JP2013100169A - Sheet ejection device and image formation system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve alignment performance at sheet ends even if a sheet is thin.SOLUTION: A sheet ejection device includes: an ejection roller 80a for ejecting the sheet; a liftable sheet ejection tray 80b which stacks the sheet ejected from the ejection roller; a sheet holding member 90 which is located above the liftable sheet ejection tray, repeats a series of movement for moving from a standby position to a sheet holding position, holding the rear end of the sheet ejected in a sheet ejection direction, and after moving to a sheet stacking position and releasing the hold of the sheet, returning to the standby position; and a control part which controls the movement of the sheet holding member so that the movement is stopped or moving speed is reduced before the sheet holding member releases the hold of the sheet in the sheet stacking position.

Description

  The present invention relates to a paper discharge device and an image forming system.

In general, an image forming apparatus such as a copying machine is provided with a paper mounting table such as a paper discharge tray for stacking paper discharged outside the apparatus.
Conventionally, when paper is discharged to the paper mounting table, the stacking position is shifted between the paper transporting roller immediately before the paper mounting table and dropping and stacking on the paper mounting table by its own weight. There was a problem that the sheets were not stacked with the edges of the sheets aligned on top.
This problem occurs regardless of whether the mounting surface of the paper mounting table is horizontal or inclined, especially when the paper transport speed is high or when the environmental conditions are severe, such as high temperature and high humidity or low temperature and low humidity. This is likely to occur.

In order to ensure the uniformity of the end portions of the sheets stacked on the sheet placing table, it is preferable to drop the sheets so as to align with the base end portion of the sheet placing table.
For this reason, when a sheet is discharged, a mechanism called a gripper is known which grips the rear end portion of the discharged sheet and pulls it to the base end portion of the sheet placing table (see, for example, Patent Document 1).

The gripper moves from the standby position to the paper gripping position to grip the paper, and in that state, moves the paper gripping position to the paper stacking position to pull the paper to the base end of the paper mounting base. A series of operations of releasing the grip and moving to the initial standby position is performed for each discharged sheet.
Here, FIG. 13 shows a time-series change in the height of the gripper when the above operation is performed. In FIG. 13, the horizontal axis represents time, and the vertical axis represents the height of the gripper.
As shown in FIG. 13, the gripper in the standby position starts to descend at a predetermined descent start timing (t1), and grips the trailing edge of the sheet when it reaches the sheet gripping position (t2). Then, the gripper moves toward the paper stacking position while holding the paper, releases the grip of the paper at the time when the paper stacking position is reached (t3), and then returns to the standby position (t4) for the next lowering. It stops at the standby position until the start timing (t1). The gripper is moved at a constant speed.

JP 2011-105440 A

  However, in the gripper mechanism that performs the above-described operation, for example, when the paper is light paper such as thin paper, the leading edge is lifted even if the trailing edge of the paper is grounded on the paper mounting table. There is a problem that the desired uniformity may not be realized in some cases.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a paper discharge device and an image forming system that can improve the alignment of the paper edge even when the paper is thin.

To solve the above problem,
The invention according to claim 1 is a paper discharge device,
A discharge means for discharging the paper;
A paper stacking unit for stacking the paper discharged by the discharging means;
Moves from the standby position to the paper gripping position above the paper stacking unit, grips the trailing edge of the paper ejected by the ejecting means, moves to the paper stacking position, and releases the gripping of the paper And a sheet gripping member that repeats a series of movement operations to return to the standby position,
A control unit that controls to stop the movement of the paper gripping member or reduce the moving speed of the paper gripping member before the paper gripping member releases the paper gripping at the paper stacking position;
It is characterized by providing.

According to a second aspect of the present invention, in the paper discharge device according to the first aspect,
The control unit increases the moving speed of the paper gripping member after the paper gripping member releases the paper gripping at the paper stacking position.

According to a third aspect of the present invention, in the paper discharge apparatus according to the first or second aspect,
The control unit increases the moving speed of the paper gripping member after the paper gripping member grips the paper at the paper gripping position, and before the paper gripping member releases the paper gripping at the paper stacking position, The movement of the paper gripping member is stopped or the moving speed of the paper gripping member is reduced.

Further, the invention according to claim 4 is the paper discharge device according to any one of claims 1 to 3,
The control unit sets a movement operation pattern of the paper gripping member according to a paper type or a paper conveyance speed.

According to a fifth aspect of the present invention, in the image forming system,
An image forming apparatus for forming an image on paper;
The paper discharge device according to any one of claims 1 to 4, wherein the paper on which the image is formed by the image forming device is discharged.
It is characterized by providing.

According to the present invention, the rear end portion of the discharged paper moved from the standby position to the paper gripping position, moved to the paper stacking position, released from the gripping of the paper, and then returned to the standby position. The movement of the paper gripping member that repeats the above movement operation is stopped or the movement speed thereof is lowered before releasing the gripping of the paper at the paper stacking position.
For this reason, it is possible to reduce the lifting of the leading edge of the paper that is gripped by the paper gripping member and stacked on the paper stacking portion, and even when the paper is thin, the alignment of the paper edge is improved. Can be improved.

1 is an overall configuration diagram of an image forming system in the present embodiment. FIG. 2 is a block diagram illustrating a control configuration of the image forming system in FIG. 1. It is a perspective view which shows a paper discharge mechanism part. FIG. 4 is a cross-sectional view taken along line AA in FIG. 3, schematically showing a state where a sheet gripping member is in a standby position. FIG. 4 is a cross-sectional view taken along line AA in FIG. 3, schematically showing a state where a paper gripping member is in a paper gripping position. FIG. 4 is a cross-sectional view taken along line AA in FIG. 3, schematically showing a state where a paper gripping member is in a paper stacking position. 6 is a flowchart for explaining a pattern 1 of a movement operation of a paper gripping member. It is a figure which shows the change of the height with respect to time of the paper holding member at the time of performing the movement operation | movement of FIG. 10 is a flowchart for explaining a pattern 2 of the movement operation of the paper gripping member. It is a figure which shows the change of the height with respect to time of the paper holding member at the time of performing the movement operation | movement of FIG. 10 is a flowchart for explaining a pattern 3 of the movement operation of the paper gripping member. It is a figure which shows the change of the height with respect to time of the paper holding member at the time of performing the movement operation | movement of FIG. It is a figure for demonstrating operation | movement of the conventional gripper.

  Embodiments of the present invention will be described below with reference to the drawings. However, the scope of the invention is not limited to the illustrated examples.

<Image forming system>
As shown in FIGS. 1 and 2, an image forming system 1000 according to an embodiment of the present invention includes an image forming apparatus A and a post-processing apparatus (paper folding apparatus) FS.

<Image forming apparatus>
The image forming apparatus A includes an image reading unit 1, an image processing unit 2, an image writing unit 3, an image forming unit 4, a paper feeding cassette 5, a paper feeding unit 6, a fixing unit 7, a paper discharging unit 8, an automatic duplex copy feeding. A paper unit (ADU) 9, an operation display unit 10, a communication unit 11, an external IF (InterFace) unit 12, a control unit 13, and the like are provided.

  An automatic document feeder DF is mounted on the upper part of the image forming apparatus A. A post-processing device FS is connected to the left side of the image forming apparatus A in FIG.

  The image reading unit 1 reads a single-side or double-side image of a document placed on the document table of the automatic document feeder DF using a predetermined optical system as an optical image, and the read optical image is a CCD image sensor 1A. To perform photoelectric conversion.

  The image processing unit 2 performs analog processing, A / D conversion, shading correction, image compression processing, and the like on the analog signal photoelectrically converted by the CCD image sensor 1A, and then sends the image signal to the image writing unit 3. .

  Based on the acquired image signal, the image writing unit 3 irradiates the photosensitive drum 4A of the image forming unit 4 with output light using a semiconductor laser, and forms an electrostatic latent image on the surface of the photosensitive drum 4A.

  The image forming unit 4 performs development processing on the latent image formed on the photoconductive drum 4A to form a toner image. The image forming unit 4 presses the recording sheet S1 fed from the sheet feeding cassette 5 by the sheet feeding unit 6 to the photosensitive drum 4A by the transfer unit 4B, and transfers the toner image onto the recording sheet S1. The recording sheet S1 onto which the toner image has been transferred is conveyed to the fixing unit 7.

  The fixing unit 7 applies heat and pressure to the recording paper S1 onto which the toner image has been transferred by the image forming unit 4 to perform a fixing process, thereby forming an image on the recording paper S1. The recording sheet S1 on which the image has been formed is conveyed from the paper discharge unit 8 to the post-processing device FS.

  When performing duplex copying on the recording sheet S1, the recording sheet S1 having an image formed on one side through the fixing unit 7 is conveyed to the automatic duplex copying sheet feeding unit 9 by the conveyance path switching plate 8A. After the front and back sides of the recording paper S1 are reversed, an image is formed again on the other surface of the recording paper S1 by the image forming unit 4 and the fixing unit 7. The recording sheet S1 on which images are formed on both sides is conveyed from the paper discharge unit 8 to the post-processing device FS.

The operation display unit 10 includes a touch panel display having an LCD (Liquid Crystal Display), and displays various setting screens, device status displays, operation states of functions, and the like on the display screen according to instructions of display signals input from the control unit 13. Is displayed.
The touch panel display is configured by covering the LCD display screen with a pressure-sensitive (resistive film pressure) touch panel configured by arranging transparent electrodes in a grid pattern, and is pressed with a finger or a touch pen. The position coordinate is detected by the voltage value.
The operation display unit 10 outputs the detected position signal to the control unit 13 as an operation signal.

  The communication unit 11 transmits and receives data to and from the post-processing device FS.

  The external IF unit 12 is an interface for connecting to a communication network such as a LAN (Local Area Network) and performing data communication with an external device such as a PC (Personal Computer).

  The control unit 13 comprehensively controls each unit of the image forming apparatus A in response to an instruction input from the operation display unit 10 or the external IF unit 12. The control unit 13 includes a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory) (none of which is shown), and the CPU reads a program stored in the ROM. The data is expanded in a work area in the RAM, and various processes are executed in cooperation with a program.

<Post-processing device>
The post-processing device FS includes a paper carry-in unit 20, insertion paper feeding units 30a and 30b, a punching processing unit 40, a folding processing unit 50, an overlay processing unit 60, a binding processing unit 70, a paper discharge mechanism unit 80, and a communication unit 100. The control unit 110 and the like are provided.

  The paper carry-in unit 20 is provided on a side surface of the post-processing apparatus FS that faces the image forming apparatus A, and is connected to the image forming apparatus A. The recording paper S1 on which an image is formed in the image forming apparatus A is carried into the paper carry-in unit 20 via the paper discharge unit 8.

The insertion sheet feeding units 30a and 30b are provided on the upper portion of the post-processing device FS. The insertion sheet feeding unit 30a is loaded with the insertion sheet S2, and the insertion sheet feeding unit 30b is loaded with another insertion sheet S3. Is done. The insertion sheets S2 and S3 are insertion sheets such as a cover sheet and an insert sheet inserted between the plurality of recording sheets S1 discharged from the image forming apparatus A. As with the recording sheet S1, punching processing and folding are performed. Processing can be performed. The insertion sheets S2 and S3 sent out from the insertion sheet feeding sections 30a and 30b are conveyed to the sheet carry-in section 20 through a downward conveying path.
In the following description, the recording sheet S1 and the insertion sheets S2 and S3 are collectively referred to as a sheet S.

  The punching processing unit 40 is disposed downstream of the paper carry-in unit 20 in the paper transport direction. In the punching processing unit 40, the punch is moved up and down by a predetermined drive mechanism, and a punch hole is punched at a predetermined position of the paper S. A transport roller 21 is disposed on the downstream side of the punching processing unit 40.

  The folding processing unit 50 is disposed on the downstream side in the sheet conveyance direction of the conveyance path H1 branched downward from the conveyance roller 21.

The superposition processing unit 60 is disposed on the downstream side of the transport path H2 branched upward from the transport roller 21, and includes transport paths H3, H4, and H5. Here, a transport roller 22 is disposed in the transport path H2, and branches from the transport roller 22 into a transport path H3 and a transport path H4. Further, a transport roller 23 is disposed in the transport path H3, and the transport roller. 23 branches to a transport path H5 and a transport path H6.
The superposition processing unit 60 waits for the subsequent paper S in the transport path H3 and the transport paths H4 and H5 in order to secure time for binding processing to the preceding paper S in the binding processing unit 70 located below. It is a mechanism for making it.

Specifically, the transport path H4 is connected to the temporary stop roller 24, and the first sheet S of sheets S to be bound is put on standby in a state where the front end of the paper is in contact with the temporary stop roller 24 whose rotation has stopped.
The conveyance path H5 is connected to the temporary stop roller 24, and the conveyance path H6 is directed to the fixed sheet discharge tray 81. While the first sheet S of sheets S to be bound is waiting on the inner conveyance path H4, the binding processing unit 70 performs the binding process of the preceding sheet S and the second sheet S is placed on the outer side. It is conveyed to the conveyance paths H3 and H5. Thereafter, the first sheet S and the second sheet S are conveyed to the binding processing unit 70 in an overlapped state.

  The fixed paper discharge tray 81 is disposed at a position that protrudes outside the post-processing device FS on the downstream side of the transport path H6. The fixed paper discharge tray 81 is for discharging the paper S that is not subjected to post-processing.

  The binding processing unit 70 is disposed below the temporary stop roller 24 and performs a binding process on the paper S conveyed from the temporary stop roller 24. The sheet S for which the binding process has been completed is conveyed to a paper discharge mechanism 80 disposed at a position protruding from the post-processing device FS on the downstream side of the binding processing unit 70.

  The paper discharge mechanism 80 includes a paper discharge roller (discharge means) 80a, a liftable paper discharge tray (paper stacking portion) 80b, an abutment portion 80c that abuts the rear end of the paper, a paper gripping member 90, and a pair of Alignment members 97 and 98 are provided.

  The paper discharge roller 80a includes a pair of rollers, is driven by a paper discharge drive motor M1 (see FIG. 4), and discharges the paper S discharged from the post-processing device FS toward the liftable paper discharge tray 80b.

The elevating sheet discharge tray 80b is a large-capacity tray that protrudes outside the post-processing apparatus FS and has a stacking capacity of about 3000 sheets, for example.
The elevating paper discharge tray 80b is movable in the vertical direction so that the uppermost surface of the discharged paper S is always at a constant height. For example, the elevating sheet discharge tray 80b can move in the direction of arrow a in FIG. 1 and can move to a position indicated by a two-dot chain line in FIG.

As shown in FIG. 3, the abutting portion 80 c includes two plate-like members arranged with a predetermined gap on the upstream side in the paper discharge direction of the paper S discharged to the liftable paper discharge tray 80 b. It is.
The abutting portion 80c serves as a reference for aligning the rear ends of the sheets S when the sheets S are stacked on the elevating type discharge tray 80b.

The paper gripping member 90 includes a pressing member 91 and a support member 93, and is used for aligning and stacking the end of the paper S discharged by the paper discharge roller 80a on the liftable paper discharge tray 80b. It is.
In the present embodiment, as shown in FIG. 3, two sets of sheet gripping members 90 (pressing member 91 and supporting member 93) are provided between the two abutting portions 80c. .

As shown in FIG. 4 and the like, the pressing member 91 is swingably held around a rotation shaft 91a parallel to the width direction of the paper S on the upper side of the paper S discharged by the paper discharge roller 80a.
The pressing member 91 is formed in an arm shape, a rotating shaft 91a that holds the pressing member 91 swingably is fixed to one end thereof, and a pressing portion 91b that presses the support member 93 via the paper S to the other end. Further, the pressing member 91 is engaged with a spring member SP that applies a pressing force for pressing the support member 93 to the pressing portion 91b. The spring member SP rotates the pressing member 91 counterclockwise. It is energized in the direction to move.
The pressing member 91 is separated from the support member 93 from the standby position to the paper gripping position.

In addition, a pressure regulating member 92 that regulates the position of the pressing member 91 is provided at a position adjacent to the pressing member 91, and the pressure regulating member 92 has a forward / reverse rotatable press that drives the pressing regulating member 92. A regulating member drive motor M2 is connected.
The pressing restricting member 92 includes a shaft portion 92a that is connected to the pressing restricting member driving motor M2 and holds the pressing restricting member 92 so as to be rotatable in both forward and reverse directions, and an engaging portion 92b that engages with the pressing member 91. The pressing member 91 swings while being engaged with the engaging portion 92b of the pressing restricting member 92 that rotates in both forward and reverse directions.
Specifically, the pressing member 91 is restricted from rotating counterclockwise by the engagement of an engaging portion 92b attached to one end of a rotating pressing restricting member 92.
Then, when the pressing restricting member drive motor M2 rotates the pressing restricting member 92 counterclockwise according to the control of the control unit 110, the restriction on the counterclockwise rotation of the pressing member 91 is released.
Further, when the pressing restriction member driving motor M2 rotates the pressing restriction member 92 clockwise according to the control of the control unit 110, the counterclockwise rotation of the pressing member 91 is restricted.
Note that the control unit 110 operates the pressing restriction member driving motor M2 in accordance with the conveyance timing of the paper S detected by a paper position detection sensor (not shown).
Specifically, when the paper S is conveyed by the paper discharge roller 80a and reaches the paper gripping position, the pressure regulating member 92 rotates counterclockwise according to the detection by the paper position detection sensor, and the pressure member 91 is regulated. Canceled.
Further, the pressing restricting member drive motor M <b> 2 can control the rotation speed of the pressing restricting member 92 according to the control of the control unit 110. For example, the swing speed of the pressing member 91 can be increased by increasing the rotation speed of the pressing restricting member 92.

  In the present embodiment, the pressing member 91 is configured to swing while being engaged with the engaging portion 92b of the pressing restricting member 92 that rotates in both forward and reverse directions, but the pressing member 91 has a predetermined timing and a predetermined speed. As long as it can rotate in both the forward and reverse directions, a configuration other than the pressing restricting member 92 may be used.

  On the other hand, the support member 93 is held on the lower side of the paper S discharged by the paper discharge roller 80a so as to be rotatable around a rotation shaft 94a parallel to the width direction of the paper S.

Specifically, the support member 93 is fixed to one end of a pair of rotating plates 94 having the same size and shape through a pair of shafts 94b.
A pair of rotating shafts 94 a are fixed to the other end of the pair of rotating plates 94, and the pair of rotating shafts 94 a are rotatably held by a holding plate 95.
In addition, a support member drive motor M3 that rotates each of the pair of rotation shafts 94a counterclockwise is coupled, and the support member drive motor M3 rotates the pair of rotation shafts 94a under the control of the control unit 110. The operation is configured to be performed simultaneously in the same direction.
The pair of rotating plates 94 are respectively installed on the inside and outside of the side surface of the support member 93, and the positions in the rotation axis direction are shifted so that they do not interfere with each other during rotation.

The support member 93 is rotatable by such a pair of rotating plates 94, a pair of rotating shafts 94a, a holding plate 95, a supporting member drive motor M3, and the like. That is, the pair of rotating plates 94 rotate simultaneously in the same direction to rotate the support member 93.
Under the control of the control unit 110, the support member drive motor M3 rotates the pair of rotating plates 94 once for each holding operation of the pressing member 91 and the support member 93 on the paper S.
At this time, the support member drive motor M3 can control the rotational speed of the pair of rotating plates 94 and thus the support member 93. For example, the rotational speed of the support member 93 can be increased by increasing the rotational speed of the pair of rotating plates 94.
Further, a sheet gripping surface 93a (described later) of the support member 93 is configured to be always a horizontal surface regardless of the rotation angle of the pair of rotating plates 94, or to be a surface that maintains a constant angle with respect to the horizontal. Is preferred.
In this way, by making the paper gripping surface 93a always a horizontal plane or a surface that maintains a certain angle with respect to the horizontal, the gripping operation of the paper S by the pressing member 91 and the support member 93 is performed in a stable and smooth state. .

  In the present embodiment, the support member 93 is configured to rotate via a pair of rotation plates 94 that rotate counterclockwise. However, the support member 93 is rotated counterclockwise at a predetermined timing and at a predetermined speed. Any structure other than the pair of rotating plates 94 may be used as long as it can rotate.

In addition, the support member 93 is formed with a paper gripping surface 93 a with which the pressing portion 91 b of the pressing member 91 contacts via the paper S.
The paper gripping surface 93a is subjected to a roughing process that increases the friction coefficient. The configuration for increasing the friction coefficient is not limited to the roughing process, and the support member 93 may be formed of a resin molded part, and a large number of minute protrusions may be formed on the paper gripping surface 93a. Alternatively, another member made of foamed soft resin or the like may be attached.

A friction member 96 is provided on the lower surface of the support member 93 (the surface opposite to the paper gripping surface 93a) via a spring member 96a.
The friction member 96 is a friction plate formed of a material made of rubber or foamed resin. The friction coefficient at the sheet contact surface (lower surface) of the friction member 96 is set to a value larger than the friction coefficient between the sheets of the plurality of sheets S stacked on the elevating sheet discharge tray 80b.
The paper contact surface of the friction member 96 can be displaced by a spring member 96a. Since the contact surface of the friction member 96 with the sheet S is displaceable, the frictional resistance to the sheet S can be kept substantially constant even when the thickness of the sheet bundle loaded on the elevating type discharge tray 80b changes. it can.

  With the configuration described above, the paper gripping member 90 grips the rear end portion of the paper S by the pressing member 91 and the support member 93 each time the paper S is discharged from the paper discharge roller 80a. The rear end in the discharging direction is pulled to the vicinity of the abutting portion 80c.

Specifically, the sheet gripping member 90 repeats the following series of movement operations.
That is, the paper gripping member 90 moves from the standby position shown in FIG. 4 to the paper gripping position shown in FIG. 5 and grips the rear end portion of the paper S discharged in the paper discharge direction by the paper discharge roller 80a. Then, by moving the paper S to the paper stacking position shown in FIG. 6 while gripping the paper S, the rear end of the paper S in the paper discharge direction is pulled to the vicinity of the abutting portion 80c and the gripping of the paper S is released. Return to the original standby position shown in FIG.
Here, the sheet gripping member 90 is moved at a first speed set in advance, but the movement is stopped by the control of the control unit 110 in a series of moving operations. "Control" and "first high speed control", "second high speed control" and "low speed control" for switching the moving speed are selectively executed.
The details of “temporary stop control”, “first high speed control”, “second high speed control”, and “low speed control” will be described later.

The pair of alignment members 97 and 98 are for aligning the end position of the paper S in a direction perpendicular to the paper discharge direction of the paper S discharged to the elevating type discharge tray 80b.
As shown in FIG. 3, the pair of alignment members 97 and 98 are disposed on the downstream side in the sheet discharge direction and above the elevating sheet discharge tray 80b.
The pair of alignment members 97 and 98 are installed so as to face each other with a predetermined gap in the paper width direction, and can be rotated in a direction in which they are in contact with and away from the elevating type discharge tray 80b around the rotation axis AX. It has become.

  The communication unit 100 transmits and receives data to and from the image forming apparatus A.

  The control unit 110 comprehensively controls each unit of the post-processing device FS. The control unit 110 includes a CPU, a ROM, a RAM (not shown), and the like. The CPU reads a program stored in the ROM, develops it in a work area in the RAM, and cooperates with the program. Perform various processes.

  Specifically, when the control unit 110 moves the paper gripping member 90, the control unit 110 controls the paper gripping member 90 to be “pause control”, “first high speed control”, “second high speed control”, “low speed control”. Is executed selectively.

Here, the “pause control” is control for temporarily stopping the movement of the paper gripping member 90 before the paper gripping member 90 releases the gripping of the paper S at the paper stacking position.
The “first high speed control” is a control for increasing the moving speed of the paper gripping member 90 after the paper gripping member 90 releases the gripping of the paper S at the paper stacking position. Specifically, the moving speed of the paper gripping member 90 after releasing the gripping of the paper S at the paper stacking position is set to a second speed higher than the first speed.
The “second high speed control” is control for increasing the moving speed of the paper gripping member 90 after the paper gripping member 90 grips the paper S at the paper gripping position. Specifically, the moving speed of the paper gripping member 90 after gripping the paper S at the paper gripping position is set to a second speed higher than the first speed.
The “low speed control” is control for lowering the moving speed of the paper gripping member 90 before the paper gripping member 90 releases the gripping of the paper S at the paper stacking position. Specifically, the moving speed of the paper gripping member 90 is set to a third speed lower than the first speed at a predetermined timing before the paper S is released from the paper stacking position.

  In other words, the sheet gripping member 90 is basically controlled to move at the first speed set in advance, but when the “pause control” is executed, the moving operation is paused at a predetermined timing. When “first high speed control”, “second high speed control”, and “low speed control” are executed, control is performed so that the moving speed is switched from the first speed to the second speed or the third speed at a predetermined timing. Is done.

The “temporary stop control” is for securing a time for the leading edge of the paper S to contact the liftable paper discharge tray 80b after the trailing edge of the paper S is pulled to the vicinity of the abutting portion 80c. Therefore, by executing the “temporary stop control”, the gripping of the sheet S is released after the leading end of the sheet S is grounded to the liftable sheet discharge tray 80b.
Further, in order to secure a temporary stop time when the “temporary stop control” is performed, “first high speed control” and “second high speed control” are appropriately executed in accordance with the sheet conveyance speed. That is, “first high speed control” and / or “second high speed control” can be executed in combination with “temporary stop control”.

Further, “low speed control” can be executed instead of “temporary stop control”. By executing the “low speed control”, the movement time from the paper gripping position to the paper stacking position can be lengthened, and the time for the leading edge of the paper S to contact the liftable paper discharge tray 80b can be secured.
Further, in order to secure a moving time when performing the “low speed control”, the “first high speed control” is appropriately executed according to the sheet conveyance speed. That is, the “first high speed control” can be executed in combination with the “low speed control”.
It is also possible to execute “second high speed control” in combination.

The movement operation pattern of the sheet gripping member 90 as described above (that is, a combination of “temporary stop control”, “first high speed control”, “second high speed control”, and “low speed control”) is the type of the paper S or the transport speed of the paper S. Is set by the control unit 110 according to the above.
For example, when the sheet S is a thin sheet of 50 g / mm or less and the sheet conveyance speed is set to a normal level, the control unit 110 executes only “pause control”.
For example, when the paper S is a thin paper of 50 g / mm or less and the paper conveyance speed is set slightly faster than normal, the control unit 110 performs “pause control”, “first high speed control”, and “first speed control”. “2 High-speed control” is executed.
For example, when the paper S is a thin paper of 50 g / mm or less and the paper conveyance speed is set to be much faster than usual, the control unit 110 executes “low speed control” and “first high speed control”. .

  In the present embodiment, the paper discharge mechanism 80 and the control unit 110 constitute a paper discharge device.

Next, the movement operation of the paper gripping member 90 will be specifically described with reference to FIGS.
As described above, the movement operation pattern of the paper gripping member 90 is set according to the type of the paper S and the conveyance speed of the paper S, but typical movement operation patterns 1 to 3 are exemplified.

<Movement operation pattern 1: When the paper gripping member 90 performs “pause control”>
FIG. 7 is a flowchart showing the operation of the paper gripping member 90 in the movement operation pattern 1, and FIG. 8 is a diagram showing time-series changes in the height of the paper gripping member 90 when the operation of the movement operation pattern 1 is performed. It is. In FIG. 8, the horizontal axis represents time, and the vertical axis represents the height of the paper gripping member 90.

  First, when the paper S transported in the post-processing device FS reaches the paper discharge roller 80a, the control unit 110 starts transporting the paper S by the paper discharge roller 80a (step S11) and is in the standby position. The paper gripping member 90 starts moving at the first speed (t11) (step S12).

  Next, the control unit 110 drives the paper discharge roller 80a to discharge the paper S (step S13), and the paper gripping member 90 causes the paper to be gripped by the paper gripping member 90 at the timing when the rear end of the paper S to be discharged reaches the paper gripping position. The rear end of S is gripped (t12) (step S14).

  Next, the control unit 110 moves the paper gripping member 90 in the state of gripping the paper S to the paper stacking position (step S15), and stops the movement of the paper gripping member 90 in the state of gripping the paper S at the paper stacking position. (T13) (Step S16).

  Next, when a predetermined time elapses after the movement of the paper gripping member 90 is stopped, the control unit 110 releases the gripping of the paper S by the paper gripping member 90 (t14) (step S17), and the paper gripping member 90 is moved to the first state. The speed is moved to the standby position (t15) (step S18), and the process for one sheet S is completed.

  According to the operation of the movement operation pattern 1, the movement of the paper gripping member 90 stops before the paper gripping member 90 releases the gripping of the paper S at the paper stacking position. For this reason, it is possible to secure time for the leading edge of the paper S to fall. That is, the sheet S can be released after the leading edge of the sheet S is grounded.

<Movement Operation Pattern 2: When the Paper Gripping Member 90 Performs “Pause Control”, “First High Speed Control”, and “Second High Speed Control”>
FIG. 9 is a flowchart showing the operation of the paper gripping member 90 in the movement operation pattern 2, and FIG. 10 is a diagram showing time-series changes in the height of the paper gripping member 90 when the movement operation pattern 2 is performed. It is. In FIG. 10, the horizontal axis is time, and the vertical axis is the height of the paper gripping member 90.

  The movement operation pattern 2 is set when, for example, in the operation of the movement operation pattern 1, the temporary stop time cannot be secured due to the conveyance speed of the paper S and the control may be broken.

  First, when the paper S transported in the post-processing device FS reaches the paper discharge roller 80a, the control unit 110 starts transporting the paper S by the paper discharge roller 80a (step S31) and is in the standby position. The paper gripping member 90 starts moving at the first speed (t21) (step S32).

  Next, the control unit 110 drives the paper discharge roller 80a to discharge the paper S (step S33), and the paper gripping member 90 causes the paper to be gripped by the paper gripping member 90 at the timing when the rear end of the paper S to be discharged reaches the paper gripping position. The rear end of S is gripped (t22) (step S34).

  Next, the control unit 110 sets the moving speed of the paper gripping member 90 to the second speed (step S35), moves the paper gripping member 90 in the state of gripping the paper S to the paper stacking position (step S36), and sets the paper stacking position. The movement of the paper gripping member 90 in the state of gripping the paper S is stopped (t23) (step S37).

  Next, when a predetermined time elapses after the movement of the paper gripping member 90 is stopped, the control unit 110 releases the gripping of the paper S by the paper gripping member 90 (t24) (step S38), and the moving speed of the paper gripping member 90 is reached. Is set to the second speed (step S39), the sheet gripping member 90 is moved to the standby position (t25) (step S40), and the process for one sheet S is completed.

  According to the operation of the movement operation pattern 2, after the paper gripping member 90 grips the paper S at the paper gripping position, the moving speed of the paper gripping member 90 is increased from the first speed, and the paper gripping member 90 is further moved to the paper stacking position. Then, after the gripping of the paper S is released, the moving speed of the paper gripping member 90 is increased from the first speed. For this reason, it is possible to secure a pause time without causing a control failure in performing the pause control.

<Pattern 3: When the paper gripping member 90 performs “low speed control” and “first high speed control”>
FIG. 11 is a flowchart showing the operation of the paper gripping member 90 in the movement operation pattern 3, and FIG. 12 is a diagram showing time-series changes in the height of the paper gripping member 90 when the movement operation pattern 3 is operated. It is. In FIG. 12, the horizontal axis represents time, and the vertical axis represents the height of the paper gripping member 90.

  First, when the paper S transported in the post-processing device FS reaches the paper discharge roller 80a, the control unit 110 starts transporting the paper S by the paper discharge roller 80a (step S51) and is in a standby position. The paper gripping member 90 starts moving at the first speed (t31) (step S52).

  Next, the control unit 110 drives the paper discharge roller 80a to discharge the paper S (step S53), and the paper gripping member 90 causes the paper to be gripped by the paper gripping member 90 at the timing when the rear end of the paper S to be discharged reaches the paper gripping position. The rear end of S is gripped (t32) (step S54).

  Next, the control unit 110 sets the moving speed of the paper gripping member 90 in the state of gripping the paper S as the third speed (step S55), moves the paper gripping member 90 to the paper stacking position (step S56), and the paper gripping member. The gripping of the paper S by 90 is released (t33) (step S57).

  Next, the control unit 110 sets the moving speed of the paper gripping member 90 to the second speed (step S58), moves the paper gripping member 90 to the standby position (t34) (step S59), and ends the processing for one paper S. To do.

  According to the operation of the movement operation pattern 3, before the paper gripping member 90 releases the grip of the paper S at the paper stacking position, the moving speed of the paper gripping member 90 is lowered from the first speed, and the paper gripping member 90 After releasing the gripping of the paper S at the stacking position, the moving speed of the paper gripping member 90 is increased from the first speed. For this reason, it is possible to lengthen the movement time of the paper gripping member 90 to the paper stacking position, and therefore it is possible to secure the time for the leading edge of the paper S to fall.

As described above, according to the present embodiment, the paper discharge roller 80a that discharges the paper S, the liftable discharge tray 80b that stacks the paper S discharged by the discharge roller 80a, and the liftable discharge tray 80b. Is moved from the standby position to the paper gripping position, grips the rear end of the paper S discharged in the paper discharge direction by the paper discharge roller 80a, moves to the paper stacking position, and releases the grip of the paper S. Thereafter, the paper gripping member 90 that repeats a series of movement operations to return to the standby position, and before the paper gripping member 90 releases the gripping of the paper S at the paper stacking position, the movement of the paper gripping member 90 is stopped or the paper gripping is performed. And a control unit 110 that controls to lower the moving speed of the member 90.
For this reason, it is possible to reduce the lifting of the leading end of the paper S that is held by the paper holding member 90 and stacked on the elevating paper discharge tray 80b, and even if the paper S is thin, the paper The evenness of the end can be improved.

Further, according to the present embodiment, the control unit 110 increases the moving speed of the paper gripping member 90 after the paper gripping member 90 releases the gripping of the paper S at the paper stacking position.
For this reason, it is possible to easily ensure the stop time or the deceleration time of the paper gripping member 90 before releasing the gripping of the paper S.

Further, according to the present embodiment, the control unit 110 increases the moving speed of the paper gripping member 90 after the paper gripping member 90 grips the paper S at the paper gripping position, and the paper gripping member 90 moves to the paper stacking position at the paper stacking position. Before releasing the gripping of S, the movement of the paper gripping member 90 is stopped or the moving speed of the paper gripping member 90 is lowered.
For this reason, it is possible to easily ensure the stop time or the deceleration time of the paper gripping member 90 before releasing the gripping of the paper S.

Further, according to the present embodiment, the control unit 110 sets the movement operation pattern of the paper gripping member 90 according to the type of the paper S or the transport speed of the paper S.
For this reason, an appropriate movement pattern of the paper gripping member 90 is set according to the type of the paper S or the transport speed of the paper S, so that the paper S is in a state where the leading edge of the paper S is lifted. It is possible to prevent the gripping from being released as much as possible.

  In the above embodiment, the configuration in which the control unit 110 is provided in the post-processing apparatus FS has been described as an example. However, the overall operation of the image forming system 1000 is performed by the control unit 13 provided in the image forming apparatus A. It is good also as controlling overall.

In the above-described embodiment, the image forming system 1000 has been described with the configuration including the image forming apparatus A and the post-processing apparatus FS. However, the image forming system 1000 may not include the post-processing apparatus FS.
In this case, the image forming apparatus A can be configured to include the paper discharge mechanism 80.

1000 Image forming system A Image forming apparatus 1 Image reading unit 2 Image processing unit 3 Image writing unit 4 Image forming unit 5 Paper feed cassette 6 Paper feed unit 7 Fixing unit 8 Paper discharge mechanism unit 9 Automatic duplex copy paper feed unit 10 Operation Display unit 11 Communication unit 12 External IF unit 13 Control unit FS Post-processing device 20 Paper carry-in unit 30a, 30b Inserted paper feed unit 40 Hole punching unit 50 Folding processing unit 60 Overlay processing unit 70 Binding processing unit 80 Paper discharge mechanism unit (Paper discharge device)
80a Paper discharge roller (discharge means)
80b Elevating paper tray (paper stacking unit)
80c Abutting part 90 Paper gripping member 91 Pressing member 93 Support member 100 Communication part 110 Control part (paper discharge device)

Claims (5)

A discharge means for discharging the paper;
A paper stacking unit for stacking the paper discharged by the discharging means;
Moves from the standby position to the paper gripping position above the paper stacking unit, grips the trailing edge of the paper ejected by the ejecting means, moves to the paper stacking position, and releases the gripping of the paper And a sheet gripping member that repeats a series of movement operations to return to the standby position,
A control unit that controls to stop the movement of the paper gripping member or reduce the moving speed of the paper gripping member before the paper gripping member releases the paper gripping at the paper stacking position;
A paper discharge device comprising:   The paper discharge device according to claim 1, wherein the control unit increases the moving speed of the paper gripping member after the paper gripping member releases the paper gripping at the paper stacking position.   The control unit increases the moving speed of the paper gripping member after the paper gripping member grips the paper at the paper gripping position, and before the paper gripping member releases the paper gripping at the paper stacking position, The paper discharge device according to claim 1, wherein the movement of the paper gripping member is stopped or the moving speed of the paper gripping member is decreased.   The paper discharge device according to claim 1, wherein the control unit sets a movement operation pattern of the paper gripping member according to a paper type or a paper conveyance speed. An image forming apparatus for forming an image on paper;
The paper discharge device according to any one of claims 1 to 4, wherein the paper on which the image is formed by the image forming device is discharged.
An image forming system comprising:

Images