JPH1045317A - Sheet post-processing device for image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sheet post-processing device capable of preventing the occurrence of buckling due to the catch of a sheet bundle to a stapler, and realizing smooth offsetting, in performing the offset for a sheet bundle by utilizing a pair of taper for performing matching for a sheet bundle on a collating tray. SOLUTION: In this sheet post-processing device wherein plural recording sheets, discharged from an image forming device such as a copying machine, are housed in a collating tray, and such the recording sheets are matched by tampers 7a and 7b, then are applied stapling, and moreover offsetting is applied to the recording sheets by the tampers 7a and 7b; staplers 5, for performing stapling, are movably arranged along the moving direction of the tampers 7a and 7b, to move the staplers 5 together with the tampers 7a and 7b in offsetting the recording sheet bundle 10 on the collating tray by using such the tampers 7a and 7b.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a collating process for recording sheets discharged from an image forming apparatus such as a copying machine.
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet post-processing apparatus for performing stapling processing and the like, and more particularly, to an improvement in an apparatus capable of performing offset processing of a collated sheet bundle.

[0002]

2. Description of the Related Art As a sheet post-processing apparatus of this type, two sheet storage trays, that is, a collating tray for storing a series of recording sheets discharged from a copying machine or the like while aligning them and forming a predetermined sheet bundle. And a discharge tray on which the sheet bundle formed on the collation tray is sequentially discharged and stacked, and a post-processing unit such as a stapler or a puncher provided for the collation tray forms the sheet bundle. On the other hand, a device that performs a predetermined post-processing is known.

Further, if the sheet bundle aligned on the collating tray is directly stacked on the discharge tray, the division of each sheet bundle tends to be unclear on the discharge tray. Offset processing,
That is, the sheet bundle is shifted (offset) in a staggered manner and discharged from the collating tray.
Such a process is particularly effective when a binding process such as a stapling process is not performed on the sheet bundle.

Conventionally, as a mechanism for performing the offset processing, a sheet transport roll for moving a recording sheet in a direction orthogonal to the discharge direction is newly provided, and the transport roll is used to set the sheet on the collation tray. What offsets a recording sheet (Japanese Utility Model Laid-Open No. 3-59553,
Japanese Patent Application Laid-Open No. 55-165882) is known, but such a transport roll is a mechanism dedicated to offset processing, and has the drawback that the apparatus becomes complicated and the production cost increases.

On the other hand, in this type of sheet post-processing apparatus, since it is necessary to perform sheet bundle alignment processing prior to stapling processing or the like, the sheet post-processing apparatus appropriately abuts both side edges of recording sheets stored in a collating tray. In many cases, a tamper for aligning a sheet bundle is provided.
Japanese Patent Publication No. 227733 discloses a sheet post-processing apparatus that performs offset processing using this tamper.

More specifically, the sheet bundle is aligned by moving a pair of tampers in directions opposite to each other, while the tamper pair sandwiching the sheet bundle from both sides is moved in the same direction to move the sheet bundle. The bundle is configured to be offset, and the offset processing can be performed without adding a mechanism dedicated to the offset processing.

[0007]

However, when the sheet bundle is offset by the pressing force of the tamper, the sheet bundle pressed by the tamper is caught by the post-processing unit disposed on the collating tray. In addition, there is a problem that bending called sheet buckling easily occurs, the sheet bundle is hardly offset, and when the sheet bundle having buckling is suddenly extended, the alignment state is broken.

If a pair of tampers performing the sheet bundle alignment processing is also used for the offset processing, the combination of the moving directions of these tampers will be different between the alignment processing and the offset processing. However, there has been a problem that it is necessary to drive each tamper independently, and the driving mechanism of the tamper must be complicated.

SUMMARY OF THE INVENTION The present invention has been made in view of such a problem, and an object of the present invention is to perform offset processing of a sheet bundle using a pair of tampers for aligning the sheet bundle. It is an object of the present invention to provide a sheet post-processing apparatus that enables smooth offset processing by preventing buckling of a sheet bundle.

Another object of the present invention is to drive a pair of tampers for performing both sheet bundle alignment processing and offset processing by one motor, and to perform the offset processing with a simple and inexpensive configuration. It is an object of the present invention to provide a sheet post-processing apparatus capable of performing the following.

[0011]

In order to achieve the above object, a sheet post-processing apparatus according to the present invention accommodates a series of recording sheets sequentially discharged from an image forming apparatus and forms a predetermined sheet bundle. A collating tray, a post-processing unit for performing post-processing on such a sheet bundle, and an appropriate contact with both side edges of the recording sheets accommodated in the collating tray to perform the sheet bundle aligning process. And a pair of tampers for performing an offset process for moving the sheet bundle in a direction orthogonal to the conveying direction of the sheet bundle. In the offset processing, the post-processing unit is moved together with the pair of tampers.

According to the present invention, the sheet bundle accommodated in the collation tray is offset on the collation tray by a pair of tampers. After the sheet bundle is subjected to stapling processing and punching processing, The processing unit is disposed so as to be movable along the moving direction of the tamper,
When the offset processing is performed, the post-processing unit is moved together with the tamper, so that the sheet bundle to be offset by the tamper is not caught by the post-processing unit and buckling does not occur. Can be performed.

In such a technical means, from the viewpoint of avoiding complication of the apparatus, it is preferable that the pair of tampers for aligning the sheet bundle be driven by the same drive system. In this case, it is difficult to move these tamper pairs in the same direction. Therefore, in the present invention, the post-processing unit moves together with the tamper at the time of the offset processing, so that at the time of such offset processing, one of the tampers located in the offset direction of the sheet bundle is pressed by the post-processing unit, thereby It is preferable to configure so as to move in the offset direction. According to such a configuration, both the alignment process and the offset process of the sheet bundle can be performed while the pair of tampers are driven by the same drive system, and the configuration of the apparatus can be simplified.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A sheet post-processing apparatus according to the present invention will be described below in detail with reference to the accompanying drawings. FIG. 1 shows an embodiment of a sheet post-processing apparatus (hereinafter, referred to as a finisher) of the present invention which is used by being attached to an image forming apparatus such as a laser beam printer. In FIG. A sheet transport path for introducing and transporting the recording sheets 1 discharged from the forming apparatus, reference numeral 3 denotes a compiler tray for sequentially receiving and collating the introduced recording sheets 1, and reference numeral 4 denotes a recording collated by the compiler tray 3. Reference numeral 5 denotes a stapler for performing a stapling process on a sheet bundle formed on the compiler tray 3, from which the bundle of sheets 1 or the recording sheet 1 is directly discharged from the sheet conveying path 2.

First, the sheet transport path 2 includes a plurality of transport rolls 21, and at the exit thereof, a discharge switch 6 for switching the discharge direction of the recording sheet 1 to the compiler tray 3 or the discharge tray 4 is provided. The recording sheet 1 is configured to be discharged toward the upper part of the compiler tray 3 that is arranged at an angle. The discharge switching device 6 includes a drive roll 61 and an orbit roll 62 that rotates in a planetary manner around the drive roll 61. The orbit roll 62 is positioned at a position indicated by a solid line in FIG.
When the recording sheet 1 is discharged while holding the recording sheet 1, the recording sheet 1 is sent out to the discharge tray 4 as it is, while the leading end of the recording sheet 1 is nipped between the driving roll 61 and the orbit roll 62. When the orbit roll 62 is moved to the position shown by the dashed line, the recording sheet 1 is turned over and stored in the compiler tray 3 while forming a loop. Further, among the guide plates forming the sheet transport path 2, the guide plate 22 on the upper side on the front side of the discharge switch 6 is configured to jump up in accordance with the movement of the orbit roll 62, and the recording sheet 1 A larger loop is formed so that it can be smoothly turned over.

On the other hand, at the uppermost end of the compiler tray, there are provided a discharge roll 23 for sending out the recording sheet toward the discharge tray, and a clamper 24 which can freely contact and separate from the discharge roll 23. The opening and closing of the clamper 24 is performed depending on the direction in which the recording sheet 1 is discharged from the printer. That is, the sheet transport path 2
When the recording sheet 1 is ejected to the ejection tray 4 from
In the case where the clamper 24 is held at the solid line position in the drawing and the conveying force of the discharge roll 23 is transmitted to the recording sheet 1, while the recording sheet 1 is stored from the sheet conveying path 2 to the compiler tray 3, The clamper 24 is held at the position indicated by the broken line in the drawing to prevent the rear end of the recording sheet 1 from being caught on the clamper 24.

If the recording sheet 1 is sent out from the sheet conveying path 2 toward the discharge tray 4 with the clamper 24 opened, the recording sheet 1 falls onto the compiler tray 3 by its own weight without being turned upside down. Alternatively, the recording sheet 1 can be stored in the compiler tray 3 without turning over the recording sheet 1.

Therefore, in this finisher, the recording sheet discharged from the image forming apparatus can be stored in the compiler tray 3 as it is, or it can be turned upside down depending on the combination of the operations of the orbit roll 62 and the clamper 24. 3 can be stapled from both the front and back sides of the sheet bundle even if the stapler 5 drives staples only from one side of the compiler tray. I have.

On the other hand, a stapler 5 divided into an upper head 51 and a lower head 52 is disposed substantially at the center of the compiler tray 3, and the recording sheets stored in the compiler tray are divided into the upper head 51 and the lower head. 52. The position corresponding to the stapler 5 of the compiler tray 3 is the tray 3
Stopper 3 for locking the lower end of recording sheet 1 stored in
When the recording sheet 1 is locked by using the stopper 31, a stapling process in a so-called edge binding mode in which a staple is driven into an end of the recording sheet 1 is performed. It can be done. A paddle wheel 32 that rubs the recording sheets stored in the compiler tray 3 toward the stopper 31 is provided slightly above the end binding stopper 31. Together, the recording sheets 1 are aligned.

A stopper 33 and a paddle wheel 34 are provided at the lower end of the compiler tray 3 so as to be freely retractable. When the recording sheet 1 is locked using the stopper 33, the recording sheet 1 is locked. A so-called saddle stitching mode stapling process in which a staple is driven into the center in the length direction of the device 1 can be performed. In the stapling process in the saddle stitching mode, since the center of the recording sheet 1 in the longitudinal direction needs to correspond to the stapling process position T regardless of the size of the recording sheet 1, the saddle stitching stopper 33 and the paddle wheel 34 are required. Are movably disposed along the compiler tray 3. For example, when performing stapling processing in the saddle stitching mode on the A3 size recording sheet 1, the lowermost end of the compiler tray 3 (broken line in the figure) (Position indicated by).

Further, between the saddle stitching stopper 33 and the stapler 5, there are provided a transport roll 35 and a clamper 36 which can be brought into and out of contact with the transport roll, and the recording sheet stapled in the saddle stitch mode. The bundle can be discharged from the compiler tray 1. When the recording sheet 1 is accommodated in the compiler tray 3, the clamper 36 does not impede such accommodation.
5 away.

A sheet folding device is provided below the finisher (not shown). The sheet bundle stapled in the saddle stitching mode is placed in the compiler tray 3.
The sheet is discharged from the sheet discharge path 37 provided at the lower end of the paper folding apparatus to the folding apparatus, and the folding processing is performed following the stapling processing. A gate 38 is provided at the entrance of the sheet discharge path 37 so as to open the sheet discharge path 37 in accordance with the sheet bundle discharge timing.

FIG. 2 shows the stapler 5 described above. The stapler 5 is divided into an upper head 51 and a lower head 52 as described above, and the lower head 52 has a stitcher member 5 for driving staples into a sheet bundle.
Each of the upper heads 51 has a clincher member 54 that bends the tip of the staple. Therefore, the stapler 5 drives the staples from below into the recording sheet 1 stored in the compiler tray 3.

The upper head 51 is connected to the guide shaft 5
5a and 55b, the lower head 52 is provided with a guide shaft 56.
a, 56b, respectively, and move in the direction according to the rotation of the pair of timing belts 57, 58 stretched along the width direction of the compiler tray 3 (perpendicular to the plane of FIG. 1). Is configured. These timing belts 57 and 58 are wound around a drive shaft 60 driven by a motor 59, and the upper head 51 and the lower head 52 move together in accordance with the forward / reverse rotation of the motor 59 and are accommodated in the compiler tray 3. The stapling process can be performed at an arbitrary position on the set sheet bundle.

FIG. 3 shows a pair of tampers 7a and 7b arranged on both sides of the stapler 5. As shown in FIG. These tampers 7a and 7b perform a so-called tamping operation in which the both sides of the recording sheet 1 inserted into the stapler 5 are hit during the stapling process in the saddle stitching mode. Is performed.

The tampers 7a and 7b are both guided by guide shafts 71a and 71b, and are freely movable along the width direction of the compiler tray 3 (perpendicular to the plane of FIG. 1). However, the guide shaft 71
Stoppers 72, 73 forming the home positions of these tampers 7a, 7b are provided at the front end (front side of the drawing) of a and the rear end (paper feeding side) of the guide shaft 71b, respectively. And the above tamper 7
a, 7b cannot move beyond these stoppers 72, 73.

A pulley 7 is provided on the front tamper 7a.
The drive wires 76 wound around the pulleys 74a, 74b are connected to the rear side tamper 7b, while the drive wires 76 wound around the pulleys 74b, 75b are connected to the rear side tamper 7b. The shaft 78 is fitted. Therefore, when the drive shaft 78 is rotated by the motor 79, the drive wire 7
6, 77 are circulated, and the pair of tampers 7a, 7b are simultaneously moved by the same distance. However, since the drive wire 76 of the front tamper 7a and the drive wire 77 of the rear tamper 7b are wound in opposite directions,
The rotation of the drive shaft 78 causes the front tamper 7a and the rear tamper 7b to move in opposite directions.

Further, the pulleys 74a and 74b are connected to the drive shaft 7 via slip clutches 80 and 81, respectively.
The pulleys 74a and 74b slip on the drive shaft 78 when an external force greater than a predetermined value acts on the tampers 7a and 7b. For example, when the stapler 5 moving toward the stapling processing position on the front side interferes with the tamper 7a, the pressing force of the stapler 5 causes the pulley 74 to move.
a between the drive shaft 78 and the drive shaft 78,
The tamper 7a moves to the front side together with the stapler 5. Therefore, in this finisher, the tamper 7
The stapler 5 can be moved regardless of the stop positions of a and 7b.

If slippage occurs between the pulleys 74a and 74b and the drive shaft 78, the positional relationship between the front tamper 7a and the rear tamper 7b may be deviated. Even if the tampers 7a and 7b are retracted to the home position where they contact the front-side stopper 72 and the rear-side stopper 73, the positional relationship between the tampers 7a and 7b is also initialized by the action of the slip clutches 80 and 81. Can be.

As described above, in the finisher of this embodiment, the front tamper 7a and the rear tamper 7b move simultaneously and in the opposite direction by the same distance, so that the recording sheet 1 is positioned at the center in the width direction of the sheet conveying path. The structure is suitable for a so-called center register in which a transport reference is set. That is, as shown in FIG. 4A, if the front side stopper 72 and the rear side stopper 73 are arranged symmetrically with respect to the center register reference, these stoppers 7
Both tampers 7a initialized by 2, 73,
7b recording sheet 1 by moving the equidistant x ₁ together
This is because it comes into contact with the side edge of.

[0031] However, in the case of so-called side registration of conveyance reference of the recording on the front side sheet 1 of the sheet conveying path is set, as shown in FIG. 4 (b), the moving distance x ₂ of the front tamper 7a it is necessary to set a large moving distance x ₃ the rear side tamper 7b for, in order to perform the matching processing of the recording sheet 1 housed in the compiler tray 3 at the side registration is toward the rear side tamper 7b to the front side It is necessary to stop the front tamper 7a with reference to the side registration while moving. Therefore, when the image forming apparatus provided with the finisher ejects the recording sheet by the side registration, a latch mechanism for locking the front tamper 7a on the basis of the side registration is added to the above-described configuration.

FIG. 5 shows such a latch mechanism. The latch lever 83 urged by a spring 82 is used to stop the rotation of a pulley 74a around which the drive wire 76 of the front tamper 7a is wound. It is configured to be. Specifically, a gear 84 that rotates together with the pulley 74a is provided, and a latch gear 85 that is locked only in one specific direction by the latch lever 83 is meshed with the gear 84. The latch gear 85 has a locking groove formed only at one position on the circumference thereof, and the locking groove is located at a position matching the toe of the latch lever 83 when the front side tamper 7a is set on the basis of the side registration. Is formed. The latch gear 85 is used only when the front tamper 7a advances toward the center of the compiler tray 3, that is, only when the front tamper 7a rotates in the direction of arrow A.
When the front tamper 7a is retracted toward the home position, the front tamper 7a can freely rotate.

Therefore, when the front tamper 7a is advanced from the home position, the toe of the latch lever 83 is caught in the locking groove of the latch gear 85 when the tamper 7a reaches the side registration reference, and the front tamper 7a The clutch is locked on the side registration basis by the action of the slip clutch 80. Also, even if the front tamper 7a is locked on the side registration basis in this way, the drive motor 79 itself of the tamper still continues to rotate, so that the rear tamper 7b continues to move forward. As a result, FIG. As shown in FIG. 7, the tampers 7a and 7b can be brought into contact with both side edges of the recording sheet 1 stored in the compiler tray 3 by the side register. On the other hand, the latch lever 83 is
5, the front tamper 7
a can move backward in the direction of the home position, the drive motor 79 of these tampers 7a, 7b is rotated in the reverse direction by a predetermined amount and again rotated in the normal direction, whereby the tampers 7a, 7b
Thus, a tamping operation of hitting both side edges of the recording sheet 1 can be performed.

As will be described later, when the offset processing is performed on the sheet bundle that has been subjected to the alignment processing by the side registration, the front tamper 7a needs to move to the rear side beyond the reference of the side registration. In the above-described latch mechanism, a solenoid 86 is connected to the latch lever 83 so that the latched state between the latch gear 85 and the latch lever 83 can be released against the urging force of the spring 82.

The finisher of this embodiment configured as described above accommodates the recording sheets 1 continuously discharged from the image forming apparatus in the compiler tray 3 sequentially and uses the tampers 7a and 7b. The alignment process is performed, the stapling process is performed as necessary, and then the sheet bundle is discharged to the discharge tray 4 or a paper folding device (not shown). Can be selected in a staggered manner in the width direction.

Hereinafter, specific procedures of the stapling process and the offset process when the recording sheet is aligned by the side registration will be described with reference to FIGS. 6 and 7. FIG. First, each time one of the recording sheets 1 is stored in the compiler tray 3, the tampers 7a and 7b perform a tamping operation to perform the alignment process of the sheet bundle 10 on which the recording sheets 1 are stacked (FIG. 6; reference). At this time, the latch is not released by the solenoid 86 in the above-mentioned latch mechanism, and the front tamper 7a does not move to the center from the side registration reference. And sheet bundle 1
Compiler tray 3
Then, the tampers 7a and 7b come into contact with both side ends of the sheet bundle 10 to hold down the sheet bundle 10, and the clampers 24 and 36 that have been opened in this state close and sandwich the sheet bundle 10 (see FIG. b).

As a result, the sheet bundle 10 is fixed on the compiler tray 3 in an aligned state, and subsequently, the stapling process is started. That is, the tampers 7a, 7
After b has retreated to the home position (see FIG. c), the stapler 5 moves to the first processing position on the front side to perform stapling processing, and further moves to the second processing position on the rear side to perform stapling processing. (See Figure d).

When the stapling process is completed as described above, the offset process is executed subsequently. However, in order to discharge a plurality of continuous sheet bundles 10 in a staggered manner, it is sufficient to perform offset processing for every other part.
Is discharged from the compiler tray 3 at this point.

At the start of the offset processing, first, the tampers 7a and 7b are set again to the registration positions on both side ends of the sheet bundle 10. At this time, the front tamper 7a
Is not released yet, the tamper 7a stops on the basis of the side registration, while the rear tamper 7b contacts the stapler 5 set at the second processing position before contacting the side end of the sheet bundle 10. Are locked as they are (see FIG. 7, a separate drawing a). The clampers 24 and 36 that have sandwiched the sheet bundle 10 are released at this time.

After the front tamper 7a is unlatched by the solenoid 86, the sheet bundle 10 is offset by moving the front tamper 7a and the stapler 5 to the rear side (see FIG. B). ). At this time, the stapler 5 moves together with the sheet bundle 10 offset to the rear side.
Are not caught by the stepper 5 and the sheet bundle 10 can be smoothly offset.

When the front tamper 7a is moved to the rear side, the rear tamper 7b originally moves to the front side. However, the tamper 7b contacts the stapler 5 that moves to the rear side together with the sheet bundle 10. Because of the contact, the slip clutch 81 interposed in the drive system of the tamper 7b pushes the stapler 5 to move to the rear side. Therefore, while the front tamper 7a is driven by the same motor 79 as the rear tamper 7b,
Offset processing can be performed by these tampers 7a and 7b. In this case, it is necessary to set the slip torque of the slip clutch 81 to be equal to or less than the driving force of the stapler 5.

When the offset processing is completed in this manner (see FIG. C), the sheet bundle 10 is sandwiched again by the clampers 24 and 36, and the sheet bundle 10 is discharged from the compiler tray 3 (see FIG. D). . Also, Tampa 7
a and 7b are reset to the home position in preparation for the next collation of the sheet bundle 10, and the front tamper 7a is again latched to the side registration reference (partial drawing e).
reference).

The above description of the stapling process and the offset process is for the case where the recording sheet is conveyed by the side register, but the same applies to the case of the center register except for the description of the latch of the front tamper 7a. Only the processing position is different.

[0044]

As described above, according to the sheet post-processing apparatus of the present invention, the offset processing of the sheet bundle is executed by using the tamper for aligning the sheet bundle stored in the collating tray. Since the post-processing unit that performs stapling processing and punching processing on the sheet bundle is moved together with the tamper,
The occurrence of buckling in the sheet bundle to be offset can be effectively prevented, and the offset processing can be performed smoothly.

Further, in the sheet post-processing apparatus of the present invention, at the time of the offset processing, one of the tampers located in the offset direction of the sheet bundle is pressed by the post-processing unit which moves together with the other tamper, whereby the tamper is pressed. It can be configured to be moved in the offset direction, and while performing a pair of tampers abutting on both side ends of the sheet bundle by one motor, both the alignment process and the offset process of the sheet bundle are performed by these tampers. Becomes possible.

[Brief description of the drawings]

FIG. 1 is a schematic view showing an embodiment of a sheet post-processing apparatus to which the present invention is applied.

FIG. 2 is a perspective view showing a stapler of a sheet post-processing apparatus according to the embodiment and a driving system thereof.

FIG. 3 is a perspective view illustrating a tamper and a drive system of the sheet post-processing apparatus according to the embodiment.

FIG. 4 is a diagram illustrating a center register and a side register in a recording sheet alignment process.

FIG. 5 is a perspective view showing a latch mechanism of a front tamper of the sheet post-processing apparatus according to the embodiment.

FIG. 6 is a diagram illustrating an example of a stapling process of the sheet post-processing apparatus according to the embodiment.

FIG. 7 is a diagram illustrating an example of an offset process of the sheet post-processing apparatus according to the embodiment.

[Explanation of symbols]

5 stapler (sheet post-processing unit), 7a front tamper, 7b rear tamper, 10 sheet bundle

Claims (2)

[Claims] A collating tray for receiving a series of recording sheets sequentially discharged from an image forming apparatus and forming a predetermined sheet bundle; a post-processing unit for performing post-processing on the sheet bundle; A pair of offset processing for appropriately aligning the sheet bundle by abutting on both side edges of the recording sheets stored in the collating tray and, if necessary, moving the sheet bundle in a direction orthogonal to the conveying direction. In the sheet post-processing apparatus provided with the tamper, the post-processing unit is disposed so as to be movable along the moving direction of the tamper, and in the offset process, the post-processing unit is moved together with the pair of tampers. A sheet post-processing device. 2. The sheet post-processing apparatus according to claim 1, wherein the pair of tampers for performing the alignment processing of the sheet bundle are driven by the same drive system, and in the offset processing, in the offset direction of the sheet bundle. A sheet post-processing apparatus wherein one of the tampers is moved by being pressed by the post-processing unit which moves together with the other tamper.