JP2014201434A - Paper sheet post-processing device, and image forming system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a paper sheet post-processing device structured so that an introduced paper sheet and a discharged paper sheet do not collide with each other.SOLUTION: A paper sheet post-processing device includes: a paper sheet edge detection sensor detecting a condition for receiving a paper sheet toward a staple tray; a discharge sensor capable of detecting a paper sheet bundle discharged from the staple tray; and a control unit to the input side of which an operation panel provided with a unit for inputting a paper sheet bundle is connected, and to the output side of which a drive unit for members used for a staple processing unit and a conveying part is connected. The control unit receives a successive paper sheet in the midst of discharging the paper sheet bundle from the staple tray, and makes a conveying speed of the successive paper sheet slower than an ordinary conveying speed if having started a discharge motion of the paper sheet bundle subjected to the staple processing, when stacking the paper sheet bundle on a stacking part.

Description

  The present invention relates to a sheet post-processing apparatus and an image forming system for recording sheets and the like, and more particularly to sheet introduction and discharge control with respect to a tray provided at a binding processing position.

Sheets printed out by an image forming apparatus such as a copying machine, a printer, or a printing machine, in addition to being discharged from the image forming apparatus, may be partially bound with a stapler while a predetermined number of sheets are collected. Post-processing may be performed.
As a device for this purpose, a paper post-processing device connected to the paper discharge unit of the image forming apparatus is used.

The binding process is executed by stacking a plurality of sheets in a pre-stack unit provided in the middle of the sheet conveyance path and conveying the sheets to the binding mechanism.
When stacking sheets in the stack unit, the preceding sheet is temporarily stopped in the pre-stack unit, and the transport of the sheet that has been temporarily stopped is resumed at the timing when the subsequent sheet enters, and is disposed in the vicinity of the binding mechanism. There is known a configuration for discharging to a staple tray (for example, Patent Document 1).

  On the other hand, considering the fact that the frictional resistance against the paper varies depending on the number of sheets stacked on the stack, the conveyance speed during conveyance is changed to ensure stable discharge against load fluctuations such as frictional resistance. The structure which can perform is proposed (for example, patent document 2).

By the way, in Patent Document 2 in which a configuration including a configuration capable of stably discharging a sheet against load fluctuations is disclosed, a conveyance speed when discharging a group of sheet bundles stacked on a stack tray is a target. Can be stabilized.
However, when a configuration in which a part of the staple tray as disclosed in Patent Document 1 is shared as a prestack portion is targeted, the following new problem occurs.
In other words, in the staple tray, in addition to the paper introduced as the prestack unit, a group of paper subjected to the staple processing is discharged, so that there is a possibility that both sheets moving in the opposite directions on the staple tray collide with each other. There is.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a sheet post-processing apparatus having a configuration capable of preventing a collision between a sheet to be introduced and a sheet to be discharged in view of a problem when a staple tray is shared as a part of a prestack unit. And providing an image forming system.

  In order to achieve this object, the present invention has a stack unit for stacking and transporting a plurality of sheets in the middle of a sheet transport path, and the stack unit has the same configuration as a staple tray for performing a stapling process. A sheet post-processing apparatus shared by a plurality of parts, wherein an inlet sensor for detecting the state of introduction of the sheet toward the staple tray is connected to the input side, and a sheet bundle discharged from the staple tray can be detected on the output side A control unit to which a discharge sensor is connected, and the control unit receives a next sheet while discharging the stack of sheets from the staple tray and stacks the stack on the stack unit. In the paper post-processing apparatus, the transport speed of the next paper is decelerated from the normal transport speed.

  According to the present invention, the receiving speed of the next sheet is reduced with respect to the discharging speed of the sheet bundle discharged from the staple tray, thereby preventing the next sheet from colliding with the discharged sheet bundle. it can.

1 is a schematic diagram for explaining a configuration of an image forming system using a sheet post-processing apparatus according to an embodiment of the present invention. It is a block diagram for demonstrating the structure of the control part used for a paper post-processing apparatus. FIG. 3 is a schematic diagram for explaining the contents of sheet conveyance control by the control unit shown in FIG. 2. It is a timing chart for demonstrating the conveyance speed switching timing set by the control part shown in FIG. FIG. 6 is a tying chart for explaining a modified example of the conveyance speed switching set by the control unit shown in FIG. 3. FIG. It is a flowchart for demonstrating the effect | action of the control part shown in FIG. It is a flowchart for demonstrating another effect | action performed by the control part shown in FIG.

DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments for carrying out the present invention will be described based on illustrated embodiments.
FIG. 1 is a schematic diagram for explaining an image forming system using a sheet post-processing apparatus according to an embodiment of the present invention.
In FIG. 1, an image forming system 100 includes a sheet post-processing apparatus 300 that is continuously attached to and connected to a sheet discharge unit in an image forming apparatus 200 such as a copying machine, a printer, or a printing machine.

  The sheet post-processing device 300 used in the image forming system 100 has a function as a post-processing device that performs a folding process such as a binding process for binding a plurality of sheets together and a folding process.

In the image forming system 100, after an image is formed on the paper P in the image forming apparatus 200, the paper post-processing apparatus 300 receives the paper P from the image forming apparatus 200 and performs various post-processing on the received paper P.
Examples of the various post processes include an end binding process, a so-called stapling process, and a middle folding process. The half-folding process includes a saddle stitching process.

In the present embodiment, a sheet post-processing device 300 used for the edge binding process and the saddle stitching process is attached to the image forming apparatus 200 and binds using a part of a sheet bundle instead of using a needle.
The sheet post-processing apparatus 300 that performs such various post-processing has a discharge mode, an end binding mode, and a middle folding mode as operation modes.

The image forming apparatus 200 has a known configuration, and an example is an electrophotographic color image forming apparatus.
In the image forming apparatus 200, for example, a control unit, an image forming unit, an optical writing unit, a paper feeding unit, a paper feeding conveyance path, an image reading unit, an intermediate transfer unit, a fixing unit, a paper discharge conveyance path, a double-side conveyance path, and the like ( Neither is shown), and an image is formed on both sides or one side of the paper 5.

In FIG. 1, the principle structure of the sheet post-processing apparatus 300 will be described together with the operation as follows.
The sheet post-processing apparatus 300 includes an introduction path 1 for receiving the image-formed sheet P discharged from the image forming apparatus and three paths branched from the introduction path 1.
The three paths include an upper transport path 2 toward the proof tray 6, a straight transport path 3 that performs shift processing, end binding, or two-point binding processing, and a lower transport path 4 that performs saddle stitching and folding processing. ing.
An inlet roller 10 and an inlet sensor 13 are arranged in the introduction path 1, and it is detected by these sensors that the paper P is carried into the paper post-processing apparatus.

A transport roller front 11 is disposed downstream of the entrance roller 10. Further, the branching claws 7 and 8 positioned at the branching portion at the end portion of the introduction path 1 can sort the paper transporting direction into the upper transporting path 2, the straight transporting path 3, and the lower transporting path 4 by rotating. it can.
The straight conveyance path 3 is provided with a conveyance roller rear 12 positioned behind the branch claw 7 in the conveyance direction, and the sheet P is conveyed to the conveyance path 3 through this.
In the conveyance path 3, a paper discharge roller 26 and a paper discharge sensor 28 used as a discharge sensor are arranged.

  In the sort mode, the conveyance roller rear 12 having the shift mechanism is driven by a driving means (not shown). That is, when driven, the sheet P is moved by a certain amount in a direction perpendicular to the conveying direction during conveyance, whereby the sheet P is shifted by a certain amount, and discharged by the sheet discharge roller 26 toward the sheet discharge tray 5 and sequentially stacked. To go.

The paper discharge outlet to the paper discharge tray 5 has a pair structure in which a paper or a bundle of paper is sandwiched between a paper discharge roller 26 and a driven roller 27 and discharged.
This is because the discharge guide provided with the driven roller 27 with respect to the discharge roller 26 can be selectively moved between a closed state in which a sheet or a sheet bundle can be discharged and an unopened state in which the sheet is discharged. After the paper shift operation is completed, the paper is nipped and discharged.
Further, a filler 40 is disposed in the vicinity of the upper portion of the paper discharge port so as to freely rotate at a position near the center of the paper P when stacked, and the tip of the filler 40 is in contact with the upper surface of the paper P.
Near the base of the filler 40, there is an upper surface detection sensor (not shown) that detects the height position of the tip of the filler 40, and detects the paper surface height of the stack paper P by these.

When the upper surface detection sensor is turned on as the sheet height rises due to the increase in the number of sheets deposited on the discharge tray 5, the control unit 1000 shown in FIG. 13 controls the drive means (not shown) of the discharge tray 5. The paper discharge tray 5 is lowered to maintain the paper surface height at a fixed position.
That is, when the upper surface detection sensor turns off when the discharge tray 5 is lowered after being raised, the lowering of the discharge tray 5 is stopped. This operation is repeated, and when the paper discharge tray 5 reaches the specified tray full height, a stop signal is issued from the sheet post-processing device to the image forming device to stop the image forming operation of the system.

A staple tray 21 capable of conveying a plurality of sheets in a stacked manner is disposed in the conveyance path 3 located in the middle of the sheet conveyance path.
A return roller denoted by reference numeral 41 performs a pendulum motion so as to contact the paper, and abuts the rear end of the paper against the rear end fences 24 and 25 to align the vertical position of the paper bundle.
On the staple tray 21, jogger fences 22 and 23 are provided for advancing and retreating in the direction orthogonal to the paper surface and aligning the position in the width direction of the paper P discharged onto the staple tray 21.
By performing these two operations, the sheet bundles P discharged on the staple tray 21 are aligned and stacked.
When the edge binding mode is selected for the aligned sheet bundle P, the stapler 50 moves in a direction perpendicular to the paper surface to bind an appropriate portion of the lower edge of the sheet bundle, and the discharge claw 29 moves the sheet bundle P in the sheet discharge direction. The paper is discharged and paper discharge processing is performed.

During the paper discharge, the paper discharge roller 26 and the driven roller 27 face each other so that the paper is nipped and conveyed, and a paper bundle is arranged on the paper discharge tray 5 to be discharged.
In the lower conveyance path 4, saddle stitch conveyance rollers 61, 62, 63 and a stapler 51 for saddle stitching are arranged.
When the sheets are conveyed to the saddle stitching position by these members, the binding process is performed at a predetermined position in the width direction.

The sheet that has been subjected to the saddle stitching process is conveyed to the sheet folding stopper 64 of the sheet folding section by the saddle stitch conveying rollers 62 and 63, and is folded by the sheet folding blade 71 and the middle folding plate 72. Is discharged to the middle folding tray 9.
The paper folding stopper 64 is a member that can move along the paper conveyance direction.
The position of the sheet folding stopper 64 is changed by the control unit 1000 described in FIG. 13 along a sheet conveyance direction via a stepping motor (not shown) as a drive source, and the moving speed at the time of the change is also changed. It is a member to be changed.

A branch claw 8 is used to transport the paper to the lower transport path 4.
When the sheet that has passed through the straight conveyance path 3 is detected by the sheet leading edge detection sensor 14, it waits for the time for the trailing edge of the sheet to pass through the branching portion of the lower conveyance path 4, and the conveyance roller is switched in accordance with the switching of the branch claw 8. 12 is reversed and switched back and guided to the lower transport path 4.

The features of the present embodiment will be described with the above configuration as an object.
A feature of the present embodiment is that when the staple tray 21 is shared by a part of the prestack portion, a conveyance mode is set in which the sheet bundle discharged from the staple tray 21 and the sheet received by the staple tray 21 do not collide. There is.
FIG. 2 is a block diagram showing a configuration of a control unit used for exhibiting the above characteristics.
In the figure, the control unit 1000 is a computer having a CPU, a storage unit, a communication interface, and the like.
The storage unit of the control unit 1000 is configured by a ROM, a RAM, and the like, and stores a program executed by the CPU.
The controller 1000 is connected to the following devices and members on the input side and the output side as members related to the present embodiment via an interface (not shown).
Used for the sheet leading edge detection sensor 14, the discharge sensor 28, the processing unit 116, the first bundling unit 128, the saddle stitch folding unit 133, the conveyance unit 151 and the path switching unit 152, the operation panel 1001, the staple processing unit and the conveyance unit 151. Connected to the drive unit.

  The operation panel 1001 is provided with an input unit for the number of sheets constituting a sheet bundle per job.

The controller 1000 changes the transport speed of the next sheet when the next sheet corresponding to the succeeding sheet is received and stacked in the stage where the sheet bundle is discharged from the staple tray 21.
Specifically, when the next sheet corresponding to the succeeding sheet is received by the staple tray 21 while the bundle of sheets is being discharged from the staple tray 21, the conveyance speed of the next sheet is set to the normal conveyance speed. Than to slow down.

FIG. 3 is a view showing the arrangement of the sheet leading edge detection sensor 14 for detecting the reception of the sheet with respect to the staple tray 21 and the discharge sensor 28 corresponding to the discharge sensor, and the conveyance state of the sheet and sheet bundle moving between these sensors. is there.
As shown in FIG. 5A, when the leading edge of the next sheet is detected by the sheet leading edge detection sensor 14, the discharge sensor 28 detects the state in which the sheet bundle is discharged on the staple tray 21. Then, when detected by the discharge sensor 28, the conveyance speed of the next sheet is reduced from the conveyance speed V1 ′ to V2 (see FIG. 3B).

  In FIG. 3, the conveyance speed V <b> 2 that is decelerated for the next sheet is the time during which the leading edge of the next sheet does not reach the staple tray 21 before the trailing edge of the sheet bundle is released from the staple tray 21 ( This corresponds to the conveyance speed at which t1) is obtained. That is, after the discharge of the sheet bundle from the staple tray 21 is completed, the speed is reduced to a speed at which the timing at which the leading edge of the next sheet is received by the staple tray 21 can be obtained.

  Therefore, the next sheet does not reach the staple tray 21 until the discharge sensor 28 detects that the sheet bundle is completely discharged from the staple tray 21, so that the collision between the two can be avoided.

On the other hand, FIG. 3C shows that when the sheet bundle is completely discharged from the staple tray 21, in other words, when the trailing edge of the sheet bundle is detected by the discharge sensor 28, the conveyance speed of the next sheet is reduced. A state in which the conveyance speed (V2) is changed to a higher speed (V3) is shown. In this case, the next sheet conveyance speed (V3) is set to be slower than the sheet bundle conveyance speed (V1).
As a result, only when there is no sheet bundle on the staple tray 21, the next sheet can be conveyed at high speed without colliding with the rear end of the sheet bundle.

FIG. 4 is a timing chart of the conveyance state shown in FIG.
In the same figure, when the leading edge of the next sheet is detected by the sheet leading edge detection sensor 14 until the trailing edge of the sheet bundle discharged from the staple tray 21 is detected by the discharge sensor 28, the next sheet is conveyed. The speed is decelerated (V2) from the normal transport speed (V1 ′).

On the other hand, FIG. 5 is a timing chart for the conveyance state shown in FIG.
In the figure, when it is determined from the signal from the discharge sensor 28 that the sheet bundle has been discharged from the staple tray 21, the transport speed (V2) of the next paper that has been decelerated so far is higher than this speed. It is changed to (V3).

The conveyance control by the control unit 1000 as described above is executed based on the flowcharts shown in FIGS.
FIG. 6 is a flowchart for the conveyance state shown in FIG.
That is, FIG. 6 shows a case where the next sheet starts to be conveyed when the sheet bundle to be bound per job is positioned on the staple tray 21.
In FIG. 6, the sheet bundle that has been subjected to the binding process on the staple tray 21 is started to be conveyed toward the staple tray 21 (S1). It is determined whether or not there is (S2).

  When it is determined in step S2 that the discharge operation is in progress or before the discharge by detecting the presence or absence of the sheet bundle by the discharge sensor 28, the transport speed of the next sheet is reduced (S3). The deceleration speed in this case corresponds to a speed at which the next sheet is received by the tray 21 after the trailing end of the sheet bundle is completely discharged from the staple tray 21 as shown in FIG. As the conveyance speed, when the normal conveyance speed is 500 mm / s, the discharge speed from the image forming apparatus 200 is 300 mm / s, which is slower than the normal conveyance speed.

  In step S2, if the discharge operation is not being performed, that is, if the trailing edge of the sheet bundle is not detected by the discharge sensor 28, the next sheet is normally conveyed at the normal conveyance speed. It is received by the staple tray 21 (S4).

By the above processing, when the sheet bundle remains on the staple tray 21, the next sheet is conveyed so as not to collide with the sheet bundle.
It should be noted that after the sheet bundle is completely discharged from the staple tray 21, the speed relationship is not limited to the leading edge of the next sheet being received by the staple tray 21. That is, it is also possible to set the conveyance state in which a slight gap is placed between the trailing edge of the sheet bundle and the leading edge of the next sheet due to the speed difference described above.

On the other hand, FIG. 7 shows another process in the control unit 1000. The process in this case is not the collision between the sheet bundle and the next sheet, but the discharge claw 29 (used for discharging the sheet bundle). 1), the leading edge of the next sheet is prevented from colliding.
In FIG. 7, for example, a result of determining whether or not the discharge claw 29 is present at this position (hereinafter referred to as the discharge position 1 for the sake of convenience) with reference to a position when 200 ms has passed after the discharge claw 9 has started to discharge. The conveyance speed is set to a plurality of stages according to the above.
In FIG. 7, when the conveyance of the next sheet is started, the sheet is accepted toward the staple tray 21. However, when the conveyance of the next sheet is started before the discharging operation, the next sheet is fed at a normal conveyance speed. It is conveyed (S1, S2, S4).
It is determined whether or not the discharge claw 29 has passed the discharge position 1 described above (S5). If the discharge claw 29 has not passed, the next sheet is decelerated to a conveyance speed 1 slower than the normal conveyance speed (S6). In this case, the transport speed 1 is 200 mm / s, which is slower than the next paper discharge speed of 500 mm / s.

If it is determined that the discharge position 1 has been passed, 300 mm / s, which is higher than the transport speed 1 and slower than the normal transport speed, is set as the transport speed of the next sheet (S7).
By this processing, the next paper transport speed can be selected according to the result of detecting the position of the discharge claw 29, so that the next paper can be prevented from colliding with the discharge claw 29, and the transport speed 2 can be increased. By setting the speed higher than the conveyance speed 1, it is possible to prevent work delay due to rapid acceptance.

14 Paper leading edge detection sensor 21 Staple tray 28 Ejection sensor 100 Image forming system 200 Image forming apparatus 300 Paper post-processing apparatus 1000 Control unit 1001 Operation panel

JP 2013-50708 A JP 2006-137538 A

Claims (4)

A paper post-processing apparatus having a stack unit for transporting a plurality of sheets in the middle of a paper transport path, and the stack unit partially sharing a configuration with a staple tray for performing stapling processing;
An operation panel having a sheet leading edge detection sensor for detecting a receiving state of the sheet toward the staple tray, a discharge sensor capable of detecting a sheet bundle discharged from the staple tray, and an input unit for the number of sheets constituting the sheet bundle. Connected to the input side, the output side is equipped with a control unit to which the drive unit of the member used for the staple processing unit and the transport unit is connected,
When the control unit accepts the next sheet while discharging the sheet bundle from the staple tray and stacks it on the stack unit, when starting the discharge operation of the sheet bundle subjected to the stapling process, A paper post-processing apparatus, characterized in that a transport speed of a next paper is decelerated from a normal transport speed.   2. The control unit according to claim 1, wherein after the discharge of the sheet bundle from the staple tray is completed, the control unit decelerates to a speed at which a timing at which the leading edge of the next sheet is received by the staple tray is obtained. Paper post-processing device.   The control unit detects the discharge position of the sheet bundle by the discharge sensor, and changes the conveyance speed of the next sheet to a plurality of stages according to the discharge position of the sheet bundle when starting the reception of the next sheet. The sheet post-processing apparatus according to claim 1, wherein the sheet post-processing apparatus is provided.   An image forming system using the sheet post-processing apparatus according to claim 1.

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