JP2003128315A - Sheet post-processing device and image forming device equipped therewith - Google Patents

Abstract

PROBLEM TO BE SOLVED: To stabilize kicking-out of a sheet by a pair of knurling belt rollers in a finisher using knurling belts for ejecting and pulling a sheet to a process tray. SOLUTION: The rotational speed of the knurling belt is kept same as the ejecting speed until the rear end of an ejected sheet drops and stands still on the process tray. A traction means for drawing the knurling belt according to the number of sheets is provided. The speed of ejecting sheet is changed so that the jumping amount of the rear end of the sheet ejected from the outer peripheral surface of the downstream side knurling belt, variable according to the drawing amount, can be made constant.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet post-processing apparatus, and more particularly, to a sheet post-processing apparatus mounted on an image forming apparatus for discharging, stacking and aligning sheet materials, and an image forming apparatus including the same. It is about.

[0002]

2. Description of the Related Art Conventionally, as this type of image forming apparatus,
A number of techniques relating to a combination with a sheet post-processing device that ejects image-formed sheets to a processing tray for aligning and stapling them, and after processing them and discharges them in a bundle to another stack tray are proposed in JP-A-11-199123. ing.

An outline of the sheet post-processing apparatus according to this proposal will be described.

FIG. 17 is a main sectional view showing a schematic structure of a processing tray of a conventional sheet post-processing apparatus.

In the figure, reference numeral 130 denotes a processing tray for receiving sheets to be image-formed and discharged on the image forming apparatus side, and 200 denotes a bundle discharge roller pair 180 for the processed sheet bundle.
A stack tray for receiving the sheet through the sheet tray is shown. Around the processing tray 130, a trailing edge stopper 131 that locks the trailing edge of the received sheet, a jogger 140 that aligns the sheet, and a sheet is pulled back to the trailing edge stopper 131. A paddle 160, a stapler (not shown) for binding sheets as needed, and a pair of discharge rollers 7, 7 for discharging the sheets to the processing tray 130 are arranged.

A part of the inner peripheral surface is wound around the lower roller 7a of the discharge roller pair 7, 7 and the outer peripheral surface facing the upper roller 7b is in contact with the upper roller 7b to form a nip portion, so that the sheet is processed in the processing tray. An elastically deformable endless belt-shaped feed belt (hereinafter referred to as a knurled belt) 182 that pulls the uppermost sheet stacked on the processing tray into the rear end stopper 131 at the same time as discharging the sheet to the rear end stopper 131 is disposed. Knurled belt 182
Further, a traction roller 191 is provided on the inner peripheral surface of and is moved between a solid line position and a broken line position by traction means (not shown). At this time, the knurled belt 182 is also pulled and deformed into a solid line shape and a broken line shape.

Since each of the above operations is described in detail in the above-mentioned document, the description thereof will be omitted here.

In this apparatus, the knurled belt 182 has the stopper 13 against the uppermost sheet as described above.
However, since the stacking height of the processing tray 130 is changed depending on the number of sheets, the carrying force becomes unstable, and when the carrying force is low, a drawing failure occurs.
On the contrary, if the conveying force is too high, buckling or scratches at the rear end of the sheet may occur. Therefore, by using the pulling means of the knurled belt 182, the stacking surface of the processing tray 130 and the knurled belt 182 are arranged according to the number of sheets.
If the distance from the outer peripheral surface of the sheet is controlled to be constant, the conveying force can be stabilized.

[0009]

However, in the above-mentioned conventional apparatus, when the knurling belt 182 is pulled by the pulling means, the distance L from the roller nip to the outer peripheral surface of the knurling belt 182 is also displaced. The distance L is shortened in inverse proportion to the pulling amount of the knurled belt 182.

Therefore, regardless of the distance L, if the discharge speed of the sheet is uniformly controlled, the amount of protrusion of the sheet from the roller nip becomes uniform, but the distance between the trailing edge of the discharged sheet and the knurled belt 182 may be different. The time required for this sheet to fall again by its own weight and to come into contact with the knurled belt 182 is not constant because it changes depending on This means that the place where the discharged sheet hits the knurled belt 182 is not fixed, which causes a problem that the pullback behavior becomes unstable. If the distance L is too long, the time until the discharged sheet is returned by the knurled belt 182 increases, and if the distance L is too short, the discharged sheet hits above the center of the knurled belt 182 and the returning force cannot be applied.

Further, the knurled belt 182 in the above-mentioned conventional device has elasticity, and its shape changes with the change of the rotation speed. It has a characteristic that the distance L also extends in proportion to the rotating speed. Therefore, if the discharged sheet falls under its own weight and the rotational speed (discharging speed) of the knurled belt 182 is changed before settling, the distance L is also changed between them and stable pullback behavior is not achieved, as described above. Is.

[0012]

SUMMARY OF THE INVENTION The present invention provides an apparatus which solves the problems of the above-mentioned conventional apparatus.

According to the present invention, (1) a processing tray on which a stacking surface for receiving and stacking sheets is formed, and a rear end stopper portion for locking the rear end of the sheets is arranged; A part of the inner peripheral surface is wound around one of the pair of discharge rollers for discharging, and the opposite outer peripheral surface contacts the other of the pair of discharge rollers to form a nip portion, and the sheet is discharged to the processing tray, and at the same time, the processing tray is discharged. A pair of belt rollers having an elastic knurled belt that draws the upper sheet into the trailing end stopper, and pulls the knurled belt in the required direction to displace the distance between the belt roller nip and the outer surface of the knurled belt downstream of the nip. In the sheet post-processing apparatus having the pulling means for controlling and the control means for controlling the operation of each part, the amount of protrusion of the sheet from the outer peripheral surface of the knurled belt becomes constant. By controlling the discharge speed of the pair of belt rollers according to the pulling amount of the pulling means as described above, the time until the discharged sheet again contacts the knurled belt and the place where it hits the knurled belt can be made constant. A stable pullback operation is possible regardless of the pulled state.

(2) A stacking surface for receiving and stacking sheets is formed, and one of a processing tray having a rear end stopper portion for locking one end of the sheet and a pair of discharge rollers for discharging the sheet to the processing tray is provided. A part of the inner peripheral surface is wrapped around, and the opposing outer peripheral surface contacts the other of the pair of discharge rollers to form a nip portion, which discharges the sheet to the processing tray and at the same time pulls the sheet on the processing tray to the stopper portion. In a sheet post-processing apparatus having a belt roller pair having a knurled belt and a control means for controlling the operation of each part,
The predetermined discharging speed of the pair of belt rollers for discharging the sheet to the processing tray is maintained at a constant speed until the falling and settling of the discharged sheet on the processing tray is completed, and the outer peripheral surface of the knurled belt is Since the sheet is not deformed, the time until the discharged sheet comes into contact with the knurled belt again and the position where it hits the knurled belt can be made constant, and a stable pullback operation can be performed.

(3) Stabilizing the pullback operation can be further enhanced by combining the configurations and controls of (1) and (2).

Further, in more detail, the present invention can solve the above problems by the following constitution.

(1) An inner peripheral surface is formed on one of a stacking tray that forms a stacking surface for receiving and stacks sheets and has a stopper portion that locks one end of the sheets, and one of a pair of discharge rollers that discharges the sheets to the stacking tray. Part of the sheet is wound around, and the opposing outer peripheral surfaces are in contact with the other of the pair of discharge rollers to form a nip portion, which discharges the sheet to the stacking tray and at the same time draws the sheet on the stacking tray into the stopper portion. A pair of belt rollers having an endless belt-shaped feed belt, pulling the endless belt-shaped feed belt in a required direction, and a belt roller nip portion,
In a sheet post-processing apparatus having a traction means for varying the distance to the outer peripheral surface of the endless belt-shaped belt downstream and a control means for controlling the operation of each portion, there are both places where the sheet pops out from the outer peripheral surface of the endless belt-shaped belt. To be quantitative
A sheet post-processing apparatus characterized in that the discharge speed of a pair of belt rollers is controlled according to the amount of pulling of the pulling means.

(2) A stacking tray that forms a stacking surface for receiving and stacks sheets and has a stopper portion that locks one end of the sheet, and a stopper portion that discharges the sheet to the stacking tray are one of a pair of discharge rollers. Wrap a part of the inner surface around
The opposing outer peripheral surfaces are in contact with the other of the pair of discharge rollers to form a nip portion, and at the same time when the sheets are discharged to the stacking tray, an elastic endless belt-shaped endless belt feeding belt that draws the sheet on the stacking tray to the stopper portion is formed. In a sheet post-processing apparatus having a pair of belt rollers and a control means for controlling the operation of each part, a predetermined discharging speed of the pair of belt rollers for discharging a sheet to a stack tray is set so that the sheet discharged to the processing tray can be dropped or settled. A sheet post-processing apparatus that is maintained at a constant speed until completion.

(3) Forming a stacking surface for receiving and stacking sheets, and stacking a part of the inner peripheral surface on one side of the stacking tray having a stopper portion for locking one end of the sheet and the discharge roller pair, A belt roller having an elastic endless belt-shaped feed belt that forms a nip portion by contacting the other outer peripheral surface with the other of the pair of discharge rollers to discharge the sheet to the stack tray and at the same time pulls the sheet on the stack tray to the stopper portion. In a sheet post-processing apparatus having a pair, a pulling means for pulling the endless belt-shaped feed belt in a desired direction to displace the distance between the roller nip portion and the outer peripheral surface of the endless belt-shaped feed belt, and a control means for controlling the operation of each portion, The discharging speed of the pair of belt rollers is controlled according to the pulling amount of the pulling means so that the amount of protrusion of the sheet from the outer peripheral surface of the belt-shaped belt becomes a predetermined amount. Issued sheet is dropped, the sheet post-processing apparatus, characterized in that it is maintained at a constant until settled.

(4) An image forming apparatus comprising an image forming means for forming a sheet image and the sheet post-processing apparatus described in (1) to (3) above.

[0021]

FIG. 16 shows an example of an image forming apparatus (copying machine) 310 (see FIG. 1) having a sheet processing apparatus 1 according to the present invention in an image forming apparatus main body (copying machine main body) 300. Shows.

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, a lens system 908, a sheet supply unit 909, an image forming unit (image forming unit) 902, and a document on a platen glass 90.
An automatic document feeder (RDF) 500 for feeding the sheet to the image forming apparatus 6 and the sheet processing apparatus 1 according to the embodiment of the present invention for stacking the image-formed sheets discharged from the copying machine main body 300 are provided.

The sheet processing apparatus 1 according to the embodiment of the present invention is incorporated not only in the main body of a copying machine, but also in the main body of a facsimile, a printer, a complex machine of these, or the like. Therefore, the image forming apparatus according to the present invention is not limited to the main body of a copying machine, but also a facsimile, a printer,
In addition, it also includes multifunctional machines of these.

The sheets include plain paper, thin resin sheets which are substitutes for plain paper, postcards, cardboard,
There are envelopes and thin plastic plates.

The sheet supply unit 909 is for recording sheets P.
A cassette 91 that can be attached to and detached from the device main body 300
It has decks 913 located at 0, 911, and pedestal 912. The image forming unit 902 includes a cylindrical photosensitive drum 914, a developing device 915 around the photosensitive drum 914, a transfer charger 916, a separation charger 917, a cleaner 918, a primary charger 919, and the like. At the downstream side of the image forming unit 902, the conveying device 920 and the fixing device 90 are provided.
4, a pair of discharge rollers 905 and the like are provided.

A detailed description of the automatic document feeder (RDF) 500 will be omitted.

The operation of the image forming apparatus main body 300 will be described.

When a sheet supply signal is output from the control device 930 provided on the apparatus main body side 300, the sheet P is fed from the cassette 910, 911 or the deck 913. On the other hand, the light reflected by the light source 907 applied to the document D placed on the document table 906 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 sheet feeding unit 909 is corrected for skewing by the registration rollers 901, and further fed to the image forming unit 902 at a timed timing.
In the image forming unit 902, the toner image on the photosensitive drum 914 is transferred to the sheet S that has been sent by the transfer charger 916, and the sheet S onto which the toner image has been transferred is transferred by the separation charger 917. Is charged to the opposite polarity and 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. The sheet S having the image fixed thereon is ejected from the apparatus main body 300 by the ejection roller pair 905.

In this way, an image is formed on the sheet S fed from the sheet feeding section 909, and the sheet S is discharged to the sheet processing apparatus 1 according to the present invention.

Next, the sheet processing apparatus according to the embodiment of the present invention will be described.

In FIG. 1, the finisher (sheet processing apparatus) 1 is installed in the image forming apparatus main body 300.

Reference numeral 905 denotes a discharge roller of the image forming apparatus main body 300. Reference numeral 2 denotes a roller roller pair having the finisher 1. Reference numeral 3 indicates a pair of conveying rollers. Reference numeral 31 denotes a sheet detection sensor. Reference numeral 50 denotes a punch unit for making a hole near the rear end of the conveyed sort. Reference numeral 5 denotes a large conveyance roller. Reference numerals 12, 13, and 14 denote pressing rollers that press and convey the sheet.

The switching flapper 11 is adapted to switch between the non-sort path 21 and the sort path 22. The switching flapper 10 includes a sort path 22 and
The buffer path 23 for temporarily storing the sheets is switched. Reference numeral 6 indicates a carrying roller. On the intermediate tray (hereinafter referred to as “processing tray”) 130,
The sheets can be temporarily collected, aligned, stapled, and the like.

The discharge roller 7 discharges the sheet onto the processing tray 130. Bundle discharge roller 180
b is supported by the swing guide 150, and when the swing guide 150 is moved to the closed position, the sheets b on the processing tray 130 are bundle-conveyed in cooperation with the rollers 180a arranged on the processing tray 130 to stack the stack tray 200. It is designed to discharge the bundle up.

Next, the processing tray unit 129 will be described with reference to FIGS.

The processing tray unit 129 is arranged in the middle of the transport section for transporting the sheets from the image forming apparatus main body 300 and the stack tray 200 for receiving and containing the sheet bundle processed on the processing tray 130. .

A sensor 183 for detecting a sheet moving on the sort path 22 is provided on the sort path 22 near the pair of discharge rollers 7a and 7b in the transport section. The sensor 183 is connected to the control circuit 301 of the sheet processing apparatus 1. The control circuit 301 is connected to the control device 930 in the main body of the copying machine and controls not only the operation of the sheet processing apparatus but also the smooth operation of the linking operation with the main body of the copying machine.

Further, the control circuit 301 includes a sensor 183.
Each time it detects a sheet, it counts the sheet based on the sheet detection signal sent, and controls the motors M141 and M142 that rotate pinions 143 and 144, which will be described later, according to the sheet, and performs the front alignment. Mechanism 141
Then, the alignment member 142 is moved.

A trailing end dropping member 18 is provided around the downstream end of the sort path 22 in which the discharge roller pairs 7, 7 of the transport section are arranged.
1 and a knurled belt 182 and the like.

The knurled belt 182 is an elastic body, and a part of the inner peripheral surface of the lower roller 7a of the discharge roller pair 7 and 7.
The outer peripheral surface facing each other is pressed by the roller 7b to form a nip portion. Further, in the knurled belt 182, in the vicinity of the rear end stopper 131, the knurled belt 18 is brought into contact with the inner peripheral surface and moved in the arrow direction.
2 from the state of the home position (solid line shape) where the lowermost surface 181a contacts the stacking surface of the processing tray 130
State where 1a is separated from and contacted with the processing tray 130 (broken line shape)
A towing roller 191 for deforming the space between is provided. The towing roller 191 is connected to the motor M190 via a driving means (not shown), and is capable of moving as described above.
The motor M190 that moves the towing roller 191 is configured so that the pressure applied by the lowermost surface 181a of the knurled belt 182 to the stacking surface that is displaced depending on the number of stacked sheets is constant, that is, the distance from the stacking surface to the lowermost surface 181a is substantially constant. Is controlled by the control circuit 301 so that

The trailing edge removing member 181 is provided on the swing center shaft 181d in the vicinity of the roller nip so as to be swingable in the vertical direction, and if there is no passage of a normal sheet, the position shown by the solid line (lower position) in FIG. Waiting at And
At one end of the trailing edge drop member 181, a flip-up lever 181a is provided which extends in the lowered position so as to intersect the transport path. When the sheet is conveyed, the leading edge of the sheet pushes up the flip-up lever 181a (state of broken line), and the trailing edge dropping member 181 swings clockwise in FIG. After that, when the sheet passes through the flip-up lever 181a, the pressing surface 181c of the trailing edge dropping member 181 pushes the trailing edge of the sheet downward, so that the floating sheet is dropped and settled.

The sheet discharging operation from the discharge roller pair 7, 7 to the processing tray 130 will be described. The details of the operation of each part of the processing tray unit 129 will be described later.

FIG. 6 shows a state in which no sheets are stacked on the processing tray 130, and FIG. 7 shows a state in which sheets are stacked on the processing tray 130 to some extent. In FIG. 6, the traction roller 191 is in contact with the knurled belt 182 at the home position, and the knurled belt 182 is the lowermost surface 182a.
Is in contact with the processing tray 130. Outer surface 181b of the knurled belt downstream from the roller nip, distance L
Then, in this case, it becomes L1.

On the other hand, in FIG. 7, the knurled belt 182 is pulled by the pulling rollers 191 according to the thickness of the stacked sheets as described above. At this time, the distance L is L2, and the relationship between L1 and L2 is L1.
> L2. The distance L decreases in proportion to the amount of traction of the knurled belt 182, and the relationship is recorded in advance in the control circuit 301 by measurement. The pair of discharge rollers 7 and 7 are rotating in a direction (arrow direction) for discharging the sheet to the processing tray 130, and the knurled belt 182 hung on the pair is also rotating in the same direction (counterclockwise direction in the drawing). The control circuit 301 controls the discharge speed of the fed sheet so that the distance K between the outer peripheral surface 181b of the knurled belt 182 and the discharged rear end becomes constant regardless of the pulled state of the knurled belt 182. Discharge roller pair 7,7
Is discharged to the processing tray 130. The amount K + L of protrusion at the rear end from the nip is proportional to the discharge speed, and the relationship is also recorded in the control circuit 301 in advance measurement.

The sheet whose discharge is controlled as described above is dropped and settled by its own weight and the action of the trailing edge dropping member 181, and again comes into contact with the knurled belt 182, so that the conveying force to the trailing edge stopper 131 is increased. Given. At this time, since the distance K between the outer peripheral surface of the knurled belt and the rear end is constant, the time and place of contact with the knurled belt 182 are substantially the same, and the sheet discharging speed capable of stable returning operation is set. For example, the stability is maintained every time regardless of the number of sheets loaded (the knurled belt is pulled). The stable return operation is not accompanied by an increase in the return time caused by a large amount of the sheet being caught, or being caught above the belly (center) of the knurled belt 182 caused by the small amount of the sheet protruding. .

The predetermined discharging speed is maintained until the trailing edge of the sheet discharged at the above predetermined discharging speed falls and is settled. Therefore, in the case where the knurled belt 182 is an elastic body as in this embodiment, when the rotational speed of the belt is changed, the outer peripheral surface of the knurled belt 182 is displaced by vibration or the like. Since the outer peripheral surface 181b of the knurled belt 182 is kept constant during discharging, dropping, and settling, the time and place where the trailing edge of the discharged sheet again contacts the knurling belt 182 are substantially the same as above. A stable return operation can be performed.

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

5 to 10, 14 and 15, the operation of the trailing edge dropping member 181 and the knurled belt 182 shown in FIG. 2 will be described with reference to FIGS. 2 to 4. Therefore, it is omitted.

When the user designates the non-sort mode on the operation unit (not shown) of the main body of the image forming apparatus, as shown in FIG. 13, the entrance roller pair 2, the conveyance roller 3, and the conveyance large roller 5 rotate. The sheet P on which the image is conveyed is conveyed from the image forming apparatus main body 300. The flapper 11 rotates to the position shown in the figure by the action of a solenoid (not shown), and conveys the sheet P 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 the sample tray 2
The sheet P is discharged to 01. The discharged sheet P has the rear end of the sheet P received by the grounding piece 216 and is grounded, and the static electricity charged on the sheet is discharged.

Therefore, the sheets P do not come into close contact with each other, and the sheets can be easily separated one by one. Further, when the user grips the sheet P, the user will not be shocked by static electricity.

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

As shown in FIG. 6, the entrance roller pair 2, the conveying roller 3, and the large conveying roller 5 rotate to convey the sheet P conveyed from the image forming apparatus main body 300. The flappers 10 and 11 are stopped at the positions shown in the figure. Sheet P
Passes through the sort path 22 and is discharged to the stapler 101 by the discharge roller 7. At this time, the emergence tray 170
Is at the protruding position, receives the leading edge of the sheet P discharged by the discharge roller 7, prevents the sheet P from hanging down, eliminates the defective return of the sheet P, and enhances the alignment of the sheets on the processing tray. ing.

The discharged sheet P begins to move to the rear end stopper 131 (FIG. 2) by its own weight, and the paddle 160 stopped at the home position is rotated counterclockwise by the drive of the motor M160. Move to facilitate movement of the sheet. When the trailing edge of the sheet P surely abuts against the stopper 131 and stops, the rotation of the paddle 160 is also stopped, and the discharged sheet is aligned with the front alignment mechanism 141 and the alignment member 142.
Match.

The aligning operation of the sheet P will be described later.

When all the sheets of the first set are discharged onto the processing tray 130 and aligned, the swing guide 150 descends as shown in FIG. 7, the roller 180b rides on the sheet bundle, and the stapler 101 , Staple the sheet bundle.

On the other hand, in the meantime, the image forming apparatus main body 300
The sheet P ₁ discharged from the
It is wound around the large conveyance roller 5 by the guidance of the flapper 10 and stops at a predetermined distance from the sensor 32. When the next sheet P ₂ advances from the sheet detection sensor 31 by a predetermined distance, as shown in FIG. 8, the large conveyance roller 5 rotates, and the second sheet P ₂ is moved from the first sheet P ₁ to the second sheet P ₂ . Are overlapped with each other by a predetermined distance, and are wound around the large conveyance roller 5 as shown in FIG. On the other hand, the sheet bundle on the processing tray 130 is
As shown in FIG. 9, when the bundle is discharged onto the stack tray 200 and static electricity is charged, the static electricity is grounded by the ground piece 216. However, at this time, the retractable tray 170 moves the sheet bundle to the home position before the sheet bundle passes through the discharged sheet bundle roller in order to drop the sheet bundle onto the stack tray 200. As shown in FIG. 10, when the third sheet P ₃ reaches the predetermined position, the large transport roller 5 rotates, the sheets P ₃ are shifted by a predetermined distance and overlapped, and the flapper 10 rotates to rotate the three sheets. The sheet P is conveyed to the sort path 22.

As shown in FIG. 11, the rocking guide 150 is lowered and the three sheets P are received by the rollers 180a and 180b. When the trailing edge of the sheet P passes through the roller 7 as shown in FIG. 180a and 180b reverse,
Before the rear end contacts the stopper 131, the swing guide 150 moves up and the roller 180b moves away from the sheet surface, as shown in FIG. The fourth and subsequent sheets P pass through the sort path 22 in the same manner as the operation of the first copy, and the processing tray 130
Discharged on top. After the third copy, the same operation as that of the second copy is performed, and the set number of copies are stacked on the stack tray 200, and the process ends.

In stacking and conveying the plurality of sheets,
As shown in FIG. 13, each sheet P is offset in the transport direction, the sheet P ₂ is offset downstream from the sheet P ₁ , and the sheet P ₃ is offset downstream from the sheet P ₂ .

Offset amount of sheet P and swing guide 15
The rising timing of 0 is the bundle discharge rollers 180a, 180
It is related to the settling time of the sheet by the returning speed of b. That is, it is determined by the processing capacity of the image forming apparatus main body 300, and in the present embodiment, the sheet conveying speed 750.
mm / s, an offset amount (b = 20 mm), and a bundle discharge roller return speed of 500 mm / s, the sheet P ₁ contacts the stopper 131 at the separated position of the bundle discharge rollers 4
The timing is such that the value (a) is reached before 0 mm or less.

Next, the sort mode will be described.

The user sets the original on the RDF 500, designates the sort mode on the operation unit (not shown), and turns on the start key (not shown). The entry roller 2 and the transport roller 3 rotate as shown in FIG. 11 and are stacked on the processing tray 130 as in the staple sort mode. The sheet P on the processing tray 130 is aligned by the aligning device 140. After a small number of sheets P are stacked and aligned on the processing tray 130, the swing guide 150 descends to convey a small number of sheet bundles.

Next, the sent sheet P passes over the flapper 10 and is wound around the large conveyance roller 5 in the same manner as in the staple sort mode, and is discharged to the processing tray 130 after the bundle discharge is completed. To be done. When the number of the small number of bundles to be discharged in a bundle is 20 or less (however, this is not the case when the sheets are bound), the number of originals ≧ the number of discharged sheets ≦ 20 sheets is satisfied. To be Therefore, if the number of sheets to be discharged in a bundle is set to 5 when a program is set up, when the number of originals is 4, four sheets are discharged in a bundle. When the number of originals is 5 or more, for example, when the number of originals is 14, the originals are divided into 5 sheets + 5 sheets + 4 sheets, aligned, and discharged in a bundle.

In this embodiment, since the sheet bundle is bound, the number of sheets in one bundle may be 20 or more.

The control circuit 301 inputs 1 input by the user.
Information on the number of sheets per bundle is sent from the control device 930 of the copying machine main body 300 as the number of sheets per bundle. For example, if the number of sheets per bundle is 39, offset control is performed. If there are 40 or more,
The offset control is not performed, and the sheet bundle P is controlled to be stacked.

When the offset control is performed, when all the stapled bundles of the first set have been discharged, the front alignment mechanism 141 moves together with the back alignment member 142,
The alignment position of the second copy is offset from the alignment position of the first copy. The details of this operation will be described later.

The second copy is aligned at the offset position, stapled in the same manner as the first copy, and discharged as a bundle. When all the bundles for the second set have been discharged, the back alignment member 1
42 moves to the back, and the front alignment mechanism 141 aligns the sheets with the back alignment member 142 as a reference, and further offsets the alignment position of the third copy from the alignment position of the second copy.

The third copy is also aligned at the offset position, stapled in the same manner as the second copy, and discharged as a bundle.

When all the bundles of the third set have been discharged, the front aligning mechanism 141 moves to the front together with the back aligning member 142 to return the aligning position of the fourth set to the aligning position of the first set.

Similarly, the fifth copy is offset to the same position as the second copy.

In this way, the offsets of all the set copies are completed while shifting the bundles.

[0073]

As described above, the present invention has the following effects.

(1) A stacking surface for receiving and stacking sheets is formed, and one of the pair of discharge rollers for discharging the sheet to the processing tray and the rear end stopper for locking the rear end of the sheet is disposed inside A part of the peripheral surface is wound, and the opposing outer peripheral surface contacts the other of the pair of discharge rollers to form a nip portion,
At the same time that the sheet is discharged to the processing tray, a pair of belt rollers having an elastic knurled belt that pulls the sheet on the processing tray to the trailing end stopper, and pulls the knurled belt in a required direction to form a belt roller nip portion, In a sheet post-processing apparatus having a pulling means for displacing the distance from the outer peripheral surface of the knurled belt and a control means for controlling the operation of each part, the amount of protrusion of the sheet from the outer peripheral surface of the knurled belt is made constant. By controlling the discharge speed of the pair of belt rollers according to the amount of pulling of the pulling means, the time and the place until the discharged sheet comes into contact with the knurled belt again can be made constant. Instead, a stable pullback operation is possible.

(2) A stacking surface for receiving and stacking sheets is formed, and one of a processing tray having a rear end stopper for locking the rear end of the sheet and one of a pair of discharge rollers for discharging the sheet to the processing tray is provided. A part of the inner peripheral surface is wrapped around, and the opposing outer peripheral surface contacts the other of the pair of discharge rollers to form a nip portion,
A sheet post-processing apparatus having a belt roller pair having an elastic knurled belt for pulling a sheet on the processing tray to a stopper portion at the same time as discharging the sheet to the processing tray, and a sheet post-processing apparatus having a control means for controlling the operation of each portion. The predetermined discharge speed of the pair of belt rollers discharging to the processing tray is maintained at a constant speed until the sheets discharged onto the processing tray are completely dropped and settled, and the outer peripheral surface of the knurled belt is not deformed during that time. Therefore, the time until the discharged sheet comes into contact with the knurled belt again and the place where it hits the knurled belt can be made constant, and a stable pullback operation can be performed.

(3) By providing the configurations and controls of (1) and (2) together, the stability of the pullback operation can be further enhanced.

[Brief description of drawings]

FIG. 1 is a front sectional view showing a schematic configuration of an entire sheet processing apparatus of the present invention.

FIG. 2 is a vertical sectional side view of a swing guide and a processing tray.

FIG. 3 is an operation explanatory diagram of a sort roller unit.

FIG. 4 is an operation explanatory view of a sort roller unit.

FIG. 5 is an operation diagram of the sheet processing apparatus in a non-sort mode.

FIG. 6 is an operation diagram of the sheet processing apparatus in a staple sort mode.

FIG. 7 is an operation diagram of the sheet processing apparatus in a staple sort mode.

FIG. 8 is an operation diagram of the sheet processing apparatus in a staple sort mode.

FIG. 9 is an operation diagram of the sheet processing apparatus in a staple sort mode.

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

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

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

FIG. 13A is an operation diagram of the sheet processing apparatus showing a state where a swing guide is raised in a staple sort mode;
FIG. 6B is an operation diagram of the sheet processing apparatus showing a state where the swing guide is lowered in the staple sort mode.

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

FIG. 15 is an operation diagram of the sheet processing apparatus in the sort mode.

FIG. 16 is a front view of an image forming apparatus to which the sheet processing apparatus according to the present invention can be applied.

FIG. 17 is a schematic front sectional view of a conventional sheet processing apparatus.

[Explanation of symbols]

1 Finisher (sheet processing device) Roller with 2 3 Conveyor roller pair 5 Large rollers 6 running rollers 7 discharge roller 10 Switching flapper 11 Switching flapper When pressing 12, 13, 14 21 Non-sorted path 22 Sort Path 23 buffer pass 31 sheet detection sensor 50 punch units 101 stapler 129 Processing tray unit 130 processing tray (sheet intermediate stacking means) 131 Rear end stopper (sheet receiving member) 140 Matching device 141 Front alignment mechanism 141a rack 141 Front alignment mechanism 142 Alignment member 143, 144 pinion 150 swing guide 180 roller pair 180a roller 180b bundle discharge roller 181 Rear end drop member 181a Bounce lever 181c Pressing surface 181b Knurled belt outer peripheral surface 181d Swing center axis 182 knurled belt 182a bottom surface 183 sensor 301 control circuit M141, M142, M160, M190 Motor K distance P sheet

Claims (4)

[Claims] 1. A stacking tray for forming a stacking surface for receiving and stacking sheets and arranging a stopper portion for locking one end of the sheet, and one of a pair of discharge rollers for discharging the sheet to the stacking tray, which has an inner peripheral surface. Wrap a part and the outer peripheral surface facing
A belt roller pair having an elastic endless belt feed belt that forms a nip portion in contact with the other of the pair of discharge rollers and discharges the sheet to the stack tray at the same time as pulling the sheet on the stack tray to the stopper portion; In a sheet post-processing apparatus having a belt feeding nip portion, a pulling means for varying the distance between the belt roller nip portion and the outer peripheral surface of the endless belt-like belt downstream of the nip portion, and a control means for controlling the operation of each portion. A sheet post-processing apparatus characterized in that the discharge speed of the pair of belt rollers is controlled according to the pulling amount of the pulling means so that the amount of the sheet jumping out from the outer peripheral surface of the endless belt is a predetermined amount. 2. A stacking tray for forming a stacking surface for receiving and stacking sheets and arranging a stopper portion for locking one end of the sheet, and a stopper portion for discharging the sheet to the stacking tray on one of a pair of discharge rollers. A part of the inner peripheral surface is wrapped around, and the opposing outer peripheral surface contacts the other of the pair of discharge rollers to form a nip portion, which discharges the sheet to the stacking tray and simultaneously pulls the sheet on the stacking tray to the stopper portion. In a sheet post-processing apparatus having a belt roller pair having a belt-shaped endless belt feeding belt and a control means for controlling the operation of each part, a predetermined discharging speed of the belt roller pair discharging a sheet onto a stack tray is set on the processing tray. A sheet post-processing device characterized in that it is maintained at a constant speed until the sheets discharged onto the sheet are completely dropped and settled. 3. A stacking tray, which forms a stacking surface for receiving and stacks sheets, and is provided with a stopper portion for locking one end of the sheet, and one of the pair of discharge rollers is wound around a part of the inner peripheral surface to face each other. The outer peripheral surface is in contact with the other of the pair of discharge rollers to form a nip portion, and discharges the sheet to the stacking tray, and at the same time, pulls the sheet on the stacking tray to the stopper portion. And a sheet post-processing apparatus having a pulling unit that pulls the endless belt-shaped feed belt in a desired direction to displace the distance between the roller nip portion and the outer surface of the endless belt-shaped feed belt, and a control unit that controls the operation of each unit, The discharging speed of the pair of belt rollers is controlled according to the pulling amount of the pulling means so that the amount of the sheet protruding from the outer peripheral surface of the belt becomes a predetermined amount. A sheet post-processing device characterized in that the formed sheet is kept constant until it is dropped and settled. 4. An image forming unit for forming a sheet image,
An image forming apparatus comprising: the sheet post-processing apparatus according to claim 1.