JP2005041586A - Sheet post processing device and image forming device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sheet post processing device for preventing misalignment due to release of a restricting and holding means, and to provide an image forming device. <P>SOLUTION: When a loading tray 18 is lowered as an illustrated arrow, firstly restricting operation by a knurled belt 19 is started to move the loading tray 18, and the restricting operation by the knurled belt 19 is stopped after movement of the loading tray 18 is stopped. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention is used as an image forming apparatus combined with an image forming apparatus main body such as a copying machine, a printer, or a multifunction peripheral, and discharges and stacks sheets discharged from the image forming apparatus main body onto a tray provided to be movable up and down. The present invention relates to a sheet post-processing apparatus.
[0002]
[Prior art]
2. Description of the Related Art A sheet post-processing apparatus having a stacking tray that is connected to an image forming apparatus main body such as a copying machine and can stack sheets discharged from the image forming apparatus main body is known.
[0003]
Some of such sheet post-processing apparatuses perform alignment in the conveyance direction of discharged sheets.
[0004]
For example, when the sensor detects the position of the trailing edge of the sheet, the paddle driven by the timing belt and the solenoid rotates together with the roller, and the sheet is knocked down to the stacking tray by the paddle.
[0005]
Then, the sheet is sent from the roller arranged at the lower part of the roller to a plurality of parallel knurled belts that are regulated as alignment references driven via the timing belt, and the sheet is rotated by the knurled belt on the rear end side of the sheet. It is abutted in the direction of the loading wall.
[0006]
This aligns the stacked sheets in the sheet conveyance direction, and aligns the side surfaces in the sheet width direction with a jogger each time a sheet is discharged in order to align the width direction intersecting the sheet conveyance direction. The mechanism was common. Then, a mechanism is known in which the stacked sheet bundle is discharged to another stacking tray, and the other stacking tray moves up and down according to the number of sheets discharged to the other stacking tray (for example, Patent Document 1). ).
[0007]
Also, a mechanism for moving the stacking tray in the width direction intersecting the sheet conveyance direction to sort the discharged sheets, and a sheet is discharged every time it is discharged to align the discharge direction of the discharged sheets. By controlling the position of the holding roller so that the leading edge of the sheet does not move by pushing the loaded paper, and by aligning the discharged sheet against the end face, the upper surface of the stacking tray is detected, and the stacking A mechanism in which the tray moves up and down is known (for example, Patent Document 2).
[0008]
[Patent Document 1]
JP 2002-37512 A
[Patent Document 2]
JP 2002-167105 A
[0009]
[Problems to be solved by the invention]
By the way, in such a conventional sheet post-processing apparatus, when the stacking tray on which the sheets are stacked is moved up and down and when the sheets are handled, the pressure of the knurled belt on the sheets is released. There has been a problem that misalignment occurs at the upper part of the stacked sheets due to the influence of the knurled belt to which the pressure is released.
[0010]
Also, especially when the stacked sheets are stacked in the width direction that intersects the sheet conveyance direction, and when the stacking tray is moved up and down and when handling the sheets, the pressing rollers that hold the stacked sheets so as not to move are applied to the sheets. If the pressing pressure is released, there is a problem that misalignment occurs at the top of the stacked sheets due to the vertical movement of the stacking tray.
[0011]
SUMMARY An advantage of some aspects of the invention is that it provides a sheet post-processing apparatus and an image forming apparatus that prevent misalignment due to the release of a restriction holding unit.
[0012]
[Means for Solving the Problems]
In order to achieve the above object, in the sheet post-processing apparatus of the present invention, in the sheet post-processing apparatus provided with a sheet stacking tray that can be moved up and down to stack the sheets formed and discharged one by one, A sheet knocking means for knocking down the sheet conveyed to the sheet stacking tray, and a sheet edge of the sheet stacked on the sheet stacking tray is brought into contact with the stacking wall portion to regulate the sheet edge as an alignment reference. A regulation holding unit, and an alignment unit that aligns a width direction intersecting a sheet conveyance direction on the sheet stacking tray, and operates the regulation holding unit until the operation of raising and lowering the sheet stacking tray is completed. It is characterized by keeping.
[0013]
The uppermost surface detecting means for detecting the uppermost surface height of the stacked sheets on the sheet stacking tray, and the uppermost surface detecting means for raising the sheet stacking tray before performing the operation of raising and lowering the sheet stacking tray. It is preferable to detect the uppermost surface of the stacked sheets.
[0014]
In a sheet post-processing apparatus having a sheet stacking tray that can be moved up and down to stack sheets discharged after image formation one by one, the sheet edge of the sheets stacked on the sheet stacking tray is applied to the stacking wall portion. It has a regulation holding means for contacting and regulating the sheet edge as an alignment reference, and the regulation holding means is operated until the operation of raising and lowering the sheet stacking tray is completed.
[0015]
An image forming apparatus according to the present invention includes the sheet post-processing apparatus and an image forming apparatus main body that discharges a sheet on which an image has been formed on the sheet post-processing apparatus.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
Exemplary embodiments of the present invention will be 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 only to those unless otherwise specified. Absent.
[0017]
First, a main body (image forming apparatus main body) 900 of a copying machine (image forming apparatus) provided with the sheet post-processing apparatus of the embodiment will be described with reference to FIG.
[0018]
The main body 900 includes a platen glass 906 as a document placement table, a light source 907, a lens system 908, a paper feeding unit 909, an image forming unit 902, and the like.
[0019]
The sheet feeding unit 909 includes cassettes 910 and 911 that store recording sheets S and are detachable from the main body 900 and a deck 913 disposed on the pedestal 912.
[0020]
The image forming unit 902 includes a cylindrical photosensitive drum 914 and a developing unit 915 around it, a transfer charger 916, a separation charger 917, a cleaner 918, a primary charger 919, and the like.
[0021]
Further, a conveyance device 920, a fixing device 904, a discharge roller pair 905, and the like are disposed on the downstream side of the image forming unit 902 in the sheet conveyance direction.
[0022]
An automatic document supply / discharge device 940 that automatically supplies and discharges the document D onto the platen glass 906 is provided at the top of the main body 900.
[0023]
Next, the operation of the copying machine main body 900 will be described.
[0024]
When a paper feed signal is output from the control device 922 provided in the main body 900, the sheet S is fed from the cassettes 910 and 911 or the deck 913.
[0025]
On the other hand, the light reflected from the light source 907 on the document D placed on the platen glass 906 is applied to the photosensitive drum 914 through the lens system 908.
[0026]
The photosensitive drum 914 is charged in advance by a primary charger 919. When the photosensitive drum 914 is irradiated with light, an electrostatic latent image is formed, and then the developing unit 915 develops the electrostatic latent image to form a toner image.
[0027]
The sheet S fed from the sheet feeding unit 909 is corrected for skew by the registration roller pair 901 and further sent to the image forming unit 902 at the same timing.
[0028]
In the image forming unit 902, the toner image on the photosensitive drum 914 is transferred by the transfer charger 916 in synchronization with the fed sheet S.
[0029]
The sheet S to which the toner image has been transferred is charged to a polarity opposite to that of the transfer charger 916 by the separation charger 917 and separated from the photosensitive drum 914.
[0030]
The separated sheet S is conveyed to the fixing device 904 by the conveying device 920, and the toner image is permanently fixed on the sheet S by the fixing device 904.
[0031]
The sheet S on which the toner image is fixed is discharged from the main body 900 by the discharge roller pair 905.
[0032]
In this manner, in the main body 900, an image is formed on the sheet S fed from the paper feeding unit 909 and discharged. A sheet post-processing apparatus that performs post-processing on the discharged sheet S is connected to the main body 900 of FIG.
[0033]
Next, the sheet post-processing apparatus of this embodiment will be described. First, an outline of features of the present embodiment will be described with reference to FIG.
[0034]
In FIG. 1, a stacking tray 18 is provided as a sheet stacking tray on which sheets discharged from the main body 900 are stacked.
[0035]
Above the stacking tray 18, for example, a knurled belt 19 is disposed as a regulation holding unit that comes into contact with the uppermost surface of the stacked sheets. The knurling belt 19 is a knurling belt that is always brought into contact with the stacking wall portion 20 to align the sheets, and 54 is a timing belt that moves the stacking tray 18 up and down.
[0036]
The sheets stacked on the stacking tray 18 are always aligned with the stacking wall portion 20 by the regulating operation of the knurled belt 19. That is, when the stacking tray 18 is lowered as indicated by the arrow in FIG. 1, the regulation operation is first started by the knurling belt 19, the loading tray 18 is moved, and the regulation operation by the knurling belt 19 is stopped after the movement of the stacking tray 18 is stopped. I do.
[0037]
Hereinafter, the present embodiment will be described in detail with reference to FIGS.
[0038]
A stacker as a sheet post-processing apparatus shown in FIG. 2 is provided on the side of the main body of a copying machine (not shown), and includes an upper stacking tray 18 and a lower stacking tray 37.
[0039]
The sheet conveyance / discharge path will be described.
[0040]
The upper sheet conveyance path is connected to the connection gear 4 via a timing belt 5 connected to the rotation shaft of the conveyance drive motor 6. Further, a plurality of upper entrance rollers 1 arranged in parallel by the timing belt 3 are driven from the connecting gear 4.
[0041]
Therefore, the sheet discharged from the main body 900 passes through the upper entrance roller 1 and the driven roller 2 that follows it.
[0042]
In addition, a plurality of upper discharge rollers 11 arranged in parallel are driven from the drive motor 7 via the timing belt 8 and from the connection gear 9 via the timing belt 10.
[0043]
Therefore, the sheet that has passed through the upper entry roller 1 and the driven roller 2 driven thereby is then conveyed to the upper discharge roller 11 and the driven roller 12 driven thereby.
[0044]
An entrance sensor S1 is provided at a portion of the upper entrance roller 1 in front of the sheet conveyance direction. The entrance sensor S1 detects the leading edge and the trailing edge of the conveyed sheet.
[0045]
Further, a flapper 13 is disposed immediately after the inlet sensor S1. The flapper 13 can change the sheet conveying direction in the stacker to either the upper stacking tray 18 side or the lower stacking tray 37 side by a driving solenoid 14.
[0046]
An upper paper discharge sensor S <b> 2 is provided on the front side of the upper paper discharge roller 11 in the transport direction. The upper sheet discharge sensor S2 detects the leading edge and the trailing edge of the conveyed sheet.
[0047]
When the upper sheet discharge sensor S2 detects the position of the trailing edge of the sheet, the sheet conveyed by the upper sheet discharge roller 11 is knocked down by the timing belt 15 and the upper paddle solenoid 16 via the upper sheet discharge roller 11. For example, the paddle 17 is rotated as a means.
[0048]
The paddle 17 knocks the sheet onto the upper stacking tray 18 by rotation. As a result, the sheet dropped on the upper stacking tray 18 is arranged below the upper discharge roller 11 as an alignment reference for the sheet edge driven from the upper discharge roller 11 via the timing belt 10. For example, a sheet is fed to a plurality of knurled belts 19 arranged in parallel as the restriction holding means for restriction.
[0049]
Then, the sheet is abutted against the wall surface of the stacking wall portion 20 by the rotation of the knurled belt 19, so that the sheet edges of the sheets stacked on the upper stacking tray 18 are aligned.
[0050]
Similarly to the upper-stage sheet conveyance / discharge path, the lower-stage sheet conveyance / discharge path includes a lower-stage inlet roller 21 driven by the conveyance drive motor 6, the timing belt 5, and the connection gear 4 via the inlet sensor S 1. The sheet is conveyed to a driven roller 22 that is driven by it.
[0051]
The sheet is conveyed from the lower entrance roller 21 to the vertical path 1st roller 24 driven via the timing belt 23 and the driven roller 25 driven thereby. Further, the sheet is conveyed from the vertical path 1st roller 24 via the timing belt 26 to the vertical path 2nd roller 27 and a driven roller 28 driven by the roller.
[0052]
Then, the paper is transported from the upper paper discharge roller 11 to the lower paper discharge roller 30 driven via the timing belt 29 and the driven roller 31 driven thereby.
[0053]
A vertical path 1st sensor S3 is provided in front of the vertical path 1st roller 24, a vertical path 2nd sensor S4 is provided in front of the vertical path 2nd roller 27, and a lower output sensor S5 is provided in front of the lower output roller 30. ing. Each of the sensors S3, S4, S5 detects the leading edge and the trailing edge of the conveyed sheet.
[0054]
When the lower sheet discharge sensor S5 detects the trailing edge of the sheet, for example, a paddle 34 is rotated as sheet hitting means driven by the lower paddle solenoid 33 from the lower sheet discharge roller 30 via the timing belt 32.
[0055]
The paddle 34 knocks the sheet onto the lower stacking tray 37 by rotation. As a result, the sheet dropped on the lower stacking tray 37 is arranged below the lower discharge roller 30 as an alignment reference for the sheet edge driven from the lower discharge roller 30 via the timing belt 35. For example, a sheet is sent to the knurled belt 36 as a regulation holding means for regulation.
[0056]
Then, the sheet is abutted against the wall surface of the stacking wall 38 by the rotation of the knurled belt 36, so that the sheet edges of the sheets stacked on the lower stacking tray 37 are aligned.
[0057]
Note that, in the sheets stacked on the stacking trays 18 and 37, the alignment in the width direction in the sheet conveying direction is performed by the right jogger 39 and the left jogger 40 mounted on the timing belt 43 as shown in FIG.
[0058]
Here, for example, a jogger moving mechanism will be described with reference to FIG. The right jogger 39 and the left jogger 40 are reciprocably attached to a jogger fence rod 41 spanned between the right jogger 39 and the left jogger 40. The right jogger 39 and the left jogger 40 have one sheet. It has a function as an alignment means for aligning each discharge.
[0059]
The right jogger 39 and the left jogger 40 are fixed to the middle portion of the timing belt 43 driven by the jogger driving motor 42. The right jogger 39 and the left jogger 40 are fixed to different sides (opposite positions) of the timing belt 43, so that the right jogger 39 and the left jogger 40 are reciprocated symmetrically in the left-right direction. Yes.
[0060]
The right jogger 39 is provided with a detection plate 39a, and the detection plate 39a shields the detection portion of the home position sensor S6 provided on the apparatus side, so that the home positions of the right jogger 39 and the left jogger 40 ( HP) can be detected.
[0061]
In the above mechanism, the right jogger 39 and the left jogger 40 are moved symmetrically and aligned with the center in the width direction in the sheet conveying direction. However, as the alignment means, for example, the left jogger 40 is not operated and is fixed to the stacking tray. A reference position abutting plate may be used, and only the right jogger 39 may be fixed to the middle portion of the timing belt 43 driven by the jogger driving motor 42. As a result, the right jogger 39 is fixed to the timing belt 43, and the right jogger 39 is reciprocated in the left-right direction so that the sheet can be aligned with the abutting plate fixed to the stacking tray.
[0062]
Although not shown in the drawings, as a width direction aligning unit in the sheet conveying direction, for example, the stacking tray itself may be moved in the width direction in the sheet conveying direction, and the sheets may be stacked and sorted according to the position.
[0063]
Next, the conveyance direction alignment will be described with reference to FIGS. In order to align the conveyance direction, it is necessary to strike the sheet onto the stacking trays 18 and 37 and align the end of the sheet in the sheet width direction. Therefore, when the rear end of the first sheet is detected by the upper and lower discharge sensors S2 and S5, the paddles 17 and 34 driven by the timing belts 15 and 32 and the solenoids 16 and 33 from the upper and lower discharge rollers 11 and 30, respectively. Rotates. At this time, the leading edge of the sheet has already passed through the upper and lower discharge rollers 11 and 30.
[0064]
Since the rear end of the sheet is in the vicinity of the knurled belts 19 and 36 as shown in FIG. 4, the sheet can be reliably pulled in and the rear end can be aligned.
[0065]
On the stacking trays 18 and 37, there are sheet on-tray detection sensors S8 and S9, and the presence or absence of sheets on the stacking trays 18 and 37 is detected.
[0066]
In the stacking tray mechanism, as shown in FIG. 2, the bases of the stacking trays 18 and 37 are fixed on the upper and lower tray bases 44 and 45, respectively.
[0067]
Upper and lower guide rollers 60, 61, 62, and 63 are rotatably attached to the upper and lower tray bases 44 and 45, respectively. The guide rollers 60, 61, 62, and 63 are not shown in the figure, and are engaged with the lower guide rail so that the upper and lower tray trays 44 and 45 and the lower stack trays 18 and 37 move in the vertical direction. It has become.
[0068]
Further, the upper and lower tray drive motors 46 and 47 are driven through timing belts 48, 49, 54 and 55 and connection gears 50, 51, 52 and 53, respectively.
[0069]
Since the upper and lower tray bases 44 and 45 are fixed to the upper and lower timing belts 54 and 55, the upper and lower trays 18 and 37 are moved up and down by the tray drive motors 46 and 47.
[0070]
As for the position of the rear end of the sheet, the sheet outputs the detection results of predetermined sensors S2 and S5 to the CPU 500 shown in FIG. The CPU 500 determines the position of the stacking trays 18 and 37 based on the detection result of the sensor and the calculation result of a predetermined time after passing the sensor or the detection of the motor rotation speed.
[0071]
In addition, as shown in the figure, the CPU 500 also includes an inlet sensor S1, an upper discharge sensor S2, a vertical pass 1st sensor S3, a vertical pass 2nd sensor S4, a lower discharge sensor S5, and an uppermost top detection sensor S7. Various detection signals from the home position sensor S6, the upper tray upper sheet detection sensor S8, the lower tray upper sheet detection sensor S9, the lower uppermost surface detection sensor S10, etc., and sheet discharge from an operation unit (not shown) provided in the main body 900 A number signal or the like is input.
[0072]
Based on these signals, the CPU 500 selectively feeds the upper drive roller 6 and the lower drive roller 21 shown in FIG. 7 through the drivers D1 to D8, and the upper and lower sheets. Drive solenoid 14 for causing the motor to enter, a connecting gear 9, an upper discharge roller 11, a lower discharge roller 30, a knurling belt 19, 36 and a drive motor 7 for rotating paddles 17, 34 and an upper paddle solenoid 16. The lower paddle solenoid 33 is controlled.
[0073]
Further, the CPU 500 controls the upper and lower tray driving motors 46 and 47 for moving the stacking trays 18 and 37 up and down, the jogger driving motor 42 for operating the left and right joggers, and the like.
[0074]
Note that the CPU 500 controls the movement amount, speed, and the like of each motor and the like by control input pulses or encoder inputs that detect the rotation amount.
[0075]
Next, detection of the uppermost surface of the sheets on the stacking trays 18 and 37 will be described. The conveyed sheets are abutted against the stacking wall portion 20 one by one by the paddle 17 and the knurled belt 19, and the sheets are stacked on the stacking tray 18, so that the uppermost surface of the sheet rises. At this time, the uppermost surface for detecting the position of the uppermost surface of the sheet in the vicinity of the knurled belt 19 as shown in FIG. As the detecting means, for example, the uppermost sheet detection sensor S7 detects the uppermost sheet surface based on the detected ON signal, and moves the stacking tray 18 to a predetermined position.
[0076]
A seat lowermost surface detection sensor S10 similar to the above is also installed in the vicinity of the lower knurled belt 36.
[0077]
By this control, the sheet discharged from the main body 900, knocked down by the paddles 17 and 34 to the stacking trays 18 and 37, and abutted against the stacking wall portions 20 and 38 by the knurled belts 19 and 36 is the sheet top surface height and the knurled belt. Since the distance between 19 and 36 is stabilized, the pressing amount of the knurled belts 19 and 36 is also stabilized, and the discharged sheet can be stably pressed.
[0078]
The positions of the stacking trays 18 and 37 can be determined by detecting the number of rotations of the motor.
[0079]
By the way, in the present embodiment, when the CPU 500 raises and lowers the stacking trays 18 and 37 in order to detect the uppermost surface of the stacking trays 18 and 37, the sheet conveyed on the stacking trays 18 and 37 is transferred. In some cases, the stacking trays 18 and 37 are moved up and down while the operation of the knurling belts 19 and 36, for example, is performed as the regulation holding means.
[0080]
Next, control for raising the stacking trays 18 and 37 while the knurling belts 19 and 36 are operated will be described with reference to the flowchart shown in FIG.
[0081]
A tray position initial signal is input from the CPU 500 (S101). Then, the CPU 500 checks whether or not sheets are stacked on the stacking trays 18 and 37 from the information of the upper tray upper sheet detection sensor S8 and the lower tray upper sheet detection sensor S9 (S102).
[0082]
If there is no sheet on the stacking trays 18 and 37, the top surface is detected (S103). Therefore, the tray raising / lowering operation is not performed. If the uppermost surface cannot be detected in S103, the stacking trays 18 and 37 are moved up (S104). Further, the uppermost surface is detected (S105). If it can be detected, the raising of the stacking trays 18 and 37 is stopped (S106).
[0083]
If there are sheets on the stacking trays 18 and 37 in S102, the uppermost surface is detected (S107). If the uppermost surface is detected, the knurled belts 19 and 36 are operated (S108), and the stacking trays 18 and 37 are lowered (S109). When it is lowered 20 mm from the uppermost surface detection position (S110), the stacking tray is stopped (S111), and then the stacking tray is raised until the uppermost surface of the sheet is detected (S112, S113). When the uppermost surface is detected again (S113), the raising of the stacking trays 18 and 37 is stopped (S114), and the operation of the knurling belts 19 and 36 is stopped after the operation of the stacking trays 18 and 37 is stopped (S115). .
[0084]
If there is a sheet on the stacking trays 18 and 37 in S102 and the uppermost surface cannot be detected in S107, the knurling belts 19 and 36 are operated (S116) to raise the stacking trays 18 and 37 (S117). The uppermost surface of the sheet is detected (S118). When the uppermost surface is detected, the raising of the stacking trays 18 and 37 is stopped (S119). Thereafter, the steps after S110 are performed.
[0085]
In the present embodiment, the CPU 500 releases the pressing force of the uppermost surface of the stacked sheets and the knurled belts 19 and 36 in order to maintain alignment of the sheets stacked on the stacking trays 18 and 37 and facilitate handling. The stacking tray is lowered without doing so.
[0086]
The lowering control of the stacking trays 18 and 37 when the pressing force of the uppermost surface of the stacking trays 18 and 37 and the knurling belts 19 and 36 is not released will be described with reference to the flowchart of FIG.
[0087]
A lowering signal of the stacking trays 18 and 37 is input from the CPU 500 (S120). Then, the uppermost surface of the sheet is detected (S121).
[0088]
If the uppermost surface of the sheet is detected in S121, the operation of the knurled belts 19 and 36 is started (S122), and then the stacking trays 18 and 37 are lowered (S123). Then, the stacking trays 18 and 37 are lowered from the uppermost surface detection position to a position where the pressure of the knurled belts 19 and 36 can be released (50 mm in this embodiment) (S124). Here, the lowering of the stacking trays 18 and 37 is stopped (S125). Next, after the lowering operation of the stacking trays 18 and 37 is stopped, the operation of the knurled belts 19 and 36 is stopped (S126).
[0089]
If the lowering signal of the stacking trays 18 and 37 is input in S120 and the uppermost surface of the sheet is not detected in S121, the knurled belts 19 and 36 are operated (S127), and the uppermost surface is detected. The stacking trays 18 and 37 are raised (S128, S129), and after the uppermost surface is detected, the raising of the loading trays 18 and 37 is stopped while the knurling belts 19 and 36 are operating (S130). Steps after S123, which is a descending operation, are performed.
[0090]
As described above, in the present embodiment, the stacking trays 18 and 37 are moved up and down while the knurling belts 19 and 36 are operated, thereby preventing misalignment of the upper portions of the stacking sheets due to the pressure release of the knurling belts 19 and 36. can do.
[0091]
Further, when the sheets are aligned and stacked on the stacking tray in the width direction of the sheet conveying direction, it is possible to particularly prevent the alignment shift when the stacking trays 18 and 37 are moved up and down.
[0092]
【The invention's effect】
As described above, according to the present invention, when the sheet stacking tray is moved up and down, the sheet stacking tray is moved up and down while the regulation holding unit is operated, thereby preventing the alignment deviation of the upper portion of the stacked sheets due to the release of the regulation holding unit. can do. Further, when the sheets are aligned and stacked on the stacking tray in the width direction of the sheet conveyance direction, it is possible to prevent the alignment shift particularly remarkably.
[Brief description of the drawings]
FIG. 1 is a schematic cross-sectional view showing a main part of a characteristic part of an embodiment.
FIG. 2 is a cross-sectional view illustrating a schematic configuration of a sheet processing apparatus according to the embodiment.
FIG. 3 is a schematic diagram illustrating a configuration of a width direction alignment unit of the sheet processing apparatus according to the embodiment.
FIG. 4 is a perspective view illustrating a configuration of a conveyance direction alignment unit of the sheet processing apparatus according to the embodiment.
FIG. 5 is a flowchart for explaining an operation at the time of raising and lowering the stacking tray according to the embodiment.
FIG. 6 is a flowchart illustrating an operation when the stacking tray is lowered according to the embodiment.
FIG. 7 is a control block diagram of the sheet processing apparatus according to the embodiment.
FIG. 8 is a schematic cross-sectional view illustrating an image forming apparatus according to an embodiment.
[Explanation of symbols]
17,34 paddle
18 Upper tray
19, 36 Knurled belt
20,38 Loading wall
37 Lower stacking tray
900 body

Claims (4)

In a sheet post-processing apparatus provided with a sheet stacking tray that can be moved up and down to stack sheets ejected after image formation one by one,
Sheet knocking means for knocking down the sheet conveyed to the sheet stacking tray;
Restriction holding means for restricting the sheet edge as an alignment reference by bringing the sheet edge of the sheet stacked on the sheet stacking tray into contact with the stacking wall portion;
Alignment means for aligning the width direction intersecting the sheet conveying direction on the sheet stacking tray;
Have
The sheet post-processing apparatus, wherein the restriction holding unit is operated until the operation of raising and lowering the sheet stacking tray is completed. A top surface detecting means for detecting a top surface height of the stacked sheets on the sheet stacking tray;
2. The sheet post-processing apparatus according to claim 1, wherein the uppermost surface of the stacked sheets is detected by the uppermost surface detection unit before the sheet stacking tray is moved up and down. . In a sheet post-processing apparatus provided with a sheet stacking tray that can be moved up and down to stack sheets ejected after image formation one by one,
Regulation holding means for regulating the sheet edge as an alignment reference by bringing the sheet edge of the sheet stacked on the sheet stacking tray into contact with the stacking wall portion;
The sheet post-processing apparatus, wherein the restriction holding unit is operated until the operation of raising and lowering the sheet stacking tray is completed. The sheet post-processing apparatus according to claim 1, 2, or 3,
An image forming apparatus comprising: an image forming apparatus main body that discharges an image-formed sheet to the sheet post-processing apparatus.

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