JP2011195239A - Paper processing device, image forming device, and shifting processing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To carry out shifting processing without elongating a carriage distance even for a short paper interval time.SOLUTION: This paper processing device includes a sorting means for sorting carried-in paper after offset in the direction perpendicular to the carrying direction. The sorting means includes a plurality of shifting rollers 9a, 9b arranged in proximity to a position where they do not contact each other, and first and second approaching/separating mechanisms 21a, 21b for the plurality of shifting rollers 9a, 9b to each approaching/separating to/from a roller paired with the shifting rollers. The approaching/separating mechanisms 21a, 21b are controlled for alternately operating the shift rollers 9a, 9b to shift paper.

Description

  The present invention relates to a sheet processing apparatus that performs a predetermined process on a sheet-like recording medium that has been carried in (referred to as “paper” in the present specification), a copier, printer, facsimile, The present invention relates to an image forming apparatus such as a digital multi-function peripheral and a shift control method executed by the sheet processing apparatus or the image forming apparatus.

  A shift method using a roller is known as a shift method for shifting when a sheet is discharged. As this type of shift system, for example, the invention described in Patent Document 1 (Japanese Patent Laid-Open No. 2004-250229) or Patent Document 2 (Japanese Patent Laid-Open No. 2009-012910) is known. Among these, Patent Document 1 discloses a technique for offsetting a sheet by one shift roller, and Patent Document 2 discloses a technique for dividing an offset amount by a plurality of shift rollers.

  By the way, in the method of offsetting the sheet by one shift roller as described above, after the sheet is offset, it is necessary to return the shift roller to the original position within the sheet interval time and offset the next transport sheet. As the productivity of the paper increased and the time between papers became shorter, there was a limit to the response.

  Further, in the method in which a plurality of shift rollers are provided and the offset amount is divided by a plurality of shift rollers and offset is performed, the time between sheets can be shortened, but a plurality of shift rollers are arranged side by side, so that the conveyance distance becomes long.

  Therefore, the problem to be solved by the present invention is to enable shift processing without increasing the transport distance even in a short time between sheets.

  In order to solve the above problems, the first means is a paper processing apparatus having a sorting means for sorting the incoming paper by offsetting it in a direction perpendicular to the transport direction, wherein the sorting means do not contact each other. A plurality of shift rollers arranged close to a position, a proximity separation mechanism that makes each of the plurality of shift rollers approach and separate from a pair of rollers, and the proximity separation mechanism; And a control means for shifting the paper.

  The second means is the first means in which the sheet is nipped and offset by any one of the plurality of shift rollers, and the next sheet is nipped and offset by a shift roller different from the shift roller. And a second operation mode in which the sheet is offset using only one of the plurality of shift rollers, and the control means is carried in. One of the first and second operation modes is selected based on the sheet interval time, and the sheet is shifted.

  The third means is characterized in that, in the first or second means, the control means separates the paper discharge roller on the downstream side of the shift roller in synchronization with the separation operation of the shift roller.

  The fourth means is characterized in that the image forming apparatus includes the sheet processing apparatus according to any one of the first to third means.

  According to a fifth means, in the fourth means, the image forming apparatus includes an image reading device and a main body of the image forming apparatus, and the paper processing device is installed on the main body and the main body. It is arrange | positioned in the space part between the said image reading apparatuses, It is characterized by the above-mentioned.

  A sixth means is a shift processing method in the paper processing apparatus for sorting the incoming paper by offsetting it in the direction perpendicular to the transport direction, wherein the sorting means are arranged close to positions where they do not contact each other. A plurality of shift rollers, and a proximity separation mechanism for approaching and separating each of the plurality of shift rollers with respect to the pair of shift rollers, and after shifting the preceding paper, return to the original position. A first mode in which the following paper can be nipped by the same roller and a second mode in which the subsequent paper cannot be nipped are set. In the first mode, the paper is fed by any one of the plurality of shift rollers. The second sheet is nipped and offset by a shift roller different from the shift roller. In the second mode, the plurality of sheets are offset. Characterized by offsetting the sheets using any one of the shift rollers of controllers.

  In the embodiment described later, the sorting means is the first and second shift rollers 9a, 9b, 203a, 203b, the sheet processing apparatus is denoted by reference numeral 200, and the proximity separation mechanism is the first and second proximity separation mechanisms 21a. , 21b, the control means is the CPU 401, the discharge roller is the reference numeral 10 or the discharge driven roller 205a, the image forming apparatus is the reference numeral 100, the image reading apparatus is the reference numeral 300, and the space is the output of the image forming apparatus 100. Each corresponds to the space above the tray 180.

  According to the present invention, since each of the plurality of shift rollers can be moved close to and away from the pair of shift rollers, the sheet is offset by a single shift roller, and the next sheet is The offset can be offset by another shift roller, and as a result, the shift process can be performed without increasing the transport distance even in a short time between sheets.

1 is a schematic configuration diagram illustrating a system configuration of a system including a sheet processing apparatus and an image forming apparatus according to Embodiment 1 of an embodiment of the present invention. It is a figure which shows schematic structure of the sort conveyance path which used the shift roller in FIG. 1 as a two-roller structure. FIG. 6 is a plan view of the movement of a sheet and a roller as viewed from above when a sheet is received with the sheet discharge roller nipped and the sheet is separated before being offset when the sheet interval time in Embodiment 1 is short. It is a top view which shows a state when shifted from the state of FIG. It is the figure which looked at the motion of the roller after the 1st sheet | seat was offset from the apparatus front. FIG. 6 is a plan view showing a state when a second sheet is received after the first sheet is offset. It is the figure which looked at the motion of the roller when offsetting the 2nd sheet | seat from the apparatus front. It is a top view which shows the state in which the 2nd sheet | seat is offset to the apparatus back side by the 2nd shift roller. It is the figure which looked at the motion of the roller after the 2nd sheet | seat was offset from the apparatus front. It is a figure which shows a state when the 3rd sheet is received after offsetting the 2nd sheet. It is the figure which looked at the motion of the roller when offsetting the 3rd sheet | seat from the apparatus front. It is a figure which shows the state in which the 3rd sheet | seat is offset to the apparatus back side by the 1st shift roller. FIG. 6 is a plan view illustrating a state of a shift operation when the time between sheets is long in the first exemplary embodiment. FIG. 10 is a diagram illustrating a system configuration of an image forming apparatus according to a second embodiment. FIG. 10 is a plan view of a sheet processing apparatus in Embodiment 2. FIG. 6 is a front view illustrating a schematic configuration of a sheet processing apparatus according to a second embodiment. FIG. 10 is a block diagram illustrating a control configuration of a system in a second embodiment.

  In the present invention, a plurality of shift rollers are provided so that a shift process can be performed without increasing the transport distance even in a short time between sheets. Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a schematic configuration diagram illustrating a configuration of an image forming system including a sheet processing apparatus and an image forming apparatus, for example, a copying machine, according to a first embodiment. In FIG. 1, the system includes an image forming apparatus 100 and a sheet processing apparatus 200. The sheet processing apparatus 200 according to the present embodiment has a function of 1) discharging a sheet conveyed from the image forming apparatus 100 as it is, 2) shifting (sorting) the sheet, and discharging 3) binding and discharging the sheet. Therefore, it is also called a paper post-processing device.

  When the sheet processing apparatus 200 discharges the sheet as it is in 1), the sheet is discharged from the entrance conveyance path 31 to the proof tray 8 via the proof conveyance path 32 and discharged in a 2) shift. When the sheet is offset by a predetermined amount by the shift roller 9 from the entrance conveyance path 31 through the sort conveyance path 33 and then discharged to the stacking tray 11 by 3), the sheet is stipple conveyed from the entry conveyance path 31. The paper is discharged to the stacking tray 11 through the path 34 and the staple tray 16.

  For this reason, the inlet transport path 31 includes the inlet guide plate 1 at the most upstream portion, and includes the first and second transport rollers 2 and 3 in the transport path before reaching the first and second branch claws 4 and 5. . The proof conveyance path 32 is a conveyance path that branches upward and is opened by rotating clockwise in the figure in both the first and second branch claws 4 and 5, and includes a third conveyance roller 6 and a discharge roller 7. The paper is discharged from the paper discharge roller 7 to the proof tray 8.

  The sort conveyance path 32 is a straight discharge conveyance path that is opened by rotating the first branch claw 4 in the counterclockwise direction and the second branch claw 5 in the clockwise direction in the figure. The paper is discharged from the paper discharge roller 10 after being shifted a predetermined amount in the direction orthogonal to the transport direction by the shift roller 9.

  The staple conveyance path 34 is a conveyance path for stapling a bundle of sheets, and includes fourth to sixth conveyance rollers 12, 13, 14 and a staple discharge roller 15, and after the sheet is discharged to the staple tray 16. Each time a sheet is discharged, the trailing edge of the sheet is knocked down to the side of the reference fence 18 by the tapping roller 17, the sheet conveying direction is aligned with respect to the reference fence 18, and the direction perpendicular to the sheet conveying direction by the jogger fence 19. To match. When the number of sheets corresponding to one copy is discharged, the same operation is repeated, and when the operation of aligning the last sheet of one copy is completed, the stapler 20 drives the binding needle into a predetermined position at the rear end of the sheet. A binding process is performed. The bound sheet bundle is lifted to the position of the paper discharge roller 10 by a discharge claw (not shown), and is discharged onto the stacking tray 11 by the paper discharge roller 10.

  2 to 13 are diagrams showing a schematic configuration of the sort transport path in the present embodiment in which the shift roller 9 in FIG. 1 has a two-roller configuration. In the present embodiment, the shift roller 9 in FIG. 1 is composed of two shift rollers, a first shift roller 9a on the upstream side in the sheet conveying direction and a second shift roller 9b on the downstream side, each consisting of a cam and a link. The first and second proximity / separation mechanisms 21a and 21b are provided so that the state where the driven roller is nipped from the driving roller and the state where the driven roller is separated can be arbitrarily set. Note that if the paper is nipped by the paper discharge roller 10 when shifting the paper, the paper cannot be shifted and may cause a paper jam. The roller can be moved close to and away from the driving roller.

  The sheet offset operation by the first and second two shift rollers 9a and 9b is performed as follows.

FIG. 2 shows the positional relationship between the second transport roller 3, the first shift roller 9a, the second shift roller 9b, and the paper discharge roller 10 from when the first sheet is received to when the sheet is offset. It is the figure which looked at from the front. The sheet is conveyed in the direction of the arrow D1 shown in the figure. In this state, the first shift roller 9a is in the nip state and the second shift roller 9b is in the separated state, and can be freely separated by the first and second proximity / separation mechanisms 21a and 21b, respectively.

  The paper discharge roller 10 receives the paper in the nipped state and separates it before offsetting the paper. 3 and 4 are plan views of the movement of the paper and the rollers in the meantime, as viewed from above. FIG. 3 shows a state where the first sheet S1 has been conveyed. At this time, the paper discharge roller 10 is nipped. FIG. 4 shows a state in which the first sheet S1 is offset to the back side by the first shift roller 9a. That is, the first shift roller 9a shifts in the direction of arrow D2 (moves in a direction orthogonal to the paper transport direction), and accordingly, the paper S1 moves in the direction of arrow D3 while being transported. At this time, in addition to the second shift roller 9b, the paper discharge roller 10 is also separated. The shift mechanism is a known technique as disclosed in the above-mentioned Patent Documents 1 and 2, and the present invention is not characterized by the shift mechanism itself of the shift roller. Description of is omitted.

  FIG. 5 is a view of the movement of the roller after the first sheet is offset as viewed from the front of the apparatus. After the first sheet is offset, the second shift roller 9b and the sheet discharge roller 10 which have been separated from each other nip. FIG. 6 shows a view of the movement of the paper and the roller in this state from above. FIG. 6 shows a state where the second sheet S2 is received after the first sheet S1 is offset. FIG. 5 shows that the first and second shift rollers 9a and 9b do not nip the same sheet at the same time.

  FIG. 7 is a view of the movement of the roller when the second sheet is offset as seen from the front of the apparatus. Before offsetting the second sheet, the first shift roller 9a and the paper discharge roller 10 are separated. FIG. 8 is a top view of the movement of the paper and the roller in this state. FIG. 8 is a plan view showing a state in which the second sheet S2 is offset to the back side (in the direction of arrow D2) by the second shift roller 9b. At this time, the shifted shift roller 9a is returned to the original position (in the direction of arrow D4).

  FIG. 9 is a view of the movement of the roller after the second sheet is offset as viewed from the front of the apparatus. After the second sheet is offset, the first shift roller 9a and the sheet discharge roller 10 which have been separated from each other nip. FIG. 10 is a view of the movement of the paper and the roller in this state as viewed from above. FIG. 10 shows a state where the third sheet S3 is received after the second sheet S2 is offset.

  FIG. 11 is a view of the movement of the roller when the third sheet is offset as seen from the front of the apparatus. The second shift roller 9b is separated before the third sheet is offset. FIG. 12 shows a view of the movement of the paper and the roller in this state from above. FIG. 12 shows a state where the third sheet S3 is offset to the back side of the apparatus by the first shift roller 9a. At this time, the separated second shift roller 9b is returned to the original position.

  As described above, the first and second shift rollers 9a and 9b shown in FIG. 2 to FIG. It becomes possible.

When the paper interval time is long When the paper interval time is long, the operation is the same as when the paper interval time is short until the paper of FIGS. 2 to 4 is offset. After that, since it is not necessary to use the second shift roller 9b, the second shift roller 9b is left separated, and the shift roller 9a is nipped between the first sheet S1 and the second sheet S2 as in the past as shown in FIG. To the center (in the direction of arrow D4), and the operation of niping and offsetting the next sheet at the center is repeated.

  In the first embodiment, the short paper interval corresponds to a case where the preceding paper is shifted and then returned to the original position, and the succeeding paper cannot be nipped by the same roller. Corresponds to the case where the preceding sheet is shifted and then returned to the original position, and the succeeding sheet can be nipped by the same roller.

  14 is a diagram illustrating an example of an image forming apparatus according to a second embodiment in which a sheet processing apparatus including two shift rollers 203a and 203b is arranged in a space between the image reading apparatus and the image forming apparatus, and FIG. The top view of the processing apparatus 200 and FIG. 16 are front views showing a schematic configuration.

  In FIG. 2, the image forming system according to the second embodiment includes an image forming apparatus 100, a sheet processing apparatus 200, and an image reading apparatus 300.

  The image forming apparatus 100 is an indirect transfer type tandem color image forming apparatus. In the figure, an image forming unit 110 having a four-color image forming station 111 disposed substantially in the center thereof is adjacent to the lower side of the image forming unit 110. The optical writing unit 113 provided below, the paper feeding unit 120 provided below the image forming unit 110, and the paper feeding conveyance for conveying the paper picked up by the paper feeding unit 120 to the secondary transfer unit 140 and the fixing unit 150. A path (vertical conveyance path) 130, a paper discharge path 160 for conveying the paper on which the image is fixed to the paper processing apparatus 200, and double-sided conveyance for reversing the paper on which an image is formed on one side and forming an image on the other side A path 170 is provided.

  The image forming unit 110 includes a photosensitive drum for each color of YMCK of the image forming station 111, and a charging unit, a developing unit, a primary transfer unit, a cleaning unit, and a charge eliminating unit arranged along the outer periphery of the photosensitive drum. And an intermediate transfer belt 112 for intermediate transfer of an image formed on the photosensitive drum by a primary transfer unit, and an optical writing unit 113 for writing an image for each color on the photosensitive drum. The optical writing unit 113 is disposed below the image forming station 111, and the intermediate transfer belt 112 is disposed above the image forming station 111. The intermediate transfer belt 112 is rotatably supported by a plurality of support rollers, and one of the support rollers 114 is opposed to the secondary transfer roller 115 via the intermediate transfer belt 112 in the secondary transfer unit 140, and the intermediate transfer belt 112. The upper image can be secondarily transferred to the paper. The image forming process of the indirect transfer tandem color image forming apparatus is well known and is not directly related to the gist of the present invention, and thus detailed description thereof is omitted.

  The paper feeding unit 120 includes a paper feeding tray 121, a pickup roller 122, and a paper feeding / conveying roller 123, and feeds the paper picked up from the paper feeding tray 121 upward along the vertical conveying path 130. The fed sheet is transferred with an image by the secondary transfer unit 140 and sent to the fixing unit 150. The fixing unit 150 includes a fixing roller and a pressure roller, and heat and pressure are applied in a process in which the paper passes through the nip between the two, and the toner is fixed to the paper.

  A paper discharge conveyance path 160 and a double-sided conveyance path 170 are provided downstream of the fixing unit 150, both of which are branched in two directions by a branching claw 161 and conveyed to the paper processing apparatus 200 side, and a double-sided conveyance path 170. The transport path is selected according to the case where the transport path is transported. A branch conveyance roller 162 is provided in the immediate vicinity of the branch claw 161 on the upstream side in the sheet conveyance direction, and applies a conveyance force to the sheet.

  The sheet processing apparatus 200 is disposed inside the image forming apparatus 100 or mounted on a paper discharge tray (housing tray) 180 of the image forming apparatus 100 and is used for a predetermined image formed sheet conveyed from the image forming apparatus 100. And is stacked on the discharge tray 206 located on the most downstream side, which will be described in detail later. When the image reading apparatus 300 is provided as shown in FIG. 1, the sheet processing apparatus 200 is between the image forming apparatus 100 and the image reading apparatus 300, and is an upper surface of the casing of the image forming apparatus 100. The paper discharge tray 180 formed in the above, that is, a so-called housing tray, is attached to a portion that was originally a space portion. Thereby, space can be used effectively and space saving can be promoted.

  The image reading device 300 is a known device that optically scans an original set on a contact glass and reads an image on the original surface. Since the configuration and function of the image reading apparatus 300 itself are known and are not directly related to the gist of the present invention, detailed description thereof is omitted.

  In FIG. 15, the sheet processing apparatus 200 includes an inlet roller pair 202, a rear end reference fence 212, a jogger 213, a stapler 215, a front reference fence 214, first and second shift rollers 203a and 203b from the upstream side in the sheet conveyance direction. A tapping roller 210, a paper discharge roller 205, a paper discharge driven roller 205 a, a paper trailing edge press 208, a paper discharge tray movable portion 207, and a paper discharge tray 206 are provided.

  As can be seen from FIG. 16, the sheet processing apparatus 200 also includes a guide plate 201, a staple tray 209, a rear end return roller 211, a rear end reference fence 212, a jogger fence 213, and a paper discharge opening / closing guide plate 204. .

  That is, a guide plate 201 that receives paper from the paper discharge conveyance path of the image forming apparatus 100 is disposed in the paper receiving portion of the paper processing apparatus 200, and the inlet roller pair 202 is disposed on the most upstream side in the paper conveyance direction of the guide plate 201. The first and second shift rollers 203a and 203b having a function of shifting the sheet to the sheet discharge tray 206 and discharging the sheet are provided on the most downstream side, and an inlet roller pair 202 and a shift roller 203a, The sheet is conveyed along the guide plate 201 by rotating 203b.

  In the case of this embodiment, the first and second shift rollers 203a and 203b also have a proximity / separation mechanism, operate in the same manner as the first and second shift rollers 9a and 9b in the first embodiment, and function in the same manner. A description of the operation is omitted.

  FIG. 17 is a block diagram illustrating a control configuration of the system according to the second embodiment.

  In the figure, control of the image forming apparatus 100 is executed by an image forming apparatus control unit 410 having a built-in CPU 411, ROM 412, RAM 413, nonvolatile RAM 414, serial I / F 415, timer 416, and the like. The program code for control is stored in the ROM 412, and the CPU 411 expands the program code in the RAM 413, stores data necessary for control in the RAM 413, and uses the RAM as a work area, and defines the program code defined by the program code. To control each part.

  The image forming apparatus control unit 410 includes a motor used in the image forming unit 110 such as a photosensitive member, various DC loads 450 such as various motors and clutches in the sheet feeding unit 120, the sheet feeding conveyance path 130, and the double-side conveyance path 170, Various AC loads 470 and various sensors 460 such as a temperature sensor for detecting the temperature of the fixing roller are connected. Further, the image reading apparatus 300 and the operation display unit 440 are connected, and each unit is controlled via the image forming apparatus control unit 407.

  The control of the sheet processing apparatus 200 is executed by a sheet processing apparatus control unit 400 including a CPU 401, a ROM 402, a RAM 403, a serial I / F 404, a timer 405, and the like. The program code for control is stored in the ROM 402, and the CPU 401 expands the program code in the RAM 403, stores data necessary for control in the RAM 403, and uses the RAM as a work area, and the control defined by the program code. And various DC loads 420 are controlled. Note that the shift motor (not shown) for shifting the first and second shift rollers 203a and 203b and the inlet motor are controlled by the CPU 401 because a DC motor such as a stepping motor is used. Similarly, the first and second shift rollers 9a and 9b in the first embodiment are also controlled by a CPU of a control circuit (not shown) to sort the sheets.

  The CPU 401 of the sheet processing apparatus 200 receives information such as the sheet size, sheet interval time, and linear speed from the control unit 410 of the image forming apparatus 100 via the serial I / Fs 415 and 404 and is continuously sent from the image forming apparatus 100. An operation method in which the incoming paper is offset by any one of the first and second shift rollers 203a and 203b, and the next paper is offset by a shift roller different from the shift roller, and the first In addition, any one of the operation methods for offsetting the sheet using only one of the second shift rollers 203a and 203b can be selected. By this selection control, it is possible to suppress wasteful power consumption and to save power. The same applies to the system of the first embodiment. In addition, when the paper interval is short and the paper interval is long, the preceding paper is shifted as described above and then returned to the original position, and it is determined whether the subsequent paper can be nipped by the same roller. Information such as the paper size, the paper interval time, and the linear velocity is used for this determination. Basically, the information is used to determine whether or not the succeeding sheet can be nipped by the same roller after returning to the original position after shifting the preceding sheet.

  In addition, although two shift rollers are used in both the first and second embodiments, at least two shift rollers are necessary to perform the above-described shift control. If necessary, more shift rollers are used. It goes without saying that it is also good.

As described above, according to the present embodiment,
1) The two shift rollers 9a, 9b, 203a, and 203b are arranged at close intervals so as not to contact each other, and are provided so as to be separated from each other. After the offset, the next sheet can be offset by one of the plurality of shift rollers different from the shift roller without waiting for the shift roller to return to the original position. Furthermore, since the first shift roller is moved away from the original position while the next sheet is being offset, it can be prepared for the next transport sheet, so that even if the time between sheets is very short, the shift is possible. Can be made. Thereby, high productivity can be realized.
2) The CPU 401 of the sheet processing apparatus 200 receives the sheets continuously sent from the image forming apparatus 100 side based on information such as the sheet size, the sheet interval, and the linear velocity received from the image forming apparatus 100 side. An operation method in which a sheet is offset by any one of the shift rollers, and a next sheet is offset by a shift roller different from the shift roller, and any one shift roller among the plurality of shift rollers It is possible to select an operation method for offsetting the paper using only the paper. As described above, since the operation method is selectively determined based on the information from the image forming apparatus 100 side and the shift operation is performed, it is possible to promote power saving.
3) Since the sheet processing apparatus is arranged in the space between the image reading apparatus (image reading section) and the image forming apparatus (image forming section), space saving can be realized.
There are effects such as.

  It should be noted that the present invention is not limited to the present embodiment, and various modifications are possible, and all technical matters included in the technical idea described in the claims are subject to the present invention. Needless to say.

DESCRIPTION OF SYMBOLS 10 Paper discharge roller 9a, 9b, 203a, 203b 1st and 2nd shift roller 21a, 21b 1st and 2nd proximity separation mechanism 100 Image forming apparatus 200 Paper processing apparatus 205a Paper discharge driven roller 300 Image reading apparatus 401 CPU

JP 2004-250229 A JP 2009-012910 A

Claims (6)

A paper processing apparatus having a sorting unit that sorts an incoming paper by offsetting it in a direction perpendicular to the transport direction,
The sorting means is
A plurality of shift rollers arranged close to positions that do not contact each other;
For each of the plurality of shift rollers, a proximity separation mechanism that makes the shift roller approach and separate from the pair of rollers, and
Control means for controlling the proximity / separation mechanism to alternately nip and offset the paper with different shift rollers;
A sheet processing apparatus comprising: The sheet processing apparatus according to claim 1,
A first operation mode in which a sheet is nipped and offset by any one of a plurality of shift rollers, and the next sheet is nipped and offset by a shift roller different from the shift roller;
A second operation mode in which the sheet is offset using only one shift roller of the plurality of shift rollers;
With
The paper processing apparatus, wherein the control unit selects either the first or second operation mode based on a time between papers carried in, and offsets the paper. The sheet processing apparatus according to claim 1 or 2,
The sheet processing apparatus, wherein the control unit separates the paper discharge roller on the downstream side of the shift roller in synchronization with the separation operation of the shift roller.   An image forming apparatus comprising the sheet processing apparatus according to claim 1. The image forming apparatus according to claim 4,
The image forming apparatus includes an image reading device and a main body of the image forming device,
The image forming apparatus, wherein the sheet processing device is disposed in a space portion between the main body and the image reading device installed on the main body. A shift processing method in a paper processing apparatus that sorts paper that has been carried in by offsetting in a direction perpendicular to the transport direction,
The sorting means is
A plurality of shift rollers arranged in proximity to positions that do not contact each other, and a proximity separation mechanism that causes each of the plurality of shift rollers to approach and separate from a pair of rollers with the shift roller,
After shifting the preceding paper, return to the original position, set the first mode that can nip the following paper with the same roller and the second mode that can not nip,
In the first mode, the sheet is nipped and offset by any one of the plurality of shift rollers, and the next sheet is nipped and offset by a shift roller different from the shift roller,
In the second mode, the sheet is offset by using any one of the plurality of shift rollers.