JP5078094B2 - Paper post-processing device - Google Patents

Description

  The present invention relates to a sheet post-processing apparatus that arranges sheets discharged from an image forming apparatus at predetermined positions.

  As the paper post-processing apparatus, the paper is discharged to a paper stacking tray arranged in an inclined manner, and the front end of the paper is pressed by a front end stopper after the rear end of the paper falls on an abutting member (hereinafter referred to as a reference fence). There is a type that discharges a sheet, conveys it back by a return roller, drops it onto a reference fence, and then presses the leading edge of the sheet by a leading edge stopper.

As technologies related to the sheet post-processing apparatus, there are inventions disclosed in Patent Documents 1 to 3.
The inventions disclosed in Patent Documents 1 and 3 relate to a mechanism for aligning the leading edge of the alignment tray by normal rotation and reverse rotation of a claw for discharging the paper stacked on the alignment tray.
In the invention disclosed in Patent Document 2, the vertical alignment member moves for alignment operation only when the final sheet is discharged onto the sheet stacking table.
JP 2003-192213 A JP 2003-17105 A JP 2007-76874 A

  In the case of a paper post-processing device that aligns the paper loaded on the alignment tray with the leading edge stopper, the distance from the leading edge of the stacked paper in the transport direction to the reference fence is greater than the paper size due to paper deflection, curl, curvature, etc. Are often smaller. For this reason, if the leading end stopper does not move from the reference fence to a position that is smaller than the size in the paper transport direction (it bites in the paper transport direction), the leading end stopper will not reach the leading edge of the paper and alignment may not be performed reliably. To do.

  In the invention disclosed in Patent Document 2, the alignment member moves only when the final sheet is discharged. Therefore, there is a case where the leading end stopper does not reach the leading end of the sheet and the alignment is not performed reliably. It cannot be solved.

  SUMMARY An advantage of some aspects of the invention is that it provides a sheet post-processing apparatus that can reliably align a leading end stopper with the leading end of a sheet to perform alignment.

In order to achieve the above object, the present invention provides means for transporting sheets discharged from an image forming apparatus and discharging and stacking them on an alignment tray that is inclined, and pressing the leading edge of the sheets discharged to the alignment tray. In addition, the sheet post-processing apparatus includes a movable leading end stopper for aligning the sheet in the transport direction by bringing the trailing end of the sheet into contact with the abutting surface of the trailing end abutting member. pressing amount variable der the sheet conveying direction is, when moving the leading edge stopper to the sheet pressing position, by varying the speed before and after reaching the conveying direction leading end of at least the sheet to shift more than two stages, paper By changing the moving speed at the time of retracting the leading end stopper after the leading end is pressed and aligned at least before and after retracting from the abutting member to the position based on the paper size to be aligned, two steps There is provided a sheet post-processing apparatus characterized that you shift above.

  According to the present invention, it is possible to provide a paper post-processing apparatus that can reliably align the front end stopper with the front end of the paper.

A preferred embodiment of the present invention will be described. FIG. 1 shows a configuration of a sheet post-processing apparatus according to a preferred embodiment of the present invention. The paper discharged from the image forming apparatus 100 by the paper discharge roller 101 passes through the entrance guide plate 201 of the paper post-processing apparatus 200, is carried into the paper post-processing apparatus 200 by the transport roller 202, and the transport path downstream of the transport roller 203 To the branch point of. The conveyance paths 220 and 221 are conveyance paths when the sheet is not bound, and the conveyance direction of the sheet is switched by the branching claws 230 and 231. When the binding process is performed, the sheet is transported in the direction of the transport path 222 and is transported in the direction of the binding device 404 by the transport rollers 208, 209 or 212, 210.
When the non-staple mode is selected in the operation unit of the image forming apparatus 100, the sheet passes through the branch claws 230 and 231 (the normal branch claws 230 and 231 are positioned in the direction of the non-staple conveyance path 220). The paper is discharged and stacked on the stacking tray 301 by the transport roller 204 and the paper discharge roller 205. Depending on the setting, it is also possible to feed the paper in the direction of the transport roller 206 with the branching claw 231 and discharge the paper out of the housing with the paper discharge roller 207.

  2 and 3 show the configuration of the drive mechanism of the tip stopper 402. FIG. In FIG. 3, in order to make it easy to understand the movement of the tip stopper 402, the configuration other than the tip stopper 402 is omitted. The leading edge stopper 402 moves in the direction of the arrow in the drawing, and aligns the leading edge of the paper loaded on the staple tray 405.

  FIG. 4 shows the configuration of the control system related to the driving of the tip stopper 402. When the CPU 250 of the sheet post-processing apparatus 200 receives a signal (post-processing control signal) from the control unit (main body CPU 110) of the image forming apparatus 100 via the I / F 251, the CPU 250 drives each driver 253 stored in the ROM 252. The operation of each motor including the tip stopper motor 255 is controlled in accordance with the output from the sensor 254 (paper detection sensor) arranged in each part.

  When the leading end stopper 402 moves to the reference fence 403 side, the discharged paper is pressed against the reference fence 403 to align the paper transport direction. The sheet alignment by the leading end stopper 402 is performed every time the sheet is discharged to the stacking tray, so that the alignment accuracy is improved. After that, the front end stopper 402 is stopped for a predetermined time and retracted to the subsequent sheet receiving position, and at the same time, the jogger 401 performs horizontal alignment.

  As described above, when aligning the sheets stacked on the alignment tray with the leading edge stopper 402, as shown in FIG. 5, the leading edge stopper 402 is moved from the reference fence 403 to the alignment position of the distance Lp in the sheet conveying direction by the distance Ls. You can do it.

  However, in actuality, as shown in FIG. 6, the size of the stacked paper to the front end in the conveyance direction is the size Lp of the paper size from the reference fence 403 to the front end of the paper due to bending, curling, bending, etc. of the stacked paper. Are often smaller. For this reason, as shown in FIG. 7, if the tip stopper 402 does not reach the leading edge of the sheet unless it is moved by a distance La more than the moving distance Ls of the leading edge stopper 402 (in other words, to the position of Lp−La), the alignment is surely achieved. There is a possibility that it will not be done.

  For this reason, the moving distance Ls of the leading end stopper 402 at the time of paper alignment is set to a length that is set shorter than the position at which the alignment position (distance from the reference fence 403) becomes the paper conveyance direction dimension Lp.

  Further, the pressing portion of the front end stopper 402 can be bent, and as shown in FIGS. 8 and 9, there is no sheet bending or curling, and the distance from the front end stopper 402 to the reference fence 403 is the same as the paper size. In this case, when the front end stopper 402 is pushed in more than the paper size, the pressing portion of the front end stopper 402 is bent. By adopting such a structure, the load is absorbed, and the tip stopper 402 is prevented from being damaged and the driving portion of the tip stopper 402 is prevented from being overloaded. For example, the load can be absorbed by making the holding portion of the tip stopper 402 a spring-like structure.

  However, since the distance from the leading edge of the paper loaded on the alignment tray 405 to the reference fence 403 differs depending on the paper thickness, paper size, curl, paper stiffness (rigidity), etc., the alignment position is excessive or insufficient.

  For this reason, in this embodiment, the alignment accuracy is improved by changing the distance pressed by the tip stopper 402 according to these situations.

  For example, as described above, when the stacked sheets are less curled or bent, the leading end stopper 402 is structured to escape, but when the number of sheets is small or the sheets are weak. As shown in FIG. 10, the front end stopper 402 may bend the paper, and the paper at the time of stapling may be misaligned or the binding position may be misaligned.

  Therefore, in the present embodiment, the moving distance Ls of the front end stopper 402 is changed according to the number of sheets. For example, Ls is decreased when the number of sheets is small, and Ls is increased when the number of sheets is large. Further, the type of paper to be matched can be set by the image forming apparatus 100. For example, when the paper thickness is thin, control is performed so that Ls is set smaller than when the paper thickness is thick. Similarly, when the sheet to be matched is strong (high rigidity), Ls is set to be smaller than when the paper is low (rigidity is low).

  As a result, the front end stopper 402 presses the paper too much, causing the stacked paper to bend, the binding position of the staples to be shifted due to the bending, and the repulsive force of the paper when the front end stopper is retracted from the press position. Can prevent the alignment accuracy from worsening.

  Also, the amount of bending and curling of the paper varies depending on the size of the stacked paper, and when the paper size is large, it is more likely to buckle than when the paper size is small. Therefore, as shown in FIGS. Ls is set larger than when L is small.

  Next, the moving speed when aligning with the tip stopper 402 will be described. The productivity is improved when the leading end stopper 402 is moved as fast as possible. However, when the sheets are aligned, alignment at a low speed is less likely to cause the sheet to be out of order and the alignment accuracy is improved. In this embodiment, the speed toward the paper alignment position and the speed of the alignment operation are changed in two or more stages. As shown in FIG. 17, the speed at which the tip stopper 402 moves to the position of the distance Lp from the reference fence 403 is V1, the speed at which the tip stopper 402 moves from the position of Lp to the alignment position is V2, and V1> V2.

When the leading end stopper 402 is retracted after the alignment operation is finished, as shown in FIG. 18, it is retracted at a speed V4 from the Lp position to the subsequent sheet receiving position at a speed V4 as shown in FIG. Although V4> V3, the speed relationship between V4 and V1, and V3 and V2 can be arbitrarily set.
When the leading end stopper 402 is retracted, the leading end stopper 402 is retracted for a certain distance, and then temporarily stopped to suppress the paper ramping and wait until the generated ramping is converged. Jumping out and slipping can be prevented.

  Note that the sheet conveyed to the pre-stack unit (portion between the conveyance roller 208 and the conveyance roller 210) is conveyed to the first route 222a by the branch claw 232 and temporarily stops. The next sheet is conveyed to the second route 222b, overlapped with the sheet of the first route 222a, and discharged from the sheet discharge roller 211 to the alignment tray 405. Similarly, the leading edge stopper 402 and the jogger 401 are used to remove the sheet. Matching is done. By pressing the direction orthogonal to the transport direction with the jogger 401 and performing the binding process while pressing the transport direction of the sheet with the front end stopper 402, the alignment accuracy in both the vertical and horizontal directions is improved.

  The same operation is repeated for a predetermined number of copies to create a matched sheet bundle on the alignment tray 405. In this manner, the alignment operation in the vertical transport direction is performed for each sheet that is discharged on one or more sheets stacked on the stacking tray.

  When a series of alignment of the final paper is completed, the stapler 404 is activated to bind the paper bundle. The final paper conveyance direction is aligned and stopped by the leading end stopper 402, and the direction perpendicular to the conveyance direction is aligned by the jogger 401. By stapling at the position where the stapling is completed and starting the retracting operation of the leading end stopper 402 and the jogger 401 at the timing when the stapling is completed, the sheet can be prevented from shifting. By retracting the leading end stopper 402 and the jogger 401 at the timing when the sheet binding operation is completed, the operation of releasing the sheet bundle after the binding process is not hindered, and the productivity is improved.

  The purpose of this operation is to stack the sheets inside the trailing edge abutting member (reference fence 403) with an inclined sheet stacking tray. If the number of sheets is large, The degree of freedom in the space behind the paper in the paper transport direction is small, and the papers overlap with each other without a gap, but if the number of papers is small, the degree of freedom in the space behind the paper in the paper transport direction is large and the gap between the papers This is because the sheet trailing edge in the stacking tray is likely to be bent and curved.

  Therefore, when the sheets are overlapped with no gaps but the number of sheets is small, the trailing edge of the sheet comes into contact with the binding means at the time of binding processing, and the sheet is shifted, and the sheet is likely to be misaligned and missing. Become. Further, when the curved rear end portion is bound, the binding position from the paper rear end portion varies depending on the state of the paper and is not stable. The above operation is effective to prevent this, but such a problem is unlikely to occur when the number of sheets to be bound is large, and thus the above operation need not be performed. Therefore, it is preferable to improve productivity by controlling whether or not to perform the above operation according to the number of sheets to be bound.

  The stapled sheet bundle is hooked by the claw 406 a of the discharge belt 406 and discharged from the alignment tray 405 to the paper discharge tray 301.

With the above operation, the stapling of the paper is completed.
Thereafter, the above operation is repeated for the designated number of copies.
As described above, since alignment can be performed in a state where a plurality of sheets are stacked, the time required for the alignment operation of the jogger 401, the tip stopper 402, and the like can be shortened, and high-speed image forming apparatuses can be handled.
However, depending on the number of sheets in a bundle, there is a case where the last sheet of a set is not overlapped and becomes one sheet. In that case, if the last sheet is conveyed without being stopped, the leading edge stopper 402 and the jogger 401 are still in the alignment operation, so that the sheet may hit and a jam may occur. In this embodiment, when there is only one sheet to be aligned at the end, the alignment operation for the previously conveyed sheet is not started or is canceled and the leading end stopper 402 and the jogger 401 are operated. Return to the standby position. After the last sheet is discharged to the alignment tray 405, alignment by the leading edge stopper 402 and the jogger 401 is performed together with the previous sheet.
Thereby, even when the last sheet to be aligned becomes one sheet, it is possible to save time by stopping the sheet on the conveyance path and conveying the sheet after completion of alignment of the previous sheet.

  As described above, the sheet post-processing apparatus according to this embodiment can perform alignment by reliably bringing the leading end stopper into contact with the leading end of the sheet. Further, when the front end fence is moved close to the sheet and retracted, the sheet is moved at a low speed only in the vicinity of the sheet, so that the sheet can be reliably aligned while improving productivity.

  In addition, the said embodiment is an example of suitable implementation of this invention, and various deformation | transformation are possible for this invention, without being limited to this.

It is a figure which shows the structure of the paper post-processing apparatus which concerns on suitable embodiment of this invention. It is a figure which shows the structure of an alignment tray. It is a figure which shows the structure of a front-end | tip stopper. The structure of the control system regarding the driving of the tip stopper is shown. It is a figure which shows operation | movement of a front-end | tip stopper. It is a figure which shows operation | movement of a front-end | tip stopper. It is a figure which shows operation | movement of a front-end | tip stopper. It is a figure which shows operation | movement of a front-end | tip stopper. It is a figure which shows operation | movement of a front-end | tip stopper. It is a figure which shows operation | movement of a front-end | tip stopper. It is a figure which shows operation | movement of a front-end | tip stopper. It is a figure which shows operation | movement of a front-end | tip stopper. It is a figure which shows operation | movement of a front-end | tip stopper. It is a figure which shows operation | movement of a front-end | tip stopper. It is a figure which shows operation | movement of a front-end | tip stopper. It is a figure which shows operation | movement of a front-end | tip stopper. It is a figure which shows operation | movement of a front-end | tip stopper. It is a figure which shows operation | movement of a front-end | tip stopper.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 Image forming apparatus 101 Paper discharge roller 110 Main body CPU
200 Paper post-processing device 201 Entrance guide plate 202, 203, 204, 206, 208, 209, 210, 212 Conveyance roller 205, 207, 211 Discharge roller 220, 221, 222 Conveyance path 222a First route 222b Second Route 230, 231, 232 Branch claw 301 Paper discharge tray 401 Jogger 402 Tip stopper 403 Reference fence 404 Stapler 405 Alignment tray 406 Discharge belt 406a Claw

Claims (8)

Means for transporting paper discharged from the image forming apparatus and discharging and stacking it on an alignment tray that is inclined, and abutting the trailing edge abutting member while pressing the leading edge of the paper discharged to the alignment tray A paper post-processing device comprising a movable front end stopper for aligning the paper in the transport direction by bringing the paper rear edge into contact with the surface,
Ri pressing amount variable der the sheet conveying direction of the leading edge stopper,
When the leading end stopper is moved to the sheet pressing position, the speed is changed at least before and after reaching the leading end in the sheet conveying direction, and the speed is changed in two or more stages.
By changing the moving speed at the time of retraction of the front end stopper after pressing and aligning the front end of the paper at least before and after retreating to the position based on the paper size to be aligned from the abutting member, the speed is changed in two or more steps. sheet post-processing apparatus according to claim to Rukoto. Means for transporting paper discharged from the image forming apparatus and discharging and stacking it on an alignment tray that is inclined, and abutting the trailing edge abutting member while pressing the leading edge of the paper discharged to the alignment tray A paper post-processing device comprising a movable front end stopper for aligning the paper in the transport direction by bringing the paper rear edge into contact with the surface,
The pressing amount of the leading end stopper in the paper conveyance direction is variable,
When the leading end stopper is moved to the sheet pressing position, the speed is changed at least before and after reaching the leading end in the sheet conveying direction, and the speed is changed in two or more stages.
When retracting the leading edge stopper after matching pressing the paper edge, after temporarily stopping retracts arbitrary distance from said abutment member, Ru is retracted the distal end stopper to a position for receiving the succeeding sheets sheet post-processing apparatus for you, characterized in that. 3. The sheet post-processing apparatus according to claim 1, wherein a pressing amount of the leading end stopper in the sheet conveyance direction is variable according to the number of sheets to be aligned. 4. The sheet post-processing apparatus according to claim 1, wherein a pressing amount of the leading end stopper in a sheet conveyance direction is variable according to a type of sheets to be aligned. 5. The pressing amount of the sheet conveying direction of the tip stopper, the sheet post-processing apparatus according to any one of the four claim 1, wherein the variable der isosamples accordance with the size of paper to be aligned. Each time the a predetermined number of sheets is discharged into the matching tray, the sheet post-processing apparatus according to any one of claims 1 to 5 characterized in that the aligning operation of the sheet at the leading edge stopper. Means for transporting the paper discharged from the image forming apparatus and discharging and stacking it on an alignment tray that is inclined, and pressing the leading edge of the paper discharged to the alignment tray to abut the trailing edge abutting member of the paper A movable front end stopper for aligning the transport direction by bringing the rear end of the sheet into contact with the surface, a sheet binding means for binding the sheets stacked on the alignment tray, and a direction for aligning the sheets in a direction perpendicular to the transport direction A sheet post-processing apparatus having an alignment mechanism,
Each time a predetermined number of sheets are discharged to the alignment tray, the alignment operation of the sheets is performed by the leading end stopper,
The leading edge stopper and the alignment mechanism and paper for you, characterized in that the sheet binding means is moved to the aligning operation position both whether to perform sheet stapling operation is determined depending on the number of stapled sheets Post-processing device. 8. The sheet post-processing apparatus according to claim 7 , wherein the leading edge stopper and the jogger are retracted at a timing when the sheet binding unit ends the sheet binding operation .

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