JPH11130330A - Sheet after-treatment device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sheet after-treatment device capable of improving working responsiveness to eliminate bulging produced on a recording sheet by simplifying constitution used for it. SOLUTION: A staple tray to store a group of recording sheets in the lump is provided on a staple treatment part and a means 28 to fix the recording sheets on the staple tray by making contact with the recording sheets with pressure and a driving part 33 of this means are arranged in the lump in the neighbourhood of this staple tray on a sheet after-treatment device free to select a case to transfer a group of the recording sheets bound and treated in the staple treatment part toward a sheet discharge tray and a case to transfer the recording sheets toward the sheet discharge tray as they are without carrying out staple treatment after picture image formation by arranging the staple treatment part to bind the discharged recording sheets by collecting them in a group in the middle of a sheet discharging route toward the sheet discharge tray to load and store the recording sheets after picture image formation.

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 device attached to an image forming apparatus, and more particularly, to a case where a recording sheet after image formation is discharged and stored as it is and a group of recording sheets collectively. The present invention relates to a sheet post-processing apparatus that can select a case where a bundle of sheets is bound, discharged, and stored.

[0002]

2. Description of the Related Art Processing of recording paper discharged from an image forming apparatus such as a copying machine after forming an image includes processing of directly stacking the discharged recording paper on a discharge tray, and processing of the discharged recording paper as a group. And a process of discharging the bundle of sheets bound by a stapler to a discharge tray. Conventionally,
A configuration in which the above two types of processing are performed on recording paper discharged from the same image forming apparatus is disclosed in
No. 2,766,691.

[0003] In the above publication, a paper discharge path on the side of the image forming apparatus is branched up and down, and a paper discharge path extending upward is provided with a shift sorting section having a tray for loading recording paper.
A staple portion is disposed in the paper discharge path extending downward, and a paper discharge path switching claw is provided in a branch of the shift sorting section and the paper discharge path to the staple section to switch the recording paper transport path. An arrangement is disclosed. The recording paper transported to the staple unit for stapling is sequentially discharged onto the guide plate by a discharge roller provided in a discharge path leading to the staple unit and a fur brush rotating in conjunction with the discharge roller. It has become.
The recording paper discharged onto the guide plate is pressed by the fur brush, is formed into a wavy shape in the width direction by the projection on the guide plate, and is placed on the guide plate with a certain bending strength. It has become.

[0004]

It is desirable that the required number of sheets of recording paper to be bundled for stapling be ensured in the storage section, but the stored recording paper will undergo buckling deformation. If it is deformed, a part may swell in the discharge direction. For this reason, if the bulges are piled up, the progress of the recording paper to be stored next is hindered by the bulges, and the edges of the stacked recording papers may be uneven. Therefore,
Conventionally, a roller for moving the recording paper toward the end fence of the tray is arranged near a tray in which a group of recording papers are collectively stored during stapling processing, and this roller is formed on the recording paper by a driving source such as a solenoid. It has been considered to be provided so as to be able to come and go with respect to it. With this configuration, when the roller comes into contact with the recording sheet and moves toward the end fence, the recording sheet is forcibly expanded, thereby eliminating the swelling. However, in the case of such a configuration, the configuration becomes complicated. In addition, in order to secure a recording paper accommodating space around the tray, a roller, a solenoid that is a drive source for the separation and contact of the roller, and a rotary drive source for the roller are provided. When the distance between the power source and the power source is large, the size of the transmission member provided between the power source and the power source increases, so that the load on the power source also increases. For this reason, the drive response of each drive source is deteriorated by the load, and there is a possibility that an operation timing for best elimination of the swelling of the recording paper may be missed.

In the case of using a roller which can contact and separate from the recording sheet, the contact and pressing time between the roller and the recording sheet is often constant, so that the contact between the roller and the portion where the swelling occurs depends on the size of the recording sheet. As a result, there is a possibility that the time for pressing is not obtained and the swelling is not completely eliminated.

Normally, the swelling of the contacted recording paper can be eliminated by one pressing contact for each recording paper. However, the recording paper delivered last to the tray in the recording paper bundle bundled in a group can be used. In contrast, if only one press contact is made, and if the swelling fails, the swelling remains unresolved because there is no subsequent press contact with the roller. You cannot do it correctly. The recording paper other than the last recording paper itself is affected by the roller when it comes into contact with the next fed recording paper, so even if the swelling is not completely eliminated, the pressing of the roller against another recording paper Since it is pressed again by the contact action, the swelling is easily eliminated.

SUMMARY OF THE INVENTION In view of the above-mentioned problems in the conventional sheet post-processing apparatus, an object of the present invention is to simplify the structure used to eliminate the swelling of the recording sheet and to improve the operational responsiveness for the purpose. It is to provide a device.

Another object of the present invention is to eliminate the swelling of the recording sheet regardless of the size of the recording sheet, thereby enabling the edge of the recording sheet to be stapled to be aligned well. Is to provide.

Another object of the present invention is to provide a sheet post-processing capable of satisfactorily eliminating the swelling of the last sheet of recording paper to be bundled into a group and ensuring the edge alignment of the recording paper. It is to provide a device.

[0010]

In order to achieve this object, according to the first aspect of the present invention, the recording paper after the image formation is discharged in the middle of a paper discharge path toward a paper discharge tray for stacking and storing. A case where a staple processing unit for arranging and binding the recording papers in a group is disposed, and a group of recording papers bound by the staple processing unit is transferred to the discharge tray,
After image formation, in a sheet post-processing apparatus that can select whether to directly transfer to the discharge tray without performing stapling processing, the staple processing unit includes a staple tray that collectively stores a group of recording sheets. Provided,
In the vicinity of the staple tray, means for pressing the recording paper into contact with the recording paper and fixing the recording paper on the staple tray and a drive unit of the means are collectively arranged.

According to a second aspect of the present invention, in the sheet post-processing apparatus according to the first aspect, the means for pressing and contacting the recording paper moves the rear end of the recording paper in the transport direction toward the positioning portion of the staple tray. And the pressing contact time is made longer as the size of the recording paper becomes larger.

According to a third aspect of the present invention, in the sheet post-processing apparatus according to the first aspect, the means for pressing and contacting the recording paper performs one pressing contact for each recording paper stacked on the staple tray. The recording paper is characterized in that it comes into contact with the last recording paper twice.

[0013]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. FIG. 1 is a schematic diagram for explaining a configuration of a main part of a sheet post-processing apparatus according to an embodiment of the present invention. The sheet post-processing apparatus 1 includes a not-shown image forming apparatus such as a copying machine, a printer, or a facsimile machine. It is connected to the paper discharge unit. The sheet post-processing apparatus 1 includes a sheet discharge tray 1 provided at a position higher than the sheet introduction section 1A on the opposite side to the sheet introduction section 1A provided opposite to the sheet discharge section of the image forming apparatus.
A non-staple transport path and a staple transport path are provided in a housing 1C having a B. The non-staple transport path is a transport path for directly transferring the recording paper discharged after image formation to the discharge tray 1B without performing the stapling process. The staple transport path is a group of recording paper discharged after image formation. This is a transport path for transporting a group of recording sheets bound to a paper output tray to a paper output tray after binding them together.

The non-staple transport path is a transport path which is located on the upstream side in the transport direction of the recording paper S indicated by arrow A and extends from the paper introduction section 1A to the vicinity of the paper discharge tray 1B. From the relay guide plates 1A1 and 1A2 and the sheet introduction unit 1A
A transport guide member 2 for transporting the paper toward B and lower transport guide members 3, 3 'opposed thereto. The transport guide member 2 includes a sheet introduction unit 1A in which the introduction direction of the sheet is horizontal, and the sheet introduction unit 1A.
A horizontal portion and a diagonal portion that rises obliquely upward toward the discharge tray 1B following the horizontal portion to communicate with the paper discharge tray 1B provided at a higher position than the horizontal portion. The transport lower guide members 3, 3 'facing the transport guide member 2 are also oriented in the same manner. In the present embodiment, the rising angle of the oblique direction portion is set to 70 degrees, and the connection position between the horizontal direction portion and the oblique direction portion is set to 45 degrees.

The non-staple transport path includes a pair of transport sections that are opposed to and abut each other with the paper transport path interposed therebetween near the horizontal section, the oblique section, near the end of the oblique section, and near the position where these directions are switched. Rollers 4, 5, 6, 7
Are arranged respectively.

A swingable transport path switching claw 8 is provided near a relay portion of the non-staple transport path where the transport direction is switched. Transport path switching claw 8
Is provided to switch the paper transport path between a non-staple transport path and a staple transport path described later in conjunction with a solenoid (not shown). The transport path switching claw 8 is normally oriented so that the paper transport path is set as a non-staple transport path by a biasing means such as a spring (not shown). The time when the conveyance path switching claw 8 swings from the normal state to guide the sheet to the staple conveyance path described later is set near the conveyance roller 4 located at the sheet introduction unit 1A when the stapling process is set. This is the time when the passage of the sheet is detected by the sheet detection sensor 9 disposed.

The staple transport path includes a staple tray 10 which is parallel to a transport lower guide member 3 'installed in a direction for transporting a sheet diagonally upward among transport lower guide members constituting a non-staple transport path. Have. The staple tray 10 is disposed near the transport path switching claw 8, and can receive the sheet from the sheet introduction unit 1A when the transport path switching claw 8 swings from the normal state. The staple tray 10 is one component of a staple processing unit. The staple processing unit includes a sheet aligning device 15, a sheet binding device 22, and a sheet discharging device 23 disposed near the staple tray 10.
Is arranged. Each of these devices will be described later.

In the sheet transport direction indicated by the arrow in the drawing, the non-staple transport path and the downstream side of the staple transport path,
In FIG. 1, at the upper end of each transport path, a paper discharge transport path including a paper discharge guide member 11 and a paper discharge roller 12 is provided. The paper discharge transport path is a path for connecting the non-staple transport path and the staple transport path with the paper discharge tray 1B, and has an angle smaller than 70 degrees which is the angle of the non-staple transport path and the staple transport path. In the example, an angle of 25 degrees is set.

As shown in FIGS. 1 and 2, the paper discharge guide member 11 is a member capable of seesaw movement with the support shaft 11A as a fulcrum, and includes a non-staple transport path and a staple transport path among the swing ends. One end opposing the exit side is a stopper piece 11B having a shape capable of closing the exit of the non-staple transport path, and a rotatable driven roller 11C is provided at the other end of the swing end. An eccentric cam 14 driven by a drive motor 13 provided in the vicinity of the discharge guide member 11 abuts against the upper surface of the stopper 11B, and the driven roller 1 according to the rotation of the eccentric cam 14.
1C is brought into contact with and separated from a paper discharge roller 12 arranged opposite thereto. In this embodiment, a state in which the driven roller 11C is separated from the discharge roller 12 is set as the initial state of the discharge guide member 11, and the driven roller 11C is set to the discharge roller 12 from this initial state. The contact is made. The contact timing between the driven roller 11C and the paper discharge roller 12 in the paper discharge guide member 11 depends on whether the recording paper fed from the non-staple transport path or the staple transport path is set in the discharge tray 1.
B, and the separation time is long before the discharge of the recording paper toward the discharge tray 1B and the staple conveyance path is of a long size, that is, when the recording paper exceeds the discharge roller 12 from the staple tray 10. It is assumed that the recording paper having a length is stored in the staple tray 10 and the binding process is performed.

Next, the configuration of the stapling unit will be described with reference to FIG.
This will be described with reference to FIGS. The staple processing unit includes a sheet aligning device 15, a sheet binding device 22, and a sheet discharging device 23, of which the sheet aligning devices 15 are disposed on both side surfaces of the staple tray 10 corresponding to both ends in the width direction of the recording sheet. A jogger fence 16 and a side fence 17 are provided.

As shown in FIGS. 3 and 4, the jogger fence 16 and the side fence 17 are formed of a U-shaped cross section which can hold the staple tray 10 inside and sandwich the staple tray 10.
Staple tray 10 out of the one part located on the front and back
The sheet portions 16A and 17A facing the sheet mounting surface of the above-described sheet form an opening for introducing a sheet by inclining the lower end thereof upward. As shown in FIG. 1, the direction of the inclined surfaces of the one-side portions 16A and 17A is set such that the conveying path switching claw 8 is rotated.
When the conveyance path switching claw 8 swings and the conveyance path of the recording paper conveyed from the paper introduction section 1A is switched to the staple conveyance path, the recording paper S The leading end is set to the staple tray 10 side so as to be easily introduced.

As shown in FIG. 4, a boss 16 is provided on another piece 16B, 17B facing the piece 16A, 17A.
C, 17C and frame bodies 16D, 17D are formed respectively, and guide shafts 18 supported by immovable parts (not shown) are inserted through the bosses 16C, 17C.
The guide shaft 18 is set and supported in an axial direction parallel to the width direction of the recording paper, and can guide the jogger fence 16 and the side fence 17 in the width direction of the recording paper. As shown in FIG. 4, drive motors 19, 19 'and pulleys 20, 20' are provided on the pieces 16D and 17D.
Between the timing belts 21 and 2
1 'is integrated, and the timing belts 21, 2
The jogger fence 16 and the side fence 17 can move in the width direction of the recording paper in conjunction with the movement of 1 '. The drive motors 19 and 19 'record the jogger fence 16 and the side fence 17 according to the size information of the recording paper when the recording paper after the image formation is introduced into the paper introduction unit 1A when the stapling process is selected. The drive motor 20 on the side that drives the jogger fence 16 performs rotation for moving to a position where paper can be stored,
The recording paper rotates in a direction in which one end in the width direction of the stored recording paper can be pushed and moved toward the side fence 17 side.

In the case of this embodiment, when the jogger fence 16 and the side fence 17 move at the same time, the jogger fence 16 and the side fence 17 move to a position about 10 mm wider than the width of the recording sheet introduced into the sheet introduction section 1A, and thereafter. The jogger fence 16 moves to a position corresponding to the width of the recording paper. As the jogger fence 16 moves, the recording paper is aligned with the side fence 17 based on the side fence 17. The operation of pressing the recording paper when the jogger fence 16 moves is continued until the stapling operation of the paper binding device 22 ends. As shown in FIGS. 1, 3, and 4, the rear end of the recording paper is abutted by an end fence 10A that is bent at a lower end of the staple tray 10 at right angles to the paper mounting surface of the staple tray 10. It can be aligned by doing.

The sheet binding device 22 is provided at the lower end of the staple tray 10 so as to be able to advance and retreat with respect to the corner between one side surface in the width direction of the recording paper and the rear end surface, similarly to this kind of binding device. Staples can be driven into predetermined positions according to the width of the sheet. The sheet binding device 22 is retracted from the corner of the recording sheet until the edge alignment of the recording sheet is completed. When the edge alignment is completed, the sheet binding device 22 advances to the corner and drives staples.

As shown in FIGS. 1 and 3, the sheet discharging device 23 includes a discharging belt 24 movable along the sheet mounting surface of the staple tray 10 and a discharging claw fixed to a part of the discharging belt 24. 25. Release belt 2
4 is a drive pulley 24A disposed near both ends in the longitudinal direction of the staple tray 10 along the sheet mounting surface,
Driven pulley 24B and each of these pulleys 24A, 24B
Of the staple tray 10 in the width direction. The ejection claw 25 is a hook-shaped member capable of hitting the rear end of the recording sheet, similarly to the end fence 10A described above, and can be moved by pushing the rear end of the recording sheet as the ejection belt 24 moves. ing. The discharge belt 24 is rotationally driven by a timing belt 26A (see FIG. 1) wound around a drive pulley 24A and an output shaft of a drive motor 26 (see FIG. 1), and is placed on the staple tray 10. The recording paper can be moved in a direction of transporting the recording paper toward the discharge tray 1B. As shown in FIG. 1, the ejection claw 25 has a position deviated from the sheet mounting surface of the staple tray 10 as an initial position.
Is set as the rotation amount for one cycle.

The staple processing unit is provided with a configuration for pressing the recording paper introduced into the staple tray 10 toward the paper mounting surface of the staple tray 10. The above configuration corresponds to the guide member 27 and the sheet hitting member 28 facing the sheet placement surface of the staple tray 10. Hereinafter, these members will be described. FIG. 5 is a view showing the vicinity of the lower end of the staple tray 10. In FIG. 5, the lower conveyance guide 3 extending from the paper introduction unit 1 </ b> A is bent near the conveyance roller 5 and has a flat supporting portion. 3A, and the guide member 2 is provided on the support portion 3A.
The base of 7 is fixed.

In FIG. 5, the guide member 27 is a one-piece member made of a low friction member having elasticity. The guide member 27 is supported in a state where its tip is inclined so as to be located below the support portion 3A, and its tip is a staple tray. 10 are opposed to each other at a position close to the paper mounting surface. The guide member 27 slides the trailing end of the recording sheet S in the transport direction along the surface when the recording sheet S fed by the transport roller 5 falls by its own weight, guides the recording sheet S to the end fence 10A of the staple tray 10, and performs recording. When the leading end of the sheet S comes into contact with the surface of the sheet S, the surface of the recording sheet S can be traced. As a result, the vicinity of the rear end of the recording sheet S in the transport direction is
The swelling, which is a buckling deformation in the transfer direction, can be eliminated by tracing the surface in addition to the guide at the time of falling by its own weight by the guide member 27.

The sheet hitting member 28 is equivalent to a pressing contact means for the recording sheet S, and includes a roller 28A disposed at a position closer to the transport roller 4 than the center position in the longitudinal direction of the staple tray 10. I have. Roller 28
A is supported on the swinging end of a swinging arm 30 having a rotating shaft 29 driven by a drive source (not shown) as a fulcrum, as shown in FIGS. The timing belt 31 wrapped around the driving pulley 29A and the pulley on the roller 28A side can rotate the recording paper S in a direction in which the recording paper S can be moved toward the end fence 10A of the staple tray 10. . The swing arm 30 has a habit of swinging the roller 28 </ b> A toward the sheet placement surface side of the staple tray 10 by the bias of the torsion spring 32 fitted on the rotation shaft 29. As shown in FIG. 7, the swing arm 30 is formed with a piece 30A that protrudes beyond the fulcrum position corresponding to the rotation shaft 29, and the piece 30A is formed with a roller 28A as shown in FIG. It is operated by a solenoid 33 which is disposed in the vicinity of the swing arm 30 at a place where the swing arm 30 is put together. For this reason, one of the swing ends of the swingable drive lever 34 is connected to the actuator 33A of the solenoid 30, and the other swing end of the drive lever 34 is abutted against the one part 30A of the swing arm 30. This causes the swing arm 30 to swing.

The drive lever 34 is swingably supported by a support shaft 34A. One of the swing ends comes into contact with a portion 30A of the swing arm 30, and the other swing end has an actuator for the solenoid 33. 33A. One end of a spring 35 having a habit of rotating the drive lever 34 in the counterclockwise direction in FIG.
Has a higher elastic force than the torsion spring 32 of the swing arm 30. For this reason, when the solenoid 33 is not excited, the drive lever 34 swings counterclockwise in FIG. 6, and one of the swing ends of the drive lever 34 pushes up the half 30 </ b> A of the swing arm 30. Swing arm 3
When the one part 30A of the zero is pushed up, the swing arm 30
In FIG. 7, the roller 28 </ b> A swings counterclockwise, and the roller 28 </ b> A at the swinging end can be separated from the sheet mounting surface side of the staple tray 10. The state in which the roller 28A is separated from the sheet placement surface side is set as an initial state.

When excited, the solenoid 33 draws the actuator 33A inside against the bias of the spring 35, and moves the roller 28A in the above-mentioned initial state toward the sheet mounting surface side of the staple tray 10. . The excitation timing of the solenoid 33 is determined every time the recording paper S is introduced toward the staple tray 10, and the excitation operation time is set along the introduction direction of the specially large size A3 plate or double letter size (DTL). The length is set to 450 msec in the case of the longitudinal (longitudinal) direction, and to 350 msec in the case of other sizes. Further, the number of times of excitation is once for each recording sheet to be introduced in cases other than the recording sheet to be finally introduced, but is excited twice so that the recording sheet to be finally introduced can be hit twice. It has become so. The setting of the excitation operation time is intended to prevent the occurrence of swelling even when the size is large by keeping the ratio of the pressing time constant irrespective of the paper size. This is because, unlike other recording papers, there is no opportunity to be hit next, so that it is possible to prevent a case where the bulging cannot be eliminated easily.

Since the present embodiment has the above configuration,
As shown in FIGS. 6 and 7, a sheet hitting member 28 provided in the stapling section and capable of pressing and contacting the recording sheet S includes a roller 28A and a driving source for bringing the roller 28A into and out of contact with the recording sheet. , A swing arm 30 for converting a driving force of the solenoid 33 into a contact / separation operation of the roller 28A, and a drive lever 34 are collectively arranged near the roller 28A.

When the post-processing mode of the recording sheet after image formation is selected by an operation unit (not shown), the sheet post-processing apparatus 1 having the sheet striking member 28 having the above-described configuration operates in accordance with the selected mode. The position of the transport path switching claw 8 is set. The position switching of the transport path switching claw 8 is as follows.
This is performed when the leading edge of the recording paper S is detected by the paper detection sensor 9 provided in the paper introduction unit 1A.

When the non-stapling process is selected, the transport path switching claw 8 causes the recording paper S introduced from the paper introduction section 1A to move with the transport guide member 2 as shown by a solid line in FIGS. It is in a state where it can be transported to a non-staple transport path constituted by the transport lower guide member 3 '. In FIG. 1, the paper discharge guide member 11 can hold the leading end of the recording paper that has passed through the non-staple transport path because the driven roller 11C is in contact with the paper discharge roller 12, thereby discharging the recording paper. The sheet is transferred and discharged to the paper tray 1B.

When the stapling process is selected as the post-processing mode of the recording sheet, the position of the transport path switching claw 8 is set in the same manner as described above. The attitude in this case is shown in FIG.
As shown by the two-dot chain line in FIG.
It is said that it can be introduced toward zero.

In the staple processing section, the jogger fence 16 and the side fence 17 move to positions corresponding to the width of the recording paper to be introduced, and the recording paper is stored. Jogger fence 16 and side fence 17
As described with reference to FIGS. 3 and 4, the timing belt 2 linked to the drive of the drive motors 19 and 19 'is used.
1, 21 ', the recording paper is fixed at a position about 10 mm wider than the width of the recording paper stored in the staple tray 10. When the recording paper is stored in this state, the jogger fence 16 presses and aligns one side surface thereof. .

In FIG. 5, the roller 28A of the sheet hitting member 28 comes into contact with the surface of the recording paper in synchronization with the trailing end of the recording paper S fed by the transport roller 5 in the transport direction coming off the transport roller 5. In this case, since the solenoid 33 is excited, the drive lever 34 described with reference to FIGS. 6 and 7 swings, and the one part 30A of the swing arm 30 with which one of the swing ends is in contact is pushed up. The swing arm 30 swings so as to move the roller 28 </ b> A to the sheet placement surface side of the staple tray 10 (the state shown by the two-dot chain line in FIG. 7). The roller 28A is pressed by the roller 28A irrespective of the difference in size based on the excitation time and the number of times of excitation which are set in advance as the operation state of the solenoid according to the size of the recording paper S stored in the staple tray 10. Are assumed to be the same. By pressing twice against the final recording sheet, the same conditions as those performed on the recording sheet previously fed from the transport roller 5 are applied, that is, when the roller 28A comes into pressure contact with another recording sheet. The roller 28A presses the recording sheet S in the same manner as when receiving pressure, and when the roller 28A comes into contact with the recording sheet S, a habit of moving the recording sheet S toward the end fence 10A of the staple tray 10 is provided. Accordingly, the position near the rear end in the transport direction of the recording paper S fed from the transport roller 4 is pressed regardless of the difference in size, and the bulging, which is a buckling deformation, which tends to occur in that portion is eliminated. Then, it is possible to prevent a situation in which the recording paper S fed from the transport roller 5 is prevented from advancing due to the swelling of the recording paper S stacked on the staple tray 10 in advance. Therefore, the transport rollers 5 are continuously
The recording paper S fed out of the staple tray 10
The same progress state is obtained when the transfer rollers 5
When the rear end comes off the end fence, the rear end is aligned with the end fence 10A.

In FIG. 5, the recording paper fed out by the transport roller 5 (for convenience, indicated by reference numeral S0) falls by its own weight, but the rear end in the transport direction is guided by a guide member 27 as indicated by reference numerals S1 to S3. Fall while being
It falls from the gap between the tip of the guide member 27 and the sheet placement surface of the staple tray 10 toward the end fence 10A of the staple tray 10.

The tip of the guide member 27 has a support portion 3A.
, The recording paper S can be guided to the end fence 10A without hindering its fall due to its own weight. In addition, when the trailing end of the recording sheet S in the transport direction falls onto the end fence 10A of the staple tray 10, the recording sheet S is traced on the surface to eliminate the swelling of the recording sheet S, and is further stacked on the staple tray 10. Even if the recording paper S becomes large and the highest one interferes with the tip of the guide member 27, the guide member 27 is elastically deformed, and the surface of the recording paper S can be pressed by the elastic restoring force. In addition, the swelling due to the buckling deformation of the recording paper S can be eliminated irrespective of the number of stacked recording papers S, and the state in which the recording paper S is stacked flat can be maintained.

When the stapling process by the sheet binding device 22 is completed, the bound recording sheet bundle is released from the sheet discharging device 23.
Is transported toward the discharge tray 1B. In this case, as described with reference to FIGS. 1 and 4, the ejection belt 24 starts to move in conjunction with the driving of the drive motor 26, and the recording paper S is stopped at the rear end in the transport direction by the ejection claw 25. The sheet is transported toward the discharge tray 1B in a state where the sheet is ejected. When the discharge of the recording sheet is started along with the movement of the discharge belt 24, the discharge guide member 11 swings in a direction in which the driven roller 1C comes into contact with the discharge roller 12. Discharge guide member 11
However, the eccentric cam 14 driven by the drive motor 13 causes the small-diameter portion to face the upper surface of the stop piece 11B of the paper discharge guide member 11, so that the driven roller 11C comes into contact with the paper discharge roller 12. In the present embodiment, the rear end of the recording paper in the transport direction is the discharge roller 12 as the contact timing.
It is the time when it has reached 80 mm before. Thereby, when the recording sheet is nipped and conveyed by the driven roller 11C and the sheet discharging roller 12, the displacement between the lower side and the upper side of the recording sheet S which comes into contact with the rollers 11C and 12 is minimized. It has become.

According to the above-described embodiment, the non-staple transport path and the discharge guide member 11 located at the end of the staple transport path can be commonly used as a recording sheet discharge member. Need not be provided for each transport path, making it possible to simplify the configuration of the recording paper discharge section.

[0041]

As is apparent from the above embodiments, according to the first aspect of the present invention, the means for pressing the recording paper into contact with the recording paper and fixing the recording paper on the staple tray and the driving unit thereof are summarized. Since it is arranged near the staple tray, the means and the drive source can be handled as a unit of the pressing contact portion of the recording paper. As a result, it is possible to eliminate a response delay of the pressing contact due to an increase in the load on the driving source without increasing the length of the transmission path of the driving force. For this reason, it is possible to smoothly eliminate the swelling that occurs in the recording paper and to properly align the edges of the recording paper accommodated in the staple tray.

According to the second aspect of the present invention, by increasing the pressing contact time as the size of the recording paper increases, the ratio of the pressing contact time of the recording paper can be made the same regardless of the size. Thereby, even if the location where the swelling occurs differs due to the difference in size, it is possible to secure a sufficient pressing contact time to eliminate the swelling. Therefore, it is possible to easily align the edges of the stacked recording papers without eliminating the stacking failure due to the swelling.

According to the third aspect of the present invention, the swelling of the recording paper is temporarily reduced by one pressing, unlike the recording paper other than the last recording paper, by performing the pressing contact twice with the final recording paper. Even if the swelling of the recording paper cannot be eliminated by the contact, it is possible to completely eliminate the swelling by the pressing once again. For this reason, it is possible to eliminate the swelling of all the recording sheets regardless of the ejection order of the recording sheets stacked on the sheet ejection tray.

[Brief description of the drawings]

FIG. 1 is a schematic diagram for explaining a configuration of a sheet post-processing apparatus according to an embodiment of the present invention.

FIG. 2 is a partially enlarged view for explaining a transport path of the sheet post-processing apparatus shown in FIG.

FIG. 3 is a perspective view for explaining a main configuration of a sheet aligning device used in the sheet post-processing apparatus shown in FIG. 1;

FIG. 4 is a perspective view illustrating a configuration of a back side of the sheet aligning device illustrated in FIG. 3;

FIG. 5 is a partial schematic diagram for explaining an arrangement configuration of a guide member and a sheet hitting member in the sheet post-processing apparatus shown in FIG.

FIG. 6 is a side view for explaining a main configuration of a sheet hitting member used in the sheet post-processing apparatus shown in FIG.

FIG. 7 is a front view for explaining a main configuration of the sheet hitting member shown in FIG. 6;

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Paper post-processing apparatus 1A Paper introduction part 1B Discharge tray 1C Case 3, 3 'Side guide member which conveyed 4, 5, 6, 7 Conveyance roller 8 Conveyance path switching claw 10 Staple tray 10A End fence 15 Paper alignment device 16 Jogger fence 17 Side fence 22 Paper binding device 23 Paper discharging device 24 Release belt 25 Release claw 27 Guide member 28 Paper hitting member 28A serving as pressing contact means 28A Roller 30 Swing arm 33 Solenoid 34 serving as a driving source of the sheet hitting member Drive lever

Claims (3)

[Claims] A staple processing unit is arranged in a paper discharge path toward a paper discharge tray for stacking and storing recording paper after image formation. The staple processing unit is configured to collectively bind and bind the discharged recording papers. Paper post-processing that can be selected between a case where the group of recording papers bound in step (1) is transferred to the discharge tray and a case where the group is transferred directly to the discharge tray without performing stapling after image formation. In the apparatus, the staple processing unit is provided with a staple tray that collectively stores a group of recording sheets, and in the vicinity of the staple tray, the recording sheet is pressed into contact with the recording sheet and is placed on the staple tray. A sheet post-processing apparatus, wherein a fixing unit and a driving unit of the unit are collectively arranged. 2. The paper post-processing apparatus according to claim 1, wherein the means for pressing and contacting the recording paper has a habit of moving a rear end of the recording paper in a transfer direction toward a positioning portion of the staple tray. A sheet post-processing device, wherein the pressing contact time is increased as the size of the recording sheet increases. 3. The paper post-processing apparatus according to claim 1, wherein the means for pressing and contacting the recording paper makes one pressing contact for each recording paper stacked on the staple tray,
A sheet post-processing device, which is configured to be pressed against a final recording sheet twice.