JP2000351523A - Paper accumulation device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a paper accumulation device capable of improving use efficiency of an gathering machine and accumulating bundles of papers at a high speed. SOLUTION: Bundles of papers gathered by a gathering machine 1 are carried into a carry-in path 23 of a paper accumulation device 20 from a discharge part 11. A first conveyance path 24, a first assorting mechanism 40 assorting bundles of papers, a first paper accumulation part 21, a second conveyance path 25, a second assorting mechanism 60 assorting bundles of papers, and a second paper accumulation part 22 having larger paper bundle accumulation amount than the first paper accumulation part are provided in the paper accumulation device 20. A change-over gate 26 sets a paper bundle conveyance path to the first conveyance path 24 or the second conveyance path 25, carries bundles of papers into the first paper accumulation part 21 and the second paper accumulation part 22 alternately, assorts them, and accumulates them.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet stacking apparatus for alternately stacking a sheet bundle formed of a plurality of sheets collated by a collating machine to a plurality of sheet stacking units. .

[0002]

2. Description of the Related Art In a bookbinding process, a plurality of sheets printed using a collating machine are collated in a page order, a sheet bundle of one book is formed, and sequentially conveyed to a paper stacking section. When the sheet bundle is accumulated in the sheet accumulation unit, the sheet bundle may be transported from the sheet accumulation unit to the next process such as a binding process.

[0003] A mounting table that moves up and down is provided in the sheet stacking section, and a stack of sheets is placed on the mounting table and sequentially stacked. When a predetermined amount of the sheet stack is stacked, the operation of the collating machine is temporarily stopped. Then, the sheet bundle is taken out of the mounting table and transported to the next process. After that, it is known to raise the lowered mounting table, restart the operation of the collating machine, and start stacking the sheet bundle.

[0004] Further, a container called a pallet having wheels is provided in the sheet stacking section, and when a predetermined amount of sheet stacks are stacked, the operation of the collating machine is temporarily stopped, and the pallet is pulled out from the sheet stacking section and the next time. Transport to the process. Next, it is known that a separately prepared empty pallet is arranged in a sheet stacking section, and the operation of the collating machine is restarted to stack a stack of sheets on the pallet.

[0005] As described above, in the conventional paper stacking apparatus, when a predetermined amount of the sheet bundle is accumulated, the operation of the collating machine is stopped once, the accumulated sheet bundle is taken out and transported to the next step. The operation of the collating machine is restarted to accumulate the sheet bundle.

[0006]

By the way, the collating operation of the collating machine tends to be accelerated due to the recent development of technology, and a predetermined amount of sheet bundle is accumulated in the sheet accumulating section in a short time. . However, since the operation of the collating machine is stopped every time a predetermined amount of paper bundle is accumulated in the paper accumulating section, there is a problem that the operation time of the collating machine is shortened and the use efficiency of the collating machine is reduced. there were.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has as its object to provide a sheet stacking apparatus capable of increasing the use efficiency of a collating machine and accumulating a sheet bundle at high speed.

[0008]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a paper stacking apparatus, comprising: a paper stacking device; A first transport path through which the sheet bundle is transported, a first sheet stacking section, a first sorting mechanism, a second transport path through which the sheet bundle is transported by branching from the loading path; A second sheet stacking unit having a different stacking amount of the sheet bundle from the sheet stacking unit, a second sorting mechanism, and a branching point where the first conveying path and the second conveying path branch from the carry-in path. And a switching gate for setting the transport path of the sheet bundle to the first transport path or the second transport path.
This is achieved by providing a configuration in which the sheet bundle is alternately carried into the first sheet accumulation unit and the second sheet accumulation unit, and the sheet bundle is sorted and accumulated.

According to a second aspect of the present invention, in the sheet stacking apparatus according to the first aspect, the transport speed of the sheet bundle is set, and the operation timing of the switching gate is adjusted in accordance with the transport speed. And a control device for controlling the operation speed of the first sorting mechanism and the second sorting mechanism.

According to a third aspect of the present invention, in the paper stacking device according to the first or second aspect, the first sheet stacking device is provided with the first
The paper stacking section and the second paper stacking section are arranged substantially linearly with respect to the carry-in path, and the second transport path is arranged across the top of the first sheet stacking section.

According to a fourth aspect of the present invention, in the paper stacking apparatus according to any one of the first to third aspects, the first sorting mechanism and the second sorting mechanism are arranged at an end of a sheet bundle. Are alternately shifted for sorting.

According to a fifth aspect of the present invention, in the sheet stacking apparatus according to any one of the first to fourth aspects, a sheet bundle is placed on the first sheet stacking section and the second sheet stacking section. A sensor for detecting that a certain amount of sheets are accumulated is provided, and when one of the sensors is operated, a switching gate is operated so as to form a conveyance path for a sheet bundle in a sheet accumulation part on a side where the sensor does not operate. In addition, the transport speed of the sheet bundle and the operation speed of the sorting mechanism for sorting the sheet bundle are controlled to be lower than those in the normal operation.

As described above, in the invention according to the first aspect, the transport path of the bundle of sheets collated by the collating machine is switched by the switching gate, and the first sheet stacking unit and the second sheet stacking unit are switched. The stack of sheets is stacked alternately in each section. For this reason, the time required for a predetermined amount of sheet bundle to be stacked on each sheet stacking unit is:
This is twice as large as when a single sheet stacking unit is used, so that the operation time of the collating machine can be extended and the use efficiency thereof can be increased.

Further, in the invention according to claim 2, since the operation timing of the switching gate and the operation speed of the sorting mechanism are set in accordance with the transport speed of the sheet bundle, the collating machine is used. Stacked paper stacks at high speed.

Further, in the invention according to claim 3, the first paper stacking section and the second paper stacking section are arranged substantially linearly with respect to the carry-in path, and the second transport path is formed by the first transport path. Since the paper stacking unit is disposed across the upper portion, the space required for installing the paper stacking device can be saved.

In the invention according to the fourth aspect, the first sorting mechanism and the second sorting mechanism sort the sheet bundle by shifting the ends of the sheet bundle alternately, so that the next step such as the binding processing is performed. In this case, there is no need to separately sort the sheet bundle, so that there is an advantage that the bookbinding process can be performed quickly.

In the invention according to claim 5, when a predetermined amount of sheet bundle is accumulated on one sheet accumulating portion, the conveying speed of the sheet bundle, that is, the sheet discharging speed of the collating machine, and the other sorting operation are performed. By reducing the operation speed of the mechanism from the speed in the normal state, it is possible to continuously accumulate the sheet bundle without stopping the operation of the collating machine even while removing the sheet bundle from the sheet accumulating unit. Therefore, the sheet bundle can be efficiently accumulated.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a paper stacking apparatus according to the present invention will be described below with reference to the drawings. FIG. 1 is a schematic side view of the paper stacking device of the present invention. In FIG. 1, the sheet bundle collated by the collating machine 1 is configured to be stacked by a sheet stacking device 20. The collating machine 1 has 8
The paper feed stages 2a to 2h are provided, and each paper feed stage stores a predetermined number of sheets of the same page. Paper feed rollers 3a to 3h are arranged on the paper feed side of each paper feed stage, and sheets carried out by the paper feed rollers from each paper feed stage pass through vertical feed rollers 4a to 4h. The paper is fed to the vertical conveyance belt 6.

The vertical transport belt 6 is driven by vertical transport belt drive rollers 5a and 5b arranged vertically. The paper fed from each paper feed stage to the vertical transport belt 6 is sequentially stacked while being transported in the vertical direction, and collated in page order to form one paper bundle. Reference numeral 8 denotes a lateral transport belt, which is driven by lateral transport belt drive rollers 7a and 7b disposed at both ends.

One bundle of sheets fed to the vertical transport belt 6 and collated in page order is supplied to the horizontal transport belt 8 through the guide 10. A discharge roller 9a is provided at an end of the lateral conveyance belt 8, and the sheet bundle is formed by a discharge roller 9a.
a to the discharge unit 11. Reference numeral 9b denotes a roller for feeding a bundle of sheets conveyed to the lateral conveyance belt 8 from another collating machine when a plurality of collating machines are connected and used.

Reference numeral 20 denotes a sheet stacking device, in which a sheet bundle supply port 31 is formed at a position facing the discharge unit 11. The sheet stacking device 20 includes a first sheet stacking unit 21 and a second sheet stacking unit 22. Each paper stacking unit 21, 2
2 is provided with a pallet having wheels. A sheet bundle carry-in path 23 is provided at the position of the sheet bundle supply port 31, and a first transport path 24 is formed continuously with the sheet bundle carry-in path 23. The second transport path 2 branches from the sheet bundle input path 23 and includes a front transport path 25a and a rear transport path 25b.
5 are provided.

At a branch point 32 between the first transport path 24 and the second transport path 25, a switching gate 26 is disposed.
The switching gate 26 is connected to a rod 28 which reciprocates by the operation of the electromagnetic solenoid 27 (in FIG. 1, a part of the connection mechanism between the switching gate 26 and the rod 28 is omitted). The operation of the electromagnetic solenoid 27 causes the rod 2
8 operates, the switching gate 26 rotates, and the conveyance path of the sheet bundle conveyed from the sheet bundle conveyance path 23 to the sheet stacking device 20 is transferred to the first conveyance path 24 or the second conveyance path 25. Select. FIG. 1 shows a state where the first transport path 24 is selected.

The first sheet stacking section 21 and the second sheet stacking section 22 are arranged substantially linearly with respect to the sheet bundle supply port 31. In addition, a second transport path 25 branching off from the sheet bundle carry-in path 23 is disposed across the upper part of the first sheet stacking unit 21. As described above, the first sheet stacking unit 21 and the second sheet stacking unit 22 are arranged substantially linearly with respect to the sheet bundle supply port 31, and the second transport path 25 is connected to the first sheet stacking unit. By arranging across the upper part of 21, the installation space of the paper stacking device can be saved.

A first sorting mechanism 40 is provided on an upper surface of the first sheet stacking section 21, and a second sheet stacking section 22 is provided.
A second sorting mechanism 60 is provided on the upper surface of the second sorting mechanism. Details of the first sorting mechanism 40 and the second sorting mechanism 60 will be described later.

Reference numeral 29 denotes a stopper provided at the upper end of the first sheet stacking unit 21. The sheet bundle conveyed to the first sheet stacking unit 21 stops at the position of the stopper 29.
Reference numeral 21a denotes a sheet bundle mounting plate, which is initially set at the height of the sheet bundle carry-in entrance of the first sheet stacking unit 21.

As the sheet bundle is carried into the first sheet stacking unit 21, the sheet bundle is sequentially lowered in the direction of arrow X, and when the pallet is full as shown in FIG. 21 is reached. Reference numeral 33 denotes a sheet bundle height detection sensor that detects that the sheet bundle has been accumulated on the first sheet accumulation unit 21 to a predetermined height. The position of the sensor in the height direction can be arbitrarily adjusted.

Similarly, a stopper 30 is also provided at the upper end of the second sheet stacking section 22, so that the sheet bundle is sequentially lowered in the arrow X direction as the sheet bundle is carried into the second sheet stacking section 22. A placing plate 22a is provided. Reference numeral 34 denotes a sheet bundle height detection sensor that detects that the sheet bundle has been accumulated on the second sheet accumulating unit 22 to a predetermined height. In the example of FIG. 1, the size of the pallet of the second sheet stacking unit 22 is set so that the stacking amount of the sheet bundle is larger than that of the first sheet stacking unit 21.

Reference numeral 70 denotes a control device,
The conveying speed of the bundle of paper conveyed into the collating machine 1, that is, the discharging speed of the collating machine 1, is set, and the paper feed rollers 3a to 3
h, vertical feed rollers 5a, 5b, horizontal feed rollers 7
A control signal for controlling the driving motors such as a and 7b is output. Further, a detection signal of a sensor that detects a paper feeding failure of each of the paper feeding stages 2a to 2h is input.

The control device 70 outputs a control signal for controlling the operation of the electromagnetic solenoid 27, and outputs the control signal to the switching gate 26.
Control the timing of the operation. Further, it outputs control signals for controlling the driving motors of the first sorting mechanism 40 and the second sorting mechanism 60. Further, detection signals from the sheet bundle height detection sensor 33 provided in the first sheet accumulation unit 21 and the sheet bundle height detection sensor 34 provided in the second sheet accumulation unit 22 are input.

Next, the first sorting mechanism 40 will be described with reference to FIGS. FIG. 2 is a plan view, and FIG. 3 is a side view as viewed from the Y direction in FIG. 2 and 3, reference numeral 41 denotes a stop plate attached to a fixing member 42, 4
Reference numeral 3 denotes an elevating plate connected to the rod 44, which is moved up and down in the direction of arrow Q by the operation of the electromagnetic solenoid 45.

A movable plate 46 has a first reciprocating rod 47.
a, which is connected to the second reciprocating rod 47b and moves in the mounting portions 49a, 49b of the frame 48; Driving motor 50
The first pulley 51a is attached to the output shaft of
2, the torque is transmitted to the second pulley 51b.

When the second pulley 51b rotates, the rotating shaft 53 rotates, and the cam 54 rotates in the arrow R direction. At this time, the distal end of the lever mechanism 55 swings in the arrow S direction about the fulcrum 56, the first reciprocating rod 47a reciprocates via the pin 57, and the second reciprocating rod 4
7b also reciprocates in conjunction. As described above, the rotational motion of the drive motor 50 is converted into a linear motion by using the cam 54 and the lever mechanism 55, and the movable plate 46 is reciprocated in the arrow P direction.

At the timing when the movable plate 46 moves from the position a to the position b, the elevating plate 43 rises, one end of the conveyed sheet bundle A1 abuts the stop plate 41, and the other end is It comes into contact with the movable plate 46. Next, when the movable plate 46 reverses and moves from the position b to the position a, the sheet bundle A1
Falls on the mounting plate 21a. At this time, the lifting plate 43
Comes down and comes into contact with one end of the sheet bundle B1 to be conveyed next, and the other end of the sheet bundle B1 comes into contact with the movable plate 46.

When the movable plate 46 moves from the position a to the position c, the sheet bundle B1 falls on the placing plate 21a. In the same manner, the first sheet stacking unit 21 is controlled by interlocking control of the reversing operation of the movable plate 46 and the elevating operation of the elevating plate 43.
Are stacked alternately with their ends shifted to row A and row B as shown in FIG. The second sorting mechanism 60 has the same configuration as the first sorting mechanism 40.

FIG. 4 is a perspective view showing an example of a form of a sheet bundle that is sorted by the first sorting mechanism 40 described in FIGS. As shown in FIG. 4, the child bundles are alternately sorted into rows A1 to AX and rows B1 to BX, and are stacked with their ends aligned.

If the end portions of the sheet bundle are alternately shifted and accumulated in this manner, the work of separately sorting the sheet bundle at the time of the next process such as the binding process becomes unnecessary, so that the bookbinding process can be performed quickly. There are advantages. Similarly, in the sheet stacking section 22, the sheet bundle is alternately stacked in the row A and the row B with the ends shifted as shown in the perspective view of FIG. 4 by the second sorting mechanism 60.

Next, the operation of the paper stacking apparatus of the present invention will be described. The first sheet bundle of one book collated in the page order by the collating machine 1 is discharged from the discharge unit 11 and is carried into the sheet bundle carry-in path 23 of the sheet stacking device 20. Switching gate
When one of the transport paths, for example, the first transport path 24 side is set by the port 26, the sheet bundle is carried into the first sheet stacking unit 21 through the first transport path 24. At this time, the first sheet bundle is selected by the operation of the first sorting mechanism 40 into one of the rows A and B shown in FIG.

Next, the second sheet bundle ejected from the ejection unit 11 and carried into the sheet bundle carry-in path 23 of the sheet stacking device 20 is set on the second conveying path 25 side by the switching gate 26. The sheet bundle is carried into the second sheet stacking unit 22 through the second transport path 25. At this time, the form of accumulation of the sheet bundle is selected to be either the row A or the row B in FIG. 4 by the operation of the second sorting mechanism 60.

While the second sheet bundle is carried into the second sheet stacking section 22 through the second conveyance path 25, the first sorting mechanism 40 performs the reversing operation as described above, and performs the third operation. The sheet bundle carried in from one transport path 24 is stacked in the first sheet stacking unit 21 with the end shifted from the first sheet bundle. Similarly, the sheet stack is sequentially stacked on the first sheet stacking section 21 and the second sheet stacking section 22 in such a manner that the ends are alternately shifted.

The switching gate 26 moves the sheet bundle conveying path in accordance with the timing at which the sheet bundle collated by the collating machine 1 is discharged from the discharge unit 11, that is, the conveying path of the sheet bundle. The switching operation to the transport path 24 or the second transport path 25 is performed. Further, the timing (operating speed) of the reversing operation of the first sorting mechanism 40 and the second sorting mechanism 60 is also
The setting is made in accordance with the transport speed of the sheet bundle. in this way,
Timing of operation of switching gate 26 and sorting mechanism 4
Since the operation speeds 0 and 60 are set in accordance with the transport speed of the sheet bundle, the sheet bundle can be stacked at a high speed in conjunction with the collating speed of the collating machine.

When the stack of sheets is stacked on the first sheet stacking section 21 and the second sheet stacking section 22 to a predetermined height, the pallet is transferred to the next step. In the example of FIG. 1, the amount of accumulation of the second sheet accumulation unit 22 is set to be larger than the amount of accumulation of the first sheet accumulation unit 21, but the first sheet accumulation unit 21 and the second sheet accumulation unit The stacking amount of the first sheet stacking unit 22 can be set arbitrarily, and the stacking amount of the first sheet stacking unit 21 can be made larger than that of the second sheet stacking unit 22.

In the present invention, the transport path of the sheet bundle collated by the collating machine is switched by the switching gate 26, and the sheet bundle is transported to the first sheet accumulating section 21 and the second sheet accumulating section 22. Stacked alternately. For this reason, the time required to accumulate a predetermined amount of sheet bundle on each sheet accumulating section is twice as long as when a single sheet accumulating section is used, and the operation time of the collating machine is extended, and the use efficiency thereof is reduced. Can be enhanced.

Next, another embodiment of the present invention will be described. As shown in FIG. 1, the height of the pallet provided in the first paper stacking unit 21 is lower than the height of the pallet provided in the second paper stacking unit 22, so that the paper bundle is supplied to the paper stacking device 20. Then, the sheet bundle on the pallet provided in the first sheet stacking unit 21 reaches a predetermined amount (for example, full).
The fact that the pallet provided in the first sheet stacking section 21 is filled with the sheet bundle is detected by the sensor 33 and input to the control device 70.

The pallet provided in the first paper stacking unit 21 is pulled out of the paper stacking unit 20 and transported to the next step, and another empty pallet is placed in the first paper stacking unit 21 until it is arranged. Drives the switching gate 26 to set the transport path of the sheet bundle to the second transport path so that the sheet bundle is accumulated only in the second sheet accumulation unit 22.

At this time, the ability to supply the sheet bundle to the sheet stacking device 20 is reduced by half as compared with the case where the first sheet stacking unit 21 and the second sheet stacking unit 22 are used together.
For this reason, the transport speed of the sheet bundle (discharge speed of the collating machine 1) is reduced to half the speed in the normal state. Further, the sorting speed of the second sorting mechanism 60 provided in the second paper stacking unit 22 is also reduced to half the speed in the normal state.

As described above, the discharge speed of the collating machine 1 and the second
The sorting speed of the sorting mechanism 60 is reduced to half the speed of the normal state, so that the operation of the collating machine 1 is stopped without stopping the operation of the collating machine 1 even when the pallet is changed in the first sheet stacking unit 21. Since the stacking can be performed continuously, the sheet bundle can be efficiently stacked.

[0047]

As described above, according to the first aspect of the present invention, the conveying path of the sheet bundle collated by the collating machine is switched by the switching gate, and the first sheet stacking section and the first sheet stacking section are switched. The sheet bundle is alternately stacked on the second sheet stacking section. For this reason, the time required to accumulate a predetermined amount of sheet bundle on each sheet accumulating section is twice as long as when a single sheet accumulating section is used, and the operation time of the collating machine is extended, and the use efficiency thereof is reduced. Can be enhanced.

In the invention according to the second aspect, the timing of the operation of the switching gate and the operation speed of the sorting mechanism are set in accordance with the transport speed of the sheet bundle, so that the collating machine is used. Stacked paper stacks at high speed.

According to the third aspect of the present invention, the first paper stacking section and the second paper stacking section are arranged substantially linearly with respect to the carry-in path, and the second transport path is provided with the first paper stacking section. Since the paper stacking unit is disposed across the upper portion, the space required for installing the paper stacking device can be saved.

In the invention according to the fourth aspect, the first sorting mechanism and the second sorting mechanism alternately shift the ends of the sheet bundle to sort, so that the processing in the next step such as the binding processing is performed. In this case, there is no need to separately sort the sheet bundle, so that there is an advantage that the bookbinding process can be performed quickly.

In the invention according to claim 5, when a predetermined amount of sheet bundle is accumulated on one sheet accumulating portion, the conveying speed of the sheet bundle, that is, the discharging speed of the collating machine, and the other sorting operation are performed. By reducing the operation speed of the mechanism from the speed in the normal state, it is possible to continuously accumulate the sheet bundle without stopping the operation of the collating machine even while removing the sheet bundle from the sheet accumulating unit. Therefore, the sheet bundle can be efficiently accumulated.

[Brief description of the drawings]

FIG. 1 is a schematic side view of a paper stacking apparatus according to an embodiment of the present invention.

FIG. 2 is a plan view of a sorting mechanism.

FIG. 3 is a side view of a sorting mechanism.

FIG. 4 is a perspective view illustrating a form of stacking a sheet bundle.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Collating machine 2a-2h Paper feed stage 6 Vertical conveyance belt 7 Horizontal conveyance belt 10 Guides 11 Ejection part 20 Paper accumulation device 21 First paper accumulation part 22 Second paper accumulation part 23 Loading path 24 First Transport path 25 second transport path 26 switching gate 29, 30 stopper 33, 34 sensor for detecting the height of the sheet bundle 40 first sorting mechanism 60 second sorting mechanism 70 controller

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Masayuki Kashiba 1601 Asahi Jinoshita, Asahi-cho, Takashima-gun, Shiga Prefecture Inside Horizon International Co., Ltd. (72) Inventor Masato Nogawa Shin-Asahi-cho, Takashima-gun, Shiga Prefecture 1601 Oji Asahi Jonoshita Horizon International Co., Ltd. F-term (reference) 3F050 BB02 BE12 CA08 CE03 LA06 LA16 LB03 3F054 AA01 AB01 AC04 BA02 BF07 BF22 DA04

Claims (5)

[Claims] 1. A loading path into which a bundle of sheets collated by a collating machine is carried in, and a first path to which the sheet bundle is conveyed by branching from the carrying path.
, A first sheet stacking section, a first sorting mechanism, a second conveying path branched from the carry-in path to convey a sheet bundle, and the first sheet stacking section A second stacking unit, a second sorting mechanism, and a branch point where the first transport path and the second transport path branch off from the carry-in path. First transport path or second transport path
And a switching gate for setting the transport path of the sheet stack, wherein the sheet stack is alternately carried into the first sheet stacking section and the second sheet stacking section, and the sheet stack is sorted and stacked. apparatus. 2. A control for setting the transport speed of the sheet bundle and controlling the operation timing of the switching gate and the operating speeds of the first sorting mechanism and the second sorting mechanism in accordance with the transport speed. The paper stacking device according to claim 1, further comprising an apparatus. 3. The first sheet stacking section and the second sheet stacking section are arranged substantially linearly with respect to the carry-in path, and the second transport path is traversed over the first sheet stacking section. The paper stacking device according to claim 1, wherein the paper stacking device is arranged. 4. The sheet stacking apparatus according to claim 1, wherein the first sorting mechanism and the second sorting mechanism sort the sheets by alternately shifting the ends of the sheet bundle. apparatus. 5. A sensor for detecting that a predetermined number of sheet bundles have been stacked on the first sheet stacking section and the second sheet stacking section, and when one of the sensors operates, the sensor is activated. The switching gate is operated so as to form a conveyance path for the sheet bundle in the sheet stacking section on the non-operating side, and the conveying speed of the sheet bundle and the operation speed of the sorting mechanism for sorting the sheet bundle are reduced from those in the normal operation. The paper stacking device according to any one of claims 1 to 4, characterized in that the paper stacking device is controlled by: