JP2000302298A - Sheet aftertreatment device for image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the swelling of a bunch of sheets, if thick, following slackening after passing though a U-turn portion. SOLUTION: A sheet distribution passage F is provided for carrying downwardly a bunch of aftertreated sheets received from an aftertreatment end. One side of the sheet distribution passage is provided with a mail box tray (discharge tray) 8 in stages and a driving roller 50. The other side is provided with a driven roller 51 for carrying the bunch of sheets held together with the driving roller 50 in the sheet distribution passage F at a speed V1. On the other hand, a U-turn portion 56 U-turned to the side of the driven roller 51 is provided under the sheet distribution passage F. The bunch of sheets passing through the U-turn portion 56 is controlled to be carried at the speed V1 on its outer periphery and at a speed V2, slower, on its inner periphery.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus, such as a copying machine, a facsimile, a printer, or a multifunction peripheral thereof, which is installed adjacent to an image forming apparatus. Paper post-processing of an image forming apparatus that temporarily stacks and aligns on a tray, performs post-processing such as stapling and punching on the aligned paper, and then discharges the processed paper onto a paper output tray. Related to the device.

[0002]

2. Description of the Related Art Conventionally, a sheet post-processing apparatus of this type is provided with a plurality of discharge trays on one side of a vertical sheet distribution path such as a mailbox tray, and a post-processed sheet bundle is post-processed. There is a type in which the paper enters a paper distribution path from the processing end side, is conveyed downward, and is distributed and discharged to a multi-level paper discharge tray.

In such a sheet post-processing apparatus, a U-turn section is provided below the sheet distribution path in order to smoothly convey the sheet bundle, and the U-turn section switches back the sheet bundle. Return to the paper distribution path, and distributes and discharges the paper to a multi-stage paper discharge tray.

For example, as shown in FIG. 26, a U-turn unit 2 is provided below a paper distribution path 1, and a sheet bundle 3 is conveyed between a driving roller 4 and a driven roller 5 in the paper distribution path 1.
In the U-turn section 2, the sheet was conveyed by being sandwiched between the turn roller 6 and the driven roller 7.

[0005]

However, when the peripheral speed of the drive roller 4 and the peripheral speed of the turn roller 6 are made equal, the sheet bundle 3 extends over the sheet distribution path 1 and the U-turn section 2 as shown in the figure. In this state, the sheet bundle 3 is conveyed at the same speed on the inner circumference side and the outer circumference side by the U-turn section 2. Therefore, there is no problem when the bundle thickness t of the paper bundle 3 is small. As shown in FIG. 26, the circumferential length difference causes a slack after passing the U-turn portion 2 to cause the sheet bundle 3 to bulge,
There is a problem that the sheet bundle 3 may be broken in the subsequent conveyance.

SUMMARY OF THE INVENTION It is an object of the present invention to prevent a sheet bundle from bulging after passing a U-turn even when the sheet bundle is thick.

[0007]

Accordingly, the present invention provides
A paper distribution path for feeding the post-processed sheet bundle from the post-processing end side and transporting it downward is provided.One side of the paper distribution path is provided with multiple output trays, a drive roller is provided, and the other side is provided. A driven roller for transporting the sheet bundle in the sheet distribution path at a speed V1 sandwiched between the drive rollers is provided, and a U-turn portion for making a U-turn to the driven roller side is provided below the sheet distribution path. The sheet bundle passing through the sheet bundle is controlled to be conveyed at a speed V1 on the outer peripheral side and at a lower speed V2 on the inner peripheral side.

When the distance from the center of curvature of the U-turn section to the outer periphery of the sheet bundle passing through the U-turn section is a and the thickness of the sheet bundle is t, the speed V2 is (at) ÷ a × V1. It is good to

Further, it is preferable to provide a bundle thickness detecting means for detecting the bundle thickness of the sheet bundle, and to vary the speed V2 based on the detection result of the bundle thickness detecting means. Further, it is preferable to provide a locking member that receives the leading end of the sheet bundle and moves the sheet distribution path and the U-turn portion together with the sheet bundle.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows the overall schematic configuration of a sheet post-processing apparatus according to the present invention.

Reference numeral 1 in the figure denotes an image forming apparatus such as a copying machine, a facsimile, a printer, or a multifunction peripheral thereof. The sheet post-processing device 2 according to the present invention is installed adjacent to the side of the image forming apparatus.

The paper post-processing device 2 mainly includes a punch unit 3 for performing a punching process, a proof tray 4 for stacking fax paper and interrupt paper, and a paper for temporarily recording an image-recorded paper discharged from the image forming apparatus 1. Paper aligning tray 5 that is to be stacked in a stack, and stapler 6 that is a post-processing unit
And a multi-layered mailbox tray 8 such as a mailbox for sorting and stacking sheets, for example.

An image-recorded sheet discharged from the image forming apparatus 1 is conveyed horizontally by an inlet roller 10 and sent to a punch unit 3. This punch unit 3
Is a rotary punch synchronized with the conveyance of the sheet, and whether or not the sheet is perforated by selection on an operation panel (not shown) provided in the image forming apparatus 1.
In either case, the paper does not stop.

The sheet that has passed through the punch unit 3 is transported by transport rollers, and reaches a branch path where the branch claws 11 are located. The branch claw 11 is operated by a solenoid (not shown) according to the mode condition of the sheet processing, and switches the sheet conveyance path between two directions of A and B.

The paper transport path B is provided, for example, in a printer mode where paper is not stapled,
This is used when the paper is immediately guided to a paper distribution path F described later without passing through the above, and is distributed to the multi-stage mailbox tray 8 for discharge. The sheet transport path A is used when discharging sheets to the proof tray 4, when discharging the sheets to the large-volume discharge tray 7, and when performing staple processing on the sheets.

The paper that has advanced to the paper transport path A is
The paper feed path C toward the proof tray 4 and the paper transport path D toward the sheet alignment tray 5 and the paper discharge tray 7 are switched by the branch claws 12 in two directions.

The paper passing through the paper transport path C
3 stacks on the proof tray 4. The paper passing through the paper transport path D is transported differently in the staple mode and in the non-staple mode.

In the non-staple mode, as shown in FIG. 2, the guide plate 14 is on standby with the guide plate 14 lowered around the fulcrum position 14a, and the paper advances to the paper transport path E and is driven and discharged. The sheet is discharged to the sheet discharge tray 7 by the roller 15 and the driven discharge roller 16.

In the case of the staple mode, the guide plate 14
Are on standby around the fulcrum position 14a (the position indicated by the dashed line in FIG. 1), and the paper passes under the guide plate 14 and is temporarily stacked on the paper alignment tray 5.

In order to reduce the length of the sheet alignment tray 5, an extendable tray 17 is provided as shown in FIG. The telescopic tray 17 is provided at the center of the sheet alignment tray 5 in the depth direction. This is to prevent interference with the jogger mechanism for aligning the sheet bundle in the width direction.

The expansion / contraction tray 17 completes the operation of extending in a predetermined time after the paper ejection sensor 31 shown in FIG. 1 detects the leading edge of the paper, and waits for the paper to be stacked. At this time, the extension length of the extendable tray 17 is adjusted according to the length of the conveyed sheet. For example, if the A4 vertical size is passed, the end position of the extendable tray 17 extends to the A4 vertical end position. If the A3 vertical size is passed, the leading end position of the extendable tray 17 extends to the A3 vertical leading end position to be stacked.

The extendable tray 17 is configured to extend in two stages to reduce the length. As shown in FIG. 4, the guide rod 18 of the spring 20 is extended from the paper alignment tray 5, and a guide 19 a of the spring 20 is provided inside the first-stage telescopic tray 19. FIG.
A spring 20 is set on the guide rod 18, and a first-stage telescopic tray 19 is set on the sheet alignment tray 5. As a result, the spring 20 moves the guide rod 18
And the back wall of the guide guide 19a, the first expansion / contraction tray 19 is always applied with a force that jumps out of the paper alignment tray 5, and the first expansion / contraction tray 19 is moved by the force. Can be extended from

As shown in FIG. 6, the second-stage telescopic tray 21 is also configured in the same manner as the first-stage telescopic tray 19, and a force that always pops out of the first-stage telescopic tray 19 is applied.
With this force, the second-stage telescopic tray 21 can be extended from the first-stage telescopic tray 19.

On the other hand, as shown in FIG. 3, a string-like member 22 is locked to the base of the second-stage expansion / contraction tray 21, and the angle is changed via a pulley 23 which is supported by the sheet alignment tray 5. It is wound on a take-up pulley 24. A wheel gear 25 is provided coaxially with the take-up pulley 24, and a worm gear 26 of a drive motor 27 is meshed with the wheel gear 25. Further, a detection filler 28 is provided on the second-stage telescopic tray 21, and a sensor 29 for detecting the same is provided on the paper alignment tray 5.

As shown in FIG. 6, rollers 30 are provided on both of the first and second extendable trays 19 and 21 to smoothen the extendable operation. Thereby, the expansion / contraction tray 19.2
Drive motor 27 from the retracted state (home position)
Is rotated forward, the take-up pulley 24
2 is extended, and the expansion and contraction trays 19 and 21 are extended. At this time, the telescopic trays 19 and 21 are stopped at predetermined positions by pulse control of the drive motor 27.

In order to contract the extendable trays 19 and 21, the drive motor 27 is rotated in the reverse direction to wind up the cord-like member 22. Then, the sensor 29 stops at a predetermined position by detecting the detection filler 28.

As shown in FIG. 1, the paper temporarily stacked on the paper aligning tray 5 is fed to a rear fence 35 by a brush roller 33 disposed coaxially with a paper discharge roller 32 and a tapping roller 34. , The transport direction is aligned, the jogger fence 36 performs a horizontal alignment operation, and the stapler 6 staples. In that case, the stapler 6 can be slid by the driving unit 6A and stapled to the designated position.

In the case of the copy mode, the extendable tray 17 is then stored in the sheet aligning tray 5 by the above-mentioned mechanism. Thereafter, the guide plate 14 is lowered and the guide plate 1
A driven discharge roller 16 attached to the paper 4 presses the paper, and the rotation of the drive discharge roller 15 causes the discharge tray 7 to rotate.
Transport to

The sheets are successively discharged by a predetermined number to the discharge tray 7, and as shown in FIG. 7, the upper surface thereof is detected by the sensor 40, so that the stacked sheets are always in a fixed position. Loaded. When the transfer paper is full on the paper discharge tray 7, it is detected by the lower limit sensor 41.

The paper discharge tray 7 is hung on a vertical lift belt 42 as shown in FIG. The upper and lower lift belts 42 are driven by an elevating motor 43 via a gear train and a timing belt, and are moved up and down by forward or reverse rotation of the elevating motor 43. If necessary, the paper discharge tray 7 performs a shift operation in a direction perpendicular to the paper discharge direction to sort the paper.

When the stapled paper is discharged to the mailbox tray 8 in the printer mode, FIG.
As shown in (2), the rear end fence 35 and the stapler 6 are retracted outside the paper side edge which is closer to the front side or the back side. At that time, the rear end fence 35 moves by engaging with a part of the stapler 6 and following the sliding operation.

Next, the chuck arm pair 37, which has been waiting at the downward position indicated by the chain line in the figure, is rotated to the solid line position in the figure by the cam 38, and the fulcrum 37a sandwiches the sheet bundle at the leading end.
, And is conveyed downward to guide the sheet bundle to the sheet distribution path F from the rear end side. Chuck arm pair 3
When 7 returns to the position indicated by the dashed line, the chuck arm pair 37 opens by the operation of the cam 38, and the rotation is accelerated while releasing the sheet bundle, and the sheet bundle is taken over to the sheet distribution path F.

By the way, as shown in FIG. 1, the paper distribution path F extends vertically after passing a position corresponding to the lowermost discharge tray of the multi-tiered mailbox tray 8, and then extends upward. The U-turn portion 56 is formed so as to be folded back. Then, the passing paper is switched to a multi-stage mailbox tray 8 by switching the transport direction by a branching claw 52 serving as a deflecting unit, and is discharged.

The paper distribution path F is connected to the paper transport drive roller 50.
And a movable guide member that is movable on the side of the paper transport driven roller 51. As shown in FIG. 8A, the driven roller 51 side of the paper distribution path F is provided with a movable guide member movable at a position for guiding the paper and a wire 61.
Therefore, it is constituted. One end of the wire 61 is engaged with a pulley 65 attached to the shaft 62 so as to run idle, and a plurality of rotating members 64 are provided in parallel at intervals in the vertical direction. It is stretched by a pulley 63 attached to a member 64. The other end of the wire 61 is locked to a member (not shown) via an elastic member.

The driven rollers 51 are provided on the rotating member 64 along with the pulleys 63, and are supported by the rotating member 64 and are arranged in the vertical direction by the number of the mailbox trays 8. At this time, the driven roller 51 protrudes from the wire 61 by 1 to 2 mm toward the drive roller 50.

On the driven roller 51 side, a motor 68 is further provided.
The belt 76 is stretched over a pulley 66 driven by the pulley and a large pulley 67 provided below to provide a locking member conveying means.
The pulley 66 is driven by the motor 68 to drive the belt 76.
Is rotated to reciprocate the locking member 53 fixed to the belt 76 along the U-turn portion 56. Locking member 53
Is provided in the paper distribution path F in a key shape.

The rotating member 64 is rotatably supported on a side plate (not shown) of the sheet post-processing apparatus 2 by a fulcrum 64a, and is connected to a lever 69 at a rear end 64b. The lever 69 is pulled downward by the tension spring 70, whereby the driven roller 51, the pulley 63,
The wire 61 is urged toward the drive roller 50, and the drive roller 5
Then, the driven roller 51 is abutted. Since the lever 69 is connected to each rotating member 64, the lever 69 operates on the upstream side and the downstream side of the wire 61 simultaneously and in parallel with the sheet distribution path F.

As shown in FIG. 1, the driving roller 50 of the paper distribution path F has a driving roller 50 and a branching claw 5 serving as a deflecting means.
2 and a fixed guide member 60. The drive roller 50 protrudes from the fixed guide member 60 by 1 to 2 mm. Therefore, the interval of the paper distribution path F is usually 2 to 4 m.
m.

When a sheet bundle thinner than the width of the sheet conveying path (less than 2 to 4 mm) enters the sheet distribution path F, the sheet bundle is conveyed without displacing the wire 61. When a sheet bundle thicker than the width of the sheet distribution path F (2 to 4 mm or more) has entered, the sheet distribution path F is pushed and spread, and the sheet bundle is conveyed. If a paper jam occurs, the driven roller 5
When the pressure of 1 is released, the sheet can be removed from the sheet distribution path F.

In the illustrated example, the motor 81 shown in FIG.
By driving the eccentric cam 82 to rotate the eccentric cam 82, FIG.
(B) As shown in (c), the rotating member 64 is rotated to displace the wire 61, and the sheet distribution path F is changed according to the thickness of the sheet bundle.
Thickness can be changed. The number of sheets in the sheet bundle can be counted by a signal from the image forming apparatus or a sensor, and the magnitude of the displacement can be controlled by the rotation angle of the motor 81.

The sheet bundle that has advanced to the sheet distribution path F is conveyed downward by the driving roller 50 and the driven roller 51, and the leading end thereof is hooked by the key-shaped locking member 53 as shown in FIG. To receive. Then, as shown in FIG. 10, when the rear end of the bundle of sheets P is slightly below the position of the branching claw 52 of the mailbox tray 8 to be discharged as shown in FIG. To stop. At this time, if the paper is large-sized paper or the mailbox tray 8 to be discharged is at the lower side, the paper bundle P is sent to the U-turn unit 56 once.

By controlling the motor 68, the locking member 53 moves at a speed equal to or slower than the transport speed of the sheet bundle P.

When the sheet bundle P is stopped, the drive roller 50 and the driven roller 5 are driven by operating the lever 69 in the direction of the arrow in FIG.
1 is released, the belt 76 is rotated by the motor 68, and the sheet bundle P is pushed out by the locking member 53 as shown in FIG. 11, and the sheet bundle P is conveyed (switched back) in the reverse direction.

Then, the branch claws 52 of the mailbox tray 8 for discharging the bundle of sheets P are switched, and the locking member 53 stops just before the branch claws 52, and the discharge driving roller 58 thereafter.
Then, the sheet bundle P is discharged to the mailbox tray 8 by the discharge driven roller 59.

As shown in FIG. 12, the paper sheet heading toward the paper transport path B is discharged from the leading end side of the paper sheet by switching the branching claws 52 of the mailbox tray 8 discharged into the paper distribution path F. You. In this case, the switchback operation is not performed unlike the case of the above-described stapled sheet bundle.

The branch claw 52 must deflect the paper conveyed from the upper and lower two directions to the mailbox tray 8, so that it is divided into two, one from the top and the other from the bottom, as shown in FIG. ing. The two are meshed with each other by the gear portion 52a, and if one of them is deflected, the other can be deflected as shown in FIG. In the state of FIG. 13, the tips of the two claws intersect.
Two claws are comb-shaped to avoid interference.

When the paper is discharged to the mailbox tray 8, the presence / absence detection sensor 54 shown in FIG.
Further, when the discharged paper exceeds the allowable amount of the mailbox tray 8, the fullness detection sensor 55 notifies the printout user and the image forming apparatus 1 of the fact.

Next, the chuck arm pair 37 will be described in detail. As shown in FIG. 15, the chuck arm pair 37 has a lower chuck arm 371 rotatably attached to a fixed shaft 370, and the lower chuck arm 371 has a guide groove 371a in the length direction. .
The guide groove 371a of the lower chuck arm 371 has an upper chuck arm 372 slidably provided with the convex portion 37.
2a is fitted.

The spring 37 bridged between the upper chuck arm 372 and the lower chuck arm 371.
A force for closing the pair of chuck arms 37 is always applied by 3.

In the vicinity of the fixed shaft 370 of the chuck arm pair 37, there is provided a cam 38 fixed to the sheet post-processing device 2 side. The cam surface of the cam 38 is
The protrusions 372 a are fitted with the projections 372 a and serve to push and expand the upper chuck arm 372 depending on the position of the pair of chuck arms 37.

The fixed cam 38 has a high cam surface 38.
a and a low cam surface 38b. When the convex portion 372a of the upper chuck arm 372 comes to the high cam surface 38a, the convex portion 372a is pushed up by the cam 38, and the upper chuck arm 372 is expanded (FIGS. 15 and 16).

The upper chuck arm 3 is mounted on the lower cam surface 38b.
When the 72 convex portion 372a comes, the upper chuck arm 372 is closed by the force of the spring 373 applied to the chuck arm pair 37 (FIGS. 17 and 1).
8).

The cam 38 supports one end 39a,
9 is attached. One surface of the valve 39 has a shape that forms part of a high cam surface 38 a of the cam 38.

When the convex portion 372a of the upper chuck arm 372 moves from the lower cam surface 38b to the higher cam surface a, the valve 39 is rotated about the one end 39a as shown in FIG. The projection 372a of the arm 372 does not hinder the movement to the high cam surface 38a.

The upper chuck arm 372 is released when the cam 38 presses the convex portion 372a of the upper chuck arm 372.

When the chuck arm pair 37 rotates counterclockwise, the convex portion 37 of the upper chuck arm 372 is rotated.
2a travels on a high cam surface 38a above the valve 39. Therefore, the upper chuck arm 372 moves to the sheet alignment tray 5 while being opened (FIGS. 15 to 16).

As shown in FIGS. 17 and 18, when the convex portion 372a of the upper chuck arm 372 is on the lower cam surface 38b, and when the chuck arm pair 37 rotates clockwise, the convex portion 372a of the upper chuck arm 372 is Move on the lower cam surface 38b. At this time, the upper chuck arm 372 moves while being closed.

As shown in FIGS. 19 and 20, a portion 38c that switches from the low cam surface 38b to the high cam surface 38b.
Then, the convex portion 372a of the upper chuck arm 372 is pushed by the cam 38 and gradually opens. When the convex portion 372a of the upper chuck arm 372 changes to the high cam surface a, it rotates as shown in FIG. 19 with the one end 39a as a fulcrum while pressing the valve 39 to move to the high cam surface 38a. I try not to get in the way.

Next, the operation timing of the chuck arm pair 37 will be described. The sheets aligned on the sheet alignment tray 5 are bound by the stapler 6. At this time, the chuck arm pair 37 is retracted to a position where the chuck arm pair 37 does not hinder the movement of the stapler 6, as indicated by the two-dot chain line in FIG. This position is the home position. At this time, as shown in FIG. 15, the convex portion 372a of the upper chuck arm 372 is
a, the upper chuck arm 372 is open.

After the movement of the stapler 6, the chuck arm pair 37 rotates counterclockwise toward the holding standby position as shown in FIG. At this time, the convex portion 372a of the upper chuck arm 372 moves on the high cam surface 38a of the cam 38.
2 moves to the grip standby position shown in FIG. 16 while being opened.

The moved stapler 6 performs a binding operation on the sheet bundle P in the sheet alignment tray 5. In the present embodiment, the operation time is shortened by performing the binding operation of the stapler 6 while the chuck arm pair 37 is moving from the home position to the holding standby position.

After the binding operation by the stapler 6 is completed, the chuck arm pair 37 rotates counterclockwise from the holding standby position shown in FIG. 16 toward the holding position. At this time, the convex portion 372a of the upper chuck arm pair 372 is
As shown in FIG. 17, the high cam surface 38a of the fixed cam 38
To the lower cam surface 38b, the upper chuck arm pair 372 is closed by the force of the spring 373 and grips the stapled sheet bundle P. Thereafter, the stapler 6 and the stop member 35 move to outside the sheet width.

Next, the chuck arm pair 37 is
As shown in FIG. 18, the sheet rotates clockwise from the gripping position to the sheet bundle transfer position. Further, as shown in FIG. At this time, since the convex portion 372a of the upper chuck arm 372 moves from the lower cam surface 38b of the cam 38 to the higher cam surface 38a, the upper chuck arm pair 372 changes from a closed state to an open state. . At this time, the sheet bundle P is gripped by the sheet conveying roller pair 406 in the conveying path, and the sheet bundle P is delivered from the chuck arm pair 37 to the sheet conveying roller pair 406.

Thereafter, the chuck arm pair 37 is
As shown in (2), the sheet bundle P is rotated clockwise to the home position so as not to hinder the conveyance of the sheet bundle P.

In the illustrated sheet post-processing apparatus 2, as shown in FIG. 8A, a rubber turn roller 101 is provided adjacent to the inside of the large pulley 67 so as to rotate integrally with the large pulley 67. . The outer diameter of the turn roller 101 is made equal to the outer diameter of the belt 76 stretched over the large pulley 67.

On the other hand, as shown in FIGS.
On the outer periphery of the turn roller 101 of the turn portion 56, two support shafts 105 are rotatably supported between side plates (not shown). The base end of the lever 102 is fixed to each support shaft 105. A driven roller 103 is rotatably attached to the tip of the lever 102. Then, the driven roller 103 is pressed against the outer periphery of the turn roller 101 by hooking one end of a tension spring 104.

Now, when the peripheral speed of the driving roller 50 is V1, the peripheral speed of the sheet bundle P passing through the U-turn section 56 on the outer peripheral side is V1, and the peripheral speed on the inner peripheral side, that is, the turn roller 10
The peripheral speed of 1 becomes the lower speed V2.

For example, when the distance V from the center of curvature O of the U-turn section 56 to the outer periphery of the sheet bundle P passing through the U-turn section 56 is a and the thickness of the sheet bundle P is t,
(At) ÷ a × V1

The peripheral speed of the turn roller 101 is set to a speed V2
The period is from when the leading end of the sheet bundle P enters the U-turn unit 56 to when the bundle of sheets P exits the U-turn unit 56. Because, even after the leading end of the sheet bundle P has passed through the U-turn section 56,
This is because, if the speed V2 is maintained, the outer circumference of the sheet bundle P will be sagged and swelled.

Here, the bundle thickness t of the paper bundle P changes.
Therefore, for example, as shown in FIG. 22, a bundle thickness detecting unit 110 for detecting the bundle thickness t of the bundle of paper P on the paper alignment tray 5.
The peripheral speed V2 of the turn roller 101 is varied based on the detection result of the bundle thickness detecting means 110.

In FIG. 22, reference numeral 111 denotes a filler, and reference numeral 112 denotes a light transmission type sensor. The filler portion 111a of the filler 111 moves up and down in accordance with the thickness t of the sheet bundle P on the sheet aligning tray 5, and the shielding portion 111b moves. Is detected.

The present invention is not limited to the bundle thickness detecting means 110 as shown in FIG. 22, but also includes, for example, a counting means for counting the number of sheets forming a sheet bundle. May be provided to detect the bundle thickness of the sheet bundle.

In this sheet post-processing apparatus, the above-described locking member 53 moves at the speed V1 when in the sheet distribution path F, and turns into the turn roller 101 when it enters the U-turn section 56.
At the speed V2 together with the sheet bundle P.

FIG. 23 shows another example of the sheet post-processing apparatus according to the present invention. In this sheet post-processing apparatus, a pulley 115 is attached to one end of a roller shaft 114 of each drive roller 50.
And an endless drive belt 116 is hung on the pulley 115. The drive belt 116 includes a motor pulley 117 </ b> A of the paper transport motor 117 and two drive pulleys 1 </ b> A.
Multiply by 22.

Each drive pulley 122 is fixed to one end of the support shaft 121. Each support shaft 121 has a plurality of levers 10.
2 and the pulley 124 is fixed. One side of the endless belt 126 is hung on the pulley 124. The other side of the endless belt 126 is hung on a pulley 125 on a shaft 127 rotatably supported by the tip of the lever 102. The drive roller 123 is fixed on the shaft 127 together with the pulley 125. Then, the driving roller 1 is urged by a spring similar to the tension spring 104 shown in FIG.
23 is pressed against the outer periphery of the turn roller 101.

The other parts are the same as those of the above-described sheet post-processing apparatus shown in FIG. 1. Also in this case, the outer side of the bundle of sheets P passing through the U-turn section 56 is at the speed V1, and the inner side is higher than that. It is transported at a slow speed V2.

For example, as shown in FIG. 24, if the distance from the center of curvature O of the U-turn section 56 to the outer periphery of the sheet bundle P passing through the U-turn section 56 is a, and the thickness of the sheet bundle P is t, The outer peripheral length for the U-turn angle θ is 2aπ ×
θ / 360, the inner circumference is 2 (at) π × θ / 360, and the inner / outer circumference difference is 2aπ × θ / 360-2 (at) π × θ / 360 = t
π × θ / 360.

Assuming that the distance that the outer circumference of the sheet bundle P is transported by the turn roller 101 is b, the distance that the inner circumference is transported is (b−tπ × θ / 360). Drive roller 50
Assuming that the peripheral speed of the sheet bundle V is V1, the sheet bundle P
The time required for transport is b / V1. Therefore, at the time b / V1, the inner peripheral side of the sheet bundle P is (b−tπ × θ / 36).
0) The linear velocity for conveyance is (b-tπ × θ / 360) ÷ b / V1. Therefore, it is good to arrange this, and the peripheral speed of the turn roller 101 is set to (b-tπθ ÷ 360) ÷ b × V1.

FIG. 25 shows still another example of the sheet post-processing apparatus according to the present invention. In this example, a pulley 124 fixed to a support shaft 121 and a shaft 1
A belt 129 is hung between the pulleys 128 on the drive roller 27, and the belt 129 is replaced with the turn roller 101 instead of the drive roller 123.
Pressed against the outer periphery of. The shaft 127 is connected to the spring 13
At 0, the belt 129 is urged to stretch.

The other parts are the same as those of the above-described sheet post-processing apparatus shown in FIG. 1. Also in this case, the outer peripheral side of the sheet bundle P passing through the U-turn unit 56 is at a speed V1 and the inner peripheral side is at a higher speed. It is transported at a slow speed V2.

Here, the post-processed sheet bundle P enters the sheet distribution path F from the post-processing end side.
The rear end side of the sheet bundle P entering the turn section 56 is a free end. Further, since the U-turn unit 56 makes a U-turn toward the driven roller 51, the driven roller 51 is provided on the inner peripheral side of the sheet bundle P that makes the U-turn. Therefore, in the paper distribution path F, the speed V
When the sheet bundle P conveyed at 1 makes a U-turn at the U-turn section 56, the speed V on the inner peripheral side thereof is lower than that at that time.
Even if it is transported in step 2, the U-turn section 56
There is no sagging in front of you.

[0082]

As described above, according to the present invention, the outer peripheral side of the sheet bundle passing through the U-turn portion is transported at the same speed V1 as the paper distribution path, and the inner peripheral side is transported at a lower speed V2. Therefore, even when the thickness of the sheet bundle is large, the sheet bundle can be prevented from swelling without sagging after the U-turn portion. This allows
It is possible to prevent the sheet bundle from being broken or the like in the subsequent conveyance.

According to the second aspect of the present invention, the inner peripheral speed V2 of the sheet bundle passing through the U-turn portion is changed to the outer peripheral speed V1.
Since the sheet bundle is conveyed later by the bundle thickness according to the bundle thickness, the occurrence of the slack after the U-turn portion can be almost completely eliminated according to the bundle thickness of the individual bundles.

According to the third aspect of the present invention, since the bundle thickness detecting means is provided and the inner peripheral speed V2 of the sheet bundle passing through the U-turn portion is varied based on the detection result of the bundle thickness detecting means, The speed V2 can be automatically set according to the bundle thickness to prevent the slack of the bundle of sheets.

According to the fourth aspect of the present invention, since the locking member for receiving the leading end of the sheet bundle is moved together with the sheet bundle, it is possible to eliminate the possibility that the transport of the sheet bundle is hindered by the locking member.

[Brief description of the drawings]

FIG. 1 is an overall schematic configuration diagram of a sheet post-processing apparatus according to the present invention.

FIG. 2 is a perspective view showing the vicinity of an alignment tray together with a guide plate.

FIG. 3 is a perspective view showing the paper alignment tray together with a telescopic tray.

FIG. 4 is an exploded perspective view of the first-stage telescopic tray.

FIG. 5 is a perspective view after the assembly.

FIG. 6 is a perspective view of the entire telescopic tray.

FIG. 7 is a perspective view showing a partial schematic configuration of the sheet post-processing apparatus.

FIG. 8A is a perspective view showing the configuration of the paper distribution path on the side of a paper transport driven roller, and FIGS. 8B and 8C are explanatory views showing the state of displacement of the wire.

FIG. 9 is an explanatory diagram illustrating a state where a sheet is guided to a sheet distribution path.

FIG. 10 is an explanatory diagram showing a state in which the sheet has been sent to a U-turn section.

FIG. 11 is an explanatory diagram illustrating a state in which the sheet is switched back and discharged onto a specified discharge tray.

FIG. 12 is an explanatory diagram illustrating a state in which the sheet discharged from the image forming apparatus is immediately guided to the sheet distribution path without passing through the sheet alignment tray.

FIG. 13 is a mechanism diagram of a branch claw that guides a sheet to a discharge tray.

FIG. 14 is a diagram illustrating a state of a branch claw when a sheet is discharged to a sheet discharge tray by switching a sheet conveying direction.

FIG. 15 is an explanatory diagram showing a state where the chuck arm pair is at a standby position.

FIG. 16 is an explanatory diagram showing a state in which the chuck arm pair has been moved to a holding standby position.

FIG. 17 is an explanatory diagram showing a state where the chuck arm pair has moved to a gripping position.

FIG. 18 is an explanatory diagram illustrating a state in which a pair of chuck arms transfers a sheet bundle to a pair of sheet conveyance rollers.

FIG. 19 is an explanatory diagram illustrating a state in which the chuck arm pair is separated from the sheet bundle after delivery.

FIG. 20 is an explanatory view showing a state where the chuck arm pair has moved to a home position.

FIG. 21 is a diagram illustrating a state in which a sheet bundle is conveyed from a sheet distribution path to a U-turn unit.

FIG. 22 is an explanatory diagram showing a state in which a bundle thickness detecting unit is provided on a sheet alignment tray.

FIG. 23 is an explanatory perspective view of another example of the sheet bundle conveying mechanism provided in the sheet post-processing apparatus according to the present invention.

FIG. 24 is an explanatory diagram of a state in which a sheet bundle is conveyed past the U-turn section.

FIG. 25 is a schematic enlarged configuration diagram of a U-turn section showing still another example of the sheet bundle transport mechanism.

FIG. 26 is a diagram illustrating a state in which a sheet bundle is conveyed from a conventional sheet distribution path to a U-turn unit.

[Explanation of symbols]

REFERENCE SIGNS LIST 1 image forming apparatus 2 sheet post-processing apparatus 5 sheet alignment tray 6 stapler 8 mailbox tray (discharge tray) 50 drive roller 51 driven roller 53 locking member 56 U-turn section 67 large pulley 101 turn roller 103 driven roller 110 bundle thickness Detection means 111 Filler 112 Light transmission sensor 123 Drive roller 129 Belt a Distance from the center of curvature of the U-turn section to the outer circumference of the sheet bundle passing through the U-turn section t Sheet bundle thickness F Sheet distribution path O U-turn section Center of curvature P Sheet bundle V1 Speed of sheet bundle passing through U-turn part (speed of sheet bundle conveyed by drive roller and driven roller) V2 Speed of sheet bundle passing through U-turn part on inner peripheral side

 ──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Shinichi Ueno 2-13-13 Nishiki, Naka-ku, Nagoya City, Aichi Prefecture Inside Ricoh Elemex Corporation (72) Inventor Yuji Ueno 2-2-2 Nishiki, Naka-ku, Nagoya City, Aichi Prefecture No. 13 Ricoh Elemex Corporation (72) Inventor Minoru Hattori 2-2-1 Nishiki, Naka-ku, Nagoya-shi, Aichi Prefecture Ricoh Elemex Corporation (72) Inventor Terumitsu Higashi Nishiki, Naka-ku, Aichi Prefecture Inside Ricoh Elemex Co., Ltd. (72) Inventor Takahiro Sasaki 2-2-113 Nishiki, Naka-ku, Nagoya-shi, Aichi Prefecture Inside Ricoh Elemex Co., Ltd. (72) Inventor Masakaori Kizen Nagoya, Aichi Prefecture 2nd-13 Nishiki, Naka-ku Ricoh Elemex Co., Ltd. (72) Inventor Tomo Nomura 2-2-Nishiki, Naka-ku, Nagoya City, Aichi Prefecture No. 13 F-term in Ricoh Elemex Corporation (reference) 3F102 AA02 AA10 AA11 AB01 BA03 BA06 BB17 DA14 EA02 FA04

Claims (4)

[Claims] 1. A sheet distribution path for receiving a post-processed sheet bundle from the post-processing end side and transporting the sheet bundle downward, a multi-stage discharge tray on one side of the sheet distribution path, and a drive roller A driven roller that conveys the sheet bundle in the sheet distribution path at a speed V1 sandwiched by the driving roller on the other side, and a driven roller is provided below the sheet distribution path on the driven roller side.
The image forming apparatus is provided with a U-turn section for turning, and controls the sheet bundle passing through the U-turn section to convey at a speed V1 on the outer circumference side and at a lower speed V2 on the inner circumference side. Paper post-processing device. 2. When the distance from the center of curvature of the U-turn portion to the outer periphery of the sheet bundle passing through the U-turn portion is a and the thickness of the sheet bundle is t, the speed V2 is (at). 2. The sheet post-processing device for an image forming apparatus according to claim 1, wherein ÷ a × V1. 3. A bundle thickness detecting means for detecting a bundle thickness of a sheet bundle, wherein the speed V is determined based on a detection result of the bundle thickness detecting means.
3. The sheet post-processing device for an image forming apparatus according to claim 1, wherein 2 is variable. 4. A sheet post-processing apparatus for an image forming apparatus according to claim 1, further comprising a locking member that receives the leading end of the sheet bundle and moves the sheet distribution path and the U-turn portion together with the sheet bundle. .