the rotating winding belt 16 is shown in FIG.
They are loaded and aligned in a flat state without causing bulging deformation as shown in.

(Second Alignment Step) The passage of the paper S through the paper passage is detected by the sensor PS2, and a predetermined number of sheets (for example, 25
When the control means 100 counts the number of sheets, the control means 100 drives the motor M1 in the reverse rotation,
Rotate the discharge belt 75 clockwise in the drawing to discharge the discharge claw 76.
To the standby position (see FIG. 11B).

When the discharge claw 76 is retracted, the stack of sheets S is moved by its own weight and sliding of the take-in belt 16 so that the sheet placing table 71 is moved.
As it descends upward, the trailing edge of the bundle of sheets S contacts the sheet abutting surface portion 72A of the sheet trailing edge abutting member 72 and stops.

The rear end of the paper S is flatly aligned in the first alignment process, and the paper S is a bundle.
Since the rigidity is high, the flat alignment is maintained even when the process moves to the second alignment step. At this sheet stop position, the binding means 700 is provided near the rear end of the flat sheet S bundle.
Edge binding processing is performed.

In the embodiment of the present invention, the post-processing device connected to the main body of the copying machine has been described. However, the post-processing device connected to the main body of the image forming device such as a printer, a facsimile, a multi-function peripheral, and a light printing machine is used. It is also applicable to a processing device.

[0100]

As is apparent from the above description, the following effects can be obtained by the paper post-processing method, paper post-processing device and image forming apparatus of the present invention.

(1) Irrespective of the curl of the sheets stacked on the sheet mounting table, the sheet swells by the sheet trailing edge abutting members at both ends of the sheet trailing edge and the winding belt near the central portion of the sheet trailing edge. Since the deformation is eliminated and the trailing edge of the sheet is held flat and aligned, the binding position of the bundle of sheets after the binding process from the trailing edge of the sheet deviates from the predetermined position and the unevenness of the trailing edge of the sheet is eliminated. It In particular, when a large number of sheets are stacked on the sheet mounting table 71 and the binding process is performed, the end portions of the edge-stitched sheet bundle are accurately aligned.

(2) The paper post-processing device connected to the main body of the image forming apparatus such as a copying machine or a printer performs desired digital processing by the main body of the image forming apparatus, and after the fixing processing, the paper discharged is the main paper. The sheet post-processing device of the invention enables fast, accurate, and efficient binding processing. The sheets that are processed at a high speed by the image forming apparatus main body and discharged are bound by the sheet post-processing apparatus according to the present invention, which have excellent flatness without bending of the trailing edge of the sheet, while maintaining high productivity. Post-processing such as processing is performed at high speed.

[Brief description of drawings]

FIG. 1 is an overall configuration diagram of an image forming system including an image forming apparatus main body, an image reading apparatus, and a sheet post-processing apparatus.

FIG. 2 is an overall configuration diagram showing a sheet conveyance path in a sheet post-processing apparatus according to the present invention.

FIG. 3 is a cross-sectional view of a post-processing unit including a binding processing unit and a folding processing unit.

FIG. 4 is a plan view showing an arrangement of a sheet bundle and a binding unit when performing various binding processes.

FIG. 5 is a configuration diagram of a drive system that drives rotation of a discharge belt and swing of a discharge roller.

FIG. 6 is a plan view of a main part of a binding processing unit and a paper discharge roller.

FIG. 7 is a cross-sectional view in the vicinity of a discharge belt showing a state in which a sheet bundle after edge binding processing and saddle stitching processing is discharged.

FIG. 8 is a partial cross-sectional view showing rotation of a discharge claw of a discharge belt.

FIG. 9 is a cross-sectional view of an entrance conveyance roller pair, a paper storage unit, and a paper discharge unit.

FIG. 10 is a plan cross-sectional view showing the vicinity of an entrance conveyance roller pair.

FIG. 11 is a cross-sectional view of a first aligning step showing abutting of the rear end of the sheet by a discharge claw of a discharge belt, and a sectional view of a second aligning step showing abutting of the rear end of the sheet by a rear-end sheet abutting member.

FIG. 12 is a block diagram showing control of a first alignment process and a second alignment process.

FIG. 13 is a cross-sectional view of a sheet storage unit in a conventional sheet post-processing device.

[Explanation of symbols]

10 Post-processing unit 15 Inlet transport roller pair 15A, 15B entrance conveyance roller 15C rotating shaft 16 Paper winding member (winding belt) 60 paper ejection means 70 Binding processing section (paper storage section) 71 Paper loading table (intermediate stacker) 72 Paper trailing edge member 75 discharge belt 76 Discharge claw 100 control means 700 binding means (stapling means) A Image forming apparatus body FS paper post-processing device (post-processing device) L predetermined distance

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor, Masato Hattori             2970 Ishikawa-cho, Hachioji-shi, Tokyo Konica stock             In the company (72) Inventor Hirohiko Okabe             47, 1067 Wakamatsucho, Tokorozawa, Saitama Prefecture F-term (reference) 2H072 AB10 AB15 BA17 CA01 CA04                       CA05 FC20 GA08 JA02 JA03                 3F054 AA01 AB01 AC02 AC03 AC05                       BA03 BB09 BD02 BE04 BE09                       BF03 BF04 BF08 BF12 BF22                       BH03 BH07 BJ07 CA04 DA01                 3F108 GA02 GA03 GA04 GB01 HA02                       HA32

Claims (8)

[Claims] 1. A sheet ejected from an image forming apparatus main body is conveyed to be stacked on a sheet placing table, and the sheet is brought into contact with an abutting surface of a sheet trailing edge abutting member arranged below the sheet placing table. In the paper post-processing method, in which the sheets are aligned and aligned, the sheets are bound by the binding means, and then the sheets are ejected by the sheet ejection means, the sheet ejection means is rotatably stretched between a plurality of pulleys. A belt, a discharge claw that is integrally formed with the discharge belt, and that rotates the discharge belt to press the trailing end portion of the bound sheet bundle in the transport direction to discharge the sheet bundle; Drive means for rotating in reverse, prior to stacking and aligning the sheets on the sheet mounting table, the drive means rotates the discharge belt in the forward direction to push the discharge claws to the rear end of the sheet. The abutting surface of the abutting member After stopping at a predetermined position above the paper stack, the paper is brought into contact with the paper abutting surface of the discharge pawl and pre-aligned, and then the discharge belt is reversely rotated to retract the discharge pawl from the paper mounting table. Then, the sheet post-processing method is characterized in that the sheets stacked on the sheet tray are brought into contact with and aligned with the abutting surface of the sheet trailing edge abutting member below. 2. A sheet discharged from the main body of the image forming apparatus is conveyed and stacked on a sheet mounting table, the sheet is positioned and aligned at a predetermined position, and the sheet is bound by a binding unit.
In a sheet post-processing device that discharges to the outside of the device, a discharge belt that is rotatably stretched between a plurality of pulleys, and is integrally formed with the discharge belt, and by rotation of the discharge belt,
Below the sheet stacking table, a sheet discharging unit including a discharging claw for pressing the rear end of the bound sheet bundle in the transport direction to discharge the sheet bundle, and a driving unit rotating the discharging belt in the forward and reverse directions. A sheet rear end abutting member for abutting and aligning and aligning the sheet, and a sheet rear end abutting member disposed above the sheet rear end abutting member for slidingly contacting and rotating the sheet to guide the sheet. A sheet guide member that abuts against the abutting surface of the sheet trailing edge abutting member, and the discharge claw is abutted against the sheet trailing edge abutting member by the normal rotation drive of the discharge belt by the driving means. A first aligning step of stopping at a predetermined position above the surface, moving the paper carried into the paper loading table by rotation of the paper guide member, and abutting against the paper abutting surface portion of the discharge claw to pre-align; , The discharge A reverse rotation drive of the belt to retract the ejection claw from the sheet stacking table and align the sheets stacked on the sheet stacking table by abutting the abutting surface of the sheet trailing edge abutting member below. A sheet post-processing apparatus comprising two aligning steps. 3. The sheet post-processing apparatus according to claim 2, wherein the discharge belt is disposed at a position closer to the center of the sheet in the sheet width direction than the sheet trailing edge abutting member. . 4. The discharge belt is driven in a forward rotation after being stacked on a predetermined number of sheets on the sheet mounting table, and the discharge claw is stopped at a predetermined position above the abutting surface of the sheet rear end abutting member. The sheet post-processing device according to claim 2 or 3, wherein 5. The reinforcing member is provided on the back surface of the discharging claw in order to withstand the weight of the sheet bundle and the pressing force against the sheet, and the discharging claw is provided with a reinforcing portion. Paper post-processing device. 6. The sheet post-processing apparatus according to claim 2, wherein the sheet guide member is arranged near the discharge belt. 7. The sheet post-processing according to claim 2, wherein the sheet guide member is a belt installed between a drive pulley and a driven pulley or an impeller. apparatus. 8. An image forming apparatus main body comprising an image writing unit, an image forming unit, and a sheet conveying unit, and the sheet post-processing apparatus according to claim 2. Image forming apparatus.