JP3372857B2 - Discharge sheet stacking apparatus and image forming apparatus equipped with this apparatus - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a discharge sheet stacking device for binding and discharging and stacking an image-formed sheet by bookbinding means such as a stapler, and an image forming apparatus equipped with this device.

[0002]

2. Description of the Related Art As a discharge sheet stacking apparatus for a laser beam printer which is an image forming apparatus having a binding means such as a stapler, a sheet on which an image has been formed is mounted on the side surface of the printer body on the discharge port side for each job. A type of stapling, discharging and loading is well known. However, this type of stacking and stacking device has a switchback mechanism for stacking discharged sheets in order to stack printed sheets and stacks them in a page order. There has been a problem that the sheet throughput has to be increased, which lowers the print throughput.

As a countermeasure against this, there is a discharge sheet stacking apparatus in which the reverse mechanism is eliminated by reversing and stacking the sheets on the upper surface side of the printer, and many sheets are discharged by this discharge sheet stacking apparatus. To load
There has been a problem that the strength of the printer main body that supports it has to be increased, and the cost of the printer main body increases.

As a discharge sheet stacking apparatus for coping with these problems, a discharge sheet stacking unit is arranged under the printer main body, and a sheet discharge apparatus stacked under the printer main body in the sheet discharge path of the printer main body is provided. A flapper, which is a branching unit for branching from the flapper, is provided on the outside of the printer main body to wrap around the flapper to the sheet ejection device, and an actuator for actuating the flapper provided on the printer main body is provided in the transport section. There is a so-called bottom-mounted discharge sheet stacking device which is provided to deal with the above problem.

[0005]

However, in order to perform bookbinding by a bookbinding means such as a stapler, it is necessary to align a plurality of sheets for each job. Conventionally, the generally used aligning means is The sheet aligning portion has an inclination angle of about 10 ° to 30 ° with respect to the horizontal plane, and the inclination of the sheet aligning portion is used to bring the sheet into contact with the vertical wall portion provided at the inclined end portion to align the sheet. It is like this.

As described above, when the aligning means having the inclined surface is used in the sheet stacking section, the height of the discharged sheet stacking apparatus becomes high, and as described above, the discharged sheets stacked under the printer are used. In the case of a loading device, the overall height of the printer is high. As a result, there is a problem that it is difficult for the user to operate the printer at the top.

[Object] The present invention solves the above problems by
An object of the present invention is to provide a discharged sheet stacking apparatus and an image forming apparatus having a low height.

[0008]

A discharged sheet stacking apparatus of the present invention holds a sheet on a sheet stacking section on which a plurality of sheets are stacked and feeds the sheet from above along a sheet conveying guide. With respect to the nip portion of the sheet carry-in means for allowing the retractable sheet stopper to receive the leading edge of the sheet, the distance from the sheet stopper to the nip position of the sheet carry-in means along the sheet transport guide is The sheet is arranged at a position shorter than the length and above the sheet stacking section, and the sheet is carried in by sandwiching the rear end of the sheet even after the sheet carrying-in means abuts the leading end of the sheet against the sheet stopper. continues to operate, it the rear end of the sheet after forming the loop so as to stack the sheet on said sheet stacking portion
Holds the loop formed at the rear end of the sheet.
A biasing means for biasing the
As the sheet is moved downward from the sheet carrying-in means,
Set the rear edge of the sheet that is inclined in the direction away from the stopper
It has a biasing surface and rotates in synchronization with the sheet carrying-in means.
It is characterized by being an endless kicking belt .

Further, the output sheet stacking apparatus, the sheet stacking between the sheet stopper and the sheet carrying means
Characterized in that said sheet on parts having a sheet auxiliary conveying means for conveying an auxiliary manner.

The sheet auxiliary conveying means is an endless alignment belt which rotates in the sheet conveying direction.

[0011]

[0012]

[0013]

Further, any one of the discharged sheet stacking apparatus is characterized by including a staple unit for stapling the sheets stacked in the sheet stacking section.

Further, the image forming apparatus is equipped with any one of the above-mentioned discharged sheet stacking devices at the bottom of the main body having an image forming portion for forming an image.

[Operation] The sheets are sequentially carried into the sheet stacking section and stacked by the sheet carrying-in means.
At this time, the sheets are aligned and stacked while being abutted against the sheet stopper, but since the distance between the sheet carry-in means and the sheet stopper is set shorter than the length of the sheet, the sheets are abutted against the sheet stopper. A force in the sheet transport direction is applied to the rear end of the sheet in the pressed state, and the sheet is curved to form a loop.

The sheet is further looped, the front end of the sheet is surely pressed against the sheet stopper, and then the rear end of the sheet is completely sent out from the sheet carry-in means, so that the sheet remains in contact with the sheet stopper. The sheets are stacked on the sheet stacking unit.

In this way, the sheet is additionally conveyed by the sheet auxiliary conveying means and brought into contact with the sheet stopper to enhance the consistency of the sheet.

If the sheet auxiliary conveying means is an endless belt, it can be bent, so that the sheet is pressed by the sheet stopper by the conveying force of the sheet auxiliary conveying means and is not warped, and is pressed with an optimum pressing force. To be done.

Further, when the trailing edge of the sheet is completely sent out from the sheet carrying-in means, the loop state of the sheet is released, and the recoil of the sheet may cause the sheet to separate from the sheet stopper, thereby deteriorating the integrity of the sheet. is there. Therefore,
Even after the trailing edge of the sheet has been completely sent out from the sheet carry-in means, the biasing means applies a biasing force to the sheet in the sheet conveying direction so that the loop state of the sheet is not released all at once but gradually released. Make sure that the leading edge of the sheet does not separate from the sheet stopper. Therefore, without the integrity of the sheet is reduced, the sheet is stacked on a sheet stacking portion.

When the urging means is an endless belt, it can be bent and when the loop state of the sheet is released,
Even if the sheet has strong rigidity, it reliably receives the trailing edge of the sheet and holds it so that the leading edge of the sheet does not separate from the sheet stopper.

The endless belt stacks the sheet on the sheet stacking portion while receiving the rear end of the sheet while keeping the leading edge of the sheet in contact with the sheet stopper, thereby enhancing the consistency of the sheet.

The sheets sequentially abutted against the sheet stopper are stacked on the sheet stacking section to improve the consistency and then stapled. The stapled sheet bundle is ready to be ejected when the sheet stopper is retracted into the sheet stacking unit.

Further, since the image forming apparatus is provided with the low-height discharge sheet stacking device at the lower portion, the overall height can be reduced.

[0025]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to FIG.
It will be described with reference to FIGS.

[First Embodiment] FIG. 3 is a front sectional view of a laser beam printer which is an image forming apparatus equipped with a discharge sheet stacking apparatus 600 according to the first embodiment.

First, a printer device represented by a laser beam printer will be described.

The printer device 100 is independently connected to a computer or connected to a network such as a LAN, and the information sent from these devices causes the image forming section 102 to form an image by a predetermined image forming process. Is a device for forming and discharging the sheet.

The first sheet feeding device 200 includes a sheet cassette 201 that accommodates a plurality of sheets P and is removable,
A sheet separating / feeding unit 202 that separates the sheets P stored in the sheet cassette one by one according to a predetermined sheet supply signal and conveys the separated sheets to the printer body 101. Also,
The sheet feeding device 200 includes second and third sheet feeding devices 300 and 4 which are located in a lower layer so that they can be stacked and used.
Sheet guide portion 2 for conveying the sheet P from 00
Has 03.

The second sheet feeding device 300, like the first sheet feeding device 200, conveys the sheet P from the sheet cassette 301 for accommodating the sheets P, the sheet separating / feeding section 302, and the third sheet feeding device. Guide part 3
And 03.

The third sheet feeding device 400 includes the first and second sheets.
The sheet feeding device 200 has a configuration similar to that of the sheet feeding devices 200 and 300, and the sheet cassette 401 of the third sheet feeding device 400.
Is configured so that more sheets P can be stored than the sheet cassette 201 of the first and second sheet feeding devices 200 and 300. Further, the printer body 1 is formed to have a long length so that a long sheet can be used.
The rear end projects more than 01.

These sheet feeding devices 200, 300,
All of 400 are positioned with respect to each other by unillustrated positioning pins and fitting holes of the same shape, and when they are stacked, they are electrically coupled by a connector, and the printer 100 and the upper and lower sheet cassettes 201 are automatically connected. Three
The printer device 100 can be informed of the combined state of the printers 01 and 401.

Therefore, the user can select the number of stages and the capacity of the sheet cassette that suits the specification environment from many variations.

The duplex unit 500 includes the printer device 10.
It is configured to be mounted on the printer device 100 from the left side in the drawing along the guide shape formed in 0.

Printer device 100 and duplex unit 50
No. 0 is also electrically connected by the connectors provided on both sides, power supply and communication from the printer device 100 to the duplex unit 500 is possible, and the connection state can be confirmed on the printer device 100 side. There is.

The ejected sheet stacking device 600 is a part of the printer device 100, and the sheets sent from the printer device 100 are conveyed face down through the vertical conveyance portion 700 and the extension guide portion 800 for each predetermined job. It is a device for bundling sheets and stapling them at one place or at a plurality of places for discharge and stacking, or simply discharging and stacking face down.

Next, the discharged sheet stacking apparatus 600 according to the first embodiment of the present invention will be described along the conveyance path of the sheets P.

The sheet P selectively supplied from desired sheet cassettes 201, 301, 401 in response to a predetermined print signal transfers an image in the printer apparatus 100 by the image forming process with the image forming surface facing upward. The image transferred by the fixing unit 120 is then fixed on the sheet P.

The sheet on which the image has been fixed is printed by the FD flapper 121 in response to a predetermined signal to the printer main body 101.
The sheet is selectively branched and conveyed to the FD sheet discharge section 125 prepared above the sheet or the duplex unit 500.

The sheet P branched and conveyed to the double-sided unit 500 operates the double-sided conveyance sensor lever 501.

When the conveyed sheet is an instruction for double-sided printing, the double-sided conveyance sensor lever 501 operated by the conveyed sheet P drives the double-sided conveyance roller 502 on the downstream side at a predetermined timing, The sheet is guided to the reverse conveyance path 503. Next, after detecting that the trailing edge of the sheet P has passed through the double-sided conveyance sensor lever 501, the double-sided conveyance roller 502 is reversely driven at a predetermined timing. As a result, the sheet P is conveyed to the double-sided carry-in path 504 and is conveyed again to the printer device 100 for double-sided image processing.

Next, the movement of each part when the conveyed sheet P moves toward the discharged sheet stacking device 600 will be described with reference to the flowchart of FIG.

The discharged sheet stacking device 600 has been initialized (step 1001, hereinafter step is abbreviated as "S").

Sheet P carried into duplex unit 500
When (S1002) operates the double-sided conveyance sensor lever 501, this sensor drives the conveyance roller 502 on the downstream side at a predetermined timing, and the discharged sheet stacking device 60
A signal is output to 0, and the plunger (not shown) of the flapper solenoid 610 shown in FIG. A lever 612 shown in FIG. 11 is rotatably attached to the plunger.

Since the lever 612 is supported by a rotary shaft (not shown), the lever 612 rotates about the rotary shaft to push up the link lever (not shown) and further push up the link lever 811 so that the duplex unit 500. The flapper 505 provided at the position is rotated. By flapper 505,
The conveyance path is switched, and the sheet P is carried into the discharged sheet stacking device 600 via the extension guide 800 and the vertical conveyance unit 700.

As shown in FIGS. 3 and 4, the vertical transport unit 700 is set up at a position where the sheet cassette 401 protruding from the printer apparatus main body 101 has escaped. Located in a remote location. The sheet that has passed through the extension guide 800 and is conveyed to the vertical conveyance unit 700 is provided on the discharged sheet stacking device 600 by the vertical conveyance roller 701 and the conveyance roller 702 that is rotatably biased by the vertical conveyance roller 701. The aligning carry-in roller 601 and the aligning carry-in roller 602 rotatably biased by the aligning carry-in roller 601 carry the sheet into the sheet aligning unit (S1003).

At this time, the sheet on which the image is formed with the image forming surface facing up in the printer device 100 is carried in under the printer device main body 101 and carried in, so that the image forming surface is face-down facing downward. Is brought in.

The alignment carry-in sensor 603 provided on the upstream side of the nip of the alignment carry-in roller 601 detects the timing at which the sheet is carried in and the timing at which the trailing edge of the sheet comes out.

The alignment carry-in sensor 603 detects the timing of carrying in the sheet, and after a predetermined time, operates the lateral registration aligning plate 622 described later, operates the shutter 632, and detects the jam of the sheet. It has become.

The aligning section according to the first embodiment of the present invention includes the aligning carry-in roller 601, the upper guide 621, and the aligning table 6.
20, the vertical alignment belt 631 and the shutter 632.

The sheet P conveyed by the aligning and carrying-in roller 601 receives the upper guide 621 and the aligning table 620.
The vertical leading edge of the sheet is guided by the vertical alignment belt 631 that aligns the sheets to the right in FIG. 3, and is pulled in until the leading edge of the sheet abuts the leading edge stopper portion 633 provided on the shutter 632 in the operating state (S1005).

At this time, the upper guide 621 from the nip position of the aligning carry-in roller 601 and the nip position of the aligning carry-in roller 602, which is held rotatably with a predetermined pressure, facing the aligning carry-in roller 601, to the abutting surface of the tip stop portion 633. L is the distance of the length of the sheet conveyance guide formed by the above, and LP is the shortest length of the sheet applied to the discharged sheet stacking device.
Assuming that min, as shown in FIG. 1, L <LPmin.

For example, when the sheets applied to the discharged sheet stacking apparatus are LTR size (279 mm), L = 275 to 270 mm.

In addition, the upper guide 621 and the matching table 62
The sheet guide unit configured by 0 is configured to be narrow in the vertical direction in the vicinity of the shutter 632 on the downstream side in the transport direction so as to suppress the curl and deformation of the sheet, and in the vicinity of the upstream side and immediately downstream of the alignment carry-in roller 601. Wide in the vertical direction.

Further, the alignment carry-in roller 601 and the shutter 6
A vertical alignment belt 631 is provided between the alignment belt drive roller 635 and the alignment belt drive roller 6 in the middle of the horizontal direction of 32.
Roller 6 facing roller 35 and urged by roller spring 637
It is rotationally driven by 36 and applies a weak conveying force in the sheet conveying direction.

Therefore, the sheet P is nipped and conveyed by the aligning and carrying-in roller 601 and the aligning and carrying-in roller 602 which is rotatably biased by the aligning and carrying-in roller 601 by a spring (not shown), and the sheet P is conveyed between the roller 601 and the roller 602. When the leading edge of the sheet P strikes the shutter 632 by the carrying force, the leading edge of the sheet is vertically aligned while being constantly abutted against the shutter 632 by the transport guide including the upper guide 621 and the alignment table 620 and the vertical alignment belt 631. It is pressed by the belt 631.

At this time, since the distance L between the alignment carry-in roller 601 and the shutter 632 is shorter than the sheet length on the trailing end side of the sheet, the sheet is carried in while forming a loop.

On the other hand, as shown in FIG. 2, an endless kick-out belt 604 for kicking out the rear end of the sheet is coaxially attached to the aligning-in roller 602, so that the aligning-in roller 602 is aligned. When it is rotated by the carry-in roller 601, the endless kick-out belt 604 also rotates in the same direction as the aligning carry-in roller 602 in synchronization with this.

Therefore, the sheet P in which a loop is formed by the alignment carry-in roller 601 and the alignment carry-in roller 602 is
While the loop is smoothly absorbed by the kicking belt 604, the loop is abutted against the shutter 632 and gradually stacked toward the alignment table 620. That is, as shown in FIG. 1, the loop of the trailing end of the sheet P is large at the time when it is sent out by being sandwiched between the alignment carry-in roller 601 and the alignment carry-in roller 602. However, since the endless kick-out belt 604 is inclined in the direction away from the shutter 632 as it goes downward, the trailing edge of the sheet P gradually separates from the endless kick-out belt 604 as the sheet falls. Along with this, the loop of the sheet P gradually becomes smaller. In this way, the trailing edge of the sheet P is formed in a loop shape even when the sheet P is falling, so the leading edge of the sheet P is constantly pressed against the shutter 632.

At this time, depending on the type of the sheet, there is a sheet having a strong waist and a strong reaction force at the time of forming the loop, but these are absorbed by the bending of the endless kicking belt 604. In this embodiment, the rubber hardness is about 45 degrees to 5 degrees.
This is achieved by using a 5 degree belt.

The vertical alignment belt 631 continues to rotate in the direction for pulling in the sheet even after the leading edge of the sheet hits the shutter 632, but since the conveying force is set to be weak, the sheet is buckled or the shutter is released. It does not push open 632.

In practice, the carrying force of the vertical alignment belt 631 is set so that a carrying force of about 5 to 10 g is applied to the sheet.

When the discharged sheet stacking device 600 does not receive the stapling instruction when a plurality of sheets P are accumulated (1005), the bundle conveying rollers 640 descend (S).
1020). Then, the shutter is opened (S1021)
Then, the bundle conveying roller 640 is driven (S1022). Then, the sheet discharge roller 645 is lowered (S
1023) The sheet is discharged to the stack section 650 by cooperating with the rotating bundle conveying roller 640.

When the discharged sheet stacking device 600 receives the stapling instruction (S1005), the timing at which the trailing edge of the sheet P passes through the aligning carry-in roller 601 and the leading edge of the sheet P abuts against the shutter 632, the stepping motor is detected. The lateral registration aligning motor 623, which is the above, drives the lateral registration aligning plate 622 to align the conveyed sheet P in the lateral direction (S1007). During this time, the trailing edge of the sheet P is separated from the endless kicking belt and stacked on the alignment table 620 before the lateral alignment of the sheet P is performed. The lateral registration motor 623 controls the lateral registration aligning plate 622, which is retracted from the sheet carry-in position to a position retracted by a predetermined amount, to a position slightly narrower than the predetermined sheet width of the conveyed sheet P. When the lateral registration aligning plate 622 is pushed in to a position narrower than the sheet width, the sheet bends, and the reaction force is applied to the lateral registration aligning plate 622.
To the sheet pressing part.

This lateral registration matching plate 622 meshes with the driving pinion gear provided on the lateral registration motor 623,
A play gap is provided in the seat width direction between the rack gear receiving the driving force and the lateral registration aligning plate 622.
A spring member (not shown) that absorbs the reaction force of the sheet is constantly urged within the range of the gap to a position that narrows the width of the sheet. This play gap is set so that the lateral registration plate 622 is narrower than the sheet width and larger than the pushing amount, so that when the reaction force of the sheet exceeds a predetermined value, the lateral registration plate 6 is pushed.
The sheet aligning portion 22 loses the reaction force of the sheet and stays within the width of the sheet within the play gap.

In this way, the sheet bundle aligned and aligned in the predetermined number of sheets aligning portion enters a step of stapling by the stapling unit 670 shown in FIG. 4 (S101).
0).

Since the movement of the stapling portion is different between the case where there is one stapling point and the case where there are plural stapling points, each case will be described.

As shown in FIG. 5, the staple unit 67
0 is fixed at the upper right position in the transport direction with respect to the sheets stacked with the image forming surface below, and the corner of the sheet bundle can be bound at that position.

Therefore, in stapling at one corner of the aligned sheet bundle, first, the lateral registration aligning plate 622 is pushed narrower than the sheet width, and the sheet width position is changed from the aligning position pressed against the reference plate 624. Then, the lateral registration matching motor 623 is kept excited at this position (S1017). After that, the stapling unit 670 is driven to start the stapling operation, and the sheets are bound (S1018).

In the sheet bundle bound by the stapling unit 670, first, the lateral registration aligning plate 622 moves to the open position to release the lateral regulation (S1019), and the bundle conveying roller 640 is moved by a predetermined rotating arm. The sheet bundle is lowered so that the sheet bundle can be conveyed (S1020), and the bundle conveying backup roller 63 provided on the alignment table 620 side.
With 4 , the sheet bundle is nipped. Then, the shutter 63
2 is released (S1021), the bundle conveying roller 640 is driven in the rotation direction (S1022), and the stack portion 65 is released.
It is discharged and loaded to 0. At this time, normally, the sheet discharge roller 645 retracted by an elevator mechanism (not shown) also descends (S1023), and the sheet bundle is conveyed and discharged. By the way, the sheet discharge roller 645 is always rotated because the drive is not released even when it is in the retracted position.

When stapling the aligned sheet bundle at two or more locations, as shown in FIG. 6, the staple is not placed at the corners of the sheet bundle but at a location apart from the center of the sheet length by a predetermined position. The stapling position is different from staple. Therefore, the control method also differs between the case where there is one corner and the case where there are a plurality of corners. When stapling at a plurality of locations, the shutter is opened and the sheet bundle is conveyed to the stapling location for stapling.

First, the lateral registration aligning plate 622 is returned from the position where it is pushed against the sheet width to the sheet width position, and then,
The bundle conveying roller 640 is lowered (S1012), and is sandwiched between the bundle conveying backup roller 634 and the sheet conveying backup roller 634 which face each other with the sheet bundle interposed therebetween. Next, after opening the shutter 632 (S
1013), the bundle conveying roller 640 and the bundle conveying backup roller 634 are driven to convey the sheet bundle to a predetermined position (S1014).

After that, the staple processing is performed while the bundle conveying roller is stopped and the sheet bundle is pressed and held (S1015).

[0074] After transport to the second position after staple after staple in bundle conveying rollers 640 to a predetermined position,
Similarly nip Shitama or stop a bundle conveying rollers 640, and repeats the operation of stapling (S1014, S101
5).

After the stapling process is completed (S101
6) unfolds the lateral registration alignment plate 622 from the sheet width position (S1024), drives the bundle conveying roller 640, and the bundle conveying backup roller 634 (S102).
2) Then, the sheet discharging roller 645 at the retracted position is lowered to the transportable position (S1023), and the sheet bundle is transported and discharged and stacked on the stack unit 650.

In FIG. 4, a paper discharge sensor flag 646.
Is a flag for detecting a jam of the sheet discharge portion.

In FIG. 3, the full load detection sensor 660 is
Discharged and stacked sheets detects the had reached a predetermined stack height, and stacked more, so that no or confer to the failure of the device, damage to the stacked sheets.

[Second Embodiment] FIGS. 7 and 8 show a second embodiment of the present invention. The discharged sheet stacking device according to the second embodiment is configured such that the aligning carry-in roller 601, the aligning carry-in roller 602, and the endless kick-out belt 604 are unitized, a rack 606 is provided in this unit, and the unit is movable by the motor M. . As described above, by making the aligning and carrying-in unit unitary and movable, it becomes possible to change the distance L'and accommodate many different sheet sizes.

The moving position may be automatically moved to a predetermined position according to the sheet signal of the printer 100, or the sheet length may be detected by a sensor on the conveying path. It goes without saying that it may be configured as follows.

[Third Embodiment] FIG. 9 shows a third embodiment of the present invention. In this discharged sheet stacking device, a shutter 632 with which the sheets come into contact is movable,
The sheet P that is carried in according to the sheet size has a predetermined loop. By making the shutter 632 side movable in this way, it becomes possible to handle a large number of sheet sizes with a simpler mechanism. Of course, this shutter 632 is used for the printer device 100.
Alternatively, it may be automatically movable according to the sheet size information of the upstream side sensors and the like.

Further, as the urging means for urging the rear end of the sheet, the endless kick-out belt 604 is used in this embodiment, but if it is possible to drop the rear end of the sheet to the alignment portion while urging the rear end of the sheet. It is natural that this is not the case.

In FIG. 13, K1 is a connector for connecting the CPU in the printer body 101P and the control circuit of the duplex unit 500.

K2 is a connector connecting the control circuit of the discharged sheet stacking device 600 and the CPU in the printer body 101P.

The motors M1 to M6 connected to the control circuit of the discharged sheet stacking device 600 include rollers 701 and 6
01, 640, 641, 645, roller 602, belt 6
31 is a motor for driving the staple unit 670.

[0085]

According to the first aspect of the present invention, the distance between the sheet carrying-in means and the sheet stopper is set shorter than the length of the sheet stacked on the sheet stacking portion. Since the looped state can be maintained and the abutting state can be maintained, it is possible to obtain a discharged sheet stacking apparatus with high consistency.

Further, according to the invention of claim 1, unlike the prior art, the consistency of the sheets can be enhanced without giving an inclination to the sheet stacking portion, so that a discharged sheet stacking apparatus having a low height can be obtained. it can.

According to the invention of claim 1, the sheet carrying-in means
Energizing to urge the trailing edge of the sheet loaded from the sheet in the transport direction
If it has a means, it is looped by the sheet loading means.
The looped state of the sheet formed on the
Each time, the tip of the sheet separates from the sheet stopper.
Can be prevented and the integrity of the sheet can be improved.

According to the invention of claim 1, the biasing means is endless.
-Shaped belts can bend and loop seats
When the condition is released, the seat is tight even if the seat is strong.
Securely catch the rear edge of the
To keep the tip of the sheet
You can

According to the invention of claim 1, an endless belt
However, if the tip of the sheet is abutted against the sheet stopper,
In the state, drop while receiving the rear edge of the sheet.
And, it is possible to enhance the integrity of the sheet.

According to the invention of claim 2, the sheet carry-in means
A sheet auxiliary conveyance means is provided between the sheet stopper and the sheet stopper.
Then, the sheet is auxiliary transported and the sheet is always fed.
Easy to keep in contact with the topper
With such a configuration, it is possible to improve the sheet consistency.

As in the third aspect of the invention, the sheet auxiliary conveyance
If the means is an endless belt, the sheet auxiliary conveying means
However, the tip of the sheet hits the sheet stopper and continues to rotate.
Even if you get kicked, buckle the seat or
Be careful not to push open the topper,
It is possible to set the conveying force of the step to the optimum conveying force.

According to the invention of claim 4 , any one of the above
Since one discharge sheet stacking device has a staple unit for stapling the sheets stacked in the sheet stacking unit, it is possible to staple a highly aligned sheet bundle and obtain a good-looking bookbinding. .

According to the fifth aspect of the invention, since the image forming apparatus is provided with the discharge sheet stacking apparatus having a low height in the lower portion of the image forming section, the height can be reduced to facilitate the operation.

[Brief description of drawings]

FIG. 1 is a detailed front view of an alignment unit of a discharged sheet stacking device according to a first embodiment of the present invention.

FIG. 2 is a left side view of FIG.

FIG. 3 is a front sectional view of a printer device of the present invention equipped with the discharged sheet stacking device of the first embodiment.

FIG. 4 is a front sectional view around the discharged sheet stacking device in FIG.

5 is an explanatory diagram of a stapling process of the discharged sheet stacking device of FIG. 1. FIG.

FIG. 6 is an explanatory diagram of a stapling process of the discharged sheet stacking device of FIG.

FIG. 7 is a detailed front view of an alignment unit of the discharged sheet stacking device according to the second embodiment.

FIG. 8 is an operation explanatory diagram of FIG. 7;

FIG. 9 is a detailed front view of an alignment unit of the discharged sheet stacking device according to the third embodiment.

FIG. 10 is a flowchart of a sheet stapling operation.

FIG. 11 is a perspective view of a discharged sheet stacking device, a vertical conveyance unit, and an extension guide unit according to the first embodiment.

FIG. 12 is a perspective view of a printer device including the discharged sheet stacking device according to the first embodiment.

FIG. 13 is a block diagram.

[Explanation of symbols]

P sheet 100 Printer device (image forming device) 101 printer main body 102 image forming unit 600 discharge sheet stacking device 601 Aligning carry-in roller (sheet carrying-in means) 602 Matching carry-in roller (sheet carrying-in means) 604 Endless kicking belt (biasing means) 620 Alignment table (sheet stacking unit) 631 Vertical alignment belt (sheet auxiliary transport means) 632 Shutter (sheet stopper) 633 Tip stopper (sheet stopper) 670 staple unit

─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-5-221576 (JP, A) JP-A-62-121230 (JP, A) JP-A-60-12453 (JP, A) JP-A-3- 259857 (JP, A) JP-A-5-16568 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) B65H 29/00-31/40

Claims (5)

(57) [Claims] 1. A sheet stopper is sandwiched between a plurality of sheets on which a plurality of sheets are stacked and is fed from above along a sheet conveying guide, and a tip of the sheet is attached to a sheet stopper that can be retracted from the sheet stacking portion. The nip portion of the sheet carrying-in means for receiving the sheet is located at a position where the distance from the sheet stopper to the nip position of the sheet carrying-in means along the sheet conveying guide is shorter than the length of the sheet and above the sheet stacking portion. The sheet carry-in means holds the rear end of the sheet and continues the carry-in operation even after the leading end of the sheet abuts against the sheet stopper, and the rear end of the sheet is looped. And then stacking the sheets on the sheet stacking unit
In the discharge sheet stacking device, hold the loop formed at the rear end of the sheet.
Urging means for urging, wherein the urging means is the seat
The sheet stopper is moved downward from the carrying-in means.
Biases the rear edge of the seat inclined in the direction away from
An endless shape having a surface and rotating in synchronization with the sheet carrying-in means.
Ejection sheet stacking device, which is a kicking belt of 2. The discharged sheet stacking device according to claim 1, further comprising a sheet auxiliary transporting unit that transports the sheet on the sheet stacking unit between the sheet loading unit and the sheet stopper. A discharge sheet stacking device characterized by the above. 3. The discharged sheet stacking device according to claim 2, wherein the sheet auxiliary transport unit is an endless alignment belt that rotates in the sheet transport direction. In the output sheet stacking apparatus according to any one of 4. The method of claim 1 to 3, the discharge sheet stacking, characterized in that it comprises a stapling unit for stapling the sheets stacked on the sheet stacking portion apparatus. The lower part of the body having a 5. An image forming unit for forming an image, the image forming apparatus characterized by comprising a discharged sheet stacking apparatus according to any one of claims 1 to 4.