JPH10245148A - Sheet postprocessing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To attain size reduction in a sheet postprocessing device, and prevent carrying failure by performing width directional sheet registering processing and shift processing to sort sheets with every sheet number, and arranging the specific number of independently movable aligning members on the width directional both sides orthogonal to the sheet carrying direction. SOLUTION: In the case of a sheet P1 of the ordinary size, two aligning plates 91A and 91B respectively align a width by beating the side edge of the sheet P1 by moving to a position slightly narrower than a paper width every time when the sheet P1 is sent into the vicinity of staplers 10A and 10B. After the prescribed number of sheets P1 reach a tip part 14A of a discharge arm, a staple is driven by either one or both of the staplers 10A and 10B. Afterwards, rear end parts of the sheets P1 are discharged to a paper discharge tray by a tip part 14A of the discharge arm (a). In the case of a sheet P2 of the small size, every time when it comes into contact with the tip part 14A, one aligning plate 91B pushes the side edge, and shifts it to one side, and a staple is driven (b) after the other aligning plate 91A aligns a width.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus such as an electrophotographic copying machine, a printer or a printing machine, which receives a sheet on which an image has been formed and performs post-processing such as stapling by a stapler and shift processing. The present invention relates to a sheet post-processing apparatus that discharges a sheet to a sheet discharge tray by a discharge unit after performing the operation.

[0002]

2. Description of the Related Art A sheet post-processing apparatus called a finisher is used as an apparatus for collating and binding a plurality of image-recorded sheets discharged from an image forming apparatus for each copy by a stapler.

The finisher has a function connected to an image forming apparatus main body such as a copying machine or a printer, and is driven in accordance with a sequence operation of a copy or print process.

Therefore, for an image forming apparatus capable of performing a large amount of image forming processes at a high speed, a finisher capable of performing a function at a high speed following the processing speed is required. .

A finisher capable of such high-speed processing has been disclosed in Japanese Patent Application Laid-Open Nos. 60-142359 and 60-142359.
Japanese Patent Publication Nos. 0-158463 and 62-239169, and Japanese Patent Application Laid-Open Nos. 62-288002, 63-267667, Japanese Patent Application Laid-Open No. 2-276691, and Japanese Patent Publication No. 5-41991 are disclosed.

[0006] Sheets with images recorded thereon, which are carried out of the image forming apparatus main body, are sequentially stacked while being aligned in the intermediate stacker, and after storing one set of sheet bundles, sheet post-processing such as a stapler is performed, and binding is performed. The sheet bundle placed is conveyed on a discharge belt provided at the bottom of the intermediate stacker, further nipped by a pair of upper and lower discharge rollers, and discharged onto a discharge tray.

The sheet post-processing apparatus disclosed in Japanese Patent Application Laid-Open No. Hei 2-276691 has a structure in which two fur brushes are rotatably provided, and the tips of the fur brushes are brought into contact with a guide plate. The sheet post-processing device disclosed in the paper storage device of Japanese Patent Application Laid-Open No. 1-214565 is configured to align a sheet by rotating a paddle wheel on which a plurality of blade members are radially mounted. JP-A-63-1
In the sheet post-processing apparatus disclosed in Japanese Patent No. 16168, a part of a belt whose lower end portion is in contact with an intermediate tray is wound around a lower roller of a pair of discharge rollers, and the belt rotates together with the lower roller to rotate on the intermediate tray. The sheet conveyed out is brought into contact with the stopper.

A sheet post-processing apparatus disclosed in Japanese Patent Application Laid-Open No. 1-127556 discloses a first and second sheet conveying apparatus for conveying a sheet sent from an image forming means to a sheet post-processing means.
One sheet conveying path, and conveying direction switching means for switching between the first and second sheet conveying paths, and conveying the sheet so as to be sent to the second sheet conveying path in accordance with the operation of the sheet processing means. It has control means for controlling the direction switching means.

The recording paper post-processing apparatus described in Japanese Patent Application Laid-Open No. 8-42728 is provided with one stapler and one corresponding paper discharge tray. Also, Japanese Patent Application Laid-Open
The sheet post-processing apparatus described in Japanese Patent Application No. 76190/1990 includes two staplers and two corresponding paper discharge trays.

[0010]

In a conventional sheet post-processing apparatus, an image-formed sheet carried out of the image forming apparatus is processed by sheet post-processing means (staplers, shift means, bookbinding means, punching means, etc.). After that, the paper is discharged onto a vertically movable paper discharge tray.

FIG. 14 is a block diagram showing an example of a conventional sheet post-processing apparatus. The sheet post-processing apparatus is installed with its position and height adjusted so that the receiving portion of the sheet P coincides with the discharge port of the main body of the image forming apparatus (copier, printer, etc.).
The image forming apparatus is connected to a control system so as to be driven in response to the operation of the main body.

The conveying path of the sheet P connected to the sheet conveying downstream of the pair of rollers a at the entrance of the receiving section is a first path of the upper stage.
The transport path 100, the second transport path 200 in the middle stage, and the third transport route in the lower stage
It is branched into three systems of the transport path 300 and has a switching gate g.
The sheet P is fed to one of the conveying paths by selecting the swing angle of 1 or g2.

The first transport path 100 is a transport path for discharging a sheet P having an image forming surface facing upward to the uppermost non-post-processing discharge tray T1 without performing post-processing. Second transport path 20
0 is a sheet tray T2 which can be moved up and down after the sheet P is shifted by the shift means b in a direction orthogonal to the sheet conveying direction.
Sheet P or switch back sheet P
Is a transport path for transporting the sheet to the non-post-processing paper discharge tray T1 after reversing. The third conveyance path 300 indicates a conveyance path for storing the sheet P in the intermediate stacker c, performing sheet post-processing by the stapler ST, and then conveying the sheet P to the movable discharge tray T2.

The problems of the conventional sheet post-processing apparatus will be listed below.

(1) The illustrated sheet post-processing apparatus is provided above a first post-processing means including an intermediate stacker c, a stapler ST, and a third conveyance path 300, and above the first post-processing means. Two independent systems of a shift mechanism b and a second post-processing means including the second conveyance path 200 are required. For this reason, the sheet conveyance path becomes long and complicated, which causes a sheet conveyance failure. Also, the second transport path 2
Since it requires a branching unit between the second conveying path 300 and the third conveying path 300, a large number of conveying rollers, and a driving unit for these, there are problems that the apparatus becomes complicated, large, and the manufacturing cost increases.

(2) In a sheet post-processing apparatus capable of simultaneously moving two sets of staplers ST corresponding to various sheet sizes and stapling them at two predetermined positions,
Two sets of staplers ST approach the sheet width direction at the same time by a single driving source, and at close distances, the staplers ST interfere with each other, so that they are small in size (for example, A5R, B5R, etc.).
It is difficult to staple the sheet P. Further, in a sheet post-processing apparatus having a sheet reversing / conveying drum which has a sheet gripper means near the center in the sheet width direction and is driven and rotated, when stapling the small-sized sheet P, the stapler ST and the sheet reversing Interference with the transport drum makes it difficult to perform staple processing.

(3) The illustrated sheet post-processing apparatus includes an intermediate stacker c that conveys and places the sheets P for stapling, and a vertically movable discharge tray T2 that stacks the stapled sheets P. However, there is a problem that the size of the device is increased because the devices are completely different from each other and are arranged in series.

An object of the present invention is to solve the above problems, and (1) to make the stapler means and the shift means compact with a simple configuration, to reduce the size of the sheet post-processing apparatus, and to reduce the sheet conveyance failure. (2) Enable staple processing even for small-sized sheets, (3)
It is an object of the present invention to provide a sheet post-processing apparatus that reduces the vertical projection area occupied by a staple processing unit and a paper discharge tray, thereby achieving a reduction in a sheet conveyance path and a reduction in the size of the apparatus.

[0019]

A sheet post-processing apparatus according to the present invention, which achieves the above object, post-processes an image-formed sheet carried out from an image forming apparatus by a sheet post-processing means, and then discharges a sheet bundle. In the sheet post-processing apparatus for discharging to a paper tray means, two aligning members which can be independently moved are provided on both sides in a width direction orthogonal to the sheet conveying direction, and these aligning members are provided in the width direction. The present invention is characterized in that two processing operations, ie, an alignment processing and a shift processing for sorting sheets by the number of sheets, can be executed.

[0020]

Next, an embodiment of a sheet post-processing apparatus according to the present invention will be described with reference to the accompanying drawings.

FIG. 1 is a sectional view showing the structure of the sheet post-processing apparatus (finisher). The sheet post-processing apparatus is installed with its position and height adjusted so that the receiving portion of the sheet P coincides with the discharge port of the main body of the image forming apparatus (copier, printer, etc.), and corresponds to the operation of the main body of the image forming apparatus. Connected to a control system to be driven.

The P introduced into the movable guide plate 1 of the receiving section is conveyed while being nipped by a conveying roller pair 2 composed of a driving roller and a pinch roller, passes through a fixed guide plate 3, and passes through a sheet reversing conveying drum. Transport roller pair 5 above 4
And is conveyed onto the peripheral surface of the sheet reversal conveyance drum 4. The sheet reversing / conveying drum 4 is driven and rotated by a driving source (not shown). A sheet pressing member (gripper) 6 is swingably supported near the peripheral surface of the sheet reversing / conveying drum 4. The sheet pressing member 6 is biased by a spring and is swung by a cam mechanism (not shown).

The leading end of the sheet P sent from the nip position of the pair of carrying rollers 5 to the peripheral surface of the sheet reversing / conveying drum 4 is connected to the leading end of the sheet pressing member 6 opened by the cam mechanism and the sheet reversing / conveying. The sheet enters the V-shaped gap between the drum 4 and the peripheral surface of the rotating sheet reversing / conveying drum 4, and is pressed and sandwiched between the peripheral surface of the rotating sheet reversing / conveying drum 4 and the tip of the spring-biased sheet pressing member 6. It is transported on the peripheral surface of the reverse transport drum 4. At the time of this sheet conveyance, the peripheral speeds of the conveyance roller pair 5 and the sheet reversal conveyance drum 4 are equal.

Above the movable guide plate 1 and the conveying roller pair 2, an uppermost sheet discharging means (non-sort tray) 7 is provided. The uppermost sheet discharging means 7 includes a sheet discharging tray 7A on the left side in the figure and a sheet discharging tray 7B on the right side in the figure around the fulcrum shaft 7C.
The paper discharge trays 7A and 7B can swing about the fulcrum shaft 7C in the direction of the dashed line. The paper discharge tray 7B includes the movable guide plate 1 and the transport roller pair 2
As a result, the movable guide plate 1 and the conveying roller pair 2 also swing together as a result of the swing of the movable guide plate 1. The movable guide plate 1 shown by the solid line in FIG.
, The conveying roller pair 2 and the sheet discharge tray 7B indicate a path for conveying the sheet P discharged from the image forming apparatus to the sheet post-processing unit. The broken line in FIG. 1 indicates that the unit including the movable guide plate 1, the transport roller pair 2, and the paper discharge tray 7B is swung downward,
4 shows a path that allows a sheet that does not require sheet post-processing to be conveyed to the uppermost sheet discharging means 7.

FIGS. 2 to 7 are partial sectional views showing a sheet conveying process of the sheet post-processing apparatus.

In FIG. 2, the leading end of the sheet P is
When the conveying roller pair 5 is accelerated during the process of pressing and holding the front end portion of the spring-biased sheet pressing member 6 on the peripheral surface of the rotating sheet reversing conveying drum 4 to convey the sheet, The leading end of the sheet P is sandwiched by the sheet pressing member 6, but the vicinity of the rear end of the sheet P is increased in speed by the pair of conveying rollers 5 to feed out the sheet P excessively. The outer peripheral surface of the drum 4 is swelled outwardly.

In FIG. 3, when the sheet reversing / conveying drum 4 continues to rotate further, the moment the rear end of the sheet P separates from the nip position of the conveying roller pair 5, the conveying force of the conveying roller pair 5 is reduced. The sheet P is inverted due to the rigidity of the sheet P, and is separated from the peripheral surface of the sheet inversion transport drum 4. When the leading end of the sheet P reaches the leading end 14A of the discharge arm 14 stopped near the stapler (stapling means) 10, the sheet holding member 6 separates from the sheet P when it stops.

As the sheet reversing / conveying drum 4 continues to rotate further, as shown in FIG. 4, two sheet aligning members 8A, 8B rotatably supported at two positions in the sheet reversing / conveying drum 4. Successively rubs the vicinity of the leading end of the sheet P so that the leading end of the sheet P is
The sheet P is stopped in contact with A, and the sheets P are aligned in the transport direction. The leading end of the aligned sheet P is the intermediate output tray 9.
On 2A, the rear end portion is placed on the movable discharge tray 21.

In the process shown in FIG. 5 in which the leading end of the sheet P is brought into contact with the leading end 14A of the discharge arm 14, the alignment plate of the shift aligning means 9 described later moves in the width direction of the sheet P (perpendicular to the sheet conveying direction). Direction) (paper width alignment). Alternatively, when the shift mode is set,
The width alignment is performed by alternately shifting the alignment plate to a plurality of predetermined positions. After the sheet reversing / conveying drum 4 completes one rotation and the positioning of the first sheet P is completed, the second sheet P is fed to the sheet reversing / conveying drum 4, and the same conveyance as described above is performed, and the positioning is performed. And stop. When the number of sheets P positioned and brought into contact with the leading end portion 14A reaches a predetermined number, staples are driven into the predetermined positions of the sheets P by the stapler 10 and bound (see FIG. 5). Alternatively, when the shift mode is set, the shift operation by the matching plate is performed.

FIG. 6 shows a state in which the sheet P which has been subjected to the sheet post-processing such as the staple processing or the shift processing is discharged to the movable discharge tray 21.

The drive motor M2 includes gears G7, G8, G
The disk 12 is driven to rotate via a gear train consisting of G9 and G10. The other end of the crank 13, one end of which is supported at an eccentric position of the disk 12, is rotatably supported by a part of a discharge arm 14 that can swing about a fulcrum shaft 15. The disk 12 driven and rotated by the drive source causes the crank 13 to eccentrically move and further causes the discharge arm 14 to swing. Due to the swinging movement of the discharge arm 14, the leading end 14A of the discharge arm 14 presses the leading end of the sheet P that has been subjected to the sheet post-processing, and contacts the leading end 14A toward the movable discharge tray 21 from the position. Push out. The sheet P pushed out by the discharge arm 14 slides on the upper surface of the movable paper discharge tray 21, and then the leading end of the sheet P descends by its own weight, and a stopper surface provided on the frame 23 supporting the movable paper discharge tray 21. 231 and stops. Since the leading end portion 14A advances toward the movable sheet discharge tray 21 from a position perpendicular to the stopper surface 231, the sheet bundle is reliably transferred to the stack portion without remaining in the processing unit.

The movable discharge tray 21 is swingably supported by a fulcrum shaft 24 that is implanted in a frame 23. A swing lever 2 is provided on the bottom surface of the movable discharge tray 21 at the right end in the figure.
5 comes into contact with each other, and the movable paper discharge tray 21 is moved up and down. The base of the swing lever 25 is pivotally supported by a fulcrum shaft 26 and is swingable. A swing lever 25 is attached to one end of the fulcrum shaft 26.
The locking member 27, which is integral with the first member, is swingable. The locking member 27 is urged by a spring 28 to raise the tip of the swing lever 25. As a result, the leading end of the movable sheet discharge tray 21 is lifted and swings about the fulcrum shaft 24 in the counterclockwise direction shown in the figure. Since the tip claw portion of the locking member 27 is removably locked to the locking portion 232 provided on the frame body 23, the swing lever 25 is prevented from swinging to a predetermined position or more. The distal end of the movable paper discharge tray 21 is held at a predetermined height by being biased by a spring.

As shown in FIG. 7, when the number of the post-processed sheets P stacked on the movable discharge tray 21 gradually increases, the leading end of the movable discharge tray 21 is moved by the spring 2 due to its own weight.
8, the locking member 27 and the locking portion 232 are unlocked by depressing the swing lever 25, and the leading end of the movable discharge tray 21 is gradually lowered. I will do it. During the lowering process of the movable paper discharge tray 21, the post-processed sheet P is discharged from a post-processing unit (stapler, shift processing unit) on the uppermost layer of the sheets P stacked on the movable paper discharge tray 21. Held in position.

After the post-processed sheets P stacked on the movable discharge tray 21 gradually increase, the movable discharge tray 21 gradually descends and reaches the lower limit position. The provided actuator (not shown) is detected by a sensor PS2 fixed on the sheet post-processing apparatus main body side,
The detection signal is sent to a control unit 80 described later. Note that the sensor PS1 may be installed on the frame 23 to detect the lower limit position of the movable sheet discharge tray 21.

FIG. 8 is a cross-sectional view showing the driving of the sheet discharge tray means in the sheet post-processing apparatus having the two-stage sheet discharge tray means. Since the upper discharge tray means 20 and the lower discharge tray means 30 have the same structure, the same reference numerals will be used in the following description. In FIG. 1, the upper discharge tray 20 and the lower discharge tray 30 are lowered to the bottom dead center, and the post-processed sheet P is stored in the upper discharge tray 20. Indicates the status. FIG. 8 shows a state in which the upper discharge tray 20 and the lower discharge tray 30 are raised to the top dead center, and the post-processed sheet P is stored in the lower discharge tray 30. . Hereinafter, the lifting structure and operation of the upper discharge tray means 20 and the lower discharge tray means 30 will be described with reference to FIGS.

The sensor PS2 detects that the post-processed sheets P stacked on the movable sheet discharge tray 21 of the upper sheet discharge tray means 20 are full (upper limit of the stacking amount) and generates a signal. Then, the control unit (not shown) operates
The drive motor M1 for raising and lowering the tray is driven to raise the upper discharge tray means 20. That is, the drive motor M1
Drives G1, G2, G3, G4, G5, G
The gear train composed of 6 drives and rotates the drive pulley 41.
Between the driving pulley 41 and the upper driven pulley 42,
The drive wire 43 is wound. By the driving rotation of the driving pulley 41, the driving wire 43 reciprocates in the vertical direction.

The base of the frame 23 of the upper discharge tray means 20 is fixed to a part of the drive wire 43 by a discharge tray hanging member 44. The frame 23 of the upper discharge tray means 20 and the frame 23 of the lower discharge tray means 30
And are connected by a connecting rod 45. That is, a long groove 451 is formed in the connecting rod 45, and a pin 46 fixed to the frame body 23 of the upper sheet discharging tray means 20 comes into sliding contact with the connecting rod 45 (see FIG. 1). The vicinity of the lower end of the connecting stick 45 is fixed to the frame 23 of the lower sheet ejection tray means 30.

When the upper discharge tray means 20 is moved upward by the drive wire 43, a pin 46 (see FIG. 1) fixed to the frame 23 of the upper discharge tray means 20 is connected to the connecting rod 45. Only the upper discharge tray means 20 is moved upward in sliding contact with the long groove portion 451. When the pin 46 abuts on the uppermost end of the long groove 451 of the connecting rod 45, the moved upper discharge tray means 20 and the stopped lower discharge tray means 30 have a maximum separation distance.

The upper discharge tray means 20 is provided with the driving wire 4
3, the pin 46 of the upper discharge tray 20 moves the connecting stick 45 upward in a state of contact with the long groove 451, and is fixed to the lower end of the connecting stick 45. The lower discharge tray means 30 is lifted and moved. Therefore, the upper discharge tray means 20 and the lower discharge tray means 30 move upward integrally while maintaining the maximum separation interval.

The upper discharge tray means 20 includes the drive wire 4
3, the upper end of the frame 23 of the upper discharge tray means 20 is moved upward by the uppermost discharge means 8.
Of the paper discharge tray 7A on the left side in the figure, and push up the paper discharge tray 7A. As a result, the discharge tray 7A is
It is swung clockwise around the fulcrum shaft 7C and retracts.

When the detection means (sensor PS5) detects that the upper discharge tray means 20 has reached the top dead center, the drive motor M
1 is stopped, and the upper discharge tray 20 and the lower discharge tray 30 are stopped. At this time, the lower discharge tray 30 stops at a position for receiving the sheet P after the post-processing by the stapler 10.

FIG. 9 shows upper and lower discharge tray means (20, 3).
It is a top view of (0). The movable paper discharge tray 21 is arranged at the center of the discharged sheet P in the width direction and is swingably supported. On both sides of the movable discharge tray 21 in the sheet width direction, two fixed discharge trays 22 are fixed to a frame 23.

A total of four guide rollers 47 are rotatably supported on both sides and upper and lower sides of the base of the frame 23 in the sheet width direction. When the guide roller 47 moves along the sliding surface of the guide rail 48 fixed to the sheet post-processing apparatus main body, the upper discharge tray unit 20 and the lower discharge tray unit 30 move up and down, respectively. .

FIG. 10 is a front view of the shift matching means 9.

The shift aligning means 9 includes one aligning plate 91A.
And a second unit 90 on the right side of the drawing for moving the other matching plate 91B.
B. These two units 90A and 90B are
Since the first unit 90A has almost the same structure, the first unit 90A will be described below.

The alignment plate 91A is also fixed to a unit housing and a carriage 94A that can linearly reciprocate by sliding on a guide bar 93A fixedly supported in an intermediate discharge tray 92A. The carriage 94A has a timing belt 97 stretched between a driving pulley 95A and a driven pulley 96A.
A is fixed to a part of A by a fixing member 98A. The drive pulley 95A is connected to a gear G by a drive motor M3 as a drive source.
It is driven and rotated through 11, G12. PS6A is a home position sensor. Similarly, the second unit 90B is linearly reciprocated by the drive motor M4 of another drive source via the gear train and the timing belt 97B. In this way, the matching plates 91A and 91B each have a dedicated drive motor and can move independently.

FIG. 11 shows the alignment plate 91 during the stapling process.
It is a schematic plan view which shows operation | movement of A and 91B.

FIG. 11A shows a sheet P of a normal size.
1 shows a state in which staple processing is performed with 1 being width-aligned. The matching plates 91A and 91B are respectively provided with dedicated driving motors M3 and M
4 to move from the initial position where the home position sensors PS6A and PS6B are located to a position slightly wider than the sheet width of the sheet P1 and wait. Each time the sheet P1 is sent near the stapler, it moves to a position slightly smaller than the paper width,
The width alignment is performed by hitting the side edge of the sheet P. After a predetermined number of sheets P1 have reached the distal end portion 14A of the discharge arm 14,
Either or both of the staples SP _A and SP _B are stapled (stapled) by one or both of the staplers 10A and 10B. Stapled sheet P1
The rear end of the discharge arm 14 swings its front end 1
Paper discharge tray means (20 or 30) discharged by 4A
Is discharged.

FIG. 11B shows a small size (for example, B6
2 shows a state in which a sheet P2 having a size of A6 size, A6 size, etc. is width-aligned and stapling is performed.

When staple processing is performed on the small-sized sheet P2, one of the alignment plates 91B starts to move from the initial position every time the sheet P2 is fed from the sheet reversing conveyance drum 4 to the stapler 10 and abuts on the leading end 14A. Then, the side edge of the sheet P2 is pressed to shift the sheet P to one side, and the other alignment plate 91A starts moving from the initial position and hits the side edge of the sheet P2 to perform width alignment.

FIG. 11C is a plan view showing sheets of various sizes and stapling positions. The stapler 10
A and 10B are moved by a driving source (not shown) and stopped at predetermined positions that differ for each sheet size, and are stapled.
P _A and SP _B are stapled. When stapling on the small-sized sheet P2, the staplers 10A and 10B cannot be brought close to a predetermined stapling position by the discharge arm 14 and the like arranged near the center. Is moved to the other matching plate 91A side, and then stapled.

FIGS. 12A and 12B are schematic diagrams showing the operation of the matching plates 91A and 91B during the shift processing.

FIG. 12A shows a state where an odd-numbered sheet bundle is processed. When the shift mode (offset mode) is set, the alignment plates 91A and 91B move the same distance from an initial position that is equidistant with respect to the center line R in the conveyance direction of the sheet P, and the sheet width corresponds to the sheet size. Stopping at a slightly wider first position, the sheet bundle is received, post-processed and discharged.

FIG. 12B shows a state in which the even-numbered sheet bundle is shifted. After the even-numbered sheet bundle is received at the same position as the odd-numbered sheet bundle, the matching plates 91A, 9
1B moves and stops at a position unequal to the center line R in the transport direction of the sheet P, and is post-processed and discharged. Note that the width alignment may be performed in this shift mode.

FIG. 13 is a block diagram showing the control of the sheet post-processing apparatus according to the present invention.

In FIG. 1 and FIG.
Sensors PS1, PS2, PS3 for detecting the lower limit position of 1
Sends a detection signal indicating that the sheet P on the movable sheet discharge tray 21 is full (upper limit of the stacking amount) at the respective stop positions of the upper and lower sheet discharge tray means 20 and 30 to a control unit 80 described later. That is, the sensor PS1 is connected to the lower discharge tray unit 3
At the bottom dead center position of 0, the lower limit position of the movable discharge tray 21 is detected. The sensor PS2 is connected to the upper discharge tray 20.
The lower discharge tray means 30 detects the lower limit position of the movable discharge tray 21 at a position where the sheet is discharged onto the movable discharge tray 21 after the sheet post-processing. The sensor PS3 moves the movable discharge tray 2 at the top dead center position of the upper discharge tray 20.
1 is detected.

Hereinafter, a description will be given of the raising and lowering of the upper and lower discharge tray means 20, 30 and the control by the sensors PS1 to PS3.

(1) In the sheet post-processing apparatus, the sheet bundle after the sheet post-processing is stacked on the movable discharge tray 21 of the upper discharge tray means 20, reaches the lower limit position, and the sheet P becomes full. Is detected by the sensor PS2, a detection signal is sent to the control unit 80. The control unit 80 drives the drive motor M1 in response to the detection signal, raises the upper discharge tray unit 20, and lowers the lower discharge tray unit 30.
Follow the upper discharge tray means 20 and rise.

(2) After the lower discharge tray means 30 is stopped at a predetermined sheet post-processing position, a sheet bundle after sheet post-processing is stacked on the movable discharge tray 21 of the lower discharge tray means 30; When the sensor PS2 detects that the sheet P has reached the lower limit position and is full, the detection signal is sent to the control unit 80.
Send to When the sheets P on both the discharge tray means 20 and 30 are full, the sheet post-processing is stopped.

(3) During the above-described sheet post-processing, when the sheet P on which the sheet post-processing has been performed on both the discharge tray means 20 and 30 is removed, the weight of the sheet P on the movable discharge tray 21 becomes lighter. Then, the movable discharge tray 21 is moved upward by the bias of the spring, and the sensor PS2 emits a signal indicating that the sheets P can be stacked, and the sheet post-processing is continued.

(4) During the sheet post-processing or after the sheet post-processing, another sheet discharging tray means (lower sheet discharging tray means 30 in FIG. 1 or upper sheet discharging tray means 20 in FIG. 8). When the sheet P that has been subjected to the sheet post-processing is extracted, the weight of the sheet P on the movable discharge tray 21 becomes lighter, and the movable discharge tray 21 rises by being biased by a spring.
The sensor PS1 or PS3 emits a signal indicating that the sheets P can be stacked, and after the discharge tray unit moves, the sheet post-processing is continued.

In this way, during the sheet post-processing, the sheet P having been subjected to the sheet post-processing on the upper and lower discharge tray means 20 and 30 is arbitrarily extracted, so that the sheet post-processing operation is continued and a large amount of the sheet P is processed. The sheet P can be post-processed.

Further, a sheet post-processing means comprising one stapler 10 and one shift aligning means 9, and upper and lower discharge tray means 20 for stacking a sheet bundle processed and discharged by the sheet post-processing means, 30 and a lifting drive means 40 for raising and lowering the upper and lower discharge tray means 20, 30.
And discharges the sheet P formed in the staple processing mode onto one of the discharge tray means 20 (or 30).
It is also possible to stack, raise and lower the paper discharge tray means 20 (or 30), and discharge and stack the sheets P formed in the shift processing mode onto the other paper discharge tray means 30 (or 20). This makes it possible to easily continue the staple process and the shift process.

In the embodiment of the present invention, the sheet post-processing apparatus connected to the copying machine has been described. However, the sheet post-processing apparatus used in connection with an image forming apparatus such as a printer or a facsimile, or a light printing machine or the like. Is also applicable.

[0065]

According to the sheet post-processing apparatus of the present invention, the following excellent effects can be obtained.

(1) By reducing the size of the staple means and the shift means with a simple configuration, the size of the sheet post-processing apparatus can be reduced, and it is effective to prevent the occurrence of sheet conveyance failure. And (2) staple processing is enabled even for small-sized sheets (claim 4).
(3) An excellent effect of reducing the vertical projection area occupied by the staple processing section and the paper discharge tray to achieve a reduction in the sheet conveyance path and a reduction in the size of the apparatus can be obtained.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating a configuration of a sheet post-processing apparatus of the present invention.

FIG. 2 is a partial sectional view showing a sheet conveying process (1) of the sheet post-processing apparatus.

FIG. 3 is a partial cross-sectional view illustrating a sheet conveying process (2) of the sheet post-processing apparatus.

FIG. 4 is a partial sectional view showing a sheet conveying process (3) of the sheet post-processing apparatus.

FIG. 5 is a partial sectional view showing a sheet conveying process (4) of the sheet post-processing apparatus.

FIG. 6 is a partial sectional view showing a sheet conveying process (5) of the sheet post-processing apparatus.

FIG. 7 is a partial sectional view showing a sheet conveying process (6) of the sheet post-processing apparatus.

FIG. 8 is a cross-sectional view illustrating driving of a sheet discharge tray unit in a sheet post-processing apparatus including a two-stage sheet discharge tray unit.

FIG. 9 is a plan view of a paper discharge tray unit.

FIG. 10 is a front view of a shift matching unit.

FIG. 11 is a schematic plan view showing the operation of the alignment plate at the time of staple processing, and a plan view showing sheets of various sizes and staple positions.

FIG. 12 is a schematic plan view showing the operation of a matching plate during shift processing.

FIG. 13 is a block diagram illustrating control of the sheet post-processing apparatus according to the present invention.

FIG. 14 is a configuration diagram illustrating an example of a conventional sheet post-processing apparatus.

[Explanation of symbols]

Reference Signs List 4 sheet reversing conveyance drum 5 conveyance roller pair 6 sheet pressing member 7 uppermost sheet discharging means 9 shift alignment means (sheet post-processing means) 10, 10A, 10B stapler (stapling means,
Sheet post-processing means) 14 Discharge arm (discharge member) 20 Upper discharge tray means 21 Movable discharge tray 22 Fixed discharge tray 30 Lower discharge tray means 40 Elevation drive means 44 Discharge tray hanger 80 Control unit 90A First unit 90B Second unit 91A, 91B Alignment plate (alignment member) 92A Unit housing / intermediate discharge tray 97A, 97B Timing belt M1, M2, M3, M4 Drive motor P, P1, P2 Sheet PS1, PS2, PS3 , PS4, PS5, PS6A,
PS6B Sensor R Center line in transport direction

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification code FI G03G 15/00 534 G03G 15/00 534 (72) Inventor Yuji Kanazawa 5-1-27-1 Kichijoji Kitamachi, Musashino City, Tokyo (72 ) Inventor Takanori Yoshida 10-14, Bijogi, Toda City, Saitama Prefecture (72) Inventor Kazuki Hinomi 873-10, Terao, Kawagoe City, Saitama Prefecture Chome 12 No. 2

Claims (5)

[Claims] An image-formed sheet carried out of an image forming apparatus is post-processed by a sheet post-processing means,
In a sheet post-processing apparatus that discharges a sheet bundle to a discharge tray unit, on both sides in a width direction orthogonal to a sheet conveying direction,
Two independently movable alignment members are provided, and these alignment members can execute two processing operations of the width-wise sheet alignment processing and the shift processing for sorting sheets by the number of sheets. A sheet post-processing apparatus. 2. The image forming apparatus according to claim 1, wherein said sheet post-processing means is at least one of a staple means for binding an image-formed sheet and a shift means for shifting the image-formed sheet in a direction orthogonal to a conveying direction. The sheet post-processing apparatus according to claim 1. 3. The sheet post-processing apparatus according to claim 1, wherein the two alignment members are driven by independent drive sources. 4. A sheet conveyed to a position which does not reach the processing section of the stapling means in the width direction orthogonal to the sheet conveying direction is shifted to the processing section of the stapling means by the shift means, and then stapled by the stapling means. The sheet post-processing apparatus according to any one of claims 1 to 3, wherein the sheet is processed. 5. At the time of sheet post-processing by said sheet post-processing means, at least one end of the sheet is on an intermediate discharge tray, and the post-processed sheet is discharged from said intermediate discharge tray to said discharge tray by discharge means. 5. The sheet post-processing apparatus according to claim 1, wherein the sheet is discharged to a unit.