JP2003276932A - Sheet processor and image forming apparatus having sheet processor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce the size of a sheet post-processing apparatus, by projecting a sheet end abutting member depending on the size of a sheet, in an apparatus aligning and loading the sheets by overlapping them each time so as to implement paper sheet aligning at high ppm. <P>SOLUTION: By overlapping and aligning of the paper sheets each time, an aligning time of the paper sheets is managed to be taken, and improvement in durability by halving the number of operations of the aligning member is aimed. Further, by constituting the apparatus to be capable of winding only frequently-used small-sized papers each time, the size reduction of a machine is implemented. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet processing apparatus, and more specifically, it aligns or staples an image-formed sheet discharged from an image forming apparatus such as a copying machine or a printer with a processing tray. The present invention relates to a sheet processing apparatus for performing the above processing and an image forming apparatus including the same.

[0002]

2. Description of the Related Art Conventionally, sheets ejected from an image forming apparatus such as a copying machine or a printer are ejected one by one onto a processing tray (first stacking means) for alignment or stapling. There has been proposed a sheet post-processing device that discharges onto a stack tray (second stacking unit) by a bundle discharging roller pair (bundle discharging unit).

In addition, the top two of the one sheet bundle to be created
In the state where one sheet or three sheets are stacked, the sheet is delivered from the discharging unit to the bundle discharging roller, and the sheet is abutted against the stopper of the processing tray (first stacking unit) by the reverse rotation of the bundle discharging roller to align the sheets, Alternatively, a post-processing device for stapling has been proposed.

[0004]

However, in the above-mentioned conventional example, in the image forming apparatus which conveys the sheet to the sheet processing apparatus at a high speed and with a small number of sheets, the time required for the sheet alignment operation is the sheet interval of the sheets. It doesn't meet in time. In this case, there is a problem that the productivity of the image forming apparatus is lowered and the paper feeding / conveying speed of the image forming apparatus is remarkably increased to make the sheet interval in order to make the sheet interval of the image forming apparatus. .

Further, when the sheet is conveyed at high speed and between a small number of sheets and the aligning operation is repeated for each sheet, the size of the motor is increased due to the speeding up of the aligning operation and the durability of the aligning means due to the large number of aligning operations. There was a problem of deterioration.

In view of this, the present invention provides a sheet processing apparatus having a high alignment latitude and an image forming apparatus including the same by halving the number of operations of the aligning means and widening the distance between the sheets discharged to the stacking tray. It is intended to provide and miniaturize the device.

[0007]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and the invention according to claim 1 is a sheet stacking unit for sequentially stacking a plurality of conveyed sheets, and the sheet. Conveying means capable of conveying the sheets stacked by the stacking means, discharging means for discharging the conveyed sheets, stacking means for mounting the discharged sheets, and discharging means for projecting on the stacking means When the sheet is discharged to the stacking means by the sheet discharge means, the sheet discharge means includes a contact position for hitting the sheet discharged by It is characterized in that whether the sheet abutting means is in a projected state or in a retracted state is variable depending on a mode.

According to the second aspect of the present invention, the mode in which the sheet abutting means is made to project or retract is variable depending on the size of the sheet discharged by the discharging means, and the sheet size is a predetermined value or less ( Seat length is 2
In the case of 20 mm or less), the sheet abutting means is projected to abut the sheet.

The invention according to claim 3 is characterized in that, when the sheet is abutted by the abutting means, the number of sheets discharged by the discharging means is at least two sheets each time except for one final sheet. To do.

The invention according to claim 4 is characterized in that, when the sheets on the stacking means are discharged, the sheet abutting means is moved to a retracted position.

According to a fifth aspect of the present invention, the sheet abutting means abuts the leading edge of the sheet discharged by the sheet discharging means.

The invention according to claim 6 is characterized in that the sheet abutting means performs an aligning operation in the conveying direction of the sheet discharged by the sheet discharging means.

[0013]

With the above structure, the sheet front end abutting member projects by ejecting or retracting the sheet front end discharged according to the sheet size to the abutting position where the sheet front abutting member abuts the sheet. For small size paper, at least 2
By abutting the leading end of the sheet bundle discharged to the sheet stacking unit by the sheet stacking unit or more onto the sheet leading end abutting member, it is possible to align the sheets that are deviated in the transport direction, and on the sheet stacking unit When aligning the sheets, in the configuration that regulates the sheet bundle on the upstream side of the sheet stacking unit, the sheet leading edge abutting member aligns the sheet bundle in the transport direction, which enables sufficient alignment operation between sheets. By discharging at least two sheets by the sheet stacking means and discharging the sheets to the sheet stacking means by the discharging means, it becomes possible to perform deceleration control or the like between the sheets.

When a sheet other than the small size paper, which is used less frequently and in which the sheet front end abutting member retracts, the abutting member that abuts the front end of the sheet does not have to be projected to a position corresponding to the discharged sheet, so that the apparatus It is possible to simplify and reduce the length of the entire device.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION First Embodiment FIG. 18 shows an example of an image forming apparatus main body (copier main body) as a sheet output device equipped with a sheet processing apparatus according to the present invention. The apparatus can be incorporated in not only a printer but also other image forming apparatuses such as a copying machine, a facsimile, and a multi-function machine as a part of the apparatus. Therefore, the sheet feeding apparatus of this embodiment is not incorporated only in the main body of the printer.

The image forming apparatus main body (copier main body) 300 includes a platen glass 906 as a document mounting table and a light source 9.
07, lens system 908, paper feeding unit 909, image forming unit 90
2. An automatic document feeder 500 for feeding a document to the platen glass 906, a sheet processing device 1 for stacking image-formed sheets discharged from the copying machine body, and the like are provided.

The paper feeding unit 909 accommodates the recording sheet P and is detachably attached to the apparatus main body 300.
1 and deck 913 located in pedestal 912
have. The image forming unit 902 (image forming unit) includes a cylindrical photosensitive drum 914 and a developing device 91 around the photosensitive drum 914.
5, a transfer charger 916, a separation charger 917, a cleaner 918, a primary charger 919, etc. are provided respectively. At the downstream side of the image forming unit 902, the conveyance device 920,
A fixing device 904, a pair of discharge rollers 905, and the like are provided.

The operation of the image forming apparatus body will be described.

When a paper feed signal is output from the control device 950 provided on the apparatus main body side 300, the cassette 91
The sheet P is fed from 0, 911 or the deck 913. On the other hand, the original document D placed on the original document table 906
In addition, the light reflected by the light source 907 is applied to the photosensitive drum 914 via the lens system 908. The photosensitive drum 914 is previously charged by the primary charging device 919, and an electrostatic latent image is formed by irradiating light, and then the developing device 915 develops the electrostatic latent image to form a toner image. .

The sheet S fed from the paper feeding unit 909 is
The skew feeding is corrected by the registration roller 901, and the timing is adjusted to send the image to the image forming unit 902. In the image forming unit 902, the toner image on the photosensitive drum 914 is transferred to the sent sheet S by the transfer charger 916, and the sheet S onto which the toner image is transferred is separated by the separation charger 91.
7 is charged to the opposite polarity to the transfer charger 916,
Separated from the photosensitive drum 914.

Then, the separated sheet S is conveyed to the fixing device 904 by the conveying device 920, and the fixing device 9
The transfer image is permanently fixed to the sheet S by 04. For the sheet S on which the image is fixed, the straight sheet discharge mode in which the image surface is on the upper side, or the sheet reverse path 9 after image fixing
In the reverse sheet discharge mode in which the sheet is conveyed to 30, and the image surface is turned upside down so that the image surface is on the lower side, the sheet is discharged from the apparatus main body 300 by the pair of discharge rollers (discharge means) 399.

In this way, an image is formed on the sheet S fed from the sheet feeding unit 909, and the sheet S is discharged to the sheet processing apparatus.

Next, embodiments of the present invention will be described with reference to the drawings.

In FIG. 1, 1 is a finisher, 30
Reference numeral 0 is the image forming apparatus main body. Image forming apparatus main body 300
The detailed description of RDF and RDF is omitted here.
Reference numeral 399 is a discharge roller of the main body of the image forming apparatus, 2 is a pair of entrance rollers of the finisher 1, 3 is a conveyance roller, 31 is a paper detection sensor, 50 is a punch unit for punching near the rear end of the conveyed paper, and 5 is 12 with large conveying roller
The paper is conveyed by pressing the paper with the pressing rollers 13 and 14.

A switching flapper 11 switches between the non-sort path 21 and the sort path 22. A switching flapper 10 switches the sort path 22 and the buffer path 23 for temporarily storing paper. 6 is a carrying roller, 130 is an intermediate tray (hereinafter referred to as a processing tray) for temporarily stacking, aligning and stapling sheets, 7 is a discharging roller for discharging the sheet on the processing tray 130, and 174 is a discharging roller. The leading end abutting member for abutting the leading end of the formed sheet, 150 is a swing guide, 180b is supported by the swing guide 150, and when the swing guide 150 comes to a closed position, a roller 180 arranged on the processing tray 130 is provided.
It is a bundle discharging roller for carrying the bundle of sheets on the processing tray 130 in cooperation with a and discharging the bundle onto the stack tray (sheet stacking means) 200. The bundle discharge lower roller 18
0a, the bundle discharge upper roller 180b, the intermediate tray 13
A sheet bundle discharging roller pair (sheet bundle discharging means) configured to discharge the sheet bundle on the stack tray 200 onto the stack tray 200 is configured.

Next, the stapling unit 100 will be described with reference to FIG. 2 (main cross section), FIG. 3 (view from a) and FIG. 4 (view from b).

The stapler 101 is fixed to the movable table 103 via a holder 102. The shafts 104 and 105 fixed to the moving table 103 have rollers 106 and 105, respectively.
107 is rotatably assembled, and the rollers 106, 10
7 is a hole-shaped rail (108
a, 108b, 108c).

The rollers 106 and 107 are both fixed bases 108.
Flanges 106a, 107a larger than the rail holes of the rails, and on the other hand, below the movable table 103, support rollers are arranged at three places, and the movable table 103 supporting the stapler 101 can be mounted on the rail without coming off. Along the fixed base 108
It can be moved over. The movable table 103 moves on the fixed table 108 by means of rollers 109 rotatably provided on the movable table 103.

The rail holes (108a, 108b, 10)
8c) has two rails that branch from the middle and go in parallel in the front part and the back part. By the rail shape,
When the stapler 101 is located in front, the roller 106
Is on the rail hole 108b side, and the roller 107 is on the rail hole 108
They are fitted to the a side and are in a tilted state. And
When the stapler 101 is located at the center, the roller 10
Both 6 and 107 are fitted in the rail holes 108a and become horizontal.

Further, when the stapler 101 is located on the far side, the roller 106 is moved toward the rail hole 108a.
Is fitted to the side of the rail hole 108c, and is in an inclined state opposite to the front side.

After the two rollers 106 and 107 are fitted to the two parallel rails, they move while maintaining their postures. Then, the action of starting the direction change is performed by a cam (not shown).

Next, the moving mechanism of the stapler 101 will be described.

One roller 106 of the movable table 103 is
The pinion gear 106b and the belt pulley 106c are integrally formed, and the pinion gear is connected to a motor M100 fixed from above the moving table via a belt wound around the pulley 106c. On the other hand, a rack gear 110 is fixed to the lower surface of the fixed base along the rail hole so as to fit with the pinion gear 106b, and the forward and backward rotation of the motor M100 causes the movable base 103 to move forward and backward together with the stapler 101. Moved to.

A stopper tilting roller 112 is provided on a shaft 111 extending in the lower surface direction of the movable table 103. This is for avoiding the collision between the rear end stopper 131 and the stapler 101, which will be described later,
It plays a role of rotating the rear end stopper 131, and the details will be described in the next section.

The stapler unit 100 is provided with a sensor for detecting the home position of the stapler 101, and the normal stapler 101 stands by at the home position (the frontmost portion in this embodiment).

Next, the trailing edge stopper 131 for supporting the trailing edge of the sheets P stacked on the processing tray 130 will be described.

The rear end stopper 131 is a processing tray 130.
A supporting surface 131a having a surface perpendicular to the stacking surface for supporting the rear end of the sheet, a pin 131b for rocking by fitting into a round hole provided in the processing tray 130, and a link to be described later. It has a pin 131c for mating. The link includes a main link 132 having a cam surface 132a against which the roller 112 assembled to the stapler moving base 130 abuts and is pressed, and a pin 13 arranged at the upper end of the main link.
2b and a rear end stopper pin 131c.

The main link 132 swings around a shaft 134 fixed to a frame (not shown) as a fulcrum. Further, a tension spring 135 for urging the main link 132 in the clockwise direction is provided at the lower end of the main link 132, and the main link is positioned by the abutting plate 136. Therefore, the rear end stopper 131 is normally placed on the processing tray. Maintain a vertical posture.

When the staple moving table 103 moves, the stopper 13 that interferes with the stapler 101 is formed.
The cam surface of the main link 132 connected to 1 is pushed down by the tilting roller provided on the moving table, and the rear end stopper 1
31 is pulled by the connecting link 133, and the stapler 10
It is rotated to a position where it does not interfere with 1. Defeat roller 112
Are provided (three in the present configuration) so that the trailing end stoppers maintain this escape position while the stapler is moving.

A staple stopper 113 (two-dot chain line) having a supporting surface having the same shape as the trailing end stopper 131 is attached to both side surfaces of the holder 102 supporting the staple 101, so that the stapler 101 is in a horizontal state. The staple stopper 113 can support the trailing edge of the sheet even when the stopper 131 is pressed at the center.

Next, the processing tray unit 129 will be described (FIG. 5).

The processing tray unit 129 is arranged between the carrying section for carrying the sheets from the image forming apparatus main body 300 and the stack tray 200 for receiving and containing the bundle processed by the processing tray 130.

The processing tray unit 129 includes the processing tray 130, the rear end stopper 131, and the aligning means 14.
0, a swing guide 150, a drawing paddle 160, a retractable tray 170, and a bundle discharge roller pair 180.

The processing tray 130 is an inclined tray having a downstream side (left in the figure) as an upper side and an upstream side (right in the figure) as a lower side, and the rear end stopper is fitted to the lower end portion. ing. The sheet P discharged by the pair of discharge rollers of the transport unit is
By its own weight and the action of the paddle 160, which will be described later, it slides on the processing tray 130 until its rear end contacts the rear end stopper 131.

Further, at the upper end of the processing tray 130,
A bundle discharge roller pair and a bundle discharge upper roller 180b that comes into contact with the swing guide 150, which will be described later, are attached to each other, and can be rotated in the forward and reverse directions by being driven by the motor M18.

Next, the alignment wall (alignment means) 140 will be described with reference to FIG.

Alignment member 141 as alignment means 140
The front and rear alignment members 142 are independently movable in the front-rear direction. Front alignment member 141,
Both the inner aligning member 142 is put upright on the processing tray 131,
A support surface 1 that vertically bends from the matching surfaces 141a and 142a that press the sheet-side end surface and that supports the lower surface of the sheet P.
41, gear portions 141b and 142b that extend in the front-rear direction in parallel with the processing tray 130 and are provided with rack gears. The two aligning members are respectively supported by open guides extending in the front-rear direction of the processing tray 130,
The alignment surface is assembled on the upper surface of the processing tray 130 so that the gear portion is exposed on the lower surface of the tray.

The rack gear portions 141b, 141
42b is engaged with separate pinion gears 143 and 144, and the pinion gear is a motor M via a pulley and a belt.
141, M142, and the matching members 141, 142 are moved in the front-rear direction by the forward and reverse rotation of the motor. A sensor (not shown) for detecting the home position is attached to each of the aligning members 141 and 142, and the aligning members are normally on standby at the home position.

In the present embodiment, the front aligning member 14
The home position of 1 is set to the foremost part, and the home position of the back alignment member 142 is set to the deepest part.

The swing guide 150 supports the bundle discharge upper roller 180b on the downstream side (left in the figure), and the swing fulcrum shaft 151 is arranged on the upstream side (right in the figure). The swing guide 150 is normally in a closed state (a pair of bundle discharge rollers is in contact with and separated from) when one sheet P is discharged to the processing tray 130, and the sheets are discharged to and dropped from the processing tray 130. Then, the alignment operation is not hindered, and when the stack is discharged from the processing tray 130 to the stack tray 200, the stack moves to the closed state (the bundle discharge roller is in contact).

The rotating cam 152 is arranged at a position corresponding to the side surface of the swing guide 150, and when the rotating cam 152 rotates and pushes up the guide side surface, the swing guide 150 swings around the shaft 151. While closing, 1 from this state
The 80 ° rotating cam 152 rotates and closes when it comes in contact with or separates from the side surface of the swing guide. The rotational drive of the rotary cam 152 is performed by a motor M150 connected via a drive system (not shown).

Further, the swing guide 150 is provided with a sensor (not shown) which detects the closed position as the home position.

Next, the retractable paddle 160 will be described.

The retracting paddle 160 is fixed to the shaft 161, and the shaft 161 is rotatably supported by the front and rear side plates. The paddle shaft 161 is a motor M16.
It is connected to 0 and rotates counterclockwise when driven by the motor M160. The length of the paddle 160 is
It is set to be slightly longer than the distance to the processing tray 130, and the home position of the paddle 160 is set to a position (solid line in the figure) where the discharge roller pair does not contact the sheet P discharged to the processing tray 130. ing. In this state, the discharge of the sheet P is completed, and the sheet P is transferred to the processing tray 13.
When landing at 0, the paddle 160 is driven by the motor M150 to rotate counterclockwise and pulls the sheet P until it abuts on the trailing edge stopper 131. Then, after waiting for a predetermined time, the paddle 160 stops at the home position and prepares for ejection of the next sheet.

Next, the retractable tray 170 will be described with reference to FIG. 7 which is a d view.

The retractable tray 170 is provided with the bundle discharge lower roller 18
It is located below 0a, and moves back and forth in the sheet conveyance direction (x direction) while substantially following the inclination of the processing tray 130. In the protruding state, the tip of the retractable tray 170 has the stack tray 20.
It overlaps with the 0 side (two-dot chain line), and in the retracted state, the tip retracts to the right of the bundle discharge roller pair (solid line). The center of gravity of the sheet P discharged onto the processing tray 130 is set so as not to exceed the leading end position in the protruding state even with the large size (A3).

The retractable tray 170 is supported by rails 172 fixed to the frame 171, and is movable in the sheet discharging direction. Further, the rotation link 173 rotates on the central axis of the rotation link 173, and the retractable tray 170
Since it engages with the groove provided on the lower surface of the tray, the retractable tray 170 moves back and forth as described above with one rotation of the rotary link.

The rotation link 173 is driven by a retractable tray drive motor (drive means for retractable tray) M170 via a drive mechanism (not shown). The home position of the retractable tray 170 is the retracted position (solid line).
Is set to, and its position is detected by a sensor (not shown).

When the size of the sheet discharged from the sort discharge roller 7 is a small size, the leading end abutting member driving solenoid 175 is driven in a protruding state of the retractable tray 170, and the shaft 178 is rotated via the link member 179. By moving the drive belt 177, the tip abutting member 174 is raised to the tip abutting position around the rotation shaft 176. At this time, the tip abutting member 174 is substantially perpendicular to the processing tray 130.

Here, raising the tip end abutting member 174 is performed in a small size (here, 220 mm or less).
The only reason is that if the leading edge of the sheet discharged from the sort discharge roller 7 is to be abutted, it is necessary to dispose the abutting member at the tip of the sheet to be discharged, resulting in an increase in size of the apparatus. In addition, in order to downsize the device, it is necessary to make the processing tray 130 steeply inclined.
This is because it is difficult to satisfy the alignment and stackability of large size paper, which has weak stiffness.

Next, the stack tray 200 and the sample tray 201 will be described with reference to FIGS.

Each of these two trays has a tray drive motor (driving means) 202 so that both trays can independently move in the vertical direction, and are attached to the frame 250 of the sheet processing apparatus and the processing apparatus 1 in the vertical direction. It is designed to be attached to the rack 210 that also serves as a roller receiver.

Further, in the tray structure in which the regulation member 215 regulates the play in the front and back directions of the tray, the stepping motor 202 is attached to the tray base plate 211, and the pulley press-fitted onto the motor shaft is
Drive is transmitted to the pulley 203 by the timing belt 212.

A shaft 213 joined to the pulley 203 by a parallel pin
Is also a ratchet 20 connected to the shaft 213 with a parallel pin.
5 is transmitted to the idler gear 204, and the idler gear 204 is biased by the spring 206. The gear 205 is connected to the idler gear 204 to transmit the drive, and the idler gear 204 is connected to the gear 207, which connects the tray to the rack 210 at both the front and back sides.
In order to transmit the drive to the rack, another one is attached via the shaft 208, and the rack 210 can be moved via the gear 209. For fixing the tray, two rollers 214 on one side also serve as the rack. The roller receiver 210 is stored. Further, each tray is attached on the base plate 211 to form a tray unit.

Further, in order to prevent the tray drive system from being damaged by a foreign substance when the tray is lowered, the ratchet 205 pushes the spring 206 and spins around only in the direction in which the tray is lifted. When this vacancy takes place,
Sensor S201 for immediately stopping the driving of the motor
However, the slit incorporated in the idler gear is detected. Normally, this sensor is also used as out-of-step detection. Further, the swing guide 150 is a part of the stacking wall of the tray when the closing position is set so that the processing tray 130 having the closing portion can be traversed vertically, and a sensor detects the closing position (not shown). ) Only when you are moving.

Next, the sensor S202 is an area detecting sensor, and the upper limit sensor 2 for stopping the tray from rising too much.
The area flags from 03a to the tray sheet surface detection sensor (sheet upper surface detection means) S205 are detected. Sensor S203b for detecting 1000 sample tray position
Is the sheet 1 from the non-sorted paper surface detection sensor S204.
The sample tray 201 is arranged at a position corresponding to 000 sheets.
This is to limit the loading capacity of the vehicle by height.

In S203c, the sample tray 20
1 is for limiting the stacking amount when receiving sheets from the processing tray 130 by height, and is also arranged at a position equivalent to 1000 sheets from the paper surface detection sensor S205. S
In 203d, the stack tray 200 is the processing tray 130.
This is for limiting the stacking amount when receiving more sheets by height, and is arranged at a position corresponding to 2000 sheets from the paper surface detection sensor S205. S203e is a lower limit sensor that prevents the stack tray 200 from falling too much. Among the above sensors, only the paper surface detection sensors S204 and S205 are the front and rear transmission sensors. Further, a sheet presence / absence detection sensor 206 is arranged in each tray.

As a method of detecting the paper surface, the initial state is such that the optical axis of the paper surface detection sensor is above a predetermined amount (here, 1 mm) from the uppermost surface of each tray or the sheet bundle on each tray. After the sheets are stacked, the optical axis covered by the sheet surface detection sensor appears, and the lowering of the predetermined amount is repeated.

Next, the flow of the sheet P will be described.

The operation when the user specifies the staple sort mode will be described.

First, when the sheet length is long (A3 etc.),
As shown in FIG. 10, the entrance roller pair 2, the conveyance roller 3, and the conveyance large roller 5 rotate, and the image forming apparatus main body 300
The sheet P conveyed from is conveyed. Flapper 1
0 and 11 are stopped at the positions shown in the figure. The sheet P has 22 sort paths and is discharged by the discharge roller 7 to the processing tray 13.
It is discharged to 0. At this time, since the tip end abutting member 174 is in the retracted position and the retractable tray 170 is in the protruding position,
The leading end of the sheet P that has been discharged by the discharge roller 7 is prevented from hanging down, resulting in a defective return, and the alignment of the sheets on the processing tray is improved.

The discharged sheet P begins to move to the rear end stopper 131 by its own weight, and the paddle 160 which has stopped at the home position is rotated counterclockwise by the driving of the motor M160, and the sheet P is discharged. Facilitate the movement of. When the trailing edge of the sheet P surely contacts the stopper 131 and stops, the rotation of the paddle 160 is also stopped, and the aligning member aligns the discharged sheets.

When all the sheets of the first copy are discharged onto the processing tray 130 and aligned, the sheet bundle is stapled,
The swing guide 150 comes down, the roller 180b rides on the sheet bundle, and the sheets are discharged. This operation will be repeated.

Here, in order to prevent the last sheet from becoming one sheet,
If the previous sheet is wrapped around the buffer roller 5 which is a means for stacking the sheets two sheets before the final sheet, the final sheet and the sheet before the final sheet are wrapped around the buffer roller 5 and conveyed, If the previous two sheets are not wrapped around the buffer roller 5 which is the means for stacking the two sheets before, the last sheet and the sheet before the last sheet are conveyed so as to be stacked on three sheets and the last sheet becomes one sheet. It is prevented from catching up with the sheet piled up in front by being discharged.

Next, the sheet length is short (220 mm for A4 etc.).
In the following), the sheet P1 discharged from the image forming apparatus main body 300 is wound around the large conveyance roller 5 by the rotation of the flapper 10 as shown in FIG.
Stop a predetermined distance from and stop. Next sheet P2
When the paper has moved a predetermined distance from the paper detection sensor 31, the large conveyance roller 5 is rotated so that the leading edge of the first sheet P1 and the leading edge of the second sheet P2 are substantially the same (leading edge). Prevention of dents and scratches on the sheet when the sheet is abutted against the abutting member), the flapper 10 rotates to convey the two sheets P to the sort path 22.

The sheets sent to the sort discharge rollers 7 are conveyed in an overlapped manner each time, and the conveyed sheet bundles are placed on the retractable tray 170 in which the front end abutting member 174 is in a protruding state to abut the front ends of the sheets. The paper is ejected by the paper ejection roller 7 of the sort so that the tip of the
1). After that, the retractable tray 170 performs a substantially horizontal alignment operation with the processing tray 130 in order to align the sheets on the upstream side in the transport direction (FIG. 12). As described above, since the number of sheets conveyed to the processing tray 130 is at least two each time, the number of aligning operations of the aligning plate 141 and the leading end abutting member 174 performing the aligning operation is one when the sheets are transported one by one. Since the number of operations is less than half, the durability of the matching member can be improved, the speed of the drive motor can be reduced, and the size of the motor / device can be reduced accordingly.

By repeating this process, the sheets are aligned with the third, fourth, fifth, and sixth sheets stacked each time, and all the sheets of the first set are discharged onto the processing tray 130, and when they are aligned, The sheet bundle is stapled, the swing guide 150 comes down, the roller 180b rides on the sheet bundle, and the sheet is discharged. During this period, after the alignment of the final sheet is completed, the leading end abutting member 174 is moved to the retreat position, and after the movement, the retractable tray is pulled to the retreat position and discharged in a bundle. This operation will be repeated.

Here, although the first and second sheets in one set are overlapped and aligned, when the sheet post-processing such as stapling at two places takes a long time, 2.3
The third sheet is stacked and processed without degrading the productivity of the main body of the image forming apparatus. The stacking method of the third sheet is wound as described above, and the deviation amount of the leading edge of the sheet is almost the same. I am trying to become. Further, the final bundle of one copy is made to be two or three so that one copy of the last sheet of paper is not conveyed.

Next, when the user wants to specify the non-sort mode on the operation unit (not shown) of the image forming apparatus main body, for example, double-sided printing is performed from the image forming apparatus (here, for large size paper). When a sheet is conveyed to the sheet post-processing apparatus with a long sheet interval, as shown in FIG. 13, the entrance roller pair 2, the conveyance roller 3, and the conveyance large roller 5 rotate and are conveyed from the image forming apparatus main body 300. The incoming sheet P is conveyed. The FLAP 11 rotates to the position shown in the figure by the action of a solenoid (not shown), and the sheet P
Are conveyed to the non-sort path 21. When the sensor 33 detects the trailing edge of the sheet P, the roller 9 rotates at a speed suitable for stacking and discharges the sheet P to the sample tray 201. However, for example, when the sheet is conveyed from the image forming apparatus to the sheet post-processing apparatus such as printing only on one side (here, for small size paper) with a narrow sheet interval, when the sheet is discharged to the sample tray 201, It is necessary to decelerate and eject a sheet in order to improve stackability, but if the sheet interval is short, decelerating the sheet may catch up with the next sheet. Since the finisher receives sheets in synchronism with the sheet discharge speed of the main body, in order to increase the sheet conveying speed in the finisher and to separate the sheets, the trailing edge of the sheet comes out of the buffer roller 5. However, from the buffer roller 5 to the sort discharge roller 9
If the space is short, it may not be possible to make enough space. If there is no space between sheets, it is necessary to reduce the productivity of the main body. Also, the buffer roller 5 and the sort discharge roller 9
It is possible to control the deceleration of the sheet by increasing the distance to the sheet and increasing the sheet interval, but this leads to an increase in the size of the apparatus. Therefore, as shown in FIGS. 11 and 12, the sheet P is discharged to the sample tray 201 in a state in which the sheets are wound (here, two sheets each time). At this time, the amount of misalignment of the stacked sheets was set to be almost non-existent during sort discharge, but there is no tip abutting member during non-sort discharge, so the stacked upper sheet reaches the stacking wall before the lower sheet. Then, since the lower sheet cannot be returned, the lower sheet of the overlapping sheet (P0) is displaced (X) toward the upstream side in the transport direction so that the overlapping sheet on the sample tray 201 can return. Then about 2 mm).

Next, the sort mode will be described.

The user sets the document on the RDF 500, specifies the sort mode on the operation unit (not shown), and turns on the start key (not shown). The entrance roller 2 and the transport roller 3 are stacked on the processing tray 130 as in the staple sort mode. The aligning unit 140 stacks a small number of sheets on the processing tray 130 while aligning the sheets P on the processing tray 130, and then, as illustrated in FIG. Convey a bundle.

Next, the sent sheet P passes over the flapper 10, is wound around the large roller 5 in the same manner as the operation described in the staple sort mode, and is discharged onto the processing tray 130 after the bundle discharge is completed. It The number of the small number of bundles discharged in the bundle is set to 5 here.

When all the bundles of the first copy have been discharged, the front alignment wall 141 moves together with the back alignment wall 142 to offset the alignment position of the second copy from the alignment position of the first copy. As a result, it becomes possible to offset the unbound bundle on the stack tray 200 in the direction perpendicular to the conveying direction.

The second copy is aligned at the offset position, and a small number of sheets are discharged in the same manner as the first copy. When the second copy is completed, the front alignment wall 141 and the back alignment wall 142 return to the positions where the first copy is aligned, and the third copy is aligned.

Next, the movement of the stack tray 200 and the sample tray 201 will be described (FIGS. 8 and 9). Before starting the operation, each tray normally waits at each sheet surface detection sensor position (normal stacking position) S204, S205.

A stack tray 200 is usually used for stacking copies or printer outputs, and can receive sheets processed by the above-mentioned stapler 101 or the like, or unbound stapled bundles discharged in small numbers. 200
It is possible to stack the equivalent of 0 sheets, and the sensor 203d
Is detected by.

At this time, when the output of the printer for copying still continues, the stack tray 200 is lowered by a position corresponding to 1000 sheets from the sensor S203d (position of S203d '). Subsequently, the sample tray 201 is lowered to the sheet surface / sheet surface detection S205 for the processing tray, and sheet reception is started again. At this time, the sample tray 201 is capable of stacking up to 1000 sheets, and the sensor 203c
To detect it.

In the present invention, the tip end abutting member 17
Although 4 is disposed downstream of the bundle discharge roller 180, the sheets stacked on the processing tray 130 are directly processed by the bundle discharge roller 180 after post-processing, which enables simplification of the apparatus and stacking with the processing tray 130. By stacking the sheets on the tray 200 while straddling them, the device can be downsized. Further, the size of the apparatus is also reduced by stacking the sheets each time only when the sheet size is a small size, but in the present embodiment, the tip abutting member 174 is discharged in a bundle as shown in FIG. It is arranged upstream of the roller 180, and instead the sheet bundle is discharged from the bundle discharge roller 18
A bundle moving member 185 that conveys to 0 is provided.

The sheet bundle P0 that has been conveyed by stacking at least two sheets is discharged to the processing 130 by the paper discharge roller 7,
The leading edge of the sheet bundle is abutted against the leading edge abutting member 174a that projects substantially at a right angle to the processing tray 130, and the trailing edge of the sheet bundle P0 moves down to the processing tray 130, and then the leading edge abutting member 174.
a moves toward the stopper 131 and aligns the sheet bundle P0 with the transport direction.

When the alignment of the final sheet is completed by the front end abutting member 174a, after the predetermined post-processing, the front end abutting member 174b contacts the rear end of the sheet bundle on the processing tray 130, and the sheet bundle is set by the bundle discharge roller 180. In a bundle,
When the bundle discharge rollers are conveyed to 180 parts, the swing guide 150
As a result, the bundle discharge roller 180 conveys the bundle from there and discharges it to the stack tray 200. Further, the leading edge abutting member 174b is stopped at the position where the leading edge abutting 174a was located, and is prepared for the abutting of the next sheet.

Further, in the previous embodiment, the structure was used as the leading end abutting member and the sheet bundle moving member, but the leading end abutting member depends on the means for conveying the bundle on the processing tray to the bundle discharge roller and the size. In the above embodiment, the same effect can be obtained even if a mechanism for changing the protruding position of the sheet is configured separately. In the above embodiment, the processing tray 130 is an inclined tray having a high downstream side in the sheet conveying direction, and the discharged sheet is discharged in the discharging direction. Although it is configured to be pulled back to the opposite side, in the present embodiment, as shown in FIG. 17, the inclined tray is low on the downstream side in the discharge direction, and the discharged sheet is applied to the leading end abutting member 174 without being pulled back in the transport direction. The sheet is abutted and aligned with the sheet aligning member 186 from the rear side of the sheet. The transport direction sheet aligning member 186 projects substantially at right angles to the surface of the processing tray 130, and is configured to be movable by a belt so that the sheet aligning member 186 can be moved according to the size of the sheet and can be moved substantially horizontally with the processing tray 130 as a sheet aligning operation. There is. When the final sheet is aligned by the transport direction sheet aligning member 186, the bundle moving member 185 comes into contact with the trailing end of the sheet bundle on the processing tray 130 after the predetermined post-processing, and the sheet bundle is bundled in the bundle discharge roller 180 direction. When being conveyed and conveyed to the bundle discharge roller 180, the swing guide 150 descends, and from there, the bundle discharge roller 180 conveys the bundle and discharges it to the stack tray 200.

In the above-described embodiment, one sheet of the last sheet is not always ejected, but the final sheet is rotated by 5 parts of the buffer roller without being wound once, and is conveyed before being conveyed. The same effect can be obtained by preventing the sheet from catching up.

[0093]

As described above, according to the present invention,
When the sheet is ejected according to the sheet size, the sheet front end abutting member projects or retracts to the abutting position where the sheet front end abutting member abuts the sheet. It is possible to perform a sufficient alignment operation in the paper room, and it is possible to simplify the device and shorten the length of the entire device except for small size paper, which is used less frequently and in which the sheet abutting member retracts. .

[Brief description of drawings]

FIG. 1 is a front view showing the overall configuration of a sheet processing apparatus of the present invention.

FIG. 2 is a side view of the stapler and the processing tray portion.

FIG. 3 is a plan view of the stapler moving mechanism in the b view of FIG.

FIG. 4 is a rear view of the stapler as seen from the view b of FIG.

FIG. 5 is a vertical sectional side view of the swing guide and the processing tray.

FIG. 6 is a plan view of the processing tray and the matching wall moving mechanism.

FIG. 7 is a plan view of the retractable tray.

FIG. 8 is a plan view of the stack tray moving mechanism.

FIG. 9 is a sensor layout diagram around the stack tray.

FIG. 10 is an operation diagram of the sheet processing apparatus in the staple sort mode.

FIG. 11 is an operation diagram of the sheet processing apparatus in the staple sort mode.

FIG. 12 is an operation diagram of the sheet processing apparatus in the staple sort mode.

FIG. 13 is an operation diagram of the sheet processing apparatus in the non-sort mode.

FIG. 14 is an operation diagram of the sheet processing apparatus in the same sort mode.

FIG. 15 is a front view showing the overall configuration of a sheet processing apparatus that is a second embodiment.

FIG. 16 is a front view showing the overall configuration of the sheet processing apparatus.

FIG. 17 is a front view showing the overall configuration of a sheet processing apparatus that is a third embodiment.

FIG. 18 is a front view of an image forming apparatus to which the sheet processing apparatus according to the present invention can be applied.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 sheet processing apparatus 4 control apparatus (control means) of sheet processing apparatus 130 processing tray 170 retractable tray 174 tip abutting member 180 bundle discharge roller pair 200 stack tray (sheet stacking means) 201 sample tray 202 tray drive motor (driving means) 300 Image Forming Apparatus Main Body 399 Discharging Roller Pair (Discharging Means) 902 Image Forming Unit (Image Forming Means) 930 Image Forming Apparatus Main Body Control Device (Control Means) 931 Sheet Number Setting Means P Sheets, Sheet Bundles M170 Emerging Tray Drive Motor ( Ejection / retraction tray driving means) S205 Paper surface detection sensor (sheet upper surface detection means)

Claims (6)

[Claims] 1. A sheet stacking unit for sequentially stacking a plurality of transported sheets, a transporting unit capable of transporting the sheets stacked by the sheet stacking unit, and a discharging unit for discharging the transported sheets. A sheet ejecting unit having a stacking unit for placing the discharged sheet, an abutting position for protruding the sheet onto the stacking unit and abutting the sheet discharged by the discharging unit, and a retreat position for retracting out of the stacking unit surface. When the sheets are discharged to the stacking means by the sheet discharging means, it is possible to change whether the sheet abutting means is in a protruding state or a retracted state according to a mode. A sheet processing apparatus comprising: 2. A mode in which the sheet abutting means is made to vary between protruding and retracting is determined by the size of the sheet discharged by the discharging means, and the sheet size is not more than a predetermined value (sheet length is 220 mm or less). )time,
2. The sheet processing apparatus according to claim 1, wherein the sheet abutting means is caused to protrude to abut the sheet. 3. The sheet according to claim 1, wherein when the sheet is abutted by the abutting means, the number of sheets discharged by the discharging means is two or more at least every time except for one final sheet. Sheet post-processing device. 4. The sheet processing apparatus according to claim 1, wherein when the sheets on the stacking unit are discharged, the sheet abutting unit is moved to a retracted position. 5. The sheet processing apparatus according to claim 1, wherein the sheet abutting unit abuts a leading edge of the sheet discharged by the sheet discharging unit. 6. The sheet processing apparatus according to claim 1, wherein the sheet abutting unit performs an aligning operation in a conveying direction of the sheet discharged by the sheet discharging unit.