JP2004262594A - Sheet post processing device and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sheet post processing device excellent in stacking ability, and to provide an image forming apparatus with the same. <P>SOLUTION: The sheet post processing device 500 performing post processing to a sheet S has a stack tray 504 for stacking the processed sheets, a rear end adjusting wall 570 pushing out and adjusting the rear ends of sheets or sheet bundles conveyed on the tray 504, and a paddle 583 for pressing the rear ends. The adjusting operation by the adjusting wall 570 and the sheet pressing operation by the paddle 583 are cooperated. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a sheet post-processing apparatus for post-processing a sheet after image formation, and an image forming apparatus including the sheet post-processing apparatus.
[0002]
[Prior art]
A conventional sheet post-processing apparatus will be described with reference to FIGS. 14 is a cross-sectional view showing the overall configuration of an image forming apparatus having a conventional sheet post-processing apparatus, FIG. 15 is a top view schematically showing a sheet stacking and aligning apparatus, and FIG. 16 employs a box-shaped horizontal stack tray. FIG. 17 is a cross-sectional view schematically illustrating a sheet post-processing apparatus that employs a horizontal stack tray having a sheet return paddle mechanism.
[0003]
As shown in FIG. 14, in a conventional image forming apparatus such as a printing machine, a copying machine, a printer, etc., a sheet S on which an image is formed by the image forming apparatus main body 200 is temporarily stored in a processing tray 540 in a sheet post-processing apparatus 500. The sheets are stacked and subjected to sheet post-processing such as alignment and binding of the sheets S, the bundle of sheets is nipped by the bundle discharge means 580, and the bundle is discharged by rotating rollers.
[0004]
The discharged sheets are stacked on a stack tray 581 having an inclined stacking surface, and the discharged sheet S moves on the inclined stacking surface of the stack tray 581 by its own weight, and the rear end of the sheet is aligned on the rear end alignment wall. Is done. The number of stacked sheets depends on the vertical operation stroke of the stack tray 581.
[0005]
In the sheet post-processing apparatus shown in FIG. 16, the sheets S are conveyed and stacked on a box-shaped stack tray 581 having a horizontal stacking surface by the gripper 582 of the bundle discharging means.
[0006]
Further, as shown in FIG. 17, in a sheet processing apparatus in which the stack tray 581 has a horizontal stacking surface, the rear end of the sheet S is aligned and stacked by rotating the sheet return member 583.
[0007]
However, as shown in FIG. 14, when stacking sheets having a weak waist or a strong curl in a stack tray 581 having a conventional inclined stacking surface, buckling due to its own weight due to a steep inclination occurs. There is a problem that the consistency is deteriorated.
[0008]
As shown in FIG. 15, when the sheet bundle S subjected to the binding processing is stacked on the stack tray 581 having the conventional inclined stacking surface, the sheet bundle S discharged to the needle of the already stacked sheet bundle S is discharged. The end was caught, the rear end of the sheet bundle S did not slide down to the rear end alignment wall 570, and there was a shift in the transport direction, which caused a problem in the stackability.
[0009]
Further, in the sheet post-processing apparatus as shown in FIG. 16, the gripper 582 is indispensable as a bundle discharging means, and the combination with a stack tray 581 having a box-shaped horizontal stacking surface makes the entire apparatus larger, resulting in cost reduction. There was also a problem that it became expensive.
[0010]
Further, in a sheet processing apparatus in which the stack tray 581 has a horizontal stacking surface as shown in FIG. 17, since the alignment by the sheet return member 583 is effective only for the sheet S stacked on the uppermost position, the bundle discharge of the sheets S is performed. There was a problem that was impossible.
[0011]
Therefore, in order to solve these problems, the rear end of the sheet bundle is conveyed until it reaches the upper end of the rear end alignment wall, and the rear end of the sheet bundle is brought into contact with the upper end of the rear end alignment wall. By adopting a configuration in which the sheets are stacked on the stack tray while being aligned in the conveyance direction by pressing, deviation in the conveyance direction at the front end and the rear end of the sheet bundle can be prevented, and the stacking consistency of the sheet bundle on the stack tray can be prevented. Can be improved.
[0012]
The above-mentioned sheet return member 583 has a function of returning the sheet bundle stacked on the stack tray 581 and a function of pressing the sheet bundle from above to crush the air layer and load more sheets on the stack tray 581. When the sheet bundle is discharged to the stack tray 581, it is necessary to perform the operation of the sheet return member 583 and the rear end alignment by the rear end alignment wall 570 described above.
[0013]
[Problems to be solved by the invention]
However, when the above configuration is adopted, the sheet bundle is returned and pressed by the sheet return member 583 after the rear end of the sheet is aligned by the rear end alignment wall 570. Therefore, in the case of weak paper, for example, only the top sheet is the rear end. In some cases, the sheet was returned to the alignment wall 570 side too much, and the sheet was wrinkled or creased (see FIG. 18).
[0014]
Also, if the sheet rear end is aligned with the rear end alignment wall 570 after the sheet bundle has been pressed by the sheet return member 583, the wall hits from where the sheet is pressed in a state where the rear end is not aligned. In some cases, the rear end was bent (see FIG. 19).
[0015]
Further, in either case, the next operation is performed after one operation is completed, so that the processing time becomes longer.
[0016]
Further, when the rear end alignment wall 570 is aligned by pushing the rear end of the sheet S on the stack tray 581, if the horizontal speed of the rear end alignment wall 570 is high, the sheet S is pushed too vigorously and the sheet S is pressed. The rear end is separated from the rear end alignment wall 570, and the rear end cannot be aligned. If the horizontal speed of the rear end alignment wall 570 is reduced in order to prevent this, the processing time becomes longer.
[0017]
SUMMARY OF THE INVENTION The present invention has been made in consideration of the above-described problems of the related art, and has as its object to provide a sheet post-processing apparatus having good stacking properties and an image forming apparatus including the same.
[0018]
[Means for Solving the Problems]
In order to achieve the above object, in the present invention,
In a sheet post-processing apparatus that performs post-processing on a sheet,
Loading means for loading the post-processed sheet;
Sheet trailing end aligning means for extruding and aligning the trailing end of the sheet or sheet bundle conveyed on the stacking means,
Sheet holding means for holding a rear end of the sheet conveyed on the stacking means,
A sheet post-processing apparatus, wherein a sheet rear-end aligning operation by the sheet rear-end aligning means and a sheet pressing operation by the sheet pressing means are performed in cooperation with each other.
[0019]
According to the above configuration, the timing of aligning the trailing edge of the sheet on the stacking unit by the trailing edge aligning unit and the timing of pressing the sheet by the sheet pressing unit can be synchronized, and the two operations can be performed in parallel. Time can be reduced.
[0020]
It is preferable that the pressing force on the sheet by the sheet pressing means changes in accordance with a change in the speed of the sheet rear end aligning operation by the sheet rear end aligning means.
[0021]
According to the above configuration, when the horizontal speed component of the sheet trailing edge aligning operation of the sheet trailing edge aligning unit increases, the sheet pressing force of the sheet pressing unit also increases, so that the sheet trailing edge aligning unit holds the sheet. Even if the sheet is pushed too vigorously, the trailing edge of the sheet does not separate from the sheet trailing edge aligning means.
[0022]
The sheet pressing means preferably generates a pressing force for pressing the sheet toward the sheet rear end aligning means after the sheet rear end aligning means starts pushing the rear end of the sheet.
[0023]
According to the above configuration, since the sheet trailing edge aligning means does not hit the sheet bundle in which the trailing edges are not aligned, the sheet trailing edge does not bend.
[0024]
At a timing earlier than the end of the sheet rear end alignment operation by the sheet rear end alignment unit, a sheet pressing operation by the sheet pressing unit is started,
Further, it is preferable that the sheet pressing operation by the sheet pressing means is ended at the same time as or later than the end of the sheet rear-end aligning operation by the sheet rear-end aligning means.
[0025]
According to the above configuration, in the case of paper having a weak stiffness or the like, the uppermost sheet of the sheet bundle is not returned too much by the sheet pressing means from the state where the rear end of the sheet has been aligned by the sheet rear end aligning means. And folds can be prevented.
[0026]
It is preferable to provide a driving structure for driving the sheet trailing end aligning means and the sheet pressing means by the same driving means.
[0027]
The drive configuration includes:
Transmits the rotation of the driving means and swingably supports the sheet trailing end alignment means.
Swing axis,
A rotating shaft that rotatably supports the sheet pressing means,
A drive system for transmitting the rotation of the swing shaft to the rotation shaft,
It is preferable that the sheet trailing end aligning means be swung with the rotation of a cam provided on the rotating shaft.
[0028]
According to the above configuration, the sheet rear end aligning unit and the sheet pressing unit can be synchronized by a simple configuration by one driving unit, and the sheet rear end aligning operation and the sheet pressing operation can be cooperated.
[0029]
In addition, the sheet post-processing device described above,
The present invention can be suitably applied to an image forming apparatus including an image forming unit that forms an image on a sheet conveyed to the sheet post-processing apparatus.
[0030]
BEST MODE FOR CARRYING OUT THE INVENTION
Preferred embodiments of the present invention will be illustratively described in detail below with reference to the drawings. However, the dimensions, materials, shapes, relative arrangements, and the like of the components described in this embodiment are not intended to limit the scope of the present invention thereto unless otherwise specified. Absent.
[0031]
Hereinafter, an embodiment of an image forming apparatus including a sheet stacking alignment device and a sheet post-processing device according to the present invention will be described with reference to the drawings.
[0032]
(overall structure)
FIG. 1 is a cross-sectional view illustrating a schematic configuration of a sheet post-processing apparatus according to the present embodiment. FIG. 2 is a cross-sectional view illustrating an entire configuration of an image forming apparatus main body equipped with the sheet processing apparatus according to the present embodiment. 1 is a top view of a sheet post-processing apparatus according to the present embodiment.
[0033]
As shown in FIG. 2, the sheet post-processing apparatus 500 is provided above the image forming apparatus main body 200 and below the document reading apparatus 100. The sheet post-processing apparatus 500 temporarily stacks the image-formed sheets S discharged from the image forming apparatus main body 200 on the processing tray 540, performs post-processing such as staple binding, alignment, and the like. The sheets S are aligned and stacked on a stack tray 504 disposed substantially horizontally. Hereinafter, the sheet post-processing apparatus 500 will be described as an example.
[0034]
However, according to the present invention, the sheet stacking aligning device that aligns and stacks the image-formed sheets S discharged from the image forming apparatus main body 200 on the stack tray 504 does not pass through the processing tray 540 but directly to the image forming apparatus main body 200. The present invention is also effective in a connected device or a device in which the sheet post-processing device 500 is mounted outside the image forming apparatus main body 200.
[0035]
2, the sheet post-processing apparatus 500 is mounted on the image forming apparatus main body 200. An original reading device 100 is mounted on an upper portion of the image forming apparatus main body 200. Although the image forming apparatus is configured by the image forming apparatus main body 200, the sheet post-processing apparatus 500, and the automatic document reading apparatus 100, the sheet post-processing apparatus 500 may not include the processing tray 540.
[0036]
As shown in FIG. 2, a document reading unit 150 is mounted on the image forming apparatus 200, and the document reading device 100 is mounted on the document reading unit 150. The document reading device 100 separates the document set upward from above, feeds the documents one by one in order from the first page to the left, transports the document onto the platen glass 102 via a curved path, and reads the document. Thereafter, the sheet is discharged to the sheet discharge tray 112.
[0037]
In the automatic document reading apparatus 100, the light of the lamp of the scanner unit 104 is irradiated on the document, and the reflected light from the document is guided to the image sensor 109 via the mirrors 105, 106 and the lens 107 to read the document. Is performed. The image of the document read by the image sensor 109 is subjected to image processing, sent to the exposure control unit 202 of the image forming apparatus main body 200, and emitted a laser beam.
[0038]
Next, in the exposure control unit 202, the laser light is reflected by the rotating polygon mirror, and is turned again by the reflection mirror to irradiate the photosensitive drum 203 whose surface is uniformly charged, and A latent image is formed. After the electrostatic latent image on the photosensitive drum 203 is developed by the developing device 205, it is transferred as a toner image onto a sheet S composed of paper, an OHP sheet, or the like.
[0039]
The sheet S is appropriately and selectively fed out of the sheet cassettes 231, 232, 233, and 234 by a pickup roller 238 constituting a sheet feeding unit, separated by a separating unit 237, and fed one by one. After the skew is corrected, the toner image is sent to the transfer position in synchronization with the rotation of the photosensitive drum 203, and the toner image formed on the photosensitive drum 203 is transferred to the sheet S via the transfer belt 211.
[0040]
Thereafter, the sheet S is guided to the fixing roller pair 206, and the toner image transferred to the sheet S after being heated and pressed by the fixing roller pair 206 is permanently fixed. The upper fixing claw and the lower fixing claw are in contact with the fixing roller pair 206, respectively, whereby the sheet S is separated from the fixing roller pair 206.
[0041]
The separated sheet S is conveyed to the outside of the image forming apparatus main body 200 by the main body side discharge roller pair 207, and is guided to the sheet post-processing apparatus 500 connected to the image forming apparatus main body 200.
[0042]
Here, the photosensitive drum 203 for forming and fixing the toner image on the sheet S in the image forming apparatus main body 200, the developing device 205, the fixing roller pair 206, and the like constitute an image forming unit.
[0043]
(Sheet processing device configuration)
Next, the configuration of the sheet post-processing apparatus 500 will be specifically described.
[0044]
2, the sheet post-processing apparatus 500 has a processing tray 540 provided on the upstream side and a stack tray 504 provided substantially horizontally on the downstream side. The sheet S discharged from the main body side discharge roller pair 207 of the image forming apparatus 200 is conveyed in the sheet post-processing apparatus 500, post-processed by the processing tray 540, and stacked on the stack tray 504. .
[0045]
The post-processing mode performed on the processing tray 540 includes a sort mode for sorting a plurality of sets, a staple mode (staple) mode for binding a plurality of sheets by the staple unit 510, and the like. Selected and set by means.
[0046]
In the staple binding mode, a staple binding position such as one-point binding or two-point binding can be selected, and the staple unit 510 moves to the actual staple binding position based on the settings such as the sheet size and the binding position.
[0047]
As shown in FIGS. 1 and 3, the sheet S discharged from the image forming apparatus main body 200 is directed to the stack tray 504 by a discharge unit including a discharge roller 508a on the sheet post-processing apparatus 500 side and a discharge roller 508b driven by the discharge roller 508a. At the timing when the rear end of the sheet S has passed the discharge section, the rear end of the sheet S is dropped onto the processing tray 540 by the swing roller 550, and is pinched by the swing roller 550 and the driven roller 571. You.
[0048]
(Swinging roller configuration)
The operation of the swing arm 551 and the swing roller 550 will be described with reference to FIGS. FIG. 4 is a cross-sectional view illustrating the operation of the swing roller of the sheet post-processing apparatus according to the present embodiment, and FIG. 12 is a block diagram illustrating a control unit of the sheet post-processing apparatus according to the present embodiment.
[0049]
As shown in FIGS. 3 and 4, the swing roller 550 is attached to a swing arm 551 that can swing vertically about a swing roller shaft 552.
[0050]
The drive from the swing arm drive motor 643 is transmitted to the swing arm shaft 553 of the swing arm 551 via the swing cam 554. When the swing arm drive motor 643 rotates, the swing arm 551 is moved. It swings up and down about the swing roller shaft 552 integrally with the swing cam 554.
[0051]
A swing arm extension spring 555 is mounted on the swing arm 551 to assist upward swing.
[0052]
The oscillating roller 550 is connected to an oscillating roller driving motor 642 from an oscillating roller shaft 552 via an oscillating roller driving belt 556 and an oscillating roller driven pulley 557, and a driving signal from the CPU 611 shown in FIG. When transmitted to the swinging roller drive motor 642 via the moving roller drive motor driver 622, the swinging roller 550 rotates.
[0053]
(Swing roller operation)
Next, the operation of the swing roller 550 will be described in detail with reference to FIG.
[0054]
The home position of the oscillating roller 550 is set at an upper portion that does not come into contact with the sheet S discharged onto the processing tray 540 by the discharge unit (FIG. 4A).
[0055]
When the sheet S is discharged from the discharge section, the swing arm 551 is driven by the swing arm drive motor 643 and rotates counterclockwise around the swing roller shaft 552, whereby the swing roller 550 is lowered. Then, the trailing end of the sheet S is pressed by the swing roller 550, and the trailing end of the sheet is dropped into the processing tray 540 (FIG. 4B).
[0056]
The oscillating roller 550 forms a nip with the driven roller 571, and rotates counterclockwise under the drive of the oscillating roller drive motor 642, so that the rear end of the sheet S on the processing tray 540 returns to the return belt 560. The sheet S is pulled in along the lower guide 561 in the direction opposite to the previous conveying direction until the sheet S comes into contact with the sheet S (FIG. 4C).
[0057]
Thereafter, the swing roller 550 moves up to the home position again, and prepares for discharging the next sheet S (FIG. 4A).
[0058]
(Return belt operation)
Next, the operation of the return belt 560 will be described with reference to FIGS. FIG. 5 is a sectional view showing the operation of the return belt of the sheet post-processing apparatus according to the present embodiment.
[0059]
The return belt 560 is supported vertically by the discharge roller shaft 509 and is normally set at a position where it comes into contact with the sheet S on the processing tray 540.
[0060]
A return belt 560, which is at least one or more sheet feed rotating members, is disposed in a direction perpendicular to the direction in which the sheet S abuts against the sheet rear end stopper 562. The return belt 560 is supported by the discharge roller 508a and the housing 563. This is a configuration in which a belt 565 is interposed on a belt pulley 564 (see FIG. 1). The return belt 560 conveys the sheet S in the direction of the sheet rear end stopper 562 as the discharge roller shaft 509 rotates counterclockwise (FIG. 5A).
[0061]
Further, the return belt 560 is adapted to escape in the thickness direction of the sheets according to the number of sheets S stacked on the processing tray 540 (FIG. 5B).
[0062]
As described above, the counter-clockwise rotation of the swing roller 550 and the return belt 560 causes the rear end of the sheet S to be positioned at the end of the processing tray 540, and to be a sheet receiving unit that receives the sheet S on the processing tray 540. The sheet is sent to a certain sheet rear end stopper 562, and the sheet is aligned in the sheet conveying direction one by one.
[0063]
(Sheet width direction alignment)
The alignment in the sheet width direction will be described with reference to FIGS.
[0064]
The front alignment plate 541 and the rear alignment plate 542 are driven by a front alignment motor 646 and a rear alignment motor 647, respectively, and move in a direction parallel to the discharge roller shaft 509.
[0065]
When the sheet post-processing apparatus 500 is not in operation, the front alignment plate 541 and the rear alignment plate 542 stand by at positions where the unaligned front alignment home position sensor 530 and rear alignment home position sensor 531 are detected, respectively. This position is called an alignment home position position, and is set to a position where the sheet does not hit the front alignment plate 541 and the rear alignment plate 542 when the sheet is conveyed.
[0066]
The front alignment plate 541 and the rear alignment plate 542 move to a standby position according to the size of the sheet S before the sheet S is conveyed from the image forming apparatus main body 200. After the sheet S is aligned in the transport direction as described above, the front alignment plate 541 and the rear alignment plate 542 move to the alignment position in the post-processing mode set before the start of the job, thereby aligning the sheet S in the sheet width direction. Is performed.
[0067]
For example, when the sort mode is selected, when aligning the Nth sheet in the width direction, the front alignment plate 541 waits at the reference position, and the rear alignment plate 542 moves from the standby position to the sheet alignment position. Thus, the alignment is performed based on the front side, and the sheet is discharged to the stack tray 504 by the operation described later.
[0068]
When aligning the (N + 1) th sheet, the rear aligning plate 542 waits at the reference position, and the front aligning plate 541 moves from the standby position to the sheet aligning position to perform alignment based on the rear side, and stacks. The sheet is discharged to the tray 504.
[0069]
Thus, the sheets can be stacked on the stack tray 504 in a state of being sorted each time the bundle is discharged.
[0070]
Of course, it is also possible to perform alignment based on the center position of the sheet. In this case, the alignment is performed by moving both the front alignment plate 541 and the rear alignment plate 542 from the standby position to the alignment position based on the center position.
[0071]
When the staple binding mode is selected, the above-described width alignment operation is performed at a position corresponding to the set staple binding position.
[0072]
When the staple binding mode is selected, the staple binding operation is subsequently performed. The staple unit 510 performs a staple binding operation by driving a staple clinch motor 648. The staple unit 510 can be moved in the front-rear direction by driving a staple slide motor 649.
[0073]
When a job is started, the staple unit 510 moves to the actual staple binding position determined from the contents of the staple binding position set before the start of the job and the sheet size. The staple unit 510 performs a staple binding operation on the aligned sheet bundle S that has been subjected to the width direction alignment described above.
[0074]
(Bunch discharging means)
Next, the bundle discharging means will be described with reference to FIGS. FIG. 6 is a cross-sectional view illustrating a sheet bundle discharging operation of the sheet post-processing apparatus according to the present embodiment.
[0075]
After the alignment in the sheet conveying direction, the alignment in the sheet width direction, and the staple binding operation, the swing roller 550 is driven by the swing arm drive motor 643 and abuts on the sheet bundle S about the swing roller shaft 552. (FIG. 6A), forming a nip with the driven roller 571, and rotating clockwise, so that the rear end of the sheet bundle S reaches near the upper end of the rear end alignment wall 570, which is the sheet rear end alignment means. And stopped (FIG. 6B).
[0076]
Thereafter, the swing roller 550 separates from the sheet bundle S and returns to the home position (FIG. 6C). At the same time, the rear end alignment wall 570 swings around the cam swing rotation shaft 573 by the cam 572 located below the rear end alignment wall 570 in the direction opposite to the sheet conveyance.
[0077]
(Sheet trailing edge alignment)
Means for discharging the sheet bundle S on the processing tray 540 onto the stack tray 504, aligning and stacking the sheet bundle S will be described with reference to FIG. FIG. 7 is a cross-sectional view illustrating the operation of aligning the rear end of the sheet bundle of the sheet post-processing apparatus according to the present embodiment.
[0078]
The rear end alignment wall 570 is urged by a spring 512, and swings about a swing rotation shaft 573 by contacting the cam 572 at the home position (FIGS. 1 and 7).
[0079]
In a state in which the rear end of the sheet bundle S discharged by the bundle discharging unit is in contact with the upper end of the rear end alignment wall 570 (FIG. 6B), the rear end alignment wall 570 is retracted upstream in the sheet conveyance direction (FIG. 6B). 6 (c)), the rear end of the sheet bundle S is brought into contact with the slope of the rear end alignment wall 570 (FIG. 7 (a)).
[0080]
In the process of returning the retracted rear end alignment wall 570 to the home position around the pivot axis of rotation, the rear end of the sheet bundle S is pressed horizontally by the rear end alignment wall 570 to align the rear end of the sheet bundle S. While stacking, the sheet bundle S is stacked on the stack tray 504 (FIGS. 7B and 7C).
[0081]
After the sheet bundle is discharged, the sheet bundle placed on the stack tray 504 is pulled back to the rear end alignment wall 570 side by the sheet return member 583 as the sheet pressing means, and is pressed from the upper surface of the sheet bundle.
[0082]
(Seat return member)
A sheet return member (hereinafter, referred to as a “paddle”) 583 which is a paddle-shaped member rotates around a paddle rotation shaft 590 (see FIGS. 6 and 7) extending inside the rear end alignment wall 570. I have. Each time the sheet bundle is discharged onto the stack tray 504 by the swing roller 550, the paddle 583 rotates the paddle 583 one turn in a counterclockwise direction, thereby moving the discharged sheet bundle toward the rear end alignment wall 570. Each time it is pulled back, the rear end of the sheet bundle can be held down.
[0083]
The paddle 583 is held in a state as shown in FIGS. 6A and 6B except during the sheet returning operation, and holds the sheet S. At this time, the position of the paddle 583 is detected by a paddle home position sensor 532 (not shown).
[0084]
(Support mechanism and drive structure of the sheet return member (paddle))
Next, the support mechanism and drive configuration of the rear end alignment wall 570 and the sheet return member (paddle) 583 made of an elastic member will be described more specifically with reference to FIGS. 8, 9, and 10. FIG. 8 and 9 are perspective views showing the configuration of the rear end alignment wall and the paddle according to the present embodiment. FIG. 10 is a perspective view showing the positional relationship between the rear end alignment wall and the paddle, the timing, and the sheet pressing according to the present embodiment. It is a schematic diagram which shows a pressure.
[0085]
The rear end alignment wall 570 swingably supported by the swing rotation shaft 573 rotatably supports the paddle 583 and the paddle rotation shaft 590 integrated therewith via a paddle bearing 807. The paddle 583 rotates integrally with the gear portion 800b integrally provided on the paddle rotation shaft 590, by being driven and transmitted from a paddle motor 645 as a drive source and a paddle drive system 803 (each gear). The position of the paddle 583 and the rear end alignment wall 570 is detected by the sensor flag 802 and the sensor 532 that rotate integrally with the gear 808 provided on the swing rotation shaft 573.
[0086]
The gear 800 integrated with the paddle rotation shaft 590 has a cam portion 800a. The cam rail 805 provided in the device has a cam rail surface 805a that engages with the cam portion 800a. When the cam rotates, the rear end alignment wall 570 is urged by the spring 512 so that the cam comes into contact with the cam rail surface 805a. (The configuration is different from FIGS. 6 and 7, but the functions are the same.)
[0087]
That is, when the gear portion 800b and the cam portion 800a are rotated by the drive input, the posture of the rear end alignment wall 570 is changed by the cam rail 805, and the rear end aligning wall 570 rotates (oscillates) about the oscillation rotation shaft 573. In addition, the paddle shaft and the paddle 583 integrated with the gear portion 800b rotate in synchronization therewith.
[0088]
(Cooperative operation of sheet trailing edge alignment operation and sheet holding operation)
Next, referring to FIGS. 11A to 11E and FIG. 10, a description will be given of a cooperative operation in which the trailing edge alignment wall 570 as the sheet trailing edge aligning means and the paddle 583 as the sheet pressing means rotate synchronously. I do. FIG. 11 is a schematic diagram illustrating synchronization of the operations of the rear end alignment wall and the paddle according to the embodiment.
[0089]
FIG. 11A shows a state before the operation is started. At this time, the rear end matching wall 570 is perpendicular (0 °) to the horizontal plane, and the speed is zero. Paddle 583 is facing down. Since the sheet S is on the paddle 583, the sheet pressing force by the paddle 583 is 0 (see FIG. 10).
[0090]
FIG. 11B is a diagram in which the driving is transmitted and the paddle 583 starts rotating in the direction of the arrow (A). At this time, the cam portion 800a rotates in the same direction along the cam rail surface 805a by the spring 512, and the rear end alignment wall 570 swings and rotates in the arrow (b) direction by the rotation of the cam and the movement along the cam rail. Rotate about axis 573. At this time, the horizontal component of the speed of the rear end alignment wall 570 is in the direction of the arrow (b) and is not the direction in which the sheet bundle S is skipped to the stack tray 504 side. Does not occur.
[0091]
FIG. 11C shows a state in which the rear end alignment wall 570 is completely retracted. The angle of the rear end alignment wall 570 is maximum, and the speed is zero. The paddle is facing up (see FIG. 10). At this time, the paddles 583 are synchronized with each other so as to maintain an angle as shown in the drawing, which does not contact the sheet bundle S. This can be achieved by bending the cam mechanism and the cam rail surface as shown in FIG.
[0092]
FIG. 11D shows that the paddle further rotates, and the trailing end alignment wall 570 starts to rotate in the direction of pushing the sheet bundle by the cam and the cam rail surface 805a. From this point, the horizontal component of the speed of the rear end alignment wall 570 is in the direction toward the stack tray 504, and from this state, the sheet pressing force by the paddle 583 starts to be generated (see FIG. 10). The sheet pressing force increases as the paddle 583 rotates. The trailing edge of the sheet is pushed out toward the stack tray 504 by the trailing edge alignment wall 570, but the paper is not pressed away from the trailing edge alignment wall 570 because it is gradually pressed from above by the paddle 583.
[0093]
Until the paddle 583 is completely rotated, there is room for the sheet to escape to the stack tray 504 side, so that the sheet rear end does not bend as shown in FIG.
[0094]
FIG. 11E shows that the paddle 583 and the sheet rear end alignment wall 570 rotate in synchronization, and the rear end alignment, sheet return, and sheet bundle holding of the sheet bundle S have been completed. The paddle 583 is facing downward again, and the rear end alignment wall 570 is also returned to be perpendicular (0 °) to the horizontal plane and stopped. The pressing force of the sheet S by the paddle 583 in this state is the maximum (see FIG. 10).
[0095]
As described above, the positional relationship between the sheet trailing end alignment wall 570 and the paddle 583 is synchronized with each other so that a favorable alignment operation is performed in the sheet bundle alignment operation.
[0096]
The stack tray 504 is configured to be able to move up and down by a driving unit (not shown) in order to keep the upper surface height of the stacked sheet bundle S constant.
[0097]
In the present embodiment, the sheet stacking surface of the stack tray 504 is set to be substantially horizontal. However, even when the sheet stacking surface is inclined, the sheet trailing edge alignment means works effectively, and the sheet stacking surface is The effect is further enhanced in the case of being substantially horizontal. Further, the sheet stacking surface 504a is inclined downward by 18 ° or less toward the sheet rear end alignment wall, so that the sheet bundle already stacked on the stack tray 504 is discharged from the processing tray 540. The apparatus can be downsized while avoiding interference with a subsequent sheet bundle.
[0098]
(System block configuration)
Next, a configuration of a controller that controls the entire image forming apparatus will be described with reference to FIG. FIG. 13 is a block diagram illustrating a configuration of a controller that controls the image forming apparatus according to the present embodiment.
[0099]
As shown in FIG. 13, the controller has a CPU circuit section 350, and the CPU circuit section 350 includes a CPU 351, a ROM 352, and a RAM 353. The CPU circuit section 350 controls the external I / F 320, the image signal control section 330, the printer control section 340, the RAM 353, the document feeder control section 360, the image reader control section 370, and the sheet after sheet according to the control program stored in the ROM 352. Each block of the processing device controller 600 is generally controlled.
[0100]
The RAM 353 temporarily stores control data and is used as a work area for arithmetic processing associated with control.
[0101]
The document feeder control section 360 controls the drive of the document reading apparatus 100 based on an instruction from the CPU circuit section 350.
[0102]
The image reader control unit 370 performs drive control on the above-described scanner unit 104, image sensor 109, and the like, and transfers an analog image signal output from the image sensor 109 to the image signal control unit 330.
[0103]
After converting the analog image signal from the image sensor 109 into a digital signal, the image signal control unit 330 performs various processes, converts the digital signal into a video signal, and outputs the video signal to the printer control unit 340. Further, the digital image signal input from the computer 310 via the external I / F 320 is subjected to various processes, and the digital image signal is converted into a video signal and output to the printer control unit 340. The processing operation of the image signal control unit 330 is controlled by the CPU circuit unit 350.
[0104]
The printer control unit 340 drives the above-described laser scanner unit 202 based on the input video signal.
[0105]
The operation unit 363 includes a plurality of keys for setting various functions related to image formation, a display unit for displaying information indicating a setting state, and the like, and outputs a key signal corresponding to an operation of each key to the CPU circuit unit 350. At the same time, the corresponding information is displayed on the display unit based on the signal from the CPU circuit unit 350.
[0106]
The sheet post-processing device control unit 600 is mounted on the sheet post-processing device 500, and controls driving of the entire sheet processing device by exchanging information with the CPU circuit unit 350. The details of this control will be described later.
[0107]
(Sheet processing device block configuration)
Next, the configuration of the sheet post-processing device control unit 600 that controls the driving of the sheet post-processing device 500 will be described with reference to FIG. FIG. 12 is a block diagram illustrating a control unit of the sheet post-processing apparatus according to the present embodiment.
[0108]
As shown in FIG. 12, the sheet post-processing device control unit 600 includes a CPU circuit unit 610 including a CPU 611, a ROM 612, a RAM 613, and the like. The CPU circuit section 610 communicates with the CPU circuit section 350 provided on the image forming apparatus main body 200 side via the communication IC 614 to exchange data, and various types of data stored in the ROM 612 based on instructions from the CPU circuit section 350. The drive of the sheet post-processing device 500 is controlled by executing the program.
[0109]
When performing this drive control, detection signals from various sensors are taken into the CPU circuit section 610.
[0110]
The various sensors include an entrance sensor 521, a swing home position sensor 522, a swing snow home position sensor 523, a tray detection sensor 524, a paper surface detection sensor 525, a return belt retreat sensor 526, a staple slide home position sensor 527, and a staple clinch home. There is a position sensor 528.
[0111]
Drivers 621 to 630 of each motor are connected to the CPU circuit unit 610, and each driver drives the motor based on a signal from the CPU circuit unit 610.
[0112]
Here, as a motor, a sheet discharge motor 641 which is a driving source of the return conveyance belt pair, the entrance conveyance roller pair, and the sheet conveyed by the entrance conveyance roller pair are returned by the swing roller 550 attached to the tip of the swing arm 551. A swinging roller drive motor 642 that also serves to drive and eject the bundle of sheets processed on the processing tray 540 to the stack tray 504, and a swinging arm to catch the trailing end of the sheet discharged to the processing tray 540. A swing arm drive motor 643, which is a drive source for driving the 551 in the vertical direction, and a drive source for driving the rear end alignment wall 570 for aligning the rear end of the sheet bundle discharged onto the stack tray 504. , A paddle motor also serving as a driving source of a paddle 583 which is a pressing member for pressing a rear end portion of a sheet bundle stacked on the stack tray 504 645, a front alignment motor 646, a rear alignment motor 647, which is a drive source of an alignment plate that aligns the sheets stacked on the processing tray 540 in the sheet conveyance direction in the vertical direction, and a drive source that performs staple binding by the staple unit 510. There are a staple clinch motor 648, a staple slide motor 649 as a drive source for driving the staple unit 510 in the front-rear direction, and a stack tray motor 650 as a drive source for the stack tray 504.
[0113]
The discharge motor 641, the swing roller drive motor 642, the swing arm drive motor 643, the paddle motor 645, the front alignment motor 646, the rear alignment motor 647, and the staple slide motor 649 are composed of stepping motors, and control the excitation pulse rate. Thus, the roller pair driven by each motor can be rotated at a constant speed or at a unique speed.
[0114]
Also, a paper discharge motor 641, a swing roller drive motor 642, a swing arm drive motor 643, a front alignment motor 646, a rear alignment motor 647, and a staple slide motor 649 are a paper discharge motor driver 621, a swing roller drive motor driver 622, respectively. The motor can be driven in forward and reverse directions by a swing arm drive motor driver 623, a front alignment motor driver 626, a rear alignment motor driver 627, and a staple slide motor driver 629.
[0115]
The staple clinch motor 648 and the stack tray motor 650 are DC motors.
[0116]
【The invention's effect】
As described above, according to the present invention, it is possible to provide a sheet post-processing apparatus having a good stacking property in which a sheet is prevented from being folded or wrinkled, and an image forming apparatus including the same.
[0117]
[Brief description of the drawings]
FIG. 1 is a cross-sectional view illustrating a schematic configuration of a sheet post-processing apparatus according to an embodiment.
FIG. 2 is a cross-sectional view illustrating an overall configuration of an image forming apparatus including the sheet post-processing apparatus according to the embodiment.
FIG. 3 is a top view of the sheet post-processing apparatus according to the embodiment.
FIG. 4 is a cross-sectional view illustrating an operation of a swing roller of the sheet post-processing apparatus according to the embodiment.
FIG. 5 is a cross-sectional view illustrating an operation of a return belt of the sheet post-processing apparatus according to the embodiment.
FIG. 6 is a cross-sectional view illustrating a sheet bundle discharging operation of the sheet post-processing apparatus according to the embodiment.
FIG. 7 is a cross-sectional view illustrating an operation of aligning the rear end of the sheet bundle of the sheet post-processing apparatus according to the embodiment.
FIG. 8 is a perspective view showing a configuration of a rear end alignment wall and a paddle according to the embodiment.
FIG. 9 is a perspective view showing a configuration of a rear end alignment wall and a paddle according to the embodiment.
FIG. 10 is a schematic diagram illustrating a positional relationship, a timing, and a sheet pressing force between a rear end alignment wall and a paddle according to the embodiment.
FIG. 11 is a schematic diagram showing synchronization of the operations of the rear end alignment wall and the paddle according to the embodiment.
FIG. 12 is a block diagram illustrating a control unit of the sheet post-processing apparatus according to the embodiment.
FIG. 13 is a block diagram illustrating a configuration of a controller that controls the image forming apparatus according to the embodiment.
FIG. 14 is a cross-sectional view illustrating an overall configuration of an image forming apparatus including a conventional sheet post-processing apparatus.
FIG. 15 is a top view schematically illustrating the sheet stacking alignment device.
FIG. 16 is a cross-sectional view schematically illustrating a sheet post-processing apparatus employing a box-shaped horizontal stack tray.
FIG. 17 is a cross-sectional view schematically illustrating a sheet post-processing apparatus employing a horizontal stack tray having a sheet return paddle mechanism.
FIG. 18 is a schematic diagram showing a state in which paddle return is performed after rear end alignment.
FIG. 19 is a schematic diagram showing a state in which rear end alignment has been performed after returning the paddle.
[Explanation of symbols]
S sheet (sheet bundle)
100 Document reading device
150 Document reading unit
200 Image Forming Apparatus Main Body
202 Exposure controller
203 Photoconductor drum
205 developer
206 fixing roller pair
211 Transfer belt
310 Computer
330 Image signal control unit
340 Printer control unit
350 circuit section
500 sheet post-processing equipment
504 stack tray
510 staple unit
520 paddle
540 processing tray
550 swing roller
551 Swing arm
552 swing roller shaft
553 swing arm axis
554 Swing cam
555 Swing arm extension spring
556 Swing roller drive belt
557 Oscillating roller driven pulley
560 Return belt
561 Lower Guide
562 sheet rear end stopper
563 housing
564 Return belt pulley
565 belt
570 Rear end matching wall
571 driven roller
572 cam
573 Swing rotation axis
574 pinion gear
575 Rear end matching wall home position sensor
577 Rack support roller
578 Rack gear
580 Bundle discharging means
581 Stack Tray
582 Gripper
583 Seat return member (paddle)
585 Tip regulation plate
590 Paddle rotating shaft
600 sheet post-processing device controller
610 Circuit section
641 paper ejection motor
642 rocking roller drive motor
643 Swing arm drive motor
645 paddle motor
646 Front alignment motor
647 Rear alignment motor
648 Staple clinch motor
649 Staple slide motor
650 stack tray motor
800 gears
802 sensor flag
803 paddle drive system
805 cam rail
807 paddle bearing
808 gear

Claims (7)

An intermediate processing unit that temporarily stacks the sheets conveyed from the sheet conveying unit and performs post-processing,
Loading means for loading the post-processed sheet;
After a sheet that can be selectively moved to a supporting position for supporting the lower surface of the sheet bundle processed by the intermediate processing unit and a retracting position for retreating from the lower surface of the sheet bundle and dropping the sheet bundle onto the stacking unit Edge alignment means;
Switching control means for switching between a supporting position and a retracted position with respect to the sheet rear end aligning means,
In a sheet post-processing apparatus having a sheet pressing unit for pressing a rear end of a sheet stacked on the stacking unit,
A sheet trailing edge aligning operation by the sheet trailing edge aligning means for aligning a trailing edge of the sheet bundle dropped on the stacking means by moving from the retracted position to the supporting position, and a sheet pressing operation by the sheet pressing means. And a sheet post-processing apparatus for performing the operations in cooperation with each other. 2. The sheet post-processing apparatus according to claim 1, wherein a pressing force on the sheet by the sheet pressing unit changes according to a change in a speed of the sheet rear end aligning operation by the sheet rear end aligning unit. 3. 3. The sheet pressing device according to claim 1, wherein the sheet pressing unit generates a pressing force for pressing the sheet toward the sheet rear end aligning unit after the sheet rear end aligning unit starts pushing the rear end of the sheet. 4. The sheet post-processing device according to 1. At a timing earlier than the end of the sheet rear end alignment operation by the sheet rear end alignment unit, a sheet pressing operation by the sheet pressing unit is started,
The sheet pressing operation by the sheet pressing means ends at the same time as or later than the end of the sheet rear end aligning operation by the sheet rear end aligning means. A sheet post-processing device according to the item. The sheet post-processing apparatus according to any one of claims 1 to 4, further comprising a driving structure for driving the sheet trailing edge aligning means and the sheet pressing means by the same driving means. The drive configuration includes:
A swing shaft for transmitting the rotation of the driving means and swingably supporting the sheet rear end alignment means,
A rotating shaft that rotatably supports the sheet pressing means,
A drive system for transmitting the rotation of the swing shaft to the rotation shaft,
6. The sheet post-processing apparatus according to claim 5, wherein the sheet rear end aligning means swings with rotation of a cam provided on the rotation shaft. A sheet post-processing device according to any one of claims 1 to 6,
Image forming means for forming an image on a sheet conveyed to the sheet post-processing apparatus,
An image forming apparatus comprising:

Images