JP3720814B2 - Sheet processing apparatus and image forming apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a sheet processing apparatus that performs processing such as stacking and alignment of sheets, and transferring and stacking a bundle after processing to a stacker unit.
[0002]
[Prior art]
A conventional sheet processing apparatus will be described with reference to FIG. FIG. 11 is a cross-sectional view showing the overall configuration of an image forming apparatus provided with a conventional sheet processing apparatus.
[0003]
As shown in FIG. 11, conventionally, in an image forming apparatus such as a printing machine, a copier, or a printer, a sheet S on which an image is formed by the image forming apparatus main body 200 is temporarily stacked on a processing tray 540 in the sheet processing apparatus 500. Then, post-sheet processing such as sheet S alignment and binding processing is performed.
[0004]
Thereafter, the bundle discharging means 580 discharges the bundle to a stack tray 581 having an inclined stacking surface as shown in FIG. 11, and the discharged sheet S moves on the inclined stacking surface of the stack tray 581 by its own weight, thereby aligning the trailing edge. The trailing edge of the sheet is aligned at the wall. The number of stacked sheets depends on the vertical operation stroke of the stack tray 581.
[0005]
[Problems to be solved by the invention]
However, the sheet bundle is slid down on the stack tray 504 configured as shown in FIG. 6 and the rear end of the sheet bundle S is pushed and stacked by the rear alignment wall so as to secure the stacking amount. In such a configuration, it is not possible to expect a return due to its own weight after discharging the paper as in the conventional example.
[0006]
Therefore, it is necessary to slow the reciprocating speed of the rear end alignment wall when discharging and aligning the sheet bundle to the stack tray to ensure the alignment of the sheet bundle, which has been a factor in reducing productivity.
[0007]
SUMMARY OF THE INVENTION The present invention has been made in view of the above-described problems of the prior art, and an object of the present invention is to provide a sheet processing apparatus that realizes securing of a load capacity and improvement of productivity without significantly changing the configuration. It is in.
[0008]
[Means for Solving the Problems]
In order to achieve the above object, in the sheet processing apparatus according to the present invention,
Intermediate processing means for stacking and processing sheets conveyed from the sheet conveying means;
Stacking means for stacking a sheet bundle processed by the intermediate processing means;
A support means capable of selectively moving to a support position for supporting the lower surface of the sheet bundle processed by the intermediate processing means or a retreat position retracted from the lower surface of the sheet bundle;
Switching control means for switching between a support position and a retracted position of the support means;
A sheet processing apparatus having transfer means capable of transferring the sheet bundle supported by the support means to the stacking means,
The switching control means includes
When the rear end of the sheet bundle reaches the upper portion of the support means by the transfer means, the sheet bundle is dropped onto the stacking means by moving the support means to the retracted position at the first moving speed,
After that, the rear end of the sheet bundle dropped on the stacking unit is controlled by moving the supporting unit from the retracted position to the supporting position at a second moving speed that is slower than the first moving speed. It is characterized by that.
[0009]
In the image forming apparatus according to the present invention,
The sheet processing apparatus;
Image forming means for forming an image on a sheet conveyed to the sheet processing apparatus;
It is characterized by providing.
[0010]
According to the above configuration, by setting the moving speed at the time of retracting the support means faster than the moving speed at the time of alignment, the alignment quality and the load amount remain the same as before, the processing time is shortened, and the productivity is improved. be able to.
[0011]
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.
[0012]
Hereinafter, embodiments of a sheet processing apparatus and an image forming apparatus including the sheet processing apparatus according to the present invention will be specifically described with reference to the drawings.
[0013]
(overall structure)
FIG. 1 is a cross-sectional view showing an overall configuration of an image forming apparatus main body equipped with a sheet processing apparatus according to the present embodiment, FIG. 2 is a top view of the sheet processing apparatus according to the present embodiment, and FIG. It is sectional drawing which shows schematic structure of the sheet processing apparatus which concerns on a form.
[0014]
As shown in FIG. 1, the sheet processing apparatus 500 is disposed above the image forming apparatus main body 200 and below the document reading apparatus 100. The sheet 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 needle binding and alignment, and then processes the processed sheets. S is aligned and stacked on a stack tray 504 arranged substantially horizontally. Hereinafter, the sheet processing apparatus 500 will be described as an example.
[0015]
However, according to the present invention, the sheet stacking alignment apparatus that aligns and stacks the image-formed sheets S discharged from the image forming apparatus main body 200 on the stack tray 504 directly on the image forming apparatus main body 200 without using the processing tray 540. It is also effective when connected or when the sheet processing apparatus 500 is mounted outside the image forming apparatus main body 200.
[0016]
In FIG. 1, the sheet processing apparatus 500 is mounted on the image forming apparatus main body 200. An automatic document reading apparatus 100 is mounted on the upper part of the image forming apparatus main body 200. The image forming apparatus main body 200, the sheet processing apparatus 500, and the automatic document reading apparatus 100 constitute an image forming apparatus, but the sheet processing apparatus 500 may not include the processing tray 540.
[0017]
As shown in FIG. 1, a document reading unit 150 is mounted on the image forming apparatus main body 200, and a document reading device 100 is mounted on the document reading unit 150. The document reading apparatus 100 separates the document set upward, feeds it one by one to the left sequentially from the first page, conveys it onto the platen glass 102 through a curved path, and reads the document. Thereafter, the paper is discharged to the paper discharge tray 112.
[0018]
In the automatic document reading apparatus 100, the light of the lamp of the scanner unit 104 is irradiated onto the document, and the reflected light from the document is guided to the image sensor 109 via the mirrors 105 and 106 and the lens 107, thereby reading the document. Is done. The image of the original read by the image sensor 109 is subjected to image processing and sent to the exposure control unit 202 of the image forming apparatus main body 200 to emit laser light.
[0019]
Next, in the exposure control unit 202, the laser beam is reflected by the rotating polygon mirror, and is further folded back by the reflecting mirror, so that the surface is uniformly charged on the photosensitive drum 203 serving as an image forming unit. Irradiation forms an electrostatic latent image. The electrostatic latent image on the photosensitive drum 203 is developed by the developing unit 205 and then transferred as a toner image onto a sheet S composed of paper, an OHP sheet, or the like.
[0020]
Sheets S are selectively and appropriately fed from sheet cassettes 231, 232, 233, and 234 by pick-up rollers 238 constituting sheet feeding means, separated by separation means 237, and fed one by one. After the skew is corrected, the toner image is transferred 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.
[0021]
Thereafter, the sheet S is guided to the fixing roller pair 206, and the toner image transferred to the sheet S by being heated and pressed by the fixing roller pair 206 is permanently fixed. The fixing roller pair 206 is in contact with a fixing upper separation claw and a fixing lower separation claw, whereby the sheet S is separated from the fixing roller pair 206.
[0022]
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 guided to the sheet processing apparatus 500 connected to the image forming apparatus main body 200.
[0023]
(Sheet processing device configuration)
Next, the configuration of the sheet processing apparatus 500 will be specifically described.
[0024]
In FIG. 1, a sheet processing apparatus 500 includes a processing tray 540 that is a sheet stacking unit disposed on the upstream side, and a stack tray 504 that is disposed substantially horizontally on the downstream side. The sheet S discharged from the main body side discharge roller pair 207 of the image forming apparatus main body 200 is post-processed by the processing tray 540 and stacked on the stack tray 504.
[0025]
The post-processing mode performed in the processing tray 540 includes a sort mode for sorting a plurality of copies, a staple binding mode for binding a plurality of sheets by the staple unit 510, and the like. It is selected and set by means.
[0026]
In the staple binding mode, it is possible to select a staple binding position such as one-point binding or two-point binding, and the staple unit 510 moves from the setting contents such as the sheet size and the binding position to the actual staple binding position.
[0027]
As shown in FIGS. 2 and 3, the sheet S discharged from the image forming apparatus main body 200 is directed toward the stack tray 504 by a discharge unit including a discharge roller 508 a on the sheet processing apparatus 500 side and a discharge roller 508 b driven by the discharge roller 508 a. The sheet S is discharged, but at the timing when the trailing edge of the sheet S passes the discharging portion, the trailing edge of the sheet S is dropped onto the processing tray 540 by the swing roller 550 and is sandwiched between the swing roller 550 and the driven roller 571. .
[0028]
(Swing 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 showing the operation of the swing roller of the sheet processing apparatus according to the present embodiment, and FIG. 8 is a block diagram showing a control unit of the sheet processing apparatus according to the present embodiment.
[0029]
As shown in FIG. 4, the swing roller 550 is attached to a swing arm 551 that can swing up and down about a swing roller shaft 552.
[0030]
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 rotated. It swings up and down around the swing roller shaft 552 integrally with the swing cam 554.
[0031]
The swing arm 551 is provided with a swing arm tension spring 555 for assisting upward swing.
[0032]
The swing roller 550 is connected to the swing roller driving motor 642 from the swing roller shaft 552 via the swing roller driving belt 556 and the swing roller driven pulley 557, and a drive signal is swung from the CPU 611 shown in FIG. When transmitted to the swing roller driving motor 642 via the moving roller drive motor driver 622, the swing roller 550 rotates.
[0033]
(Oscillating roller operation)
Next, the operation of the swing roller 550 will be described in detail with reference to FIG.
[0034]
The home position of the swing roller 550 is set at an upper portion where it does not come into contact with the sheet S discharged onto the processing tray 540 by the discharge portion (FIG. 4A).
[0035]
When the sheet S is discharged from the discharge unit, the swing arm 551 receives the drive of the swing arm driving motor 643 and rotates counterclockwise about the swing roller shaft 552, so that the swing roller 550 is lowered. Then, the trailing edge of the sheet S is pressed by the swing roller 550, and the trailing edge of the sheet is dropped onto the processing tray 540 (FIG. 4B).
[0036]
Then, the swing roller 550 forms a nip with the driven roller 571 and rotates counterclockwise under the drive of the swing roller driving motor 642, whereby the trailing edge of the sheet S on the processing tray 540 is returned to the return belt 560. The sheet S is pulled along the lower guide 561 in the direction opposite to the conveying direction until then (FIG. 4C).
[0037]
Thereafter, the swing roller 550 is again raised to the home position, and is prepared for the next sheet S to be discharged (FIG. 4A).
[0038]
(Return belt operation)
Next, the operation of the return belt 560 will be described with reference to FIGS. FIG. 5 is a cross-sectional view showing the operation of the return belt of the sheet processing apparatus according to the present embodiment.
[0039]
The return belt 560 is supported in the vertical direction by the discharge roller shaft 509 and is normally set at a position in contact with the sheet S on the processing tray 540.
[0040]
A return belt 560, which is at least one sheet feeding rotary member, arranged in a direction orthogonal to the direction in which the sheet S abuts against the sheet trailing edge stopper 562, is returned by the discharge roller 508 a and the housing 563. The belt pulley 564 is configured via a belt 565 (see FIG. 3). When the discharge roller shaft 509 rotates counterclockwise, the return belt 560 conveys the sheet S toward the sheet trailing edge stopper 562 (FIG. 5A).
[0041]
Further, the return belt 560 escapes in the sheet thickness direction in accordance with the number of sheets S stacked on the processing tray 540 (FIG. 5B).
[0042]
As described above, the rear end of the sheet S is positioned at the end of the processing tray 540 by the counterclockwise rotation of the swing roller 550 and the return belt 560, and is a sheet receiving unit that receives the sheet S on the processing tray 540. A sheet S is fed to the trailing edge stopper 562 and aligned in the sheet conveying direction one by one.
[0043]
(Sheet width alignment)
The alignment in the sheet width direction will be described with reference to FIGS.
[0044]
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.
[0045]
When the sheet processing apparatus 500 is not in operation, the front alignment plate 541 and the rear alignment plate 542 stand by at positions that detect a front alignment home position sensor 530 and a rear alignment home position sensor 531 (not shown), respectively. This position is called an alignment home position position, and is set to a position that does not hit the front alignment plate 541 and the rear alignment plate 542 when the sheet is conveyed.
[0046]
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 conveyance 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 in the sheet width direction. Is done.
[0047]
For example, when the sort mode is selected, when the Nth sheet is aligned 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 with the front side as a reference, and the sheet is discharged onto the stack tray 504 by an operation described later.
[0048]
When aligning the (N + 1) th sheet, the rear alignment plate 542 waits at the reference position, and the front alignment plate 541 moves from the standby position to the sheet alignment position to perform alignment based on the rear side. It is discharged to the tray 504.
[0049]
Thus, the sheets can be stacked on the stack tray 504 in a state of being sorted every time the bundle is discharged.
[0050]
Of course, it is also possible to align with reference to the center position of the sheet. In that case, both the front alignment plate 541 and the rear alignment plate 542 move from the standby position to the alignment position based on the center position to perform alignment.
[0051]
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.
[0052]
When the needle binding mode is selected, the needle binding operation is subsequently performed. The staple unit 510 performs a staple binding operation by driving a staple clinching motor 648. Further, the staple unit 510 can be moved in the front-rear direction by driving a staple slide motor 649.
[0053]
When the job is started, the staple unit 510 moves to the actual staple binding position calculated from the contents of the staple binding position set before the job start and the sheet size. The staple unit 510 performs a staple binding operation on the aligned sheet bundle S that has undergone the above-described width direction alignment.
[0054]
(Bundle discharging means)
Next, the bundle discharging means will be described with reference to FIGS. FIG. 6 is a cross-sectional view illustrating the sheet bundle discharging operation of the sheet processing apparatus according to the present embodiment.
[0055]
After completion of alignment in the sheet conveyance direction, alignment in the sheet width direction, and staple binding operation, the swing roller 550 is driven by the swing arm drive motor 643 and contacts the sheet bundle S around the swing roller shaft 552. (FIG. 6A), and after forming a nip with the driven roller 571, the sheet roll S is rotated clockwise and conveyed until the rear end of the sheet bundle S reaches the vicinity of the upper end of the rear end alignment wall 570, and is stopped ( FIG. 6 (b)).
[0056]
Thereafter, the swing roller 550 is separated from the sheet bundle S and returns to the home position (FIG. 6C). At the same time, the trailing edge aligning wall 570 is swung by the cam 572 located below the trailing end aligning wall 570 around the cam swinging rotation shaft 573 at the moving speed V1 in the opposite direction to the sheet conveyance.
[0057]
(Seat rear edge alignment)
A means for discharging, aligning and stacking the sheet bundle S on the processing tray 540 onto the stack tray 504 will be described with reference to FIGS. FIG. 7 is a cross-sectional view showing the alignment operation of the trailing edge of the sheet bundle of the sheet processing apparatus according to the present embodiment, and FIG. It is a graph which shows the relationship between a speed) and a change of a position.
[0058]
The rear end alignment wall 570 is biased by a spring 512, and swings about the swinging rotation shaft 573 by contacting the cam 572 at the home position (FIGS. 3 and 7).
[0059]
In a state where the rear end of the sheet bundle S discharged by the bundle discharge means is in contact with the upper end of the rear end alignment wall 570 (FIG. 6B), the rear end alignment wall 570 is moved upstream in the sheet conveying direction at a moving speed V1. The sheet bundle S is retracted (FIG. 6C), and the rear end of the sheet bundle S is brought into contact with the slope portion of the rear end alignment wall 570 (FIG. 7A). In order to increase the accuracy of sheet rear end alignment, the home position of the rear end alignment wall 570 is detected by the rear end alignment wall home position sensor 523 (FIG. 8).
[0060]
In the process of returning the retracted rear end alignment wall 570 to the home position at the center of the swinging rotation axis at the moving speed V2, the rear end of the sheet bundle S is pressed in the horizontal direction by the rear end alignment wall 570 so that the sheet bundle S While aligning the trailing edge, the sheet bundle S is stacked on the stack tray 504 (FIGS. 7B and 7C).
[0061]
As shown in FIG. 10, in the drive control of the rear end matching wall motor according to the present embodiment, when the retreat is first performed, the motor is driven so that the moving speed becomes V1, and the movement is completed. The rear end alignment motor is stopped. When a predetermined time elapses after the stop, the return operation is started and the rear end alignment motor is driven so as to have the moving speed V2. When the movement is completed, the rear end alignment motor is stopped.
[0062]
Furthermore, by setting the above-described movement speed V1 and movement speed V2 in a relationship of V1> V2, the processing time required for discharging the sheet bundle is reduced while maintaining the alignment quality by the rear end alignment wall 570. Yes.
[0063]
The sheet bundle placed on the stack tray 504 is pulled back toward the trailing edge alignment wall 570 by the sheet return member 583 after the sheet bundle is discharged and pressed from the upper surface of the sheet bundle.
[0064]
More specifically, the sheet post-processing apparatus according to the present invention is an intermediate processing unit (for example, stacking and processing the sheet S conveyed from the sheet conveying unit (for example, the main body discharge roller pair 207)). , The stapling unit 510), a stacking unit (for example, stack tray 504) for stacking the sheet bundle processed by the intermediate processing unit, and a support position for supporting the lower surface of the sheet bundle processed by the intermediate processing unit, or A supporting means (rear end alignment wall 570) selectively movable to a retracted position retracted from the lower surface of the sheet bundle, a switching control means for switching between the supporting position of the supporting means and the retracted position, and the supporting means A sheet post-processing apparatus having transfer means (swinging roller 550) capable of transferring the supported sheet bundle to the stacking means, the switching When the rear end of the sheet bundle reaches the upper part of the support means by the transfer means, the control means moves the support means to the retracted position at the first moving speed V1 to drop the sheet bundle onto the stacking means. Thereafter, the trailing end of the sheet bundle dropped on the stacking unit is aligned by moving the supporting unit from the retracted position to the supporting position at a second moving speed V2 that is slower than the first moving speed V1. It is characterized by controlling as follows.
[0065]
Here, examples of the switching control means include one that detects the movement of the sheet bundle by an electric sensor and controls the movement between the support position and the retreat position of the rear end alignment wall that is the support means, Further, the movement of the sheet bundle may be mechanically transmitted to the movement of the rear end alignment wall. Note that the switching control unit may be provided in the sheet post-processing apparatus or may be provided in the control unit of the image forming apparatus.
[0066]
(Sheet return member)
A sheet return member (hereinafter referred to as a “paddle”) 583 that is a paddle-like member rotates around a paddle rotation shaft 590 (see FIGS. 6 and 7) provided in the rear end alignment wall 570. Yes. Each time the sheet bundle is discharged onto the stack tray 504 by the swing roller 550, the paddle 583 rotates the paddle 583 counterclockwise so that the discharged sheet bundle is moved toward the rear end alignment wall 570. Each time it is pulled back, the trailing edge of the sheet bundle can be pressed.
[0067]
It should be noted that the paddle 583 is held in the state shown in FIGS. 6A and 6B except during the sheet returning operation, and holds the sheet S. The position of the paddle 583 at this time is detected by a paddle home position sensor 532 (not shown).
[0068]
Further, the stack tray 504 is configured to be lifted and lowered by a driving unit (not shown) in order to keep the upper surface height of the stacked sheet bundle S constant.
[0069]
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 aligning means works effectively, and the sheet stacking surface is When it is substantially horizontal, the effect is further increased. Further, by setting the sheet stacking surface 504a to an inclination angle of 18 ° or less downward toward the sheet rear end alignment wall, the sheet stacking surface 504a is discharged from the rear end of the bundle of sheets stacked on the stack tray 504 and the processing tray 540. The apparatus can be reduced in size while avoiding interference with the subsequent sheet bundle.
[0070]
(System block configuration)
Next, the configuration of a controller that controls the entire image forming apparatus will be described with reference to FIG. FIG. 9 is a block diagram showing a configuration of a controller that controls the image forming apparatus according to the present embodiment.
[0071]
As shown in FIG. 9, the controller includes a CPU circuit unit 350, and the CPU circuit unit 350 includes a CPU 351, a ROM 352, and a RAM 353. The CPU circuit unit 350 includes an external I / F 320, an image signal control unit 330, a printer control unit 340, a RAM 353, a document feeding device control unit 360, an image reader control unit 370, a sheet process, according to a control program stored in the ROM 352. Each block of the apparatus control unit 600 is comprehensively controlled.
[0072]
The RAM 353 temporarily stores control data and is used as a work area for arithmetic processing associated with control.
[0073]
The document feeder control unit 360 controls driving of the document reading device 100 based on an instruction from the CPU circuit unit 350.
[0074]
The image reader control unit 370 performs drive control on the scanner unit 104 and the image sensor 109 described above, and transfers an analog image signal output from the image sensor 109 to the image signal control unit 330.
[0075]
The image signal control unit 330 converts each analog image signal from the image sensor 109 into a digital signal, performs each process, converts the digital signal into a video signal, and outputs the video signal to the printer control unit 340. The digital image signal input from the computer 310 via the external I / F 320 is subjected to various types of processing, and the digital image signal is converted into a video signal and output to the printer control unit 340. The processing operation by the image signal control unit 330 is controlled by the CPU circuit unit 350.
[0076]
The printer control unit 340 drives the laser scanner unit 202 described above based on the input video signal.
[0077]
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 the 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.
[0078]
The sheet processing apparatus control unit 600 is mounted on the sheet processing apparatus 500 and performs drive control of the entire sheet processing apparatus by exchanging information with the CPU circuit unit 350. This control content will be described later.
[0079]
(Block diagram of sheet processing device)
Next, the configuration of the sheet processing apparatus control unit 600 that drives and controls the sheet processing apparatus 500 will be described with reference to FIG. FIG. 8 is a block diagram illustrating a configuration of the sheet processing apparatus control unit according to the present embodiment.
[0080]
As illustrated in FIG. 8, the sheet processing apparatus 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 unit 610 communicates with the CPU circuit unit 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 unit 350. The program is executed to control the driving of the sheet processing apparatus 500.
[0081]
When this drive control is performed, detection signals from various sensors are taken into the CPU circuit unit 610.
[0082]
The various sensors include an inlet sensor 521, a swing home position sensor 522, a rear end alignment wall home position sensor 523, a tray detection sensor 524, a paper surface detection sensor 525, a return belt retract sensor 526, a staple slide home position sensor 527, a staple clinch. There is a home position sensor 528.
[0083]
The motor circuit drivers 621 to 630 are connected to the CPU circuit unit 610, and each driver drives the motor based on a signal from the CPU circuit unit 610.
[0084]
Here, as the motor, a pair of inlet transport rollers 520, a paper discharge motor 641, which is a drive source of the return belt 560, and a swing roller 550 attached to the front end of the swing arm 551 is a sheet transported by the pair of entrance transport rollers 520. The swinging roller drive motor 642 which also serves as a drive for returning the sheet to the stacking tray 504 and the drive for discharging the bundle of sheets processed on the processing tray 540 to the stack tray 504, and the swinging roller to catch the trailing edge of the sheet discharged to the processing tray 540. A swing arm drive motor 643 that is a drive source for driving the moving arm 551 in the vertical direction, and a drive source that drives the trailing end alignment wall 570 to perform trailing end alignment of the sheet bundle discharged on the stack tray 504. A paddle as a pressing member for pressing the rear end portion of a sheet bundle stacked on a certain rear end alignment wall drive motor 644 and the stack tray 504 83, a paddle motor 645 serving as a drive source, a front alignment motor 646 serving as a drive source for an alignment plate that aligns the sheets stacked on the processing tray 540 in a direction perpendicular to the sheet conveying direction, a rear alignment motor 647, and a staple unit 510. There are a staple slide motor 649 which is a driving source for driving in the front-rear direction, a stack tray motor 650 which is a driving source for the stack tray 504, and a staple clinching motor 648 which is a driving source for staple driving by the staple unit 510.
[0085]
The paper discharge motor 641, the swing roller drive motor 642, the swing arm drive motor 643, the rear end alignment wall drive motor 644, the paddle motor 645, the front alignment motor 646, the rear alignment motor 647, and the staple slide motor 649 are stepping motors. By controlling the excitation pulse rate, the roller pair driven by each motor can be rotated at a constant speed or can be rotated at a unique speed.
[0086]
The paper discharge motor 641, the swing roller drive motor 642, the swing arm drive motor 643, the front alignment motor 646, the rear alignment motor 647, and the staple slide motor 649 are a paper discharge motor driver 621 and a swing roller drive motor driver 622, respectively. The oscillating arm drive motor driver 623, the front alignment motor driver 626, the rear alignment motor driver 627, and the staple slide motor driver 629 can be driven in the forward and reverse rotation directions.
[0087]
The staple clinching motor 648 and the stack tray motor 650 are DC motors.
[0088]
【The invention's effect】
As described above, according to the present invention, it is possible to realize the securing of the load capacity and the improvement of productivity while maintaining good alignment quality and loadability without significantly changing the configuration.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view illustrating an overall configuration of an image forming apparatus including a sheet processing apparatus according to an embodiment.
FIG. 2 is a top view of the sheet processing apparatus according to the embodiment.
FIG. 3 is a cross-sectional view illustrating a schematic configuration of a sheet processing apparatus according to an embodiment.
FIG. 4 is a cross-sectional view showing an operation of a swing roller of the sheet processing apparatus according to the embodiment.
FIG. 5 is a cross-sectional view showing the operation of the return belt of the sheet processing apparatus according to the embodiment.
FIG. 6 is a cross-sectional view illustrating a sheet bundle discharging operation of the sheet processing apparatus according to the embodiment.
FIG. 7 is a cross-sectional view showing the alignment operation of the trailing edge of the sheet bundle of the sheet processing apparatus according to the embodiment.
FIG. 8 is a block diagram illustrating a control unit of the sheet processing apparatus according to the embodiment.
FIG. 9 is a block diagram illustrating a configuration of a controller that controls the image forming apparatus according to the embodiment.
FIG. 10 is a time chart showing a driving state of a rear end alignment wall motor.
FIG. 11 is a cross-sectional view illustrating an overall configuration of an image forming apparatus including a conventional sheet processing apparatus.
[Explanation of symbols]
S sheet (sheet bundle)
100 Document Reading Device 150 Document Reading Unit 200 Image Forming Apparatus Main Body 202 Exposure Control Unit 203 Photosensitive Drum 205 Developing Device 206 Fixing Roller Pair 211 Transfer Belt 500 Sheet Processing Device 504 Stack Tray 508a Discharge Roller 508b Discharge Roller 509 Discharge Roller Shaft 510 Staple Unit 512 Rear end alignment wall bias spring 520 Inlet conveyance roller pair 521 Inlet sensor 522 Swing home position sensor 523 Rear end alignment wall home position sensor 524 Tray detection sensor 525 Paper surface detection sensor 526 Belt retraction sensor 527 Staple slide home position sensor 528 Staple clinch home position sensor 530 Front alignment home position sensor 531 Rear alignment home position sensor 532 Paddle home position sensor 540 Processing tray 541 Front alignment plate 542 Rear alignment plate 550 Oscillating roller 551 Oscillating arm 552 Oscillating roller shaft 553 Oscillating cam 555 Oscillating arm tension spring 556 Oscillating roller drive belt 557 Oscillating roller driven Pulley 560 Return belt 561 Lower guide 562 Seat rear end stopper 563 Housing 564 Return belt pulley 565 Belt 570 Rear end alignment wall 571 Driven roller 572 Cam 573 Oscillating rotation shaft 574 Pinion gear 575 Rear end alignment wall home position sensor 580 Bundle discharging means 581 Stack tray 582 Gripper 583 Sheet return member (paddle)
585 Front end regulating plate 590 Paddle rotation shaft 600 Sheet processing device control unit 610 Circuit unit 641 Paper discharge motor 642 Swing roller drive motor 643 Swing arm drive motor 644 Rear end alignment wall 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

Claims (2)

Intermediate processing means for stacking and processing sheets conveyed from the sheet conveying means;
Stacking means for stacking a sheet bundle processed by the intermediate processing means;
A support means capable of selectively moving to a support position for supporting the lower surface of the sheet bundle processed by the intermediate processing means or a retreat position retracted from the lower surface of the sheet bundle;
Switching control means for switching between a support position and a retracted position of the support means;
A sheet processing apparatus having transfer means capable of transferring the sheet bundle supported by the support means to the stacking means,
The switching control means includes
When the rear end of the sheet bundle reaches the upper portion of the support means by the transfer means, the sheet bundle is dropped onto the stacking means by moving the support means to the retracted position at the first moving speed,
After that, the rear end of the sheet bundle dropped on the stacking unit is controlled by moving the supporting unit from the retracted position to the supporting position at a second moving speed that is slower than the first moving speed. A sheet processing apparatus. A sheet processing apparatus according to claim 1;
Image forming means for forming an image on a sheet conveyed to the sheet processing apparatus;
An image forming apparatus comprising:

Images