JP2009286513A - Post-processing device and image forming system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a post-processing device capable of performing post-processing without deteriorating workability and productivity by reducing the deterioration of the uniform quality of paper, even if a curl or air involving between paper exists, for instance. <P>SOLUTION: This post-processing device has a shift part for shifting paper, a paper discharge part for accumulating discharged paper, an aligning member for energizing an end face of the paper discharged in the paper discharge part and an aligning member shift means for shifting the aligning member according to a shift position of the paper shifted by the shift part. The post-processing device has a control means capable of changing the maximum number of sheets of paper accumulated in the paper discharge part according to the combination of the presence or absence of an aligning execution of paper by the aligning member and the presence or absence of a shift execution by the aligning member shift means in relation to the presence or absence of a shift execution of paper by the shift part. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a post-processing apparatus having a paper discharge tray for collecting discharged sheets, and an image forming system having the post-processing apparatus and an image forming apparatus for forming an image.

  2. Description of the Related Art Conventionally, post-processing apparatuses that collect sheets on a sheet discharge tray when discharging the sheets are generally known.

  As the post-processing device, a shift unit that changes (shifts) the paper conveyance position as necessary, a paper discharge tray that collects the discharged paper, and an alignment member that is provided in the paper discharge tray and aligns the paper And a shift unit that changes the position of the alignment member in accordance with the sheet conveyance position (shift position) is known.

Such a post-processing device has a configuration in which the end of the paper is tapped and aligned by the alignment member after the paper is completely accumulated on the discharge tray;
A configuration in which the edge of the sheet is lightly aligned after the position of the alignment member is changed to a position that matches the position of the sheet conveyed by the shift, and
A configuration in which the discharge tray is lowered in accordance with information such as a paper lever that detects the upper surface position of the stacked paper so as to match the top surface position of the stacked paper and the discharge position. Is known (for example, Patent Document 1).
JP 2006-206331 A

  The post-processing apparatus described in Patent Document 1 lowers the discharge tray in accordance with information such as a paper lever that detects the upper surface position of the stacked sheets in order to reduce abnormal discharge to the discharge tray. The upper surface position of the sheets stacked on the paper discharge tray is aligned with the paper discharge position to the paper discharge tray.

  Then, the paper discharge tray is stopped at a position where the upper surface position of the collected paper and the paper discharge position are matched, the paper is stacked on the paper discharge tray by the alignment member, and the alignment by the shift unit. The member is shifted.

  However, depending on the type of paper, paper condition, paper stacking form, etc., for example, air entrainment between thin papers, curl, presence / absence of alignment and shift, etc. May swell.

  Such a tendency of the sheet bundle to swell significantly becomes particularly remarkable at the downstream end side of the sheet bundle stacked on the paper discharge tray.

  Accordingly, the thickness of the sheet bundle is not constant on the upstream side and the downstream side, and the upper surface on the downstream tip side is greatly convex upward.

  If the upper surface on the downstream tip side is significantly convex upward, the convexity will be increased when the paper discharge tray on which such a convex sheet bundle is placed is moved laterally (shifted). There is a problem in that the lower part of the alignment member may be caught on the upper surface of the sheet and the end surface of the sheet may become uneven.

  Further, as another configuration, even when the alignment member is moved upward (shifted) while being retracted upward (in a direction opposite to the front end of the sheet) during the shift process, the lower portion of the alignment member is not formed on the convex sheet. There was a problem that the paper could be caught and the end face of the paper would be uneven.

  As a result, there has been a problem that work for realigning a bundle of paper sheets that has become uneven is required, leading to a decrease in workability.

  In view of the above problems, the present invention can reduce post-alignment quality reduction and can perform post-processing without reducing workability and productivity regardless of the type of paper, the state of the paper, the form of paper stacking, etc. An object is to provide a processing apparatus.

  The above object of the present invention is achieved by the following.

1. A shift unit that shifts the paper in the width direction, a paper discharge unit that collects the discharged paper, an alignment member that biases an end surface of the paper discharged to the paper discharge unit, and a paper that is shifted by the shift unit A post-processing apparatus having alignment member shifting means for shifting the alignment member in the width direction in accordance with the shift position of
Depending on the combination of presence / absence of paper alignment by the alignment member and presence / absence of shift execution by the alignment member shifting means with respect to presence / absence of paper shift execution by the shift unit, the paper discharge unit A post-processing apparatus having control means capable of changing the maximum number of sheets to be stacked.

  2. An image forming system comprising: an image forming apparatus that forms an image; and the post-processing apparatus according to item 1 above.

According to the present invention, the following effects can be obtained:
Depending on the post-processing device described in Section 1.1, even if there is a paper type, a paper state, a paper stacking form, etc., for example, air entrainment between thin papers, curling, alignment / shifting, etc. Thus, it is possible to provide a post-processing apparatus that can reduce post-alignment quality reduction and can perform post-processing without reducing workability and productivity.

  2. By connecting the image forming apparatus that forms an image and the post-processing apparatus described in the above item 1, it is possible to provide an image forming system that has good sheet alignment quality and suppresses the reduction in workability and productivity.

  Embodiments of the present invention will be described below, but the description in this section does not limit the technical scope of the claims or the meaning of terms.

  Moreover, the same part number is attached | subjected to the component which has the same structure in each figure.

  In the following description, a direction perpendicular to the sheet conveyance direction is referred to as a width direction.

  Further, the upstream refers to the side on which the sheet is conveyed, and the downstream refers to the side on which the sheet is conveyed.

  FIG. 1 is a conceptual explanatory diagram showing a relationship between a paper discharge tray, a sheet bundle stacked on the paper discharge tray, and an alignment plate.

  When the paper is discharged onto the paper discharge tray A, the discharged paper does not cause a paper discharge abnormality that is caught on the upper part of the paper stacked on the paper discharge tray A. The position (height) of the uppermost surface of the sheet bundle B is adjusted to a position slightly lower than the sheet discharge outlet G of the post-processing apparatus.

  FIG. 1A is a diagram illustrating a relationship between a sheet bundle having no fixed curl or the like, a sheet discharge tray, and an alignment plate.

  When there is no curl or the like on the sheet, the upper surface on the downstream tip side of the bundle of sheets B in which the predetermined number of sheets is accumulated as described in “Problem” is not substantially convex, and the thickness is substantially the same from the upstream side to the downstream side. Become.

  For this reason, the position (height) of the upper surface of the sheet bundle B is substantially the same position (height) from the upstream side to the downstream side, that is, the position (height) of the upper surface of the sheet bundle B is rearward from the upstream side to the downstream side. The position is slightly lower than the paper discharge port G of the processing apparatus.

  For this reason, when the aligning plate C moves in the direction of the arrow D when the aligning plate is shifted (laterally moved), the lower end E of the aligning plate A is caught on the upper surface F of the sheet bundle B, thereby making the sheet end surfaces uneven. It can be moved without losing.

  FIG. 1B is a diagram showing a relationship between a sheet bundle in which the upper surface on the downstream front end side is greatly convex upward due to curling or the like, a sheet discharge tray, and an alignment plate in a conventional post-processing apparatus. .

  A predetermined number of sheets are stacked on the sheet discharge tray A as in FIG.

  For this reason, the position (height) of the upper surface of the sheet bundle B ′ is slightly lower (height) than the discharge port G of the post-processing apparatus on the upstream side, but it is on the downstream front end side due to the influence of curl or the like. The top surface is significantly convex (high).

  Further, since the upper surface F ′ on the downstream tip side is greatly convex upward, when the alignment plate C moves in the direction of the arrow D when the alignment plate is shifted (lateral movement), the alignment plate A The lower end portion E is caught by the upper surface F ′ of the sheet bundle B ′ (the upward convex portion or the subsequent slope portion of the sheet bundle B ′), and the sheet end surface becomes uneven.

  Note that the sheet bundle B 'indicated by the alternate long and short dash line is a small size sheet bundle, and the height of the convex portion is not changed from that of the large size paper bundle indicated by the solid line, and the position of the convex portion is shifted further upstream.

  For this reason, even when the alignment plate C is short in the sheet conveyance direction (two-dot chain line), when the alignment plate C moves in the direction of arrow D when the alignment plate is shifted (at the time of lateral movement), the alignment plate C The lower end portion E of the (two-dot chain line) is likely to be caught on the upper surface F ′ of the sheet bundle B ′ (the upward convex portion or the subsequent slope portion of the sheet bundle B ′).

  FIG. 1C is a view showing the relationship between a sheet bundle whose upper surface on the downstream tip side is convex upward due to curling or the like, a paper discharge tray, and an alignment plate in the post-processing apparatus of the present invention.

  The position (height) of the upper surface of the sheet bundle B ′ is slightly lower (height) than the discharge port G of the post-processing apparatus on the upstream side, but the upper surface F on the downstream front end side due to the influence of curl or the like. 'Is convex (high).

  However, in order to reduce the number of sheets constituting the sheet bundle B ', the height of the slope of the convex portion that is directed upward and the subsequent sheet bundle B' becomes lower than the conventional one.

  As a result, when the alignment plate C moves in the direction of the arrow D when the alignment plate is shifted (laterally moved), the lower end E of the alignment plate A is caught on the upper surface F ′ of the sheet bundle B ′ and the end surfaces of the sheets are uneven. It is possible to move without making it.

  The post-processing apparatus of the present invention and an image forming system having the post-processing apparatus and the image forming apparatus will be described below.

  FIG. 2 is an explanatory diagram showing an example of an image forming system having a post-processing apparatus and an image forming apparatus.

  The image forming system 1 includes an image forming apparatus 3 and a post-processing apparatus 2. The image forming apparatus 3 forms an image on the paper P, and the post-processing apparatus 2 performs set post-processing such as stapling. .

  The electrophotographic image forming apparatus 3 includes an original image reading unit 10 that reads an original image, an original conveying device 20 that conveys an original D, and an image that forms an image based on original image information read by the original image reading unit 10. A forming unit 30, a paper feeding unit 40 for feeding paper P to the image forming unit 30, a fixing unit 50 for fixing a toner image, an operation panel 90 having display means and operation switches, and a control for controlling them. Part C2.

  The post-processing device 2 includes a punching unit 120 that punches the paper P, a shift unit 130 that shifts the paper position for each job, a stapling unit 150 that performs a stapling process on a bundle of paper, and a folding unit that folds the paper bundle. A unit 160, a stacker 170 for temporarily collecting sheets, a sheet discharge unit 180 for collecting discharged sheets and the like, and a control unit C1 for controlling them.

  The paper discharge unit 180 includes a paper discharge tray 181 for placing discharged and stacked paper and the like, and an alignment unit 182 for aligning the paper placed on the paper discharge tray 181 in the width direction. ing.

  The image forming apparatus 3 and the post-processing apparatus 2 are configured so that the paper P carried out from the image forming apparatus 3 is received by the receiving unit 200 of the post-processing apparatus 2 and the paper discharge roller 76 and the post-processing apparatus of the image forming apparatus 3. The position and height are adjusted and installed so that the two receiving parts 200 match.

  Then, the fixed sheet P is conveyed from the paper discharge roller 76 of the image forming apparatus 3 to the receiving unit 200 of the post-processing apparatus 2.

  The image forming apparatus 3 and the post-processing apparatus 2 include a communication unit T2 of the image forming apparatus 3 and a communication unit T1 of the post-processing apparatus 2 and exchange various information.

For example, information related to post-processing set on the operation panel 90 of the image forming apparatus 3 is transmitted to the communication unit T1 of the post-processing apparatus 2 via the communication unit T2.
The post-processing device 2 performs post-processing based on the transmitted information related to the post-processing.

  Examples of the paper used in the image forming system 1 include paper and an OHP sheet.

  Hereinafter, the image forming apparatus 3 and the post-processing apparatus 2 of the image forming system 1 will be described in detail.

  FIG. 3 is a schematic cross-sectional view illustrating an example of an image forming apparatus.

  As an example of the image forming apparatus, an image forming apparatus referred to as a tandem type full color copying machine will be described below as an example.

  The document conveying device 20 separates and feeds the documents D stacked on the sheet feeding tray 21 one by one, conveys the documents by rollers or the like, and sends the document image to the document image reading unit 10 described later in the document reading region R. It is a device that discharges the paper to the paper discharge tray 29 after being read.

  Specifically, the documents D stacked on the sheet feeding tray 21 are separated and fed one by one by the feed roller pair 22 and sent to the registration roller pair 23 arranged on the downstream side.

  After that, the guide D is guided by the guide 25 and the like, transported along the outer peripheral surface of the transport drum 24, reaches the document reading region R, and the document D that has passed through the document reading region R is reversed in the transport direction by the reverse transport roller 26. The paper is guided by the switching guide member 27 and discharged onto the paper discharge tray 29 by the paper discharge roller 28.

  The document image reading unit 10 reads an image of the document D conveyed by the document conveying device 20 or an image of the document D placed on the platen glass 11.

  The document image reading unit 10 connects a first scanning unit 14 having a light source 12 and a first mirror 13, a second scanning unit 17 having second and third mirrors 15 and 16, and a document image to a line image sensor CCD. And an optical system 18 for imaging.

  When reading the image of the document D conveyed in the document reading area R by the stationary optical system type reading operation, the line image sensor CCD scans the document image by the first scanning unit 14 stationary at the lower part of the document reading area R. Read.

  When reading the image of the document D placed on the platen glass 11 in the moving optical system type reading operation, the first scanning unit 14 and the second scanning unit 17 are in the sub-scanning direction (right direction in the drawing). As shown by the broken line, the line image sensor CCD reads the document image while moving.

  An analog signal of the original image photoelectrically converted by the line image sensor CCD is subjected to analog processing, A / D conversion, shading correction, image compression processing, etc. in an image processing unit (not shown), and Y (yellow), M (magenta) ), C (cyan), K (black) digital image data for each color.

  A drum-shaped photosensitive member (hereinafter also referred to as a photosensitive member) 1Y, 1M, 1C, and 1K as a first image carrier corresponding to each color of Y, M, C, and K is a charging device 2Y, 2M corresponding to each color. 2C and 2K are uniformly charged.

  The exposure devices 3Y, 3M, 3C, and 3K corresponding to the respective colors form latent images on the corresponding photoreceptors 1Y, 1M, 1C, and 1K based on the digital image data for the respective colors.

  Toners for each color are supplied to developing devices 5Y, 5M, 5C, and 5K from toner replenishing devices 4Y, 4M, 4C, and 4K for replenishing new toner, and photoreceptors 1Y and 1M are developed by developing devices 5Y, 5M, 5C, and 5K. The latent images corresponding to the colors formed on 1C and 1K are visualized.

  The developing devices 5Y, 5M, 5C, and 5K and the photoconductors 1Y, 1M, 1C, and 1K are arranged in a vertical column, and rollers 71, 72, and An intermediate transfer member 70, which is a semiconductive endless belt-like second image carrier that is wound around 73 and 74 and is rotatably supported, is disposed.

  The intermediate transfer member 70 is driven in the direction of the arrow by a driving device (not shown) connected to the roller 71 by a roller 71.

  The primary transfer rollers 6Y, 6M, 6C, and 6K corresponding to the respective colors as the primary transfer unit are selectively operated according to the type of image, and are intermediately transferred to the corresponding photoreceptors 1Y, 1M, 1C, and 1K, respectively. The body 70 is pressed.

  In this manner, the toner images of the respective colors formed on the photoreceptors 1Y, 1M, 1C, and 1K are sequentially transferred onto the rotating intermediate transfer body 70 to form a combined color image.

  After the toner image is transferred to the intermediate transfer member 70 by the primary transfer rollers 6Y, 6M, 6C, and 6K, the residual toner is removed from the photosensitive members 1Y, 1M, 1C, and 1K by the cleaning units 7Y, 7M, 7C, and 7K. The

  The paper feed unit 40 that is a paper supply means has a first paper feed cassette 41a, a second paper feed cassette 41b, and a third paper feed cassette 41c that are paper storage members. The paper P is accommodated.

  The paper P stored in each paper cassette is separated one by one by the paper feed unit 42, and is conveyed to the secondary transfer region 75a through a plurality of intermediate rollers 43, 44, 45, 46, etc., and a registration roller 47. Is done.

  Then, the combined toner image on the intermediate transfer member is collectively transferred onto the paper P by the secondary transfer roller 75. The secondary transfer roller 75 is urged toward the roller 72 only when the sheet P passes through the secondary transfer roller 75 and presses the sheet P against the intermediate transfer body 70.

  After the color image is transferred to the paper by the secondary transfer roller 75, the residual toner is removed by the cleaning unit 77 from the intermediate transfer body 70 which has separated the curvature of the paper.

  The sheet on which the color toner image is transferred is subjected to a fixing process by a fixing unit 50 including a heating roller 51 including a heating source H and a pressure roller 52.

  Then, the fixed sheet is sandwiched between the sheet discharge rollers 76 and supplied from the discharge port to the post-processing apparatus in the downstream process.

  An operation panel 90 on which an operator inputs various information includes a touch panel and various operation switches.

  The control unit C2 displays a screen for setting or selecting information related to post-processing on the touch panel of the operation panel 90.

  Then, the control unit C2 reads information related to the post-processing set or selected on the screen, and transmits the information to the communication unit T1 of the post-processing device 2 via the communication unit T2.

As information relating to post-processing, in the post-processing device, information on whether or not paper shift is executed, information on whether or not paper alignment is executed, and information on whether or not alignment member shift is executed, and
Post-processing content information (for example, shift processing, alignment processing, binding processing (hereinafter referred to as stapling), folding processing, punching processing, etc.) to be performed by the post-processing device, job information [for example, predetermined number of sheets (shift number), predetermined Number of sheets (number of completed jobs), sheet size information, sheet type information), and the like.

  Hereinafter, the shift including the shift of the sheet by the shift unit and the shift of the alignment member is referred to as a shift process, and the shift of the alignment member is simply referred to as the shift process of the alignment member.

  FIG. 4 is a cross-sectional configuration diagram illustrating an example of the post-processing apparatus.

  As post-processing of paper, there are shift processing, alignment processing, stapling processing, folding processing, punching processing, etc., but below, taking shift processing, alignment processing, folding processing, stapling processing, and paper discharge as examples, The configuration and operation of the post-processing apparatus will be described.

  In the post-processing device 2, a paper feed device 110 having a first paper feed tray 111 and a second paper feed tray 112 and a fixed paper discharge tray 113 are arranged on the upper stage.

  Further, a punching unit 120 that is a punching unit, a shift unit 130 that is a shift unit that shifts the paper P in the width direction, and a discharge roller 201 that discharges the paper and the like toward the paper discharge unit 180 are arranged in the middle stage. ing.

  In the lower stage, a stapling unit 150 that is a stapling unit, a folding unit 160 that is a folding unit, and a stacker 170 that temporarily accumulates sheets are arranged in series on the same plane that forms an inclined surface.

  In addition, on the left side of the post-processing apparatus 2 in the figure, a paper discharge unit 180 having a paper discharge tray 181 and an alignment unit 182 and a fixed paper discharge for stacking processed paper bundles that have been folded into three or two. A table 115 is arranged.

  The paper discharge tray 181 can be moved in the vertical direction in the figure by a paper discharge tray moving unit 140 that moves the paper discharge tray 181 in parallel with the paper stacking direction (in the vertical direction in the figure).

  The alignment unit 182 includes a pair of alignment plates 184 (alignment plate 184a and alignment plate 184b) that urges the end of the sheet in the width direction, and a pair of widths that move the pair of alignment plates 184 in the width direction. A direction drive unit 185 (width direction drive unit 185a and width direction drive unit 185b) and a turning drive unit 187 for turning the pair of alignment plates 184 around a turning shaft 186.

  The alignment unit 182 includes a pair of alignment plates 184 (alignment plate 184a and alignment plate 184b) that urges the end of the sheet in the width direction, and a pair of widths that move the pair of alignment plates 184 in the width direction. A direction drive unit 185 (width direction drive unit 185a and width direction drive unit 185b) and a turning drive unit 187 for turning the pair of alignment plates 184 around a turning shaft 186.

  Then, the pair of width direction driving units 185 moves the pair of alignment plates 184 by a predetermined distance in opposite directions at the time of alignment, and urges and aligns the sheets from both sides in the width direction.

  Further, at the time of shifting, the sheet is moved by a predetermined distance in the same direction, and the sheets can be aligned at the shifted position, that is, at the shifted position.

  Further, during the shift, the turning drive unit 187 turns the pair of alignment plates 184 clockwise about the rotation axis 186 to retract the lower end of the alignment plate 184 upward from the uppermost surface of the paper, and The alignment plate 184 can be lowered by rotating the alignment plate 184 counterclockwise about the rotation axis 186.

As described above, the alignment plate can be aligned by reciprocating the pair of alignment plates 184 in opposite directions by the pair of width direction driving units 185, respectively.
The pair of alignment plates 184 are moved in the same direction by the pair of width direction driving units 185, respectively, and the pair of alignment plates 184 are rotated clockwise and counterclockwise by the rotation driving unit 187. By doing so, it is possible to shift the alignment member.

  The sheet P fixed in the image forming apparatus 3 is sent to the receiving unit 200.

  When the punching process is set, the paper P sent to the receiving unit 200 is punched by the punching unit 120 and conveyed toward the switching gate G2.

  When the discharge to the fixed paper discharge tray 113 is set, the switching gate G2 opens the transport path to the fixed paper discharge tray 113, and feeds the paper P to the first transport path (1) to the fixed paper discharge tray 113. Then, the paper is conveyed toward the fixed paper discharge tray 113.

  When the shift process is set, the switching gate G2 opens the transport path to the shift unit 130, feeds the paper P into the second transport path (2), transports the paper P toward the shift unit 130, and the shift unit 130 transports the paper. P is moved to the right in the width direction or to the left in the width direction by a predetermined amount for every predetermined number of sheets, and is conveyed toward the paper discharge tray 181.

  The predetermined amount and direction correspond to the shift amount and direction of the alignment plate 184.

  When either the stapling process or the folding process is set, the switching gate G2 opens the transport path to the stacker 170, feeds the paper P into the third transport path (3), and transports it toward the stacker 170.

  If the stapling process is set, the stacker 170 stacks the number of sheets to be stapled, the stapling unit 150 performs the stapling process, the stapled sheets are conveyed toward the paper discharge tray 181, and the paper discharge tray 181 to discharge.

  If the folding process is set, the stapled paper is folded at the folding unit 160, and the paper in the form of a booklet is conveyed toward the fixed paper discharge table 115. Let it drain.

  When the alignment process is set, the sheets discharged onto the discharge tray 181 by the discharge roller 201 are sequentially aligned by the reciprocating movement of the alignment plate 184 by the width direction driving unit 185.

  When the shift process is set, in order to align the pair of alignment plates 184 with the position of the sheet shifted by the shift unit 130, the pair of alignment plates 184 are retracted from the top surface of the sheet, respectively. The alignment plate is shifted by moving it in the same direction by a predetermined distance (paper shift amount in the shift unit 130).

  A paper sensor 202 that detects the paper discharged to the paper discharge tray 181 is disposed near the downstream of the discharge roller 201. When the paper sensor 202 detects the passage of the paper, detection information is input to the control unit C1.

  Here, the sheet discharge tray 181 is stacked on the sheet contact surface 183 of the sheet discharge tray 181 relative to the sheet discharge position (height) of the discharge roller 201 or on the sheet discharge tray 181. The uppermost surface (not shown) position (height) on the upstream side of the sheet is moved by the sheet discharge tray moving unit 140 to a position where the sheet discharge abnormality does not occur.

  The paper discharge tray 181 can be moved in the vertical direction in the figure by a paper discharge tray moving unit 140 that moves the paper discharge tray 181 in parallel to the paper stacking direction (in the vertical direction in the figure). It may be possible to move in the width direction (front and back direction in the figure) by a width direction moving means (not shown) that moves in the front and back direction in the figure.

  In this case, since the paper is shifted by the paper discharge tray 181, the shift unit 130 for shifting the paper is not necessary.

  Further, the alignment plate 184 can be swung upward on the paper discharge tray 181 and can be moved (i.e., shifted) in the width direction by the paper discharge tray 181, so that the width direction driving unit 185 is not required.

However, in this case as well, due to the influence of curl or the like, if the downstream front end side of the paper stacked on the paper discharge tray 181 becomes significantly convex (high),
When the paper discharge tray 181 is moved in the width direction (front and back direction in the figure), the lower surface of the alignment plate 184 swung and retracted upward by the swivel drive unit 187 may be caught on the convex (high) paper upper portion. There is sex.

  Therefore, the control unit C1 controls the width direction moving unit (not shown) to shift the paper discharge tray 181 in the width direction, and shifts the paper by the width direction moving unit (not shown). The maximum number of sheets to be stacked on the paper discharge tray 181 is changed according to whether or not the alignment of the sheets by the alignment plate 184 is performed with or without execution (that is, alignment plate shift execution).

  FIG. 5 is a block diagram relating to the paper discharge unit in the post-processing apparatus.

  In FIG. 5, the control unit C1 of the post-processing apparatus sequentially reads out the non-volatile storage means M in which the control program of the entire post-processing apparatus and various tables are stored in advance, and the control program etc. and stores them in the RAM. A CPU to be executed, a RAM for temporarily storing various data, an interface unit I / O for interfacing with the various sensors and various input / output members described above, and a bus B for connecting them. .

  Non-volatile storage means M, for example, ROM or HDD (hard disk drive), on a paper discharge tray according to the combination of alignment plate alignment processing and alignment plate shift processing presence / absence of paper shift processing presence / absence In addition, a stacking upper limit number table Ta storing the upper limit of the number of sheets to be stacked is stored in advance.

  When the paper sensor 202 detects the passage of the paper discharged to the paper discharge tray 181, the paper sensor 202 inputs paper detection information to the CPU via the interface unit I / O.

  The counter C11 counts the sheet detection information detected by the sheet sensor 202 by the CPU, and inputs the count value to the CPU. When the job is completed, the count value is reset to zero.

  The width direction drive motor 185Ma and the width direction drive motor 185Mb of the width direction drive unit 185a and the width direction drive unit 185b are controlled by the CPU via the interface unit I / O and aligned via a power transmission mechanism (not shown). The plate 184a and the alignment plate 184b are moved in the width direction.

  The turning drive motor 187M of the turning drive unit 187 is controlled by the CPU via the interface unit I / O, and turns the alignment plate 184a and the alignment plate 184b about the rotation shaft 186 via a power transmission mechanism (not shown).

  The communication unit T1 exchanges information with the communication unit T2 of the image forming apparatus, and the sheet size information set by the operator on the operation panel of the image forming apparatus, the number of sheets of job information, the alignment process presence / absence information, the shift process presence / absence Information and the like are acquired and input to the CPU.

  FIG. 6 is an explanatory diagram relating to the accumulation upper limit number table Ta.

  In the stacking upper limit number table Ta, the stacking of sheets to be stacked on the discharge tray according to the combination of the alignment process by the alignment plate 184 and the shift process by the alignment plate 184 with respect to the shift of the sheet by the shift unit 130. The upper limit values N1, N2, N3, and N4 are stored.

The accumulated number upper limit N1 is an upper limit number of accumulated sheets when there is a shift of the sheet by the shift unit 130, an alignment process by the alignment plate 184, and a shift process of the alignment plate 184.
Regardless of the sheet raised on the paper discharge tray 181 depending on the type of sheet (for example, thickness, rigidity, etc.) and the state of the sheet (for example, curled state, state in which air is caught between sheets during stacking, etc.) The stacking limit number of sheets in which the aligning plate 184 does not come into contact with the upper portion of the raised stacked sheets even when the shift process and the alignment process are performed.

  In order to perform shift processing and alignment processing of the alignment member, the paper discharge tray depends on the type of paper (for example, thickness, rigidity, etc.) and the state of the paper (for example, curled state, state in which air is caught between sheets during stacking). In order to be most affected by the sheet swelled on 181, it is necessary to reduce the number of sheets as compared with other modes.

The stacking number upper limit N2 is a stacking number upper limit when there is a sheet shift by the shift unit 130, no alignment processing by the alignment plate 184, and no alignment plate 184 shift processing,
Regardless of the sheet raised on the paper discharge tray 181 depending on the type of sheet (for example, thickness, rigidity, etc.) and the state of the sheet (for example, curled state, state in which air is caught between sheets during stacking, etc.) Since the shift process and the alignment process are not performed, the stacking limit number of sheets is such that the aligning plate 184 does not come into contact with the upper portion of the raised stacking sheets.

The stacking number upper limit N3 is the stacking number upper limit when there is no sheet shift by the shift unit 130, alignment processing by the alignment plate 184, and no alignment plate 184 shift processing,
Regardless of the sheet raised on the discharge tray 181 depending on the type of sheet (for example, thickness, rigidity, etc.) and the state of the sheet (for example, curled state, state in which air is caught between sheets at the time of stacking). This is the maximum number of sheets that can be stacked, so that the alignment plate 184 does not contact the upper portion of the raised stacked sheets.

The stacking number upper limit N4 is a stacking number upper limit when there is no sheet shift by the shift unit 130, no alignment process by the alignment plate 184, and no shift process by the alignment plate 184,
This is the sheet stacking limit number when the alignment member shift process and alignment process are not performed.

  Since the alignment member shift processing and alignment processing are not performed, depending on the type of paper (for example, thickness, rigidity, etc.) and the state of the paper (for example, curled state, state in which air is caught between sheets at the time of stacking, etc.) It is irrelevant even if it rises on the discharge tray 181.

  For this reason, the upper limit value N4 for the number of stacked sheets can be set to be the largest as compared with other modes as long as the mechanical strength allows.

  Further, the upper limit value N1, the upper limit value N2, the upper limit value N3, the upper limit value N3, and the upper limit value N4 of the accumulated number are determined in advance by experiments or the like.

  The stacking number upper limit N1 is most affected by the sheet that rises on the discharge tray 181 because the alignment member is shifted.

  When the alignment member shift process is performed (stack number upper limit N1), the type of sheet (for example, thickness, rigidity, etc.) and the state of the sheet (for example, curl state, state in which air is caught between sheets during stacking). Even when the alignment member is changed, the maximum number of stacked sheets that does not lose the alignment state when the alignment member is shifted does not perform the alignment member shift process (the stacking number upper limit value N2, the stacking number upper limit value N3, and the stacking number upper limit value N4). When the number of stacked sheets is 1/3 to 1/2 compared to the above, it has been found that the lower end portion of the alignment plate does not catch on the upper surface of the stacked sheet whose downstream side is convex upward.

  As a result, in the stacking upper limit number table Ta, for example, the stacking number upper limit N1 is 1,500, the stacking number upper limit N2 is 3,000, the stacking number upper limit N3 is 3,000, N4 is stored as 3000 sheets.

Here, in general, when stacking paper, the reason why the downstream side rises upward is as follows:
For example, when the paper is thin, the amount of air entrained at the time of stacking rises, when the curl is strong, it rises due to curling, and when punching is performed, it occurs around the punch hole It is known that it is raised by burr.

  In addition, it is known that small-size paper has a bulge amount that is almost the same as that of the large size, and the bulge position is on the upstream side of the large-size sheet, making it easier to come into contact with the alignment plate that has been swung and retracted. Yes.

The cause of the bottom edge of the alignment plate being caught on the top surface of the paper is that the paper stacked in the paper discharge tray rises upward (becomes convex)
Because the cause of the rise is based on the above thin paper, paper curl or punching process, paper size, etc.,
The upper limit value of the number of stacked sheets may be determined according to the type of paper, the curl of the paper, the type of post-processing, the size of the paper, or the like.

  A flow relating to the upper limit of the number of sheets stacked in the paper discharge tray of the post-processing apparatus will be described below.

  A program relating to the upper limit of the number of sheets stacked in the paper discharge unit 180 (paper discharge tray 181) described in the following flow is stored in the nonvolatile storage means M or the like.

  Then, it is read and executed as a subroutine during execution of a main routine (not shown) for controlling the entire post-processing apparatus by the control unit C1.

  During the processing of the main routine, information relating to the job (for example, shift process presence / absence information, alignment process presence / absence information, paper size, number of sheets, predetermined number of sheets (shift number), predetermined number of sheets (job completion number), etc.) is read. For example, it is stored in a storage means such as a RAM.

  Hereinafter, control related to the upper limit of the number of sheets stacked in the paper discharge tray will be described with reference to FIGS. 4, 5, and 7 to 11 in association with control related to alignment processing and alignment member shift processing.

  7 to 11 are flowcharts of control relating to the upper limit of the number of sheets stacked on the paper discharge tray in the post-processing apparatus.

8 to 11 are continuations of FIG. In FIG.
1. Reading job information Step S101
Information (for example, shift process presence / absence information, alignment process presence / absence information, paper size, number of sheets, predetermined number (shift number), predetermined number (job completion number), etc.) stored in the RAM;
The integration upper limit number table Ta stored in the nonvolatile storage means M is read out, and the process proceeds to the next step.

2. Shift processing presence / absence determination step S102
From the shift process presence / absence information read in step S101, the presence / absence of shift processing for the alignment member is determined. If yes (Yes), the process proceeds to the next step. If not (No), the process proceeds to step S104.

3. Determination of presence / absence of matching process Step S103
The presence / absence of the alignment process is determined from the alignment process presence / absence information read in step S101. If yes (Yes), it is determined that both the alignment member shift process and the alignment process are set (first mode). Proceed to step S105.
In the case of none (No), it is determined that only the alignment member shift process is set (second mode), and the process proceeds to step S201 (FIG. 9).

4). Determination of presence / absence of matching process Step S104
The presence / absence of matching processing is determined from the matching processing presence / absence information read in step S101. If yes (Yes), it is determined that only the matching processing is set (third mode), and the process proceeds to step S301 (FIG. 10). Proceed,
If there is none (No), it is determined that both the alignment member shifting process and the alignment process are not set (fourth mode), and the process proceeds to step S401 (FIG. 11).

5. Acquisition of upper limit of number of accumulated sheets Step S105
The accumulated upper limit number table Ta read in step S101, the accumulated number upper limit value corresponding to the combination of the read shift processing presence / absence (for example, alignment member shift processing present) and alignment processing presence / absence (for example, alignment member alignment processing present). For example, N1) is read out and stored in a RAM or the like, and the process proceeds to the next step.

6). Paper Sensor Monitoring Step S106
The output of the paper sensor 202 that detects the passage of the paper discharged to the paper discharge tray 181 is monitored, and the process proceeds to the next step.

7). Paper passage detection determination Step S107
If the paper sensor 202 detects the passage of the paper (Yes), the process proceeds to the next step to perform the alignment process, and Steps S106 and S107 are repeated until it is detected (No).

8). Alignment processing execution by alignment plate Step S108
The width direction drive motor 185Ma and the width direction drive motor 185Mb of the width direction drive unit 185a and the width direction drive unit 185b are rotated forward and backward, and the alignment plate 184a and the alignment plate 184b are reciprocated by a predetermined distance in opposite directions, respectively. Is urged so as to be sandwiched from both sides in the width direction to perform alignment processing and proceed to the next step.

  As a result, the paper edges are aligned.

9. Increment of the count of the number of sheets Step S109
+1 is added to the count value of the counter C11 that counts the paper detection information detected by the paper sensor 202, and the process proceeds to the next step (FIG. 8).

10. Counter value monitoring step S110
The count value of the counter C11 is read, and the process proceeds to the next step.

11. Determination of counter value ≧ maximum accumulated number N1 Step S111
The count value of the counter C11 read in step S110 is compared with the accumulated number upper limit value (for example, N1) acquired in step S105.

When the counter value ≧ the maximum number of accumulated sheets N1 (for example, 1,500 sheets) (Yes), if more sheets are accumulated, the lower end of the alignment plate 184 rises due to curling or the like especially during shifting, and the maximum number of sheets accumulated. Judge that there is a possibility of being caught on the top, go to the next step,
If the counter value is not equal to or greater than the maximum accumulated number N1 (Yes), it is determined that there is no possibility of being caught, and the process proceeds to step S113.

12 Stop post-processing Step S112
In order to prevent the above-described catch, the stacking of the maximum stacking number N1 (for example, 1,500 sheets) on the sheet discharge tray 181 is stopped and the process proceeds to the end.

  For this reason, (1) the stacking on the discharge tray 181 is stopped, and the stacking of sheets on the fixed discharge tray 113 is switched.

  Note that in this case, the operator is warned by transmitting the collection stop information to the discharge tray 181 to the image forming apparatus and displaying the stop information on the discharge tray 181 on the operation panel of the image forming apparatus.

  (2) Alternatively, the post-processing apparatus may be stopped, abnormal information may be transmitted to the image forming apparatus, and the image forming apparatus may be stopped.

13. Counter value ≧ predetermined number of sheets (shifted sheet number) Step S113
The count value of the counter C11 read in step S110 is compared with the predetermined number (shift number) read in step S101.

  If the counter value ≧ the predetermined number (shift number) (for example, 100) (Yes), the process proceeds to the next step. If the counter value ≧ the predetermined number (shift number) (for example, 100), the accumulation is continued. Therefore, the process proceeds to step S106 (FIG. 7).

14 Counter value ≧ predetermined number of sheets (number of completed jobs) Step S114
The count value of the counter C11 read in step S110 is compared with the predetermined number (job completed number) read in step S101.

  If the counter value ≧ predetermined number of sheets (job completed number of sheets) (for example, 5,000 sheets) (Yes), it is determined that the job has been completed, the accumulation is completed, and the process proceeds to the end. ) (No, for example, 5,000 sheets) (No) (No), the process proceeds to the next step to determine the shift execution time of the sheets stacked on the paper discharge tray 181 based on the determination in step S113 and step S114. .

15. Alignment plate shift execution Step S115
The turning drive motor 187M for turning the aligning plate 184a and the aligning plate 184b is rotated in the forward direction, and the aligning plate 184a and the aligning plate 184b are swung in a direction away from the upper surface of the sheets stacked on the paper discharge tray 181.

  After turning, the width direction drive motor 185Ma and the width direction drive move the alignment plate 184a and the alignment plate 184b in the width direction so that the alignment plate 184a and the alignment plate 184b move from the current position toward the shift position on the opposite side. The motor 185Mb is rotated and stopped when it moves a predetermined distance (predetermined shift amount).

  After the predetermined shift amount is moved, the turning drive motor 187M is rotated in the reverse direction so that the aligning plate 184a and the aligning plate 184b are swung to a position where they are in contact with the upper surface of the sheets stacked on the paper discharge tray 181.

  As a result, the alignment member shifting process is completed, the process proceeds to step S106 (FIG. 7), and steps S106 to S115 are repeated until the job is completed.

  As described above, in the mode (first mode) in which both the shift process and the alignment process are set, the number of sheets stacked on the discharge tray 181 can be limited to the first predetermined number.

  As a result, the lower end portion of the alignment plate 184 is caught on the uppermost portion of the accumulated paper that is raised due to curling or the like, so that it is possible to prevent the alignment state of the paper from being lost and the paper from becoming uneven. .

  Further, it is possible to prevent the workability from being deteriorated due to the need for the work of realigning the sheet bundle that has become uneven.

  Next, the case where it is determined in step S103 that the mode (second mode) in which only the alignment member shift process is set will be described with reference to FIG.

16. Acquisition of upper limit value of number of accumulated sheets Step S201
The accumulated upper limit number table Ta read in step S101, the accumulated number upper limit value (for example, N2) corresponding to the combination of the read presence / absence of shift processing (for example, with alignment member shift processing) and alignment processing presence / absence (for example, no alignment processing). Is stored in a RAM or the like, and the process proceeds to the next step.

17. Paper Sensor Monitoring Step S202
Since it is the same as that of step S106, description is abbreviate | omitted.

18. Paper passage detection determination Step S203
When the paper sensor 202 detects the passage of the paper (Yes), the process proceeds to the next step, and Steps S202 and S203 are repeated until it is detected (No).

19. Incrementing the count of the number of sheets Step S204
Since it is the same as that of step S109, description is abbreviate | omitted.

20. Counter value monitoring step S205
Since it is the same as that of step S110, description is abbreviate | omitted.

21. Determination of counter value ≧ maximum accumulated number N2 Step S206
The count value of the counter C11 read in step S205 is compared with the accumulated number upper limit value (for example, N2) acquired in step S201.

  If the counter value ≧ the maximum number of accumulated sheets N2 (for example, 3,000) (Yes), if more sheets are accumulated, the lower end of the alignment plate 184 rises due to curl or the like especially during shifting, and the maximum number of sheets accumulated. It is determined that there is a possibility of being caught in the upper part, and the process proceeds to the next step. For example, if it is less than 3,000 sheets (even if it is 1,500 sheets or more) (No), the sheets are accumulated even during shifting. However, it is determined that there is no possibility that the lower end portion of the alignment plate 184 is raised by curling or the like and caught on the uppermost portion of the accumulated paper, and the process proceeds to step S208.

22. Stop post-processing Step S207
In order to prevent the above-described catch, the stacking of the maximum stacking number N2 (for example, 3,000 sheets) on the discharge tray 181 is stopped.

  Since the specific method is the same as that in step S112, description thereof is omitted.

23. Counter value ≧ predetermined number of sheets (shift number of sheets) judgment Step S208
Since it is the same as that of step S113, description is abbreviate | omitted.

24. Counter value ≧ predetermined number of sheets (number of completed jobs) judgment Step S209
Since it is the same as that of step S114, description is abbreviate | omitted.

25. Alignment plate shift execution Step S210
Since it is the same as that of step S115, description is abbreviate | omitted. Steps S202 to S210 are repeated until the job is completed.

  As described above, in the mode (second mode) in which only the alignment member shift process is set, the number of sheets stacked on the discharge tray 181 can be limited to the second predetermined number.

  As a result, the lower end portion of the alignment plate 184 is caught on the uppermost portion of the accumulated paper that is raised due to curling or the like, so that it is possible to prevent the alignment state of the paper from being lost and the paper from becoming uneven. .

  Further, it is possible to prevent the workability from being deteriorated due to the need for the work of realigning the sheet bundle that has become uneven.

  Next, a case where it is determined in step S103 that the mode is the mode in which only the alignment process is set (third mode) will be described with reference to FIG.

26. Acquisition upper limit value of number of accumulated sheets Step S301
The accumulated upper limit number table Ta read in step S101, the accumulated number upper limit value (for example, N3) corresponding to the combination of the read presence / absence of shift processing (for example, no alignment member shift processing) and alignment processing presence / absence (for example, alignment processing). Is stored in a RAM or the like, and the process proceeds to the next step.

27. Paper Sensor Monitoring Step S302
Since it is the same as that of step S106, description is abbreviate | omitted.

28. Paper passage detection determination Step S303
When the sheet sensor 202 detects the passage of the sheet (Yes), the process proceeds to the next step, and Steps S302 and S303 are repeated until it is detected (No).

29. Alignment processing execution by alignment plate Step S304
Since it is the same as that of step S108, description is abbreviate | omitted.

30. Increment of the count of the number of sheets Step S305
Since it is the same as that of step S109, description is abbreviate | omitted.

31. Counter value monitoring step S306
Since it is the same as that of step S110, description is abbreviate | omitted.

32. Determination of counter value ≧ maximum accumulated number N3 Step S207
The count value of the counter C11 read in step S306 is compared with the accumulated number upper limit value (for example, N3) acquired in step S301.

  If the counter value ≧ the maximum stack number N3 (for example, 3,000 sheets) (Yes), if more sheets are stacked, the lower end of the alignment plate 184 rises due to curl or the like particularly during shifting, and the maximum stack of sheets is stacked. It is determined that there is a possibility of being caught in the upper part, and the process proceeds to the next step. For example, if it is less than 3,000 sheets (even if it is 1,500 sheets or more) (No), the sheets are accumulated even during shifting. However, it is determined that there is no possibility that the lower end portion of the alignment plate 184 rises due to curling or the like and is caught on the uppermost portion of the accumulated paper, and the process proceeds to step S309.

33. Stop post-processing Step S308
In order to prevent the above-described catch, the stacking of the maximum stacking number N3 (for example, 3,000 sheets) on the discharge tray 181 is stopped.

  Since the specific method is the same as that in step S112, description thereof is omitted.

34. Counter value ≧ predetermined number of sheets (number of completed jobs) judgment Step S309
Since it is the same as that of step S114, description is abbreviate | omitted. Steps S302 to S309 are repeated until the job is completed.

  As described above, in the mode (third mode) in which only the alignment process is set, the number of sheets stacked on the paper discharge tray 181 can be limited to the third predetermined number.

  As a result, the lower end portion of the alignment plate 184 is caught on the uppermost portion of the accumulated paper that is raised due to curling or the like, so that it is possible to prevent the alignment state of the paper from being lost and the paper from becoming uneven. .

  Further, it is possible to prevent the workability from being deteriorated due to the need for the work of realigning the sheet bundle that has become uneven.

  Next, the case where it is determined in step S103 that the mode (fourth mode) in which neither the alignment member shift process nor the alignment process is set will be described with reference to FIG.

35. Acquisition of upper limit of number of accumulated sheets Step S401
The accumulated upper limit number table Ta read in step S101, the accumulated number upper limit value (for example, N4) corresponding to the combination of the read shift process presence / absence (for example, no alignment member shift process) and alignment process presence / absence (for example, no alignment process). Is stored in a RAM or the like, and the process proceeds to the next step.

36. Paper Sensor Monitoring Step S402
Since it is the same as that of step S106, description is abbreviate | omitted.

37. Paper Passing Detection Determination Step S403
When the paper sensor 202 detects the passage of the paper (Yes), the process proceeds to the next step, and Steps S402 and S403 are repeated until it is detected (No).

38. Step S404
The sheets conveyed without performing the alignment process are stacked on the discharge tray, and the process proceeds to the next step.

39. Increment of the count of the number of sheets Step S405
Since it is the same as that of step S109, description is abbreviate | omitted.

40. Counter value monitoring Step S406
Since it is the same as that of step S110, description is abbreviate | omitted.

41. Counter value ≧ maximum accumulated number N4 determination Step S407
The count value of the counter C11 read in step S406 is compared with the accumulated number upper limit value (for example, N4) acquired in step S401.

  If the counter value ≧ the maximum number of accumulated sheets N4 (for example, 3,000) (Yes), if more sheets are accumulated, the lower end of the aligning plate 184 rises due to curl or the like especially during shifting, and the maximum number of sheets accumulated. It is determined that there is a possibility of being caught in the upper part, and the process proceeds to the next step. For example, if it is less than 3,000 sheets (even if it is 1,500 sheets or more) (No), the sheets are accumulated even during shifting. However, it is determined that there is no possibility that the lower end portion of the aligning plate 184 is raised by curling or the like and caught on the uppermost portion of the accumulated paper, and the process proceeds to step S402.

42. Stop post-processing Step S408
In order to prevent the above-described catch, the stacking of the maximum stacking number N4 (for example, 3,000 sheets) on the discharge tray 181 is stopped.

  Since the specific method is the same as that in step S112, description thereof is omitted.

43. Counter value ≧ predetermined number of sheets (number of completed jobs) judgment Step S309
Since it is the same as that of step S114, description is abbreviate | omitted. Steps S302 to S309 are repeated until the job is completed.

  As described above, in the mode (fourth mode) in which both the alignment member shift process and the alignment process are not set, the number of sheets stacked on the discharge tray 181 can be limited to the fourth predetermined number.

  As a result, the lower end portion of the alignment plate 184 is caught on the uppermost portion of the accumulated paper that is raised due to curling or the like, so that it is possible to prevent the alignment state of the paper from being lost and the paper from becoming uneven. .

  Further, it is possible to prevent the workability from being deteriorated due to the need for the work of realigning the sheet bundle that has become uneven.

The configuration / method has been described above in which the paper discharge unit 180 is provided in the paper discharge tray 181 of the post-processing device, and the upper limit of the number of sheets to be stacked is set according to the presence / absence of the alignment member shift process and the alignment process.
It goes without saying that a similar configuration and method may be provided in a paper discharge tray or the like of the image forming apparatus.

FIG. 4 is a conceptual explanatory diagram illustrating a relationship between a paper discharge tray, a sheet bundle stacked on the paper discharge tray, and an alignment plate. 1 is an explanatory diagram illustrating an example of an image forming system including a post-processing device and an image forming device. 1 is a schematic cross-sectional view illustrating an example of an image forming apparatus. It is a cross-sectional block diagram which shows an example of a post-processing apparatus. It is a block diagram regarding a paper discharge unit in the post-processing apparatus. It is explanatory drawing regarding accumulation upper limit sheet number table Ta. FIG. 10 is a flowchart of control related to an upper limit of the number of sheets stacked on a paper discharge tray in the post-processing device. FIG. 10 is a flowchart of control related to an upper limit of the number of sheets stacked on a paper discharge tray in the post-processing device. FIG. 10 is a flowchart of control related to an upper limit of the number of sheets stacked on a paper discharge tray in the post-processing device. FIG. 10 is a flowchart of control related to an upper limit of the number of sheets stacked on a paper discharge tray in the post-processing device. FIG. 10 is a flowchart of control related to an upper limit of the number of sheets stacked on a paper discharge tray in the post-processing device.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Image forming system 2 Post-processing apparatus 3 Image forming apparatus 90 Operation panel 130 Shift part 140 Paper discharge tray moving part 180 Paper discharge part 181 Paper discharge tray 182 Alignment part 184, 184a, 184b Alignment board 185 Width direction drive part 185
185Ma, 185Mb Width direction drive motor 186 Rotating shaft 187 Rotation drive unit 187M Rotation drive motor 201 Discharge roller 202 Paper sensor C1, C2 Control unit C11 Counter P Paper T1, T2 Communication means

Claims (8)

A shift unit that shifts the paper in the width direction, a paper discharge unit that collects the discharged paper, an alignment member that biases an end surface of the paper discharged to the paper discharge unit, and a paper that is shifted by the shift unit A post-processing apparatus having alignment member shifting means for shifting the alignment member in the width direction in accordance with the shift position of
Depending on the combination of presence / absence of paper alignment by the alignment member and presence / absence of shift execution by the alignment member shifting means with respect to presence / absence of paper shift execution by the shift unit, the paper discharge unit A post-processing apparatus having control means capable of changing the maximum number of sheets to be stacked. The control means, with respect to presence of paper shift execution by the shift unit, with respect to the paper sheet execution execution by the alignment member and the shift execution by the alignment member shift means, the maximum number of sheets accumulated in combination,
2. The post-processing apparatus according to claim 1, wherein the number of sheets is smaller than the maximum number of sheets accumulated in other combinations. 2. The control unit according to claim 1, wherein the control unit sets the same maximum number of sheets when the alignment member does not execute alignment of sheets regardless of whether or not the shift unit performs shift of sheets. The post-processing apparatus according to 2. The post-processing apparatus according to claim 1, wherein the paper discharge unit is a discharge tray that is movable in a paper stacking direction. An image forming system comprising: an image forming apparatus that forms an image; and the post-processing apparatus according to claim 1. The image forming apparatus includes a setting unit configured to set whether or not a paper shift is performed, whether or not a paper alignment is performed, and whether or not a alignment member is shifted in the post-processing apparatus. The image forming system according to claim 5. The image forming apparatus and the post-processing apparatus relate to the presence or absence of paper shift execution, the presence or absence of paper alignment execution, and the presence or absence of alignment member shift execution set by the setting unit. The image forming system according to claim 6, further comprising a communication unit that exchanges information. The post-processing device is a post-processing device based on information received by the communication means regarding whether or not a paper shift is performed, whether or not a paper alignment is performed, and whether or not a alignment member is shifted. 8. The image forming system according to claim 7, further comprising a control unit capable of changing a maximum number of sheets to be stacked on the paper discharge unit.

Images