JP2003054808A - Device/method for reversing paper, after-processor and image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve difficulty of increasing in a speed of reverse conveyance processing with necessity for taking a wide paper space in reverse conveyance because of existence incapability of a plurality of sheets of paper in the conventional device for reversing the paper. SOLUTION: By conveying paper reversed by using a stop member in a reverse conveyance part, a plurality of sheets of the paper can be made simultaneously running in the reverse conveyance part.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet reversing method for reversing and conveying a sheet, a sheet reversing apparatus, a post-processing apparatus having a sheet reversing apparatus, and an image forming apparatus having a sheet reversing apparatus.

[0002]

2. Description of the Related Art In many image forming apparatuses such as electrophotographic apparatuses, an image is formed on the upper surface of a conveyed sheet. Therefore, when the image-formed sheet is discharged as it is, the image becomes the upper surface of the sheet. Is ejected. Generally, in copying and printing, images are formed in ascending order from page 1, so if the paper is ejected with the image formed on the upper surface, the page order will be reversed.

In order to avoid such inconvenience, many image forming apparatuses have a reversing conveyance function. In normal mode image formation, the reversing conveyance is performed so that the image surface faces down and the sheet is discharged. Is designed to.

Further, in the double-sided image forming apparatus, an image is formed on the front surface, and then the image is formed again on the reverse surface by reversing the front and back.

[0005] For the above-mentioned reverse sheet discharge and double-sided image formation,
Many image forming apparatuses are equipped with a sheet reversing device.

Many of the conventional sheet reversing devices reverse the front and back by so-called switchback conveyance. That is, the sheet is carried into the reversing conveyance section that performs switchback conveyance, and is conveyed in one direction by the reversing roller in the reversing conveyance section. When the trailing end of the sheet in the conveyance direction reaches the position of the reversing roller, The rotation direction is reversed and switchback conveyance is performed to reverse the front and back.

[0007]

In the above-mentioned conventional sheet reversing device, since the reversing conveyance is carried out by the reversing roller provided in the reversing conveyance section, the succeeding sheet is fed while the preceding sheet exists in the reversing conveyance section. It cannot be loaded into the reverse transport section. Therefore, when the sheets are continuously reversed and conveyed, it is necessary to widen the sheet interval, and as a result, there is a problem that the processing speed of the reverse conveyance cannot be increased. Further, using the conventional paper reversing device, in order to increase the processing speed of the reversing conveyance, it is necessary to increase the conveyance linear velocity of the paper,
There is a problem that the transportation becomes unstable.

An object of the present invention is to solve the above problems in the conventional sheet reversing device.

[0009]

The above-mentioned objects of the present invention are as follows.
It is achieved by the following invention.

1. A sheet reversing device having a reversing conveyance section that reverses the front and back sides by switchback conveyance, a carrying-in means that carries a sheet into the reversing conveyance section, and a carrying-out means that carries out a sheet from the reversing conveyance section. A stop member for reversing the conveyance direction of the sheet is provided, and in the step of carrying in the sheet to the reversal conveyance section, the sheet is stopped by abutting the stop member after the trailing end of the sheet in the carrying-in direction is separated from the carrying-in means, In the step of unloading the sheet from the reversing / conveying unit, the stopping member pushes the sheet back so that the leading end of the sheet in the unloading direction reaches the unloading unit, and the sheet is unloaded by the unloading unit. .

2. The carrying-in means includes a first driving roller and a first driven roller that is in contact with the first driving roller,
2. The sheet reversing device as described in 1 above, wherein the carry-out means includes a second drive roller and a second driven roller that is in contact with the second drive roller.

3. 3. The sheet reversing device as described in 1 or 2 above, wherein in the continuous conveyance of the sheets, the subsequent sheet is carried in by the carry-in means and the preceding sheet is carried out by the carry-out means in a timely manner.

4. The stop member has a first position for receiving the paper that has left the carry-in means, a second position for avoiding the interference between the preceding paper and the succeeding paper, and the unloading of the paper between the carrying-in process of the paper and the unloading process of the paper. 4. The sheet reversing device according to any one of the items 1 to 3, wherein the front end in the direction is displaced to a third position for reaching the carry-out means.

5. 5. The sheet reversing device according to any one of 1 to 4 above, further comprising a guide member for preventing interference between the preceding sheet and the succeeding sheet.

6. 6. The sheet reversing device according to any one of 1 to 5 above, wherein the stop member is displaced according to a sheet size.

7. 7. The sheet reversing device according to any one of 1 to 6 above, wherein the reversal conveyance section is arranged so as to reversely convey a sheet in a substantially vertical direction.

8. A post-processing apparatus comprising the sheet reversing device according to any one of 1 to 7 above.

9. An image forming apparatus comprising the sheet reversing device according to any one of 1 to 7 above.

10. The sheet is carried into the reversing conveyance section that reverses the front and back sides by switchback conveyance, and the sheet is stopped in the reversing conveyance section by abutting the sheet against the stop member, and the stop member causes the sheet to reach the unloading means, and the unloading is performed. A sheet reversing method, characterized in that the sheet is carried out from the reversing and conveying section by means.

11. Any one of the above items 1 to 7, further comprising an aligning unit that performs alignment processing in the width direction of the transport path.
The sheet reversing device according to item.

12. 12. The sheet reversing device according to any one of 1 to 7 and 11, further comprising a shift unit that performs a shift process of displacing the sheet in the width direction of the transport path.

[0022]

BEST MODE FOR CARRYING OUT THE INVENTION <Sheet Reversal Conveying> First, a sheet reversing apparatus and a sheet reversing method according to an embodiment of the present invention will be described with reference to FIG.
4 will be described. FIG. 1 is a schematic diagram of a sheet reversing device according to an embodiment of the present invention, and FIGS. 2 to 4 are diagrams showing a sheet reversing method according to an embodiment of the present invention.

The sheet reversing device according to the present embodiment includes a driving roller DR, driven rollers NR1 and NR2, two parallel guide plates WL1 and WL2, guide members GD1 and GD2, and a stop member SM. The guide plates WL1 and WL2 and the stop member SM constitute a reversing conveyance unit that conveys the sheet in a switchback manner, and the driving roller DR as the first driving roller and the driven roller NR1 as the first driven roller convey the sheet to the reversing conveyance unit. The driving roller DR as the second driving roller and the driven roller NR2 as the second driven roller constitute a carrying-out means for carrying out the paper from the reversing / conveying unit.

The drive roller DR is rotationally driven in the clockwise direction in the figure as indicated by the arrow to carry the sheet into the reverse conveying section and carry out the sheet P from the reverse conveying section.

The guide plates WL1 and WL2 store the loaded paper, the guide member DG1 guides the paper at the time of loading / unloading the paper, and the guide member GD2 separates the loading path R1 and the unloading path R2. Guidance is provided so that the preceding and following sheets do not collide.

In this embodiment, the paper is guided by the guide plate W.
The paper is turned between the L1 and the WL2 and then switched back and conveyed to reverse the front and back of the paper.

2 to 4 show steps S1 to S7 in the process of reversing and conveying a plurality of sheets.

In the loading step S1 of the first sheet P1, the sheet P is driven by the driving roller DR and the driven roller NR1.
1 is carried in and the paper P1 is dropped to the stop member SM.
The stop member SM is the upper end (rear end in the carrying-in direction) P1U of the paper P1.
Is below the lower end (guide end) of the guide member GD2.
The position V1 is set.

In step S2, the stop member SM is the sheet P.
The second position V2 is set so as to raise the upper end P1U of No. 1 above the lower end (guide end) of the guide member GD2.
Due to the raising of the stop member SM to the second position V2 in step S2, the upper end P1U of the sheet P1 is retracted from the carry-in path R1 to the carry-out path R2.

The guidance of the upper end P1U of the sheet P1 to the carry-out path R2 is realized by the shapes of the carry-in path R1, the guide member GD2, and the carry-out path R2 as described later.
In addition, the upper end P1 is moved by the movement of the guide member GD2 such as rotation.
It is also possible to guide U to the carry-out route R2.

At step S3, the upper end P1U is guided to the carry-out path R2, and at this stage, the second sheet P2 is carried in by the driving roller DR and the driven roller NR1.

In the next step S4, the stop member SM is raised so that the upper end P1U (front end in the carry-out direction) of the preceding first sheet P1 is pinched between the drive roller DR and the driven roller NR2. During the transition from step S3 to step S4, the succeeding sheet P2 is conveyed and, as shown in the drawing, the guide plate WL
Drive downward between 1 and WL2.

In the next step S5, the stop member SM descends to the first position. During this period, the sheet P1 is continuously conveyed and, as shown in the figure, the sheet P2 travels upward and the sheet P2 travels downward.

Step S6 is a step in which the upper end of the sheet P2 (the rear end in the carrying-in direction) is separated from the drive roller DR and the driven roller NR1 and dropped, and is supported by the stop member SM.
be equivalent to.

Next, the third sheet P3 is carried in. At the step S7 when the carrying in of the paper P3 is started, as shown in FIG.
The sheets of paper P1 and P2 are simultaneously in the reverse conveyance section, that is,
The vehicle runs on a passage between the guide plates WL1 and WL2.

As is clear from the above description, step S1
By repeating the reverse conveyance process from S to S5, the reverse conveyance of a large number of sheets P is performed.

In the reverse conveyance process described above, the drive roller DR is continuously driven by the stepping motor M1 to continuously rotate clockwise. And the stop member SM
Are driven by a stepping motor M2, and
It is displaced to three positions V1 to V3. The control of the displacement of the stop member SM is performed by the control means CR based on the leading edge detection signal of the paper output by the detection means SS1 arranged upstream of the carry-in means including the drive roller DR and the driven roller NR1, and preferably in the vicinity upstream. Performed, the stop member SM is the detection means SS
As described above, the first to third positions V1 to V3 are displaced in a preset time from the detection of the front end by No. 1. <Image Forming Apparatus> Next, an image forming apparatus equipped with the above-described sheet reversing device will be described. In the image forming apparatus shown in FIG. 5, the post-processing apparatus B is provided with a sheet reversing apparatus. The paper reversing device may be provided in the paper discharge unit or the re-transport unit 8 of the image forming apparatus main body A.

FIG. 5 shows an image forming apparatus according to the embodiment of the present invention. The image forming apparatus comprises an image forming apparatus main body A, an automatic document feeder ADF and a post-processing apparatus B.

The illustrated image forming apparatus main body A includes an image reading unit 1, an image processing unit 2, an image writing unit 3, an image forming unit 4, a paper feeding unit 5, a conveying unit 6, a fixing unit 7, a re-conveying unit (automatic). A double-sided copy transport unit ADU) 8 and a control means 9 are provided.

The paper feeding means 5 comprises a cassette paper feeding portion 5A, a large capacity paper feeding portion (LCT) 5B, a manual paper feeding portion 5C, an intermediate paper feeding roller 5D and a registration roller 5E.

The conveying means 6 comprises a conveying belt 6A, a conveying path switching plate 6B, a paper discharge roller 6C and the like.

An automatic document feeder ADF is mounted above the image forming apparatus main body A. Image forming apparatus main body A
The post-processing device B is provided on the left side of the drawing as shown in FIG.
Are connected.

The document d placed on the document table of the automatic document feeder ADF is conveyed in the direction of the arrow and the image reading means 1
The image of one side or both sides of the original is read by the optical system of 1 and read by the CCD image sensor 1A.

The analog signal photoelectrically converted by the CCD image sensor 1A is subjected to analog processing, A / D conversion, shading correction, image compression processing, etc. in the image processing means 2 and then sent to the image writing means 3. .

In the image writing means 3, the output light from the semiconductor laser is applied to the photosensitive drum of the image forming means 4 to form a latent image. In the image forming means 4,
Processing such as charging, exposure, development, transfer, separation and cleaning is performed. An image is transferred to the paper P delivered from the paper supply unit 5 at the transfer unit.

The sheet P carrying the image is conveyed by the conveyor belt 6A.
The sheet is conveyed by the fixing means 7, fixed by the fixing means 7, and sent from the sheet discharge roller 6C to the sheet introducing section 10A of the post-processing apparatus B. Alternatively, the single-sided image-processed sheet P sent to the re-conveying means 8 by the conveying path switching plate 6B is again subjected to the double-sided image processing in the image forming means 4, and then the discharge roller 6
Emitted from C. The sheet P discharged from the sheet discharge roller 6C is sent to the post-processing apparatus B.

The post-processing apparatus B includes a sheet introducing section 10A for finishing the image recording and receiving the sheet P, a sheet feeding apparatus 11 for feeding the additional sheet F, and an aligning / shifting section 1 as a reverse conveying section.
3, folding parts 14 and 15, intermediate plate 16, binding part 17,
The center folding unit 25, the fixed sheet discharge tray 18, the vertically movable vertically movable sheet discharge tray 19, and the fixed sheet discharge unit 27 are provided, and the transport paths 10 and 20,
21, 22, 23, 24, etc. are connected.

The sheet reversing device shown in FIG. 1 is provided in the post-processing device B of the image forming apparatus of FIG. 5 or in the re-conveying means 8.

The post-processing apparatus B carries out post-processing in the following processing modes. (1) Simple paper discharge mode The paper P introduced from the paper introducing unit 10A is simply discharged in the order of introduction. In this mode, the paper P is conveyed by the conveyance path 10,
The paper is discharged to the fixed paper discharge tray 18 via 20.

(2) Shift mode The sheet is discharged by changing the sheet discharge position for each set of a plurality of sheets. In this mode, the sheet P is conveyed from the sheet introducing section 10A to the aligning / shifting section 13 as a reverse conveying section, and as described later, is subjected to a shift process in the aligning / shifting section 13 and then is conveyed as a main conveying path. The sheet is returned to the path 10 and is ejected to the elevating and ejecting tray 19 via the conveying paths 10 and 22.

(3) Folding Mode The paper P is folded at one place or two places, folded in two or folded in three, and discharged.

Paper P introduced from the paper introduction unit 10A
Is conveyed to the folding sections 14 and 15 and subjected to the folding process by the first and second folding sections, and then the conveyance path 10,
The paper is ejected to the elevating paper ejection tray 19 via the conveyance path 22. First,
There are cases where the third folding process is performed by the second folding unit and cases where the folding process is performed only by using the folding unit 14. Further, it is desirable that the matching / shifting unit 13 performs the matching process prior to the folding process.

(4) Binding mode The binding process is performed for each of the plurality of sheets P and the sheets are discharged.

The set number of sheets P conveyed from the conveying path 10 to the conveying path 23 are stacked on the intermediate tray 16 and then bound by the binding section 17, and after the binding processing, they are ejected to the elevating and ejecting tray 19. It Further, it is desirable that the matching / shifting unit 13 performs the matching process prior to the folding process.

(5) The above-mentioned (3) folding mode and (4)
Mode in which binding modes are combined and processed (6) Center-folding mode The center of the paper P is bound by the binding unit 17, and the center-folding process is performed by using the knife-shaped protrusion member 251 to discharge the paper 2
The paper is discharged to the fixed paper discharge unit 27 via 6.

In each of the above modes, the additional sheet F is fed from the sheet feeding tray 11 and added to the sheet P supplied from the image forming apparatus main body A, so that the front cover and the back cover are provided for each bundle of the sheets P. , A partition or the like can be added.

Next, the branching unit 12 and the matching / shifting unit 13
The structure of the branching portion 12 and the matching / shifting portion 13 will be described with reference to FIG.

The branching section 12 carries the sheet P1 into the aligning / shifting section 13 from the transporting path 10 as a main transporting path, and aligns the aligning / shifting section 13.
It is carried out from the shift unit 13 to the transport path 10.

The aligning / shifting unit 13 as the reversing / conveying unit performs the reversing / conveying process, the aligning process and the shifting process.

The branching section 12 carries the sheet P1 from the conveyance path 10 serving as the main conveyance path to the alignment / shift section 13 and aligns it.
It is carried out from the shift unit 13 to the transport path 10. Branch 12
Are upper guide members 124 and lower guide members 125B, 12
6B, a driving roller 122 that is driven to rotate by the stepping motor M1 and driven rollers 121 and 123, and the branch portion 12 includes a carry-in path 127 and an upper guide member 124 formed by an upper guide member 124 and a lower guide member 125B. It has a carry-out path 128 formed by the lower guide member 126B.

Drive roller 122 as first drive roller
The driven roller 121 as the first driven roller constitutes a carry-in means, and the drive roller 122 as the second drive roller.
Further, the driven roller 123 as the second driven roller constitutes a carry-out means. The projection 124A of the upper guide member 124 divides the carry-in passage 127 and the carry-out passage 128.

The vertical portions of the guide plates 125 and 126 which face each other in parallel form a paper storage portion having a passage 129, and the upper portions of the guide plates 125 and 126 opened above the lower guide members 125B and 126B. As described above, the carry-in path 127 and the carry-out path 128 for the sheet P1 are formed as described above.

The upper guide member 124 has a protrusion 124A as a guide member at its lower end. Tip Q of protrusion 124A
Is a guide plate 125 as shown by a vertical line L drawn on the tip Q.
Is set so as to occupy a position closer to the carry-in path 127 than the vertical parallel portion (paper storage portion). Due to such a shape of the projection 124A, the paper P1 carried in from the carry-in path 127
Has a driving roller 122 and a driven roller 121.
When it falls apart from the nip and is supported by the stop member 131, it surely moves from the carry-in path and is guided to the carry-out path 128.

As shown in FIG. 7, the guide plates 125 and 126 have notches 125A and 126A at the central portions in the width direction of the conveying path.
Is formed. As shown in FIG. 7, notches 125A, 1
At the portion 26A, as shown in FIG. 6, a stop member 131 having an introduction portion opened upward is provided. Stop member 13
1 is coupled to the toothed belt 135 by a coupling member 130, and is driven by a stepping motor M2 to move up and down. The stop member 131 takes first to third positions V1 to V3 as described later, and the first to third positions V1 to V3 are changed according to the paper size.

On both sides of the guide plates 125 and 126 in the width direction of the conveying path, the regulating members 13A and 13B as side end regulating members are provided.
Is provided.

Next, various processes performed in the alignment / shift unit 13 will be described. In the following description, FIGS. 1 to 4 showing the reverse conveyance process step will also be referred to. In addition,
In the following description, the reversing conveyance process will be described as a reversing conveyance process in a narrow sense in which only the reversing conveyance is performed without the matching process or the shift process. In addition to the reversal conveyance process without the shift process, the reversal conveyance process including other processes such as the reversal conveyance process while performing the matching process and the reversal conveyance process while performing the shift process is also included. An apparatus and method for carrying. <Reverse Transport Processing> The reverse transport processing will be described with reference to FIGS. 1 to 4, 6, 8 and 11. The reverse conveyance process is executed in the process already described with reference to FIGS.

The components in FIG. 6 correspond to the components in FIG. 1 as shown in Table 1.

[0068]

[Table 1]

The parts shown in Table 1 are shown in FIGS.
The sheet is continuously reversed and conveyed through the respective steps S1 to S7.

At the stage of carrying in the first sheet of paper P1, the paper P1 is carried in by the driving roller 122 and the driven roller 121, and the paper P1 is dropped to the stop member 131. FIG. 6 shows a state in which the carrying-in step is completed and the sheet P1 is supported by the stop member 131, and corresponds to S1 in FIG.
The stop member 131 is the upper end (rear end in the carrying-in direction) P1 of the paper P1.
U is the lower end Q (guide end) of the protrusion 124A as a guide member.
It is set to the first position V1 which is lower than the above.

In step S2, the stop member 131 is set to the second position V2 so as to raise the upper end P1U of the sheet P1 above the lower end Q of the protrusion 124A. Step S2
When the stop member 131 rises to the second position V2 at, the upper end P1U of the sheet P1 is retracted from the carry-in path 127 and faces the carry-out path 128.

The guide of the upper end P1U of the sheet P1 to the carry-out path 128 in this way is performed by the carry-in path 127 and the projection 12 described above.
4A and the shape of the carry-out path 128 ensure the operation. In addition, the movement of the protrusion 124A causes the upper end P1U to move to the carry-out path 1
It is also possible to lead to 28.

In step S3, the upper end P1U is guided to the carry-out path 128, and the stop member 131 moves to the second position V2.
In this step S3, the second sheet P2 is carried in by the driving roller 122 and the driven roller 121.

In the next step S4, the stop member 131 is moved up to the upper end P1U of the paper P1 (the leading end in the carry-out direction).
Is held between the driving roller 122 and the driven roller 123. During the transition from step S3 to step S4, the sheet P2 is conveyed and travels downward in the path 129 as illustrated.

In the next step S5, the stop member 131 descends to the first position. During this period, the paper P1 is continuously conveyed and travels upward as shown, while the paper P2 travels downward.

In step S6, the upper end (rear end in the carrying-in direction) of the sheet P2 is separated from the driving roller 122 and the driven roller 121 and dropped, and is supported by the stop member 131. S6, which is the loading stage of the second sheet P2, is equal to S1, which is the loading stage of the first sheet.

At step S7 when the third sheet P3 reaches the entrance of the aligning / shifting section 13, the three sheets of paper P1, P2, P3 simultaneously run in the aligning / shifting section 13 as shown in the figure.

As is clear from the above description, step S1
By repeating the reverse conveyance process from S to S5, the reverse discharge of a large number of sheets is performed. <Matching Process> Next, the matching operation in the matching / shift unit 13 will be described mainly with reference to FIGS. 2 to 4 and 6 to 11.

The aligning process is performed with respect to the side edges of the sheets stored in the aligning / shifting section 13 as shown in FIGS. 7 (a) and 7 (b).
As shown in FIG. 7, by moving the regulating members 13A and 13B in the opposite conveyance path width directions, a displacement action in the opposite direction is applied to the paper to align the paper with the regular position in the central portion. is there.

The matching process is executed by following the steps shown in FIG. FIG. 9 shows a sheet aligning method according to the embodiment of the present invention. (1) The preceding paper carry-in process drive roller 122 is rotationally driven in the clockwise direction to move the paper P1.
Is carried in from the carry-in path 127. In the preceding paper carry-in step, the stop member 131 is the upper end of the paper P1 (the rear end in the carry-in direction).
Is set to the lowest first position V1 when it is separated from the driven roller 121 and the drive roller 122, and the paper P1
Is separated from the driving roller 122 and the driven roller 121, and falls and is supported by the stop member 131 and stopped. (2) The preceding paper retreating process / alignment process stopping member 131 is raised to the second position V2, that is, the position where the upper end (rear end in the carrying-in direction) of the paper is above the guide end Q of the protrusion 124A. In the ascending stroke of the stop member 131, the upper end of the sheet P1 has the protrusion 124A as described above.
Since the guide end Q of is located closer to the carry-in path 127 than the vertical line L, it is reliably retracted from the carry-in path 127 to the carry-out path 128.

FIG. 8 shows a state in which the stop member 131 is raised to the second position V2. In the state of FIG. 8, the alignment of the paper P1 in the width direction of the transport path is executed. The matching operation will be described mainly with reference to FIG. 10A which is a cross-sectional view taken along the line YY of FIG.

The restricting members 13A and 13B have pins 230.
It is reciprocated between the position of FIG. 7 (a) and the position of FIG. 7 (b) by being driven by A and 230B, respectively. Pin 230
A is fixed to the toothed belt 235 stretched between the driven roller 233A and the driving roller 233B, and is also fixed to the regulating member 13A. The pin 230B is fixed to the toothed belt 235 at a side portion of the toothed belt 235 that faces the connecting side portion of the pin 230A, and the regulation member 13B is provided with the regulation member 13 through the vertically elongated hole 230C and the horizontally elongated hole 230D.
Engage B. In the aligning step, the toothed belt 235 is driven by the stepping motor M3 to reciprocate as shown by solid arrows and dotted arrows.

The regulating member 13B can move up and down as shown in FIG. 10 (b), and in the alignment process, the regulating member 13B is moved to the position shown in FIG.
Pin 2 is set at the lowered position shown by the solid line in (b).
30B is located in the vertically elongated hole 230C.

In the alignment process, the stepping motor M3
When the toothed belt 235 reciprocates as indicated by the solid arrow, the regulating plates 13A and 13B reciprocate in opposite directions as shown in FIG. 7 to regulate the side edge of the sheet. Align the paper to the center of the transport path.

The range of movement of the regulating members 13A and 13B during alignment is set to a range corresponding to the paper size by the control of the stepping motor M3.

Either of the raising operation of the stop member 131 to the second position and the aligning operation may be executed first, or may be executed simultaneously. (3) Subsequent Paper Loading Process (Step S3) After the preceding paper is retracted from the loading path 127 and aligned by the raising of the stop member 131 to the second position V2, the subsequent paper P2 is loaded. That is, the succeeding paper P2 is carried in by the clockwise rotation of the drive roller 122. In the carrying-in step, since the upper end (the leading end in the carrying direction) of the preceding paper P1 is retracted from the carrying-in path as described above, the succeeding paper P2 can be carried in smoothly. (4) Preceding Paper Unloading Step (Step S4) The stop member 131 is moved up to the third position V3 where the upper end of the preceding paper P1 (the leading edge in the unloading direction) reaches the nip between the driving roller 122 and the driven roller 123, and the driving roller 122 is also moved. Is rotated clockwise to carry out the preceding paper P1. FIG. 11 shows a state in which the stop member 131 is raised to the third position V3. Third position V3, that is, the preceding paper P
The stop member 131 is lowered to the first position V1 when the upper end (the leading end in the carry-out direction) of 1 is sandwiched by the drive roller 122 and the driven roller 123.

The carrying-in of the succeeding paper P2 of (3) and the carrying-out of the preceding paper P1 of (4) are executed in time. That is, by rotating the drive roller 122 in the clockwise direction, the succeeding paper P2 is carried in and the preceding paper P1 is carried out at the same time. Therefore, the preceding sheet P1 and the succeeding sheet P2 are conveyed in the accommodating member of the guide plates 125 and 126 in a manner of passing each other. When the upper end of the preceding paper P1 is sandwiched between the drive roller 122 and the driven roller 123, the stop member 131 descends, and when the upper end of the subsequent paper P2 leaves the drive roller 122 and the driven roller 123, the stop member 131 is released. Is in the first position V1, the succeeding sheet P2 is in a state (step S5) in which the (1) preceding sheet carrying-in step separated from the carrying-in means is completed.

Since the aligning process described above is performed in the aligning / shifting section 13 branched from the main transport path (transport path 10), it becomes possible to perform the alignment without lowering the transport efficiency, and the post-processing apparatus. High-speed processing and paper discharge are smoothly performed in B, and the ordered documents are collected on the paper discharge tray.

In particular, since the binding process and the folding process are performed on the aligned sheets, the binding process and the folding process are performed smoothly, and the finished document with the binding process and the folding process is produced. <Shift Process> Next, the shift process will be described with reference to FIGS.
This will be described with reference to 10 to 13. FIG. 12 shows a shift operation, and FIG. 13 shows a shift processing step.

In the shift processing, for example, when copying or printing a plurality of copies, the paper is displaced in the width direction of the transport path for each copy, and the paper is sorted and discharged onto a discharge tray for each copy. Processing.

In the present embodiment, the regulating member 13A
The shift process is performed by displacing each part from the position shown in FIG. 12A to the position shown in FIG. 12B. Note that in the example of the shift process described below, the paper discharge that displaces the paper in the width direction of the transport path and the paper discharge that does not displace are combined, but the paper is displaced in the opposite direction to the paper discharge that displaces in one direction. You may perform the shift process which combines discharge. (1) The preceding paper carry-in process drive roller 122 is rotationally driven in the clockwise direction to move the paper P1.
Is carried in from the carry-in path 127. In the preceding paper carry-in step, the stop member 131 is the upper end of the paper P1 (the rear end in the carry-in direction).
Is set to the lowest first position V1 when it is separated from the driven roller 121 and the drive roller 122, and the paper P1
Is separated from the driving roller 122 and the driven roller 121, and falls and is supported by the stop member 131 and stopped. Figure 6
Indicates the stage where the carry-in process is completed. (2) The preceding paper retreating process / shift process stopping member 131 is raised to the second position V2, that is, the position where the upper end (rear end in the carrying-in direction) of the paper is above the guide end Q of the protrusion 124A. In the ascending stroke of the stop member 131, the upper end of the sheet P1 has the protrusion 124A as described above.
Since the guide end Q of is located closer to the carry-in path 127 than the vertical line L, it is reliably retracted from the carry-in path 127 to the carry-out path 128.

FIG. 8 shows a state in which the stop member 131 is raised to the second position. In the state of FIG. 8, a shift process of displacing the sheet P1 in the width direction of the transport path is performed. The shift process will be described mainly with reference to FIG. 10 which is a cross-sectional view taken along the line YY of FIG.

The regulating members 13A and 13B are provided with pins 230.
It is driven by A and 230B respectively and set to the position of FIG. 12 (a) and the position of FIG. 12 (b). Pin 230
A is fixed to the toothed belt 235 stretched between the driven roller 233A and the driving roller 233B, and is also fixed to the regulating member 13A. The pin 230B is fixed to the toothed belt 235 at a side portion of the toothed belt 235 that faces the connecting side portion of the pin 230A, and the regulation member 13B is provided with the regulation member 13 through the vertically elongated hole 230C and the horizontally elongated hole 230D.
Engage B. In the shift process, the toothed belt 235 is driven by the stepping motor M3 and moves as shown by the solid arrow.

The regulating member 13B can move up and down as shown in FIG. 10 (b).
The pin 230B is set in the raised position indicated by the dotted line of 0 (b), and the pin 230B is positioned in the horizontally elongated hole 230D.

Stepping motor M in the shift process
12 and the toothed belt 235 moves as shown by the solid line arrow.
Although it moves from (a) to the position of FIG. 12 (b), the regulating member 123B does not move. Due to such movement of the regulating member 123A, the paper is displaced from the position of Pa in the width direction of the conveyance path and occupies the position Pb.

For example, in the case of producing a plurality of copies of a document consisting of five sheets, five sheets are conveyed at the position Pa, and a shift process is performed to displace the next five sheets to the position Pb and convey the sheets. Alternately done.

The movement range of the restriction plates 13A and 13B during the shift process is set to the range corresponding to the paper size by the control of the stepping motor M3. Alternatively, the shift process may be performed by moving the paper in the opposite direction for every plural sheets.

Either of the retracting step of raising the stop member 131 to the second position V2 and the shift step may be executed first, or may be executed simultaneously. (3) Subsequent Paper Loading Process (Step S3) After the preceding paper is retracted from the loading path 127 and aligned by the raising of the stop member 131 to the second position V2, the subsequent paper P2 is loaded. That is, the succeeding paper P2 is carried in by the clockwise rotation of the drive roller 122. In the carrying-in step, since the upper end (the leading end in the carrying direction) of the preceding paper P1 is retracted from the carrying-in path as described above, the succeeding paper P2 can be carried in smoothly. (4) Preceding Paper Unloading Step (Step S4) The stop member 131 is moved up to the third position V3 where the upper end of the preceding paper P1 (the leading edge in the unloading direction) reaches the nip between the driving roller 122 and the driven roller 123, and the driving roller 122 is also moved. Is rotated clockwise to carry out the preceding paper P1. FIG. 11 shows a state in which the stop member 131 is raised to the third position V3. Third position V3, that is, the preceding paper P
The stop member 131 is lowered to the first position V1 when the upper end (the leading end in the carry-out direction) of 1 is sandwiched by the drive roller 122 and the driven roller 123.

The carry-in of the succeeding sheet P2 of (3) and the carry-out of the preceding sheet P1 of (4) are executed overlapping in time. That is, by rotating the drive roller 122 in the clockwise direction, the succeeding paper P2 is carried in and the preceding paper P1 is carried out at the same time. Therefore, the preceding sheet P1 and the succeeding sheet P2 are conveyed in the accommodating member of the guide plates 125 and 126 in a manner of passing each other. When the upper end of the preceding paper P1 is sandwiched between the drive roller 122 and the driven roller 123, the stop member 131 descends, and when the upper end of the subsequent paper P2 leaves the drive roller 122 and the driven roller 123, the stop member 131 is released. Is in the first position V1, the succeeding sheet P2 is in a state (step S5) in which the (1) preceding sheet carry-in step separated from the carry-in means is completed. <Folding Process> The folding process will be described with reference to FIGS. FIG. 14 shows the structure of the folding parts 14 and 15.
FIG. 15 shows a tri-folding process (Z-folding process) for folding the paper P at two places.

The folding section 14 shown in FIG. 14A is composed of folding rollers 141 and 142 as driving rollers, driven rollers 143 and 144 which come into contact with these folding rollers and are driven to rotate, and a guide member 145. The folding roller 141 can be displaced as described later.

The folding section 15 shown in FIG. 14 (b) is composed of folding rollers 151 and 152 as driving rollers, driven rollers 153 and 154 that rotate in contact with these folding rollers, and a guide member 155. The folding roller 151 can be displaced as described later.

In the folding mode, the folding portion 14 with respect to the paper P is, for example, 1/4 from the front end thereof.
The first folding process is performed at the position of, and further, the folding process is performed by the folding unit 15 at the position of 1/4 (1/4 of the total length of the sheet) from the front end of the folded sheet P, and the sheet P is , For example, Z-folded.

In FIG. 15A, the folding roller 1
41 and the folding roller 142 are separated from each other, and the driven roller 1
43 and 144 are folding rollers 141 and 142, respectively.
The sheet P is conveyed in a state of being pressed against and is introduced into the folding section 14. When the sheet P is conveyed by a predetermined distance D from the reference position R, the driving of the folding rollers 141 and 142 is stopped by the sheet leading edge detection signal of the sensor SS2, and the folding process of FIG.

In FIG. 15B, the folding roller 1
41 and the driven roller 143 are displaced to bring the folding roller 141 and the folding roller 142 into pressure contact with each other, and then the folding roller 141 is rotationally driven in the same direction as the above-mentioned introduction, and the folding roller 142 is in the opposite direction to the above-mentioned introduction. Rotate to and start folding. The sheet P is bent by the conveying action of the folding rollers 141 and 142 in the opposite direction with respect to the sheet P, and a fold line enters between the folding roller 141 and the folding roller 142. A guide member 145 having a protrusion 145A for surely bending the sheet P toward the folding rollers 141 and 142 is provided. Further, as shown in FIG. 15C, the folding roller 1
The rotation of the rollers 41 and 142 is continued to perform folding, and the folded sheet P is conveyed by the conveying roller 210 and introduced into the folding section 15.

As shown in FIG. 15D, the folding portion 15
The folding rollers 151 and 152 are separated from each other, and the paper P is introduced with the driven roller 153 and the driven roller 154 in pressure contact with the folding rollers 151 and 152, respectively, and the leading end of the folded paper P is predetermined from the reference position R. At the stage of being conveyed by the distance D, the folding roller 151 is displaced based on the sheet leading edge detection signal of the sensor SS3 and brought into pressure contact with the folding roller 152. Folding roller 151 after pressure contact
Is rotationally driven in the same direction as that at the time of introduction, and the folding roller 152 is rotationally driven in a direction opposite to that at the time of introduction. The sheet P is bent by the conveying action of the folding rollers 151 and 152 in the opposite direction with respect to the sheet P, and the fold is inserted between the folding roller 151 and the folding roller 152. A guide member 155 having a projection 155A for surely bending the sheet P toward the folding rollers 151, 152 is provided. After pressing, as shown in FIG. 15E, the rotation direction of the folding roller 152 is reversed to fold the sheet P. Folding roller 1 as shown in FIG.
While continuing to rotate the sheets 51 and 152, while folding the sheet P, the sheet P is discharged from the folding unit 15 and is conveyed to the conveyance path 10.

In the example of FIG. 15, the sheet P is folded at a position ¼ from the front end. The sensors SS2 and SS3 are respectively located at the reference position, that is, the positions indicated by the tangents of the outer circumferences of 141 and 142 and the tangents of the outer circumferences of the folding rollers 151 and 152, and D = 1/4 × LT (LT is the length of the paper P in the conveyance direction. ), The leading edge of the paper P is detected. In practice, the delay time of the folding rollers 141, 142, 151, 152 is set to be slightly shorter than 1/4 × LT in consideration of the delay of the reversing time.

The sensors SS2 and SS3 are set at various positions depending on the folding mode of the sheet P or the sheet size.

As shown in the figure, in the process of folding the paper P at two points, the paper P is introduced into the folding section 14 in the direction Z1 and is moved from the folding section 14 to the folding section 1.
5 is conveyed and fed in the direction Z2 which is substantially perpendicular to the direction Z1. The sheet P folded by the folding unit is conveyed in a direction Z3 that is substantially perpendicular to the direction Z2, that is, in a direction Z3 that is substantially the same as the direction Z1.

[0109]

According to the first to fourth, seventh or tenth aspect of the present invention, since the reversing conveyance is performed by using the stop member, the sheet is carried into the reversing conveyance section and the sheet is ejected from the reversing conveyance section at the same time. Since a plurality of sheets of paper can simultaneously travel in the reverse conveyance unit, it is possible to shorten the sheet interval and perform the reverse conveyance process at high speed. Further, when the reverse conveyance processing is performed at a desired processing speed, the conveyance linear velocity of the sheet can be reduced, so that the conveyance is stabilized and the occurrence rate of conveyance failure can be reduced.

According to the fifth aspect of the invention, even when the sheet interval is shortened, high-speed reverse conveyance processing can be performed without causing interference between the preceding sheet and the succeeding sheet.

According to the invention of claim 6, it is possible to reverse and convey sheets of various sizes. According to the invention of claim 8, a post-processing device capable of high-speed reversal sheet discharge is realized.

According to the ninth aspect of the invention, an image forming apparatus capable of high-speed reversal sheet discharge is realized. According to the twelfth aspect of the invention, since the matching process is performed in the reversing conveyance unit, the matching process can be performed at high speed.

According to the eleventh aspect of the invention, since the shift processing is performed in the reversing / conveying unit, the shift processing can be performed at high speed.

[Brief description of drawings]

FIG. 1 is a schematic diagram of a sheet reversing device according to an embodiment of the present invention.

FIG. 2 is a diagram showing a sheet reversing method according to an embodiment of the present invention.

FIG. 3 is a diagram showing a sheet reversing method according to an embodiment of the present invention.

FIG. 4 is a diagram showing a sheet reversing method according to an embodiment of the present invention.

FIG. 5 is a diagram showing an example of an image forming apparatus according to an embodiment of the present invention.

FIG. 6 is a sectional view of a branch portion and a matching / shifting portion.

FIG. 7 is a diagram showing a matching operation.

FIG. 8 is a cross-sectional view of the alignment / shift portion in which the stop member is raised to the second position.

FIG. 9 is a diagram showing a process of a matching process.

10 is a cross-sectional view taken along the line YY of FIG. 6 and a partially enlarged view of the restriction member.

FIG. 11 is a cross-sectional view of the alignment / shift portion where the stop member is raised to the third position.

FIG. 12 is a diagram showing a shift operation.

FIG. 13 is a diagram showing a shift processing step.

FIG. 14 is a diagram showing a configuration of a folding portion.

FIG. 15 is a diagram showing a folding step.

[Explanation of symbols]

10 transport paths 12 branches 13 Matching / shifting section 13A, 13B regulating member 14, 15 Folding part 16 Middle plate 17 binding section 18 Fixed output tray 19 Lifting and discharging tray 121, 123 NR1, NR2 driven roller 122 DR drive roller 124 Upper guide member GD1, GD2 guide member 125, 126 Guide plate 127, R1 carry-in route 128, R2 carry-out route 129 passage 131, SM stop member A Image forming apparatus body B Post-processing device M1, M2, M3 stepping motor P, P1, P2, P3 paper

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Takeshi Tsuchiya             2970 Ishikawa-cho, Hachioji-shi, Tokyo Konica stock             In the company F term (reference) 3F053 BA03 BA12 BA14 LA02 LA06                       LA07 LB03

Claims (12)

[Claims] 1. A sheet reversing device comprising: a reversing conveyance section that reverses the front and back sides by switchback conveyance; a carry-in means that carries a sheet into the reversal conveyance section; and a carry-out means that carries out a sheet from the reversal conveyance section. A stop member for reversing the sheet conveyance direction is provided in the reversal conveyance section, and in the step of loading the sheet into the reversal conveyance section, the trailing end of the sheet in the sheet conveyance direction is abutted against the stop member after being separated from the conveyance unit. When the sheet is stopped, and in the step of unloading the sheet from the reversing / conveying unit, the stop member pushes the sheet back so that the leading end in the sheet unloading direction reaches the unloading unit and the sheet is unloaded by the unloading unit. Paper reversing device. 2. The carrying-in means comprises a first drive roller and a first driven roller that contacts the first drive roller, and the carry-out means contacts the second drive roller and the second drive roller. The sheet reversing device according to claim 1, comprising two driven rollers. 3. The continuous carrying of paper, wherein the carrying-in of the succeeding paper by the carrying-in means and the carrying-out of the preceding paper by the carrying-out means are overlapped in time. The paper reversing device described in 1. 4. The stop member has a first position for receiving the paper separated from the carry-in means between the carrying-in step of the paper and the carrying-out step of the paper, and a second position for avoiding interference between the preceding paper and the succeeding paper. The sheet reversing device according to any one of claims 1 to 3, wherein the position and the leading end of the sheet in the carry-out direction are displaced to a third position for reaching the carry-out means. 5. The sheet reversing device according to claim 1, further comprising a guide member that prevents interference between the preceding sheet and the succeeding sheet. 6. The sheet reversing device according to claim 1, wherein the stop member is displaced according to a sheet size. 7. The sheet reversing device according to claim 1, wherein the reversing and conveying unit is arranged so as to reversibly convey the sheet in a substantially vertical direction. 8. A post-processing apparatus comprising the sheet reversing device according to claim 1. 9. An image forming apparatus comprising the sheet reversing device according to claim 1. 10. The sheet is carried into a reversing conveyance section that reverses the front and back sides by switchback conveyance, the sheet is stopped in the reversing conveyance section by abutting the sheet against a stop member, and the sheet is carried out by the stop member. A sheet reversing method, characterized in that the sheet is delivered and the sheet is unloaded from the reversing and conveying section by the unloading means. 11. An aligning means for performing aligning processing in the width direction of the conveyance path is provided.
The sheet reversing device according to item. 12. The sheet reversing device according to claim 1, further comprising a shift unit that performs a shift process for displacing the sheet in the width direction of the transport path.