JP4136168B2 - Paper post-processing apparatus of image forming apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention is installed adjacent to an image forming apparatus such as a copying machine, a facsimile, a printer, or a complex machine thereof, and the image-recorded paper ejected from the image forming apparatus is temporarily placed on a paper alignment tray, for example. After stacking, the post-processing such as stipple or punching is applied to the stacked paper bundle, and then the processed paper bundle is put into the paper distribution path and conveyed downward, and distributed in the distribution path to be discharged in multiple stages. The present invention relates to a paper post-processing apparatus of an image forming apparatus that discharges onto a paper tray.
[0002]
[Prior art]
Today, in the office, for example, the number of personal computers is increasing, and a plurality of personal computers are connected to a single printer, and a plurality of people commonly use a single printer.
[0003]
In such a case, a post-processing device is provided adjacent to the printer so that the respective recorded sheets are not confused, and the post-processing device is referred to as a mailbox having a multi-stage discharge tray. In addition, it is carried out on the multi-stage paper discharge trays for individual or group sorting.
[0004]
For example, as this type of post-processing apparatus, as disclosed in Japanese Patent Laid-Open No. 7-10364, a multi-stage paper discharge tray and a multi-stage paper discharge tray are distributed on a multi-stage paper discharge tray by a deflecting means while transporting recorded paper. A paper distribution path for discharging the paper and a post-processing means provided between the paper distribution path and the multi-stage paper discharge tray so as to be movable up and down, and a post-processing means for temporarily stacking the distributed paper by the deflecting means and performing post-processing. There is.
[0005]
When using, the post-processing means is moved up and down to a position corresponding to the designated paper discharge tray, and then the image-recorded paper ejected from the image forming apparatus is put into the paper distribution path and conveyed by the deflecting means. The direction is switched and the sheet is discharged onto the sheet aligning tray of the post-processing means. If necessary, the sheets stacked on the sheet aligning tray are post-processed and discharged onto the designated discharge tray.
[0006]
When the paper is discharged onto another designated paper discharge tray, the post-processing means is moved up and down to the corresponding position, and the recorded paper is similarly discharged onto the designated paper discharge tray.
[0007]
However, in the post-processing apparatus as described above, since the paper distribution path, the post-processing means, and the multi-stage paper discharge trays are arranged in the paper transport direction, there is a problem that the width in the paper transport direction becomes large.
[0008]
Therefore, the inventors have temporarily stacked the paper discharged from the image forming apparatus on the paper alignment tray and solved the problem with the stapler and the paper stack stacked on the paper alignment tray. Post-processing is performed by post-processing means such as a punch, and the post-processing sheet bundle is conveyed downward.
[0009]
Then, for example, as shown in FIG. 21, the paper bundle 4 passing through the paper distribution path 3 is guided to the paper distribution path 3 between the guide member 1 and the belt 2, and the conveying direction is switched by the deflecting means 5 so that the discharge roller pair 6 considers a paper post-processing device that distributes and discharges paper onto a multi-stage paper discharge tray. And the applicant applied for earlier (Japanese Patent Application No. 10-345276).
[0010]
[Problems to be solved by the invention]
However, in such a post-processing apparatus, when the post-processed paper bundle 4 is transported through the paper distribution path 3, it is only transported by being sandwiched by a pair of paper transport rollers (not shown). When the clamping pressure by the pair of conveying rollers is weakened, the sheet in the middle of the bundle thickness of the sheet bundle 4 slides downward due to its own weight, and the lower end of the sheet bundle 4 is displaced in the center in the bundle thickness direction to form a convex shape. Becomes unstable, and the stacking property on the paper discharge tray becomes poor.
[0011]
[Means for Solving the Problems]
  Therefore, the invention of claim 1 isA first paper transport path that immediately guides the image-formed paper to the paper distribution path without stippling, and a second paper transport path that guides the paper to the paper distribution path after stapling;
  The paper headed to the first paper transport path is distributed without being switched back in the paper distribution path and discharged onto the multistage paper discharge tray, while the paper headed to the second paper transport path is stapled.The subsequent stack of paper is put into the paper distribution path and conveyed downward.Then switch backIn a paper post-processing apparatus of an image forming apparatus that distributes paper on a paper distribution path and discharges it onto a multi-stage paper discharge tray.
  The sheet distribution path is provided with a locking member that receives the leading end of the sheet bundle and moves with the sheet bundle.
[0012]
  According to a second aspect of the present invention, in the paper post-processing apparatus of the image forming apparatus according to the first aspect, the locking member isThe sheet bundle that has advanced to the sheet distribution path is conveyed downward by a pair of rollers that convey the sheet bundle.It is characterized by moving at the same speed as or slower than the conveying speed of the sheet bundle.
[0013]
According to a third aspect of the present invention, in the paper post-processing apparatus of the image forming apparatus according to the first aspect, the locking member is formed in a key shape to be received by hooking the leading end of the paper bundle. And
[0014]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 shows an overall schematic configuration of a sheet post-processing apparatus according to the present invention.
[0015]
Reference numeral 1 in the figure denotes an image forming apparatus such as a copying machine, a facsimile, a printer, or a complex machine thereof. A sheet post-processing apparatus 2 according to the present invention is installed adjacent to the side portion of the image forming apparatus.
[0016]
The paper post-processing device 2 mainly temporarily stacks a punch unit 3 that performs punch processing, a proof tray 4 that stacks fax paper and interrupt paper, and a paper on which an image has been discharged from the image forming apparatus 1. A sheet alignment tray 5 to be processed, a stapler 6 as post-processing means, a large volume discharge tray 7 for stacking copy sheets, for example, and a multistage discharge tray 8 such as a mail box for sorting and stacking sheets. It is configured.
[0017]
The image-recorded paper discharged from the image forming apparatus 1 is conveyed in the horizontal direction by the entrance roller 10 and sent to the punch unit 3. The punch unit 3 is a rotary punch that is synchronized with the conveyance of the paper, and may or may not perforate the paper when selected by an operation panel (not shown) provided in the image forming apparatus 1. The paper does not stop.
[0018]
The paper that has passed through the punch unit 3 is transported by the transport roller and reaches the branch path where the branch claw 11 is located. The branching claw 11 is operated by a solenoid (not shown) according to the paper processing mode condition to switch the paper conveyance path in two directions A and B.
[0019]
  FirstThe paper conveyance path B does not stap the paper in the printer mode, for example, and immediately guides the paper to the paper distribution path F (to be described later) without passing through the paper alignment tray 5 and distributes it to the multistage paper discharge tray 8. Use when discharging.SecondThe paper transport path A is used when paper is discharged to the proof tray 4, when discharged to the mass discharge tray 7, and when the paper is stipple processed.
[0020]
The paper that has advanced to the paper transport path A reaches the branch path where the branching claw 12 is located, and the paper that travels to the paper transporting path C toward the proof tray 4, the paper alignment tray 5, and the mass output tray 7 by the branching claw 12. The direction is switched in two directions of the conveyance path D.
[0021]
The paper passing through the paper transport path C is stacked on the proof tray 4 by the paper discharge roller 13. The paper passing through the paper transport path D is transported differently in the stipple mode and in the non-stipple mode.
[0022]
In the non-stipple mode, as shown in FIG. 2, the guide plate 14 stands by with the fulcrum position 14a as the center, and the sheet advances to the sheet conveyance path E and is driven by the driving roller 15. A large amount of paper is discharged onto the paper discharge tray 7 by the rollers 16.
[0023]
In the case of the stipple mode, the guide plate 14 waits in a state where the guide plate 14 is raised upward with the fulcrum position 14a as the center (the position indicated by the one-dot chain line in FIG. 1). Temporarily stacked on the sheet alignment tray 5.
[0024]
In order to reduce the length of the sheet aligning 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 that aligns the width of the sheet bundle.
[0025]
The telescopic tray 17 completes the operation of extending a predetermined time after the 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 extending length of the extendable tray 17 is adjusted according to the length of the conveyed paper. For example, if the A4 vertical size is passed, the front end position of the extendable tray 17 extends to the A4 vertical front end position. If the A3 vertical size is passed, the leading end position of the extendable tray 17 extends to the stacked A3 vertical leading end position.
[0026]
The extendable tray 17 is configured to extend in two stages in order to reduce the length. 4, the guide rod 18 of the spring 20 is extended from the sheet alignment tray 5 and a guide guide 19a of the spring 20 is provided inside the first-stage extendable tray 19, as shown in FIG. In FIG. 5, the spring 20 is set on the guide rod 18, and the first expansion / contraction tray 19 is set on the sheet alignment tray 5. As a result, the spring 20 is compressed by the base portion of the guide rod 18 and the back wall of the guide guide 19a, and the first-stage telescopic tray 19 is constantly applied with a force of jumping out of the sheet aligning tray 5. The eye expansion / contraction tray 19 can be extended from the sheet alignment tray 5.
[0027]
As shown in FIG. 6, the second-stage telescopic tray 21 is configured in the same manner as the first-stage telescopic tray 19, and a force that always pops out from the first-stage telescopic tray 19 is applied. The telescopic tray 21 can be extended from the first-stage telescopic tray 19.
[0028]
On the other hand, as shown in FIG. 3, the string-like member 22 is locked to the base of the second-stage telescopic tray 21, and the take-up pulley changes its angle via a pulley 23 that is pivotally supported by the paper alignment tray 5. It is wound around 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 engaged with the wheel gear 25. In addition, a detection filler 28 is provided on the second extension tray 21 and a sensor 29 is provided on the sheet alignment tray 5 to detect it.
[0029]
As shown in FIG. 6, both the first and second expansion / contraction trays 19 and 21 are provided with rollers 30 to smooth the expansion / contraction operation. As a result, when the drive motor 27 is rotated forward from the retracted state of the telescopic trays 19 and 21 (home position), the string-like member 22 is drawn from the take-up pulley 24 and the telescopic trays 19 and 21 are extended. At that time, the telescopic trays 19 and 21 are stopped at predetermined positions by pulse control of the drive motor 27.
[0030]
When the telescopic trays 19 and 21 are contracted, the drive motor 27 is reversed and the string-like member 22 is wound up. Then, the sensor 29 detects the detection filler 28 and stops at a predetermined position.
[0031]
As shown in FIG. 1, the paper temporarily stacked on the paper alignment tray 5 is brought into contact with the trailing edge fence 35 by the brush roller 33 disposed on the same axis as the paper discharge roller 32 and the tapping roller 34. Then, the conveyance direction is aligned, the alignment operation in the horizontal direction is performed by the jogger fence 36, and the stapler 6 is stapled. In that case, the stapler 6 can be slid by the drive unit 6A and stippled to the instructed position.
[0032]
In the copy mode, the telescopic tray 17 is then stored in the sheet alignment tray 5 by the above-described mechanism. Thereafter, the guide plate 14 is lowered, the driven roller 16 attached to the guide plate 14 pressurizes the sheet, and the sheet is conveyed to the mass discharge tray 7 by the rotation of the driving roller 15.
[0033]
A predetermined number of sheets are discharged one after another to the large number of sheet discharge trays 7, and as shown in FIG. 7, the upper surface of the sheet is detected by the sensor 40 so that the stacked sheets are always at a fixed position. Loaded. The lower limit sensor 41 detects when the transfer paper is full on the large volume discharge tray 7.
[0034]
As shown in FIG. 7, the mass discharge tray 7 is suspended by the vertical lift belt 42. The vertical lift belt 42 is driven by a lifting motor 43 via a gear train and a timing belt, and moves up and down by forward or reverse rotation of the lifting motor 43. Further, as necessary, the large volume discharge tray 7 performs a shift operation in a direction orthogonal to the sheet discharge direction to sort the sheets.
[0035]
When the stapled paper is discharged to the paper discharge tray 8 in the printer mode, as shown in FIG. 1, the rear end fence 35 and the stapler 6 are placed closer to the front side or the back side than the paper side edge closer to the front side or the back side. Evacuate to the outside. At that time, the rear end fence 35 moves by engaging a part of the stapler 6 and following the slide operation.
[0036]
Next, the chuck arm pair 37 that 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 rotated clockwise around the fulcrum 37a with the sheet bundle sandwiched at the tip. The sheet bundle is conveyed downward to guide the sheet bundle from the rear end side to the sheet distribution path F. When the chuck arm pair 37 returns to the one-dot chain line position, the chuck arm pair 37 is opened by the operation of the cam 38, the rotation operation is accelerated while releasing the sheet bundle, and the sheet bundle is taken over to the sheet distribution path F.
[0037]
By the way, as shown in FIG. 1, the paper distribution path F is vertical and passes a position corresponding to the lowermost discharge tray among the multi-stage discharge trays 8, and is further extended and folded upward. A U-turn portion 56 is formed on the surface. Then, the passing paper is distributed and discharged onto the multi-stage paper discharge tray 8 by switching the conveyance direction by the branching claw 52 which is a deflecting means.
[0038]
The paper distribution path F is composed of a fixed guide member 60 on the paper conveyance drive roller 50 side and a movable guide member that is movable on the paper conveyance driven roller 51 side. On the driven roller 51 side of the paper distribution path F, as shown in FIG. 8A, a movable guide member that can move the position for guiding the paper is constituted by a wire 61. One end of the wire 61 is locked to a pulley 65 attached to the shaft 62 so as to be idled, and a plurality of rotating members 64 are provided in parallel in the vertical direction. It is stretched by a pulley 63 attached to the member 64. The other end of the wire 61 is locked to a member (not shown) via an elastic member.
[0039]
The driven roller 51 is provided with the pulley 63 on the rotating member 64 and is supported by the rotating member 64 and arranged in the vertical direction by the number of the paper discharge trays 8. At that time, the driven roller 51 protrudes from the wire 61 toward the driving roller 50 by 1 to 2 mm.
[0040]
On the driven roller 51 side, a belt 76 is stretched over a pulley 66 driven by a motor 68 and a large pulley 67 provided below, and a locking member conveying means is provided. The pulley 68 is driven by the motor 68 to rotationally drive the belt 76, and the locking member 53 fixed to the belt 76 is reciprocated along the U-turn portion 56. The locking member 53 has a key shape and is provided in the paper distribution path F.
[0041]
The rotating member 64 is pivotally supported by a fulcrum 64a on a side plate (not shown) of the sheet post-processing apparatus 2 so as to be rotatable, and is connected to a lever 69 by a rear end 64b. The lever 69 is pulled downward by the tension spring 70, thereby urging the driven roller 51, the pulley 63, and the wire 61 toward the driving roller 50, and abuts the driven roller 51 on the driving roller 50. Since the lever 69 is connected to each rotating member 64, the upstream side and the downstream side of the wire 61 operate simultaneously and in parallel with the paper distribution path F.
[0042]
As shown in FIG. 1, the drive roller side of the paper distribution path F includes a drive roller 50, a branching claw 52 that is a deflection unit, 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 between the paper distribution paths F is usually set to about 2 to 4 mm.
[0043]
When a sheet bundle that is thinner (less than 2 to 4 mm) than the width of the sheet conveyance path enters the sheet distribution path F, the sheet bundle is conveyed without the wire 61 being displaced. When a sheet bundle that is thicker (2 to 4 mm or more) than the width of the sheet distribution path F enters, the sheet distribution path F is widened and the sheet bundle is conveyed. When a paper jam occurs, the paper can be removed from the paper distribution path F by releasing the pressure of the driven roller 51.
[0044]
In the illustrated example, the rotation member 64 is rotated as shown in FIGS. 8B and 8C by driving the motor 81 shown in FIG. The thickness of the paper distribution path F can be changed according to the thickness of the paper bundle. The number of sheets 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.
[0045]
The sheet bundle that has advanced to the sheet distribution path F is conveyed downward by the drive roller 50 and the driven roller 51, and is received by being hooked at the leading end by a lock member 53 as shown in FIG. Then, when the sheet bundle P moves together with the locking member 53 and the rear end of the sheet bundle P comes slightly below the position of the branching claw 52 of the sheet discharge tray 8 as shown in FIG. To stop. At that time, if the paper is a large size or the paper discharge tray 8 to be discharged is on the lower side, the paper bundle P is once sent to the U-turn portion 56.
[0046]
The motor 68 is controlled, and the locking member 53 moves at the same speed as or slower than the conveying speed of the sheet bundle P.
[0047]
When the sheet bundle P is stopped, the pressure of the driving roller 50 and the driven roller 51 is released by moving the lever 69 in the direction of the arrow in FIG. As shown in FIG. 11, 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.
[0048]
Then, the branching claw 52 of the paper discharge tray 8 that discharges the sheet bundle P is switched, the locking member 53 stops before the branching claw 52, and thereafter is conveyed by the discharge driving roller 58 and the discharge driven roller 59, and the paper The bundle P is discharged to the discharge tray 8.
[0049]
As shown in FIG. 12, the sheet heading toward the sheet conveyance path B is discharged from the leading end side of the sheet by switching the branching claw 52 of the sheet discharge tray 8 that is discharged into the sheet distribution path F. In this case, unlike the case of the stapled sheet bundle, the switchback operation is not performed.
[0050]
Since the branching claw 52 has to deflect the paper conveyed from the upper and lower directions to the paper discharge tray 8, it is divided into two parts from above and from below as shown in FIG. The two are engaged 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, but the two claws are comb-like to avoid interference.
[0051]
When the paper is discharged to the paper discharge tray 8, the paper presence / absence detection sensor 54 shown in FIG. 1 notifies the user of the presence or absence of mail on the personal computer, for example. Is exceeded, the full detection sensor 55 notifies the printout user and the image forming apparatus 1 of the fact.
[0052]
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 the fixed shaft 370, and the lower chuck arm 371 is provided with a guide groove 371a in the length direction. . A convex portion 372a is fitted in the guide groove 371a of the lower chuck arm 371 so that the upper chuck arm 372 can slide.
[0053]
A force is applied to the upper chuck arm 372 so as to always close the pair of chuck arms 37 by a spring 373 suspended between the upper chuck arm 371 and the lower chuck arm 371.
[0054]
In the vicinity of the fixed shaft 370 of the chuck arm pair 37, a cam 38 fixed to the sheet post-processing apparatus 2 side is provided. The cam surface of the cam 38 is engaged with the convex portion 372 a of the upper chuck arm 372, and functions to push and spread the upper chuck arm 372 depending on the position of the chuck arm pair 37.
[0055]
The fixed cam 38 has a high cam surface 38a 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 to expand the upper chuck arm 372 (FIGS. 15 and 16).
[0056]
When the convex portion 372a of the upper chuck arm 372 comes to the lower cam surface 38b, the upper chuck arm 372 is closed by the force of the spring 373 applied to the chuck arm pair 37 (FIGS. 17 and 18).
[0057]
A valve 39 is attached to the cam 38 so as to support one end 39a. One surface of the valve 39 has a shape constituting a part of the cam surface 38 a having a high cam 38.
[0058]
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 rotates the valve 39 as shown in FIG. The convex portion 372a does not interfere with the movement to the high cam surface 38a.
[0059]
The upper chuck arm 372 is released when the cam 38 surface pushes the convex portion 372 a of the upper chuck arm 372.
[0060]
When the chuck arm pair 37 rotates counterclockwise, the convex portion 372a of the upper chuck arm 372 passes through the upper side of the valve 39 and moves on the high cam surface 38a. Therefore, the upper chuck arm 372 moves to the sheet alignment tray 5 while being open (FIGS. 15 to 16).
[0061]
As shown in FIGS. 17 to 18, the convex portion 372a of the upper chuck arm 372 is on the low cam surface 38b, and when the chuck arm pair 37 rotates clockwise, the convex portion 372a of the upper chuck arm 372 has a low cam. The surface 38b is moved. At this time, the upper chuck arm 372 moves while being closed.
[0062]
As shown in FIGS. 19 to 20, in the portion 38 c where the low cam surface 38 b switches to the high cam surface 38 b, the convex portion 372 a 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, the valve 39 is pushed while rotating as shown in FIG. 19 with the one end 39a side as a fulcrum and moved to the high cam surface 38a. I try not to get in the way.
[0063]
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 that does not interfere with the movement of the stapler 6 as indicated by a 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 on the high cam surface 38a of the cam 38, so that the upper chuck arm 372 is in an open state.
[0064]
After the movement of the stapler 6 is finished, the chuck arm pair 37 rotates counterclockwise toward the holding 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, so that the upper chuck arm 372 moves to the grip standby position shown in FIG.
[0065]
After the movement, the stapler 6 performs a binding operation on the sheet bundle P in the sheet alignment tray 5. In this 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 grip standby position.
[0066]
After the binding operation by the stapler 6 is completed, the chuck arm pair 37 rotates counterclockwise from the grip standby position shown in FIG. 16 toward the grip position. At this time, the convex portion 372a of the upper chuck arm pair 372 is switched from the high cam surface 38a of the fixed cam 38 to the low cam surface 38b, as shown in FIG. Close and hold the stapled sheet bundle P. Thereafter, the stapler 6 and the stop member 35 move outside the paper width.
[0067]
Next, as shown in FIGS. 17 to 18, the chuck arm pair 37 rotates clockwise from the gripping position toward the sheet bundle delivery position. Furthermore, as shown in FIG. 19, it rotates clockwise. At this time, since the convex portion 372a of the upper chuck arm 372 moves from the low cam surface 38b of the cam 38 to the high cam surface 38a, the upper chuck arm pair 372 changes from the closed state to the open state. . At this time, the sheet bundle P is gripped by the sheet conveyance roller pair 406 on the conveyance path, and the sheet bundle P is transferred from the chuck arm pair 37 to the sheet conveyance roller pair 406.
[0068]
Thereafter, the chuck arm pair 37 is rotated clockwise to the home position so as not to interfere with the conveyance of the sheet bundle P as shown in FIG.
[0069]
【The invention's effect】
Therefore, according to the first aspect of the present invention, the sheet bundle stacked on the sheet alignment tray is post-processed by the post-processing means and guided to the lower sheet distribution path, and the conveying direction is switched by the deflecting means to change the multi-stage. In the sheet post-processing apparatus of the image forming apparatus that performs post-processing such as stipple on the recorded paper discharged from the image forming apparatus and then discharges it onto the multi-stage paper discharge tray. The paper alignment tray and the post-processing means are provided above the paper distribution path and the multi-stage discharge tray, and the conventional paper distribution path, the post-processing means, and the multi-stage discharge tray are arranged in order in the paper transport direction. The width in the paper transport direction can be reduced as compared with the conventional one.
[0070]
Further, when the post-processed sheet bundle is conveyed through the sheet distribution path, the leading end of the sheet bundle is received by the locking member, and the locking member moves together with the sheet bundle. Even if the pressure is weak, the sheet in the middle of the stack thickness of the stack will slide downward due to its own weight, and the lower end of the stack will be displaced in the center in the stack thickness direction and become convex, making the transport of the stack unstable. It is possible to eliminate the possibility that the stackability on the paper discharge tray will deteriorate.
[0071]
According to the invention described in claim 2, since the locking member moves at the same speed as or slower than the conveyance speed of the sheet bundle, the leading end of the sheet bundle is always received by the locking member and moved together with the sheet bundle. It is possible to reliably prevent a sheet in the middle of the bundle thickness of the sheet bundle from sliding downward due to its own weight.
[0072]
According to the third aspect of the present invention, since the locking member is formed in a key shape, the leading end of the sheet bundle is reliably received, and the lower end of the sheet bundle is prevented from being shifted in the center in the bundle thickness direction to be convex. can do.
[Brief description of the drawings]
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 periphery of the alignment tray portion together with a guide plate.
FIG. 3 is a perspective view showing the sheet alignment tray together with an extendable tray.
FIG. 4 is an exploded perspective view of the first-stage telescopic tray portion.
FIG. 5 is a perspective view after the assembly.
FIG. 6 is a perspective view of the entire telescopic tray portion.
FIG. 7 is a perspective view showing a partial schematic configuration of the sheet post-processing apparatus.
8A is a perspective view showing the configuration of the paper distribution path on the side of the paper conveyance 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 in which a sheet is guided to a sheet distribution path.
FIG. 10 is an explanatory diagram showing a state in which the sheet is fed into a U-turn portion.
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 a sheet discharged from the image forming apparatus is immediately guided to a sheet distribution path without passing through a sheet alignment tray.
FIG. 13 is a mechanism diagram of a branching claw for guiding paper to a paper discharge tray.
FIG. 14 is an explanatory diagram of a state of a branching claw when a paper transport direction is switched and a paper is discharged to a paper discharge tray.
FIG. 15 is an explanatory diagram showing a state where the chuck arm pair is in a standby position.
FIG. 16 is an explanatory view showing a state where a pair of chuck arms is gripped and moved to a standby position.
FIG. 17 is an explanatory view showing a state where a pair of chuck arms has moved to a gripping position.
FIG. 18 is an explanatory diagram illustrating a state in which a pair of chuck arms delivers a sheet bundle to a pair of sheet conveying rollers.
FIG. 19 is an explanatory view showing a state in which the chuck arm pair is separated from the sheet bundle after delivery.
FIG. 20 is an explanatory diagram showing a state where the chuck arm pair has moved to the home position.
FIG. 21 is an explanatory diagram showing a conveyance state of a sheet bundle in a conventional sheet post-processing apparatus.
[Explanation of symbols]
1 Image forming device
2 Paper post-processing equipment
5 Paper alignment tray
6 Stille (post-processing means)
7 Mass output tray (separate output tray)
8 Multi-stage output tray
50 Paper transport drive roller
51 Paper transport driven roller
52 Branching claw (deflection means)
53 Locking member
58 Discharge drive roller
59 Discharged driven roller
60 Fixed guide member
66 pulley
67 pulley
68 motor
69 lever
76 belt
F Paper distribution path
P Paper bundle

Claims (3)

A first paper transport path that immediately guides the image-formed paper to the paper distribution path without stippling, and a second paper transport path that guides the paper to the paper distribution path after stapling;
The paper headed to the first paper transport path is distributed without being switched back in the paper distribution path and discharged onto a multi-stage paper discharge tray, while the paper headed to the second paper transport path is after conveyed downward to put the sheet stack after stapling to the paper distribution path, and switched back, the sheet post-processing device of an image forming apparatus for discharging and distributing in the paper distribution path in a multi-stage paper ejection tray In
A sheet post-processing apparatus of an image forming apparatus, wherein a locking member that receives the leading end of the sheet bundle and moves with the sheet bundle is provided in the sheet distribution path. 2. The image according to claim 1, wherein the locking member is moved at a speed equal to or slower than a conveying speed of the sheet bundle conveyed downward by a pair of rollers conveying the sheet bundle advanced to the sheet distribution path. A sheet post-processing apparatus of the forming apparatus.   The sheet post-processing apparatus of the image forming apparatus according to claim 1, wherein the locking member is formed in a key shape that is received by hooking a leading end of the sheet bundle.

Images